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prs.layout = "LAYOUT_16x9";
prs.title = "MRI Physics & Basic Principles";

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// ── SLIDE 1: Title ──────────────────────────────────────────────────────────
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s1.addText("MRI PHYSICS &\nBASIC PRINCIPLES", { x: 0.9, y: 0.8, w: 8.6, h: 1.8, fontSize: 42, bold: true, color: WHITE, align: "left" });
s1.addText("MRI Radiology Teaching Series — Module 1", { x: 0.9, y: 2.7, w: 8.6, h: 0.6, fontSize: 18, color: CYAN, align: "left" });
s1.addText("Radiology Department  |  2026", { x: 0.9, y: 3.4, w: 8.6, h: 0.5, fontSize: 13, color: "8ECAE6", align: "left" });
s1.addText("From proton spin to diagnostic image", { x: 0.9, y: 4.1, w: 8.6, h: 0.5, fontSize: 14, color: "8ECAE6", italic: true, align: "left" });

// ── SLIDE 2: Table of Contents ───────────────────────────────────────────────
const s2 = addContentSlide("Table of Contents");
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  ["01", "What is MRI? History & Clinical Relevance"],
  ["02", "Nuclear Magnetic Resonance — Proton Spin"],
  ["03", "Magnetic Field Strengths"],
  ["04", "Larmor Frequency & Precession"],
  ["05", "RF Pulses — Excitation & Relaxation"],
  ["06", "T1 Relaxation (Longitudinal)"],
  ["07", "T2 & T2* Relaxation (Transverse)"],
  ["08", "Signal Equation: TR, TE, Flip Angle"],
  ["09", "Spatial Encoding — Gradients & K-space"],
  ["10", "Image Reconstruction & SNR"],
  ["11", "MRI vs CT Comparison"],
  ["12", "Contraindications Overview"],
  ["13", "Key Takeaways"],
];
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// ── SLIDE 3: What is MRI? ────────────────────────────────────────────────────
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s3.addText("Magnetic Resonance Imaging (MRI) uses a strong magnetic field and radiofrequency (RF) pulses to generate detailed anatomical images without ionizing radiation.", { x: 0.25, y: 0.85, w: 9.5, h: 0.7, fontSize: 14, color: DARK_TEXT });
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  ["1946", "Bloch & Purcell describe Nuclear Magnetic Resonance (NMR) — Nobel Prize 1952"],
  ["1971", "Damadian shows tumor tissue has longer T1/T2 than normal tissue"],
  ["1973", "Lauterbur uses field gradients to create first 2D NMR image"],
  ["1977", "Mansfield & Garroway develop EPI; first human body image"],
  ["2003", "Lauterbur & Mansfield awarded Nobel Prize in Physiology or Medicine"],
  ["Today", "Standard of care for brain, spine, MSK, cardiac, abdominal imaging"],
];
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// ── SLIDE 4: NMR — Proton Spin ───────────────────────────────────────────────
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s4.addText("Core Principle", { x: 0.25, y: 0.85, w: 4.5, h: 0.35, fontSize: 13, bold: true, color: DARK_CYAN, align: "center", valign: "middle" });
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  ["2", "WITH B0 field applied", "Protons align parallel or antiparallel to B0 → net longitudinal magnetization (Mz) develops"],
  ["3", "RF pulse applied", "Protons absorb energy and tip into transverse plane → transverse magnetization (Mxy) created"],
  ["4", "RF pulse off", "Protons relax back → emit RF signal detected by receiver coil → MRI signal"],
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// ── SLIDE 5: Field Strengths ─────────────────────────────────────────────────
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    { text: "Clinical Use", options: { bold: true, fill: { color: NAVY }, color: WHITE, align: "center" } },
    { text: "SNR", options: { bold: true, fill: { color: NAVY }, color: WHITE, align: "center" } },
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  ["0.3 T (Low)", "Open MRI; claustrophobic patients", "Low", "Limited soft-tissue contrast"],
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  [{ text: "3 T (High)", options: { bold: true, color: DARK_CYAN } }, "Neuroimaging, functional MRI, MSK", "Very High (2× vs 1.5T)", "More SAR, susceptibility artefacts"],
  ["7 T (Ultra-high)", "Research; cortical architecture", "Exceptional", "Inhomogeneity challenges; limited clinical approval"],
  ["≥10 T", "Preclinical / research only", "—", "Not for human use"],
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// ── SLIDE 6: Larmor Frequency ────────────────────────────────────────────────
const s6 = addContentSlide("Larmor Frequency & Precession");
s6.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.9, fill: { color: NAVY }, line: { color: NAVY } });
s6.addText("Larmor Equation:  ω₀ = γ × B₀", { x: 0.25, y: 0.85, w: 9.5, h: 0.9, fontSize: 24, bold: true, color: CYAN, align: "center", valign: "middle" });
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  ["Precession frequency", "ω₀", "Depends on B₀ (MHz)"],
  ["Gyromagnetic ratio (¹H)", "γ", "42.58 MHz/T"],
  ["Field strength at 1.5T", "B₀", "63.87 MHz"],
  ["Field strength at 3T", "B₀", "127.74 MHz"],
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s6.addText("Clinical Relevance", { x: 6.0, y: 1.85, w: 3.7, h: 0.4, fontSize: 13, bold: true, color: DARK_CYAN, align: "center", valign: "middle" });
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  { text: "• RF pulses must match ω₀ to cause resonance\n", options: { breakLine: false } },
  { text: "• Larmor freq varies by tissue via chemical shift\n", options: { breakLine: false } },
  { text: "• Fat resonates ~220 Hz lower than water at 1.5T (~440 Hz at 3T)\n", options: { breakLine: false } },
  { text: "• Basis for fat suppression techniques\n", options: { breakLine: false } },
  { text: "• Shimming corrects local B₀ inhomogeneity", options: {} },
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// ── SLIDE 7: RF Pulses ───────────────────────────────────────────────────────
const s7 = addContentSlide("RF Pulses — Excitation & Relaxation");
const rfItems = [
  { title: "90° Excitation Pulse", color: CYAN, text: "Tips net magnetization (Mz) fully into transverse plane (Mxy). Maximum signal generated." },
  { title: "180° Refocusing Pulse", color: AMBER, text: "Inverts spins. Used in Spin Echo to rephase T2* dephasing. Also used in Inversion Recovery." },
  { title: "Variable Flip Angle", color: DARK_CYAN, text: "Small flip angles (15-35°) used in GRE sequences → preserve longitudinal Mz for faster repetition (short TR)." },
];
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  s7.addText("• After RF pulse ends, protons undergo Relaxation\n• Two independent processes occur simultaneously: T1 (longitudinal) and T2 (transverse)\n• Signal detected as Free Induction Decay (FID) in receiver coil", { x: 0.35, y: yy + 0.52, w: 9.3, h: 0.8, fontSize: 11, color: MID_GRAY });
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// ── SLIDE 8: T1 Relaxation ───────────────────────────────────────────────────
const s8 = addContentSlide("T1 Relaxation — Longitudinal Recovery");
s8.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.5, fill: { color: LIGHT_CYAN }, line: { color: CYAN } });
s8.addText("T1 = time for Mz to recover to 63% of equilibrium after 90° RF pulse. Reflects spin-lattice interactions.", { x: 0.3, y: 0.85, w: 9.4, h: 0.5, fontSize: 12, color: DARK_TEXT, valign: "middle" });
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    { text: "Tissue", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
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    { text: "T1 at 3T (ms)", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
    { text: "MRI Appearance (T1W)", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
  ],
  ["Fat", "260", "370", { text: "BRIGHT (short T1)", options: { bold: true, color: "E67E22" } }],
  ["White Matter", "780", "1080", { text: "Bright", options: { color: "27AE60" } }],
  ["Grey Matter", "900", "1330", "Intermediate"],
  ["Muscle", "870", "1420", "Intermediate"],
  ["CSF", "3000–4000", "3500+", { text: "DARK (very long T1)", options: { bold: true, color: "2980B9" } }],
  ["Blood (arterial)", "1200", "1600", "Variable (flow effects)"],
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// ── SLIDE 9: T2 & T2* Relaxation ────────────────────────────────────────────
const s9 = addContentSlide("T2 & T2* Relaxation — Transverse Decay");
s9.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 4.6, h: 0.5, fill: { color: LIGHT_CYAN }, line: { color: CYAN } });
s9.addText("T2 = 63% loss of Mxy. Spin-spin interactions.", { x: 0.3, y: 0.85, w: 4.5, h: 0.5, fontSize: 12, color: DARK_TEXT, valign: "middle" });
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s9.addText("T2* includes B₀ inhomogeneity (faster decay)", { x: 5.15, y: 0.85, w: 4.55, h: 0.5, fontSize: 12, color: DARK_TEXT, valign: "middle" });
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    { text: "Tissue", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
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    { text: "T2* (ms)", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
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  ["Fat", "80", "40–50", "Intermediate–Bright"],
  ["White Matter", "90", "65", "Intermediate"],
  ["Grey Matter", "100", "66", { text: "Slightly Brighter", options: { color: "27AE60" } }],
  ["CSF", "2000–3000", "200", { text: "VERY BRIGHT", options: { bold: true, color: "2980B9" } }],
  ["Muscle", "50", "28", "Dark"],
  ["Deoxyhemoglobin", "~5–10", "~3–5", { text: "VERY DARK (T2*)", options: { bold: true, color: "C0392B" } }],
  ["Cartilage (deep)", "30–40", "~12", "Dark"],
];
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addAmberBox(s9, "T2* decay always faster than T2. Susceptibility agents (iron, air, metal) shorten T2*.", 0.25, 5.15, 9.5, 0.35, 12);

// ── SLIDE 10: Signal Equation ────────────────────────────────────────────────
const s10 = addContentSlide("Signal Equation: TR, TE & Flip Angle");
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s10.addText("S ∝ ρ(H) × (1 − e^(−TR/T1)) × e^(−TE/T2)    [Spin Echo Signal Equation]", { x: 0.25, y: 0.85, w: 9.5, h: 0.7, fontSize: 16, bold: true, color: CYAN, align: "center", valign: "middle" });
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  ["TR (Repetition Time)", "Time between successive RF excitations", "Short TR → T1 weighting\nLong TR → PD/T2 weighting"],
  ["TE (Echo Time)", "Time from RF pulse to signal readout", "Short TE → PD/T1 weighting\nLong TE → T2 weighting"],
  ["Flip Angle (α)", "Angle of magnetization tipping", "90° → full SE signal\n<90° → GRE (faster TR possible)"],
];
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// ── SLIDE 11: Contrast weighting table ───────────────────────────────────────
const s11 = addContentSlide("Contrast Weighting: TR & TE Combinations");
s11.addText("Selecting TR and TE determines tissue contrast. These combinations are fundamental to MRI sequence design.", { x: 0.25, y: 0.82, w: 9.5, h: 0.5, fontSize: 13, color: DARK_TEXT });
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    { text: "Contrast", options: { bold: true, fill: { color: NAVY }, color: WHITE, align: "center" } },
    { text: "TR", options: { bold: true, fill: { color: NAVY }, color: WHITE, align: "center" } },
    { text: "TE", options: { bold: true, fill: { color: NAVY }, color: WHITE, align: "center" } },
    { text: "Fat Signal", options: { bold: true, fill: { color: NAVY }, color: WHITE, align: "center" } },
    { text: "CSF Signal", options: { bold: true, fill: { color: NAVY }, color: WHITE, align: "center" } },
    { text: "Common Uses", options: { bold: true, fill: { color: NAVY }, color: WHITE, align: "center" } },
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  [{ text: "T1-Weighted", options: { bold: true, color: "E67E22" } }, "Short (<700ms)", "Short (<30ms)", "Bright", "Dark", "Anatomy, post-contrast, fat"],
  [{ text: "T2-Weighted", options: { bold: true, color: "2980B9" } }, "Long (>2000ms)", "Long (>80ms)", "Intermediate", "Bright", "Pathology (oedema), CSF"],
  [{ text: "PD-Weighted", options: { bold: true, color: "27AE60" } }, "Long (>2000ms)", "Short (<30ms)", "Bright", "Intermediate", "Cartilage, menisci"],
  [{ text: "T2*-Weighted", options: { bold: true, color: "8E44AD" } }, "Variable", "Long (GRE)", "Dark", "Bright", "Haemorrhage, iron, SWI"],
  [{ text: "FLAIR", options: { bold: true, color: "C0392B" } }, "Very long (9000ms)", "Long + TI=2500ms", "Bright", { text: "NULLED (dark)", options: { bold: true } }, "MS plaques, periventricular lesions"],
];
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// ── SLIDE 12: Spatial Encoding ───────────────────────────────────────────────
const s12 = addContentSlide("Spatial Encoding — Gradients");
const encSteps = [
  { n: "1", title: "Slice Selection Gradient (Gz)", desc: "Applied along z-axis during RF pulse. Determines which slice is excited by matching RF frequency to slice position via Larmor equation." },
  { n: "2", title: "Phase Encoding Gradient (Gy)", desc: "Applied after excitation. Protons at different y-positions accumulate different phase shifts. Each repetition uses a different phase-encode step." },
  { n: "3", title: "Frequency Encoding Gradient (Gx)", desc: "Applied during readout. Protons at different x-positions resonate at different frequencies, enabling spatial localisation along x-axis." },
];
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// ── SLIDE 13: K-space ────────────────────────────────────────────────────────
const s13 = addContentSlide("K-space — The Raw MRI Data Domain");
s13.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.55, fill: { color: LIGHT_CYAN }, line: { color: CYAN } });
s13.addText("K-space is the Fourier (frequency) domain representation of the MRI image. It stores raw signal data before reconstruction.", { x: 0.3, y: 0.87, w: 9.4, h: 0.5, fontSize: 12, color: DARK_TEXT, valign: "middle" });
const kData = [
  [{ text: "K-space Region", options: { bold: true, fill: { color: NAVY }, color: WHITE } }, { text: "Contains", options: { bold: true, fill: { color: NAVY }, color: WHITE } }, { text: "Clinical Impact", options: { bold: true, fill: { color: NAVY }, color: WHITE } }],
  [{ text: "Centre (low spatial frequencies)", options: { bold: true } }, "Image contrast, brightness, gross tissue boundaries", "Determines overall image contrast — most diagnostic information here"],
  [{ text: "Periphery (high spatial frequencies)", options: { bold: true } }, "Edge detail, fine structure, sharp interfaces", "Determines spatial resolution — edges and fine detail"],
  ["Full k-space", "Complete image information (contrast + detail)", "Standard full acquisition"],
  ["Partial Fourier", "~60–75% of k-space acquired; rest synthesised", "Shorter TE, faster scan; slight SNR penalty"],
  ["Radial/Spiral filling", "Non-Cartesian k-space trajectories", "Motion robustness (radial GRASP, PROPELLER)"],
];
s13.addTable(kData, { x: 0.25, y: 1.5, w: 9.5, h: 3.9, colW: [3.0, 3.5, 3.0], border: { pt: 0.5, color: "C8D6E5" }, fill: { color: WHITE }, fontSize: 12, color: DARK_TEXT, rowH: 0.66 });

// ── SLIDE 14: Image Reconstruction ──────────────────────────────────────────
const s14 = addContentSlide("Image Reconstruction & SNR Factors");
s14.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fill: { color: NAVY }, line: { color: NAVY } });
s14.addText("2D Fourier Transform of k-space → Greyscale MRI image", { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fontSize: 16, bold: true, color: CYAN, align: "center", valign: "middle" });
const snrFactors = [
  ["Field Strength (B₀)", "SNR ∝ B₀ (linear; 3T ≈ 2× SNR vs 1.5T)"],
  ["Voxel Volume", "SNR ∝ voxel size (FOV²×slice thickness / matrix²)"],
  ["Number of Excitations (NEX/NSA)", "SNR ∝ √NEX (doubling NEX → √2 SNR gain)"],
  ["Receiver Bandwidth (rBW)", "SNR ∝ 1/√rBW (narrow BW → higher SNR, more CS artefact)"],
  ["Coil Type", "Surface coils > volume coils for SNR at given region"],
  ["TR (T1-weighted)", "Longer TR → more T1 recovery → higher SNR"],
  ["TE", "Shorter TE → less T2 decay → higher SNR (but less T2 contrast)"],
];
const snrData = [[
  { text: "Factor", options: { bold: true, fill: { color: DARK_CYAN }, color: WHITE } },
  { text: "SNR Effect", options: { bold: true, fill: { color: DARK_CYAN }, color: WHITE } },
], ...snrFactors.map(r => [r[0], r[1]])];
s14.addTable(snrData, { x: 0.25, y: 1.4, w: 9.5, h: 4.0, colW: [3.5, 6.0], border: { pt: 0.5, color: "C8D6E5" }, fill: { color: WHITE }, fontSize: 12, color: DARK_TEXT, rowH: 0.5 });

// ── SLIDE 15: SNR vs Resolution Tradeoffs ────────────────────────────────────
const s15 = addContentSlide("SNR vs Spatial Resolution — Tradeoffs");
const tradeoffs = [
  { param: "Increase Matrix Size", snr: "↓ (smaller voxels)", resolution: "↑ (finer detail)", time: "↑ (more phase encodes)" },
  { param: "Reduce FOV", snr: "↓ (smaller voxels)", resolution: "↑", time: "Same" },
  { param: "Thinner Slices", snr: "↓ (less tissue per voxel)", resolution: "↑ (z-axis)", time: "Same (more slices for coverage)" },
  { param: "Increase NEX/NSA", snr: "↑ (√NEX)", resolution: "No change", time: "↑ (proportional)" },
  { param: "Wider Bandwidth", snr: "↓", resolution: "Less CS artefact", time: "↓ (faster readout)" },
  { param: "Parallel Imaging (SENSE/GRAPPA)", snr: "↓ (g-factor penalty)", resolution: "Same", time: "↓ (faster)" },
];
const tradeData = [
  [
    { text: "Parameter Change", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
    { text: "SNR Effect", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
    { text: "Resolution Effect", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
    { text: "Scan Time", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
  ],
  ...tradeoffs.map(t => [t.param, t.snr, t.resolution, t.time]),
];
s15.addTable(tradeData, { x: 0.25, y: 0.85, w: 9.5, h: 4.6, colW: [3.0, 2.0, 2.5, 2.0], border: { pt: 0.5, color: "C8D6E5" }, fill: { color: WHITE }, fontSize: 12, color: DARK_TEXT, rowH: 0.61 });

// ── SLIDE 16: MRI vs CT ──────────────────────────────────────────────────────
const s16 = addContentSlide("MRI vs CT — Comparison");
const vsData = [
  [
    { text: "Feature", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
    { text: "MRI", options: { bold: true, fill: { color: DARK_CYAN }, color: WHITE } },
    { text: "CT", options: { bold: true, fill: { color: "C0392B" }, color: WHITE } },
  ],
  ["Radiation", { text: "None (RF + magnetic fields)", options: { color: "27AE60", bold: true } }, { text: "Ionising (X-rays)", options: { color: "C0392B" } }],
  ["Soft tissue contrast", { text: "Excellent", options: { bold: true } }, "Good (limited without contrast)"],
  ["Bone cortex visualisation", "Poor (signal void)", { text: "Excellent", options: { bold: true } }],
  ["Scan speed", "Minutes to >1 hour", { text: "Seconds", options: { bold: true } }],
  ["Acute haemorrhage detection", "Good (varies by sequence)", { text: "Excellent (hyperdense)", options: { bold: true } }],
  ["Implant safety", { text: "Ferromagnetic implants — risk", options: { color: "C0392B" } }, "Generally safe (artefact)"],
  ["Claustrophobia", "Significant issue", "Less problematic"],
  ["Contrast agent", "Gadolinium (low nephrotox.)", "Iodine (nephrotoxic at high dose)"],
  ["Cost", "High", "Moderate"],
  ["Best for", "Brain, spine, MSK, liver, pelvic organs", "Trauma, chest, acute abdomen, bones"],
];
s16.addTable(vsData, { x: 0.25, y: 0.85, w: 9.5, h: 4.75, colW: [2.8, 3.35, 3.35], border: { pt: 0.5, color: "C8D6E5" }, fill: { color: WHITE }, fontSize: 12, color: DARK_TEXT, rowH: 0.43 });

// ── SLIDE 17: Contraindications ───────────────────────────────────────────────
const s17 = addContentSlide("MRI Contraindications Overview");
s17.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 4.55, h: 0.4, fill: { color: "C0392B" }, line: { color: "C0392B" } });
s17.addText("ABSOLUTE CONTRAINDICATIONS", { x: 0.25, y: 0.85, w: 4.55, h: 0.4, fontSize: 13, bold: true, color: WHITE, align: "center", valign: "middle" });
s17.addShape(prs.shapes.RECTANGLE, { x: 5.0, y: 0.85, w: 4.75, h: 0.4, fill: { color: AMBER }, line: { color: AMBER } });
s17.addText("RELATIVE CONTRAINDICATIONS", { x: 5.0, y: 0.85, w: 4.75, h: 0.4, fontSize: 13, bold: true, color: NAVY, align: "center", valign: "middle" });
const absCI = ["Non-MR-conditional cardiac pacemaker/ICD", "Cochlear implants (most older models)", "Ferromagnetic cerebral aneurysm clips", "Intraorbital metallic foreign bodies", "Ferromagnetic vascular stents (< 6 weeks)"];
const relCI = ["Pregnancy (1st trimester — caution)", "Renal impairment (gadolinium — NSF risk)", "Severe claustrophobia", "MR-conditional implants (check field strength)", "Tattoos (rarely thermal injury)", "Neurostimulators (conditional devices exist)"];
absCI.forEach((item, i) => {
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  s17.addText(item, { x: 0.65, y: 1.35 + i * 0.68, w: 3.9, h: 0.6, fontSize: 12, color: DARK_TEXT, valign: "middle" });
});
relCI.forEach((item, i) => {
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  s17.addText(item, { x: 5.4, y: 1.35 + i * 0.68, w: 4.3, h: 0.6, fontSize: 12, color: DARK_TEXT, valign: "middle" });
});

// ── SLIDE 18: Key Takeaways (dark) ───────────────────────────────────────────
const s18 = prs.addSlide();
s18.background = { color: NAVY };
s18.addShape(prs.shapes.RECTANGLE, { x: 0, y: 0, w: 0.5, h: 5.625, fill: { color: CYAN }, line: { color: CYAN } });
s18.addText("Key Takeaways", { x: 0.7, y: 0.3, w: 9.0, h: 0.8, fontSize: 32, bold: true, color: WHITE });
const takeaways = [
  "MRI exploits proton spin in magnetic fields — NO ionising radiation",
  "T1 relaxation is longitudinal (spin-lattice); T2 is transverse (spin-spin)",
  "Short T1 = bright on T1W; Long T2 = bright on T2W (e.g. CSF, oedema)",
  "Larmor frequency ω₀ = γ × B₀ (42.58 MHz/T for ¹H)",
  "SNR ∝ B₀, voxel size, and √NEX — always a tradeoff with resolution",
  "K-space centre = contrast; periphery = detail (spatial resolution)",
  "TR and TE selection drives image contrast weighting",
  "Check contraindications: metallic implants, pacemakers, foreign bodies",
];
takeaways.forEach((t, i) => {
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  s18.addText(t, { x: 1.15, y: 1.2 + i * 0.55, w: 8.6, h: 0.38, fontSize: 12, color: WHITE, valign: "middle" });
});

prs.writeFile({ fileName: "/home/daytona/workspace/mri-radiology-teaching/01_MRI_Physics.pptx" })
  .then(() => console.log("DONE: 01_MRI_Physics.pptx"))
  .catch(err => console.error("ERROR:", err));

const pptxgen = require("pptxgenjs");
const prs = new pptxgen();
prs.layout = "LAYOUT_16x9";
prs.title = "MRI Sequences & Protocols";

const NAVY = "0D1B2A";
const WHITE = "FFFFFF";
const CYAN = "00B4D8";
const AMBER = "F4A261";
const LIGHT_BG = "F5F7FA";
const DARK_TEXT = "1A2B3C";
const MID_GRAY = "4A5568";
const LIGHT_CYAN = "E0F7FA";
const DARK_CYAN = "0077A8";
const GREEN = "27AE60";

function addContentSlide(title) {
  const slide = prs.addSlide();
  slide.background = { color: LIGHT_BG };
  slide.addShape(prs.shapes.RECTANGLE, { x: 0, y: 0, w: 10, h: 0.7, fill: { color: NAVY }, line: { color: NAVY } });
  slide.addText(title, { x: 0.25, y: 0, w: 9.5, h: 0.7, fontSize: 22, bold: true, color: WHITE, valign: "middle", margin: 0 });
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  return slide;
}

function addCyanBox(slide, text, x, y, w, h, fs) {
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  slide.addText(text, { x, y, w, h, fontSize: fs || 13, bold: true, color: WHITE, align: "center", valign: "middle" });
}
function addAmberBox(slide, text, x, y, w, h, fs) {
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}
function addNavyBox(slide, text, x, y, w, h, fs) {
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  slide.addText(text, { x, y, w, h, fontSize: fs || 13, bold: true, color: WHITE, align: "center", valign: "middle" });
}

// SLIDE 1 Title
const s1 = prs.addSlide();
s1.background = { color: NAVY };
s1.addShape(prs.shapes.RECTANGLE, { x: 0, y: 0, w: 0.5, h: 5.625, fill: { color: CYAN }, line: { color: CYAN } });
s1.addShape(prs.shapes.RECTANGLE, { x: 0.5, y: 2.5, w: 9.5, h: 0.08, fill: { color: CYAN }, line: { color: CYAN } });
s1.addText("MRI SEQUENCES\n& PROTOCOLS", { x: 0.9, y: 0.7, w: 8.6, h: 1.8, fontSize: 42, bold: true, color: WHITE, align: "left" });
s1.addText("MRI Radiology Teaching Series — Module 2", { x: 0.9, y: 2.7, w: 8.6, h: 0.6, fontSize: 18, color: CYAN, align: "left" });
s1.addText("Radiology Department  |  2026", { x: 0.9, y: 3.4, w: 8.6, h: 0.5, fontSize: 13, color: "8ECAE6", align: "left" });
s1.addText("Spin Echo to EPI — understanding the full sequence toolkit", { x: 0.9, y: 4.1, w: 8.6, h: 0.5, fontSize: 14, color: "8ECAE6", italic: true, align: "left" });

// SLIDE 2 TOC
const s2 = addContentSlide("Table of Contents");
const toc = [
  ["01","Sequence Family Overview"],["02","Spin Echo (SE)"],["03","Fast/Turbo Spin Echo (FSE/TSE)"],
  ["04","Gradient Echo (GRE)"],["05","Inversion Recovery: STIR, FLAIR"],["06","Echo Planar Imaging (EPI)"],
  ["07","Diffusion Weighted Imaging (DWI)"],["08","Perfusion MRI"],["09","MRCP Sequence"],
  ["10","Fat Saturation Techniques"],["11","Parallel Imaging: SENSE & GRAPPA"],
  ["12","3D Sequences: VIBE, SPACE, CUBE"],["13","fMRI Basics"],["14","Standard Protocol Table"],["15","Key Takeaways"],
];
toc.slice(0,8).forEach((item,i)=>{
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  s2.addText(item[1], { x: 0.75, y: 0.85+i*0.56, w: 4.05, h: 0.38, fontSize: 12, color: DARK_TEXT, valign: "middle" });
});
toc.slice(8).forEach((item,i)=>{
  addCyanBox(s2, item[0], 5.1, 0.85+i*0.56, 0.38, 0.38, 12);
  s2.addText(item[1], { x: 5.55, y: 0.85+i*0.56, w: 4.1, h: 0.38, fontSize: 12, color: DARK_TEXT, valign: "middle" });
});

// SLIDE 3 Sequence Family Overview
const s3 = addContentSlide("Sequence Family Overview");
const families = [
  { name: "Spin Echo", color: DARK_CYAN, examples: "SE, FSE/TSE, RARE", note: "90°+180° pulses; T1W, T2W, PD" },
  { name: "Gradient Echo", color: "8E44AD", examples: "FLASH, FISP, SPGR, bSSFP", note: "Flip angle <90°; T1W, T2*W, dynamic" },
  { name: "Inversion Recovery", color: "C0392B", examples: "STIR, FLAIR, MP-RAGE, TI varies", note: "180° prep pulse to null tissue" },
  { name: "Echo Planar (EPI)", color: GREEN, examples: "DWI, fMRI, perfusion", note: "Entire k-space in one shot; very fast" },
  { name: "Steady-State", color: AMBER, examples: "bSSFP, TrueFISP, FIESTA, BALANCE", note: "Bright fluid; cardiac, MR myelography" },
  { name: "Spectroscopy", color: MID_GRAY, examples: "PRESS, STEAM, CSI", note: "Metabolite peaks (NAA, Cho, Cr, Lac)" },
];
families.forEach((f, i) => {
  const col = i < 3 ? 0 : 1;
  const row = i % 3;
  const x = col === 0 ? 0.25 : 5.1;
  const y = 0.85 + row * 1.55;
  slide_coloredCard(s3, f, x, y, 4.7, 1.4);
});
function slide_coloredCard(slide, f, x, y, w, h) {
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  slide.addText(f.name, { x, y, w, h: 0.38, fontSize: 13, bold: true, color: WHITE, align: "center", valign: "middle" });
  slide.addText(`Examples: ${f.examples}`, { x: x+0.1, y: y+0.42, w: w-0.2, h: 0.38, fontSize: 11, color: DARK_TEXT, bold: true });
  slide.addText(f.note, { x: x+0.1, y: y+0.78, w: w-0.2, h: 0.5, fontSize: 11, color: MID_GRAY });
}

// SLIDE 4 Spin Echo
const s4 = addContentSlide("Spin Echo (SE) — Classic Sequence");
s4.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.5, fill: { color: NAVY }, line: { color: NAVY } });
s4.addText("Sequence: 90° RF → TE/2 delay → 180° refocusing → Echo readout at TE", { x: 0.25, y: 0.85, w: 9.5, h: 0.5, fontSize: 14, bold: true, color: CYAN, align: "center", valign: "middle" });
const seData = [
  [{ text: "Parameter", options: { bold: true, fill: { color: DARK_CYAN }, color: WHITE } }, { text: "T1-Weighted", options: { bold: true, fill: { color: DARK_CYAN }, color: WHITE } }, { text: "T2-Weighted", options: { bold: true, fill: { color: DARK_CYAN }, color: WHITE } }, { text: "PD-Weighted", options: { bold: true, fill: { color: DARK_CYAN }, color: WHITE } }],
  ["TR", "Short (300–700ms)", "Long (2000–5000ms)", "Long (2000–5000ms)"],
  ["TE", "Short (10–30ms)", "Long (80–120ms)", "Short (10–30ms)"],
  ["Fat appearance", "Bright", "Intermediate", "Bright"],
  ["CSF appearance", "Dark", "Bright (white)", "Intermediate"],
  ["Scan time (brain)", "3–5 min", "5–10 min", "4–6 min"],
  ["Main use", "Anatomy, post-Gd, liver", "Pathology, oedema", "Cartilage (knee), brain PD"],
];
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addAmberBox(s4, "SE T1W: best post-contrast; T2W SE replaced by FSE in most protocols", 0.25, 5.3, 9.5, 0.3, 12);

// SLIDE 5 FSE/TSE
const s5 = addContentSlide("Fast/Turbo Spin Echo (FSE/TSE) — Workhorse Sequence");
s5.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fill: { color: LIGHT_CYAN }, line: { color: CYAN } });
s5.addText("Multiple 180° pulses per TR → multiple echoes at different TE values → fills multiple k-space lines per repetition", { x: 0.3, y: 0.85, w: 9.4, h: 0.45, fontSize: 12, color: DARK_TEXT, valign: "middle" });
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  [{ text: "Concept", options: { bold: true, fill: { color: NAVY }, color: WHITE } }, { text: "Description", options: { bold: true, fill: { color: NAVY }, color: WHITE } }],
  ["Echo Train Length (ETL)", "Number of echoes per TR. ETL = 16–32 typical; shortens scan time proportionally"],
  ["Effective TE", "The echo filling the centre of k-space determines image contrast"],
  ["Fat appearance in T2 FSE", "Fat appears BRIGHT in T2 FSE (J-coupling suppression) — different from conventional SE"],
  ["RARE sequence", "Rapid Acquisition with Relaxation Enhancement — extreme ETL (256+) for single-shot"],
  ["HASTE / SS-FSE", "Single-shot FSE — acquires entire image in one TR; motion robust; used for MRCP, abdomen"],
  ["T2 SPACE/CUBE/VISTA", "3D TSE variants; isotropic voxels; multi-planar reformatting; spine, brain"],
  ["SAR consideration", "High ETL → high SAR (specific absorption rate) — reduce with hyperecho or variable flip angles"],
];
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// SLIDE 6 GRE
const s6 = addContentSlide("Gradient Echo (GRE) — Speed & Versatility");
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s6.addText("No 180° refocusing pulse — uses gradient reversal; susceptible to T2* effects; allows very short TR with small flip angles", { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fontSize: 13, bold: true, color: CYAN, align: "center", valign: "middle" });
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  ["Spoiled GRE", "FLASH (Siemens), SPGR (GE), T1-FFE (Philips)", "T1-contrast, spoiled residual Mxy", "Dynamic liver, post-contrast, VIBE"],
  ["Coherent GRE (bSSFP)", "TrueFISP (Siemens), FIESTA (GE), Balance FFE", "Steady-state; bright fluid", "Cardiac cine, MR myelography"],
  ["In-Phase/Opposed-Phase", "DUAL echo GRE", "Fat-water signal addition/subtraction", "Liver fat, adrenal adenoma"],
  ["3D VIBE", "VIBE (Siemens), LAVA (GE), THRIVE (Philips)", "Volumetric interpolated breath-hold", "Dynamic liver, abdomen"],
  ["Ultrashort TE (UTE)", "UTE, ZTE", "TE < 0.1ms; sees cortical bone/calcification", "MSK, lung, calcium imaging"],
];
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// SLIDE 7 Inversion Recovery
const s7 = addContentSlide("Inversion Recovery: STIR, FLAIR, FSPGR");
s7.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fill: { color: LIGHT_CYAN }, line: { color: CYAN } });
s7.addText("180° inversion pulse → Inversion Time (TI) → 90° excitation. At TI = T1×ln2, the selected tissue signal = 0 (nulled).", { x: 0.3, y: 0.85, w: 9.4, h: 0.45, fontSize: 12, color: DARK_TEXT, valign: "middle" });
const irData = [
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  [{ text: "STIR", options: { bold: true } }, "150–175ms", "Fat", "T2 (fat suppressed)", "Bone marrow oedema, soft tissue, spine"],
  [{ text: "FLAIR", options: { bold: true } }, "2200–2500ms", "CSF (free water)", "T2", "MS plaques, periventricular lesions, SAH"],
  [{ text: "FLAIR (3T)", options: { bold: true } }, "2400–2800ms", "CSF", "T2", "Better grey-white differentiation"],
  [{ text: "MP-RAGE", options: { bold: true } }, "800–1000ms", "Partial fat/CSF", "T1", "High-res 3D brain anatomy, cortical thickness"],
  [{ text: "DDIR (Double IR)", options: { bold: true } }, "Dual TI", "CSF + White matter", "T1", "Cortical lesion detection (MS)"],
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addAmberBox(s7, "STIR: robust fat suppression even with field inhomogeneity — preferred over fat-sat in extremities", 0.25, 5.28, 9.5, 0.3, 12);

// SLIDE 8 EPI
const s8 = addContentSlide("Echo Planar Imaging (EPI) — Fastest MRI");
s8.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fill: { color: NAVY }, line: { color: NAVY } });
s8.addText("Entire k-space filled after single RF excitation using rapidly oscillating readout gradients — scan time ~50–100ms per slice", { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fontSize: 13, bold: true, color: CYAN, align: "center", valign: "middle" });
const epiItems = [
  { title: "DWI", desc: "Diffusion sensitising gradients added to EPI; b-values 0–1000+ s/mm²; detects acute ischaemia within minutes" },
  { title: "fMRI (BOLD)", desc: "T2*-weighted EPI; detects BOLD signal changes (deoxyHb/oxyHb ratio); temporal resolution ~1–2s" },
  { title: "DSC Perfusion", desc: "Dynamic susceptibility contrast; Gd bolus tracked; CBV, CBF, MTT maps; stroke, tumour" },
  { title: "SWI", desc: "Susceptibility Weighted Imaging; magnitude × phase image; detects microhaemorrhage, iron, calcification" },
];
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addAmberBox(s8, "EPI limitations: geometric distortion (susceptibility), N/2 ghost artefact, low spatial resolution", 0.25, 5.5, 9.5, 0.1, 12);

// SLIDE 9 DWI
const s9 = addContentSlide("Diffusion Weighted Imaging (DWI) & ADC Maps");
s9.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fill: { color: LIGHT_CYAN }, line: { color: CYAN } });
s9.addText("DWI measures Brownian motion of water molecules. Restricted diffusion → high DWI signal, low ADC value.", { x: 0.3, y: 0.85, w: 9.4, h: 0.45, fontSize: 12, color: DARK_TEXT, valign: "middle" });
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  [{ text: "Finding", options: { bold: true, fill: { color: NAVY }, color: WHITE } }, { text: "DWI (high b)", options: { bold: true, fill: { color: NAVY }, color: WHITE } }, { text: "ADC Map", options: { bold: true, fill: { color: NAVY }, color: WHITE } }, { text: "Interpretation", options: { bold: true, fill: { color: NAVY }, color: WHITE } }],
  ["Acute infarct (< 6h)", { text: "BRIGHT", options: { bold: true, color: GREEN } }, { text: "DARK (low ADC)", options: { bold: true, color: "C0392B" } }, "True restricted diffusion (cytotoxic oedema)"],
  ["Abscess (pyogenic)", "Bright", "Dark", "Thick pus with restricted diffusion"],
  ["Epidermoid cyst", "Bright", "Dark", "Keratin — key differentiator from arachnoid cyst"],
  ["High-grade tumour", "Bright", "Dark/low", "Hypercellularity restricts diffusion"],
  ["Necrosis / CSF", "Dark", "Bright (high ADC)", "Free diffusion — 'T2 shine-through' reversed"],
  ["T2 shine-through", "Bright (high T2)", "Normal/High ADC", "Not true restriction — check ADC map always"],
  ["b-values used", "b=0, b=1000 (DWI)", "ADC = −ln(S1/S0)/(b1−b0)", "ADC in units of 10⁻³ mm²/s"],
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// SLIDE 10 Perfusion MRI
const s10 = addContentSlide("Perfusion MRI — Brain & Body");
const perfItems = [
  { head: "DSC (Dynamic Susceptibility Contrast)", color: DARK_CYAN, body: "T2*-EPI; Gd bolus tracking; generates rCBV, rCBF, MTT, Tmax maps. Primary use: brain tumour grading (high rCBV = high grade), stroke penumbra." },
  { head: "DCE (Dynamic Contrast Enhanced)", color: "8E44AD", body: "T1-GRE; Gd enhancement kinetics; Ktrans, Ve, Vp parameters. Use: prostate PI-RADS, breast BI-RADS kinetics, rectal cancer staging, liver LI-RADS." },
  { head: "ASL (Arterial Spin Labelling)", color: GREEN, body: "Non-contrast; magnetically labels arterial blood as endogenous tracer. Measures CBF (ml/100g/min). Use: paediatric, renal function, dementia, repeat scans." },
];
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  s10.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: yy, w: 9.5, h: 0.42, fill: { color: item.color }, line: { color: item.color } });
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// SLIDE 11 MRCP
const s11 = addContentSlide("MRCP — MR Cholangiopancreatography");
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s11.addText("MRCP exploits the very long T2 of bile/pancreatic juice — heavily T2-weighted sequence nulls background solid organs.", { x: 0.3, y: 0.85, w: 9.4, h: 0.45, fontSize: 12, color: DARK_TEXT, valign: "middle" });
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  ["Sequences", "3D TSE (SPACE/CUBE/VISTA) ± 2D thick-slab SS-MRCP (30–70mm)"],
  ["TR/TE", "TR 2000–4000ms / TE 500–1000ms (heavily T2W)"],
  ["Bile duct diameter", "CBD normal < 6mm (up to 8mm post-cholecystectomy)"],
  ["Pancreatic duct", "Main PD normal ≤ 3mm in head, ≤ 2mm in body/tail"],
  ["Indications", "Suspected CBD stones, PSC, cholangiocarcinoma, IPMN, post-ERCP"],
  ["Stones appearance", "Low signal (dark) filling defects in bright bile — classic 'dark stone in bright duct'"],
  ["Secretin MRCP", "IV secretin (1 CU/kg) stimulates pancreatic exocrine function; quantifies PD distensibility"],
  ["Limitations", "Cannot detect microlithiasis (<3mm); peristalsis artefact; no therapeutic capability"],
];
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// SLIDE 12 Fat Saturation
const s12 = addContentSlide("Fat Saturation Techniques");
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  ["Chemical Sat (ChemSat/FATSAT)", "Frequency-selective RF pre-pulse at fat freq (63.5 MHz at 1.5T)", "Fast; good at 1.5T/3T", "Fails with B0 inhomogeneity; poor at 0.3T"],
  ["STIR", "IR with TI 150–175ms nulls fat signal", "Robust at any field strength; inhomogeneity-insensitive", "Gadolinium enhancement nulled; reduced SNR"],
  ["Dixon Method (2-point, 3-point)", "Acquires in-phase + opposed-phase; maths separates fat/water", "Quantitative fat fraction; homogeneous suppression", "Longer scan time; requires post-processing"],
  ["SPAIR / SPIR", "Adiabatic spectral inversion recovery pre-pulse", "Better than ChemSat at 3T; robust", "Moderate SAR"],
  ["Water excitation (Proset/PASTA)", "Only excites water protons via binomial pulses", "No extra SAR; fast", "Not for areas with strong susceptibility effects"],
];
s12.addTable(fatData, { x: 0.25, y: 0.85, w: 9.5, h: 4.7, colW: [2.3, 3.0, 2.2, 2.0], border: { pt: 0.5, color: "C8D6E5" }, fill: { color: WHITE }, fontSize: 12, color: DARK_TEXT, rowH: 0.68 });

// SLIDE 13 Parallel Imaging
const s13 = addContentSlide("Parallel Imaging: SENSE & GRAPPA");
s13.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fill: { color: NAVY }, line: { color: NAVY } });
s13.addText("Undersamples k-space using multiple receiver coil elements; reconstruction uses coil sensitivity maps to reduce scan time", { x: 0.25, y: 0.85, w: 9.5, h: 0.45, fontSize: 13, bold: true, color: CYAN, align: "center", valign: "middle" });
const piData = [
  [{ text: "Feature", options: { bold: true, fill: { color: NAVY }, color: WHITE } }, { text: "SENSE (Philips/GE)", options: { bold: true, fill: { color: NAVY }, color: WHITE } }, { text: "GRAPPA (Siemens)", options: { bold: true, fill: { color: NAVY }, color: WHITE } }],
  ["Domain", "Image domain (unfolding aliased images)", "K-space domain (kernel-based synthesis)"],
  ["Auto-calibration", "Separate ACS scan required", "ACS lines embedded in same acquisition"],
  ["Acceleration factor (R)", "Typically 2–3×", "Typically 2–4×"],
  ["SNR penalty", "SNR ∝ 1/(g-factor × √R)", "SNR ∝ 1/(g-factor × √R)"],
  ["g-factor", "Geometry-dependent noise amplification; depends on coil array quality", "Similar g-factor dependency"],
  ["2D PI", "SENSE-2D, mSENSE", "GRAPPA-2D"],
  ["3D PI", "CAIPIRINHA — shifts aliasing pattern in 2 directions", "Same CAIPIRINHA principle"],
];
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// SLIDE 14 3D Sequences
const s14 = addContentSlide("3D Sequences: VIBE, SPACE, CUBE, VISTA");
const seqCards = [
  { name: "VIBE\n(Siemens)", equiv: "LAVA (GE), THRIVE (Philips)", type: "3D Spoiled GRE", use: "Dynamic liver, multiphasic abdominal enhancement, post-contrast", feat: "Breath-hold; fat saturation; isotropic voxels 2–3mm" },
  { name: "SPACE\n(Siemens)", equiv: "CUBE (GE), VISTA (Philips)", type: "3D TSE with variable flip angles", use: "Brain (FLAIR, T2), spine, MRCP, joints", feat: "Isotropic 1mm³; MPR in any plane; reduces blurring vs standard 3D TSE" },
  { name: "MP-RAGE\n(Siemens)", equiv: "BRAVO (GE), TFE (Philips)", type: "3D IR-prepared GRE", use: "High-res brain anatomy; cortical thickness; white/grey differentiation", feat: "1mm isotropic; TI ~900ms at 3T; standard neuro protocol" },
];
seqCards.forEach((c, i) => {
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// SLIDE 15 fMRI
const s15 = addContentSlide("Functional MRI (fMRI) — BOLD Imaging");
s15.addShape(prs.shapes.RECTANGLE, { x: 0.25, y: 0.85, w: 9.5, h: 0.5, fill: { color: LIGHT_CYAN }, line: { color: CYAN } });
s15.addText("BOLD = Blood Oxygenation Level Dependent. Neural activity → increased CBF → oxyHb↑ / deoxyHb↓ → T2* signal ↑ (~1–5%). Detected with T2*-EPI.", { x: 0.3, y: 0.87, w: 9.4, h: 0.46, fontSize: 12, color: DARK_TEXT });
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  ["Haemodynamic response function (HRF)", "~5–6s delay from neural event to BOLD peak; lasts ~12–15s"],
  ["Task-based fMRI", "Block or event-related paradigms; language, motor, visual cortex mapping"],
  ["Pre-surgical planning", "Motor strip, Broca/Wernicke areas before tumour resection; reduces deficits"],
  ["Resting-state fMRI (rs-fMRI)", "No task; measures spontaneous low-frequency BOLD fluctuations; 'default mode network'"],
  ["Connectivity analysis", "ICA, seed-based correlation; used in Alzheimer's, depression, epilepsy research"],
  ["Limitations", "Indirect measure of neural activity; neurovascular uncoupling; motion artefact; low spatial resolution"],
  ["Typical parameters (3T)", "TR 2s, TE 30ms, flip 77°, 3mm isotropic, 200–300 volumes per run"],
];
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// SLIDE 16 Protocol Table
const s16 = addContentSlide("Standard Organ Protocol Reference Table");
const protData = [
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    { text: "Body Region", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
    { text: "Key Sequences", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
    { text: "Planes", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
    { text: "Field Strength", options: { bold: true, fill: { color: NAVY }, color: WHITE } },
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  ["Brain (routine)", "Axial FLAIR, T1 (MP-RAGE), DWI, T2; ± post-Gd T1", "Axial, coronal, sagittal", "1.5T or 3T"],
  ["Spine (cervical)", "Sagittal T1, T2; Axial T2 at disc levels; ± STIR", "Sagittal, Axial", "1.5T or 3T"],
  ["Liver (dynamic)", "Pre/art/portal/delayed VIBE; DWI; MRCP; T1 in/opp-phase", "Axial ± coronal", "1.5T or 3T"],
  ["Prostate (mpMRI)", "Axial T2, DWI (b50/b400/b800/b1400), DCE; ± MRS", "Axial, coronal, sagittal", "3T (preferred)"],
  ["Knee", "Sagittal PD FS, Sagittal T1, Coronal T2 FS, Axial PD", "Sag, Cor, Ax", "1.5T or 3T"],
  ["Shoulder", "Coronal T2 FS, PD FS, Axial T2; ± arthrogram STIR", "Cor, Ax, Sag oblique", "1.5T or 3T"],
  ["Cardiac (CMR)", "Cine SSFP, LGE, T1/T2 mapping; ± stress perfusion", "SA, 4CH, 2CH, LVOT", "1.5T or 3T"],
  ["Pelvis (female)", "Axial/Sag/Cor T2; DWI; T1 FS post-Gd", "Axial, sagittal, coronal", "1.5T or 3T"],
];
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// SLIDE 17 Key Takeaways
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s17.addText("Key Takeaways", { x: 0.7, y: 0.3, w: 9.0, h: 0.7, fontSize: 32, bold: true, color: WHITE });
const tks = [
  "SE sequences: use TR & TE to select T1W, T2W, or PD weighting",
  "FSE/TSE: multiple echoes per TR → faster; fat appears bright in T2 FSE",
  "GRE: no 180° pulse; susceptible to T2* effects; enables dynamic & cardiac imaging",
  "IR sequences: STIR nulls fat (robust fat suppression); FLAIR nulls CSF (MS plaques)",
  "DWI: high DWI + low ADC = true restricted diffusion (stroke, abscess, lymphoma)",
  "Parallel imaging (SENSE/GRAPPA) accelerates acquisition but reduces SNR (g-factor)",
  "3D sequences (VIBE, SPACE, MP-RAGE) provide isotropic voxels for multi-planar reformat",
  "Always match sequence choice to clinical question: speed, contrast, and resolution tradeoffs",
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prs.writeFile({ fileName: "/home/daytona/workspace/mri-radiology-teaching/02_MRI_Sequences.pptx" })
  .then(() => console.log("DONE: 02_MRI_Sequences.pptx"))
  .catch(err => console.error("ERROR:", err));

const pptxgen = require("pptxgenjs");
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prs.layout = "LAYOUT_16x9";
prs.title = "Brain & Neuro MRI";

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// SLIDE 1 - Title
const t = prs.addSlide();
t.background = { color: NAVY };
t.addShape(prs.ShapeType.rect, { x: 0, y: 0, w: 0.5, h: 5.625, fill: { color: CYAN } });
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t.addText("Brain & Neuro MRI", { x: 0.8, y: 0.9, w: 8.8, h: 1.6, fontSize: 44, bold: true, color: WHITE });
t.addText("MRI Radiology Teaching Series — Module 3", { x: 0.8, y: 3.1, w: 8.8, h: 0.6, fontSize: 18, color: CYAN });
t.addText("Covering: Stroke • Tumors • Demyelination • Infection • Trauma • Epilepsy", { x: 0.8, y: 3.8, w: 8.8, h: 0.5, fontSize: 13, color: "8ECAE6" });
t.addText("Radiology Department | 2026", { x: 0.8, y: 4.7, w: 8.8, h: 0.4, fontSize: 12, color: "4A7A9B" });

// SLIDE 2 - Table of Contents
const toc = addContentSlide(prs, "Table of Contents");
toc.addText([
  { text: "1.  Brain MRI Indications & Protocol", options: { breakLine: true } },
  { text: "2.  Normal Brain Anatomy on MRI", options: { breakLine: true } },
  { text: "3.  Signal Characteristics: WM vs GM", options: { breakLine: true } },
  { text: "4.  Acute Stroke — DWI/ADC Pattern", options: { breakLine: true } },
  { text: "5.  Brain Tumors — Classification", options: { breakLine: true } },
  { text: "6.  Glioma Grading & GBM", options: { breakLine: true } },
  { text: "7.  Meningioma & Metastases", options: { breakLine: true } },
  { text: "8.  Multiple Sclerosis", options: { breakLine: true } },
  { text: "9.  Intracranial Infections", options: { breakLine: true } },
  { text: "10. Hydrocephalus", options: { breakLine: true } },
  { text: "11. Traumatic Brain Injury (TBI)", options: { breakLine: true } },
  { text: "12. Epilepsy MRI", options: { breakLine: true } },
  { text: "13. Cerebrovascular Malformations", options: { breakLine: true } },
  { text: "14. Pituitary MRI", options: { breakLine: true } },
  { text: "15. Posterior Fossa & Pediatric Brain", options: { breakLine: true } },
  { text: "16. Key Takeaways" }
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toc.addText("Module 3 Focus Areas", { x: 5.2, y: 0.95, w: 4.4, h: 0.5, fontSize: 14, bold: true, color: CYAN });
toc.addText([
  { text: "• Neurological emergencies\n", options: {} },
  { text: "• Oncological brain MRI\n", options: {} },
  { text: "• White matter diseases\n", options: {} },
  { text: "• CNS infections\n", options: {} },
  { text: "• Functional & specialized MRI\n", options: {} },
  { text: "• Pediatric considerations", options: {} }
], { x: 5.2, y: 1.55, w: 4.3, h: 3.5, fontSize: 12, color: WHITE, lineSpacingMultiple: 1.5 });

// SLIDE 3 - Indications
const s3 = addContentSlide(prs, "Brain MRI — Indications & Standard Protocol");
s3.addTable([
  [{ text: "Category", options: { bold: true, color: WHITE, fill: NAVY } }, { text: "Indications", options: { bold: true, color: WHITE, fill: NAVY } }],
  ["Vascular", "Stroke/TIA, hemorrhage, venous thrombosis, vasculitis"],
  ["Neoplastic", "Primary brain tumors, metastases, meningeal disease"],
  ["Demyelinating", "Multiple sclerosis, NMOSD, ADEM"],
  ["Infectious", "Abscess, meningitis, encephalitis, HIV-related"],
  ["Trauma", "Diffuse axonal injury, contusion, post-traumatic changes"],
  ["Epilepsy", "Hippocampal sclerosis, cortical dysplasia, tumor"],
  ["Degenerative", "Dementia workup, Parkinson's, atrophy patterns"],
  ["Congenital", "Malformations, phakomatoses, migration anomalies"],
], { x: 0.25, y: 0.85, w: 9.5, h: 3.8,
  colW: [2.2, 7.3],
  rowH: [0.38, 0.38, 0.38, 0.38, 0.38, 0.38, 0.38, 0.38],
  border: { pt: 0.5, color: "D0D8E4" },
  fontSize: 11, color: "1A2B3C",
  align: "left",
  autoPage: false,
});
s3.addShape(prs.ShapeType.rect, { x: 0.25, y: 4.8, w: 9.5, h: 0.55, fill: { color: CYAN } });
s3.addText("Standard Protocol: Axial DWI + ADC | Axial FLAIR | Axial T2 | Axial T1 | Sagittal T1 | Coronal T2/FLAIR | Post-Gd T1 (axial/coronal/sagittal)", { x: 0.3, y: 4.82, w: 9.3, h: 0.5, fontSize: 10, color: WHITE, bold: true });

// SLIDE 4 - Normal Anatomy
const s4 = addContentSlide(prs, "Normal Brain Anatomy on MRI");
s4.addText("Key Anatomical Landmarks", { x: 0.25, y: 0.8, w: 4.5, h: 0.4, fontSize: 14, bold: true, color: NAVY });
s4.addText([
  { text: "Axial Plane:\n", options: { bold: true, color: CYAN } },
  { text: "• Basal ganglia: caudate, putamen, globus pallidus\n• Thalamus: central relay station\n• Internal capsule: anterior & posterior limb\n• Corpus callosum: genu, body, splenium\n• Cerebellum & brainstem: pons, medulla\n• Sylvian fissure, interhemispheric fissure", options: {} }
], { x: 0.25, y: 1.25, w: 4.5, h: 3.9, fontSize: 11, color: "1A2B3C", lineSpacingMultiple: 1.4 });

s4.addShape(prs.ShapeType.rect, { x: 5.0, y: 0.8, w: 4.7, h: 4.55, fill: { color: NAVY }, line: { color: CYAN, width: 1 } });
s4.addText("Signal Intensities — Normal Brain", { x: 5.1, y: 0.9, w: 4.5, h: 0.4, fontSize: 13, bold: true, color: CYAN });
s4.addTable([
  [{ text: "Structure", options: { bold: true, color: WHITE } }, { text: "T1W", options: { bold: true, color: WHITE } }, { text: "T2W", options: { bold: true, color: WHITE } }, { text: "FLAIR", options: { bold: true, color: WHITE } }],
  ["Grey Matter", "Isointense", "Slightly ↑", "Intermediate"],
  ["White Matter", "Slightly ↑", "Slightly ↓", "Low"],
  ["CSF", "Dark (low)", "Bright (high)", "Dark (nulled)"],
  ["Fat (marrow)", "Bright", "Intermediate", "Bright"],
  ["Blood (acute)", "Isointense", "↓ (T2*)", "Variable"],
  ["Myelination", "↑ T1 with age", "↓ T2 with age", "Changes with age"],
], { x: 5.1, y: 1.35, w: 4.5, h: 3.7,
  colW: [1.9, 0.9, 0.9, 0.9],
  rowH: [0.42, 0.42, 0.42, 0.42, 0.42, 0.42, 0.42],
  border: { pt: 0.5, color: "2E4A6A" },
  fontSize: 10, color: WHITE, fill: "1A3050",
  autoPage: false,
});

// SLIDE 5 - Stroke DWI
const s5 = addContentSlide(prs, "Acute Stroke — DWI/ADC Pattern (Ischemic)");
s5.addShape(prs.ShapeType.rect, { x: 0.25, y: 0.85, w: 4.4, h: 1.8, fill: { color: RED }, line: { color: "B02030", width: 1 } });
s5.addText("Acute Ischemic Stroke", { x: 0.35, y: 0.9, w: 4.2, h: 0.45, fontSize: 14, bold: true, color: WHITE });
s5.addText("DWI: Bright (restricted diffusion)\nADC: Dark (low ADC value)\nFLAIR: May be normal in first 6h\nT2: Subtle hyperintensity after 6-12h\nT1: Normal or subtle hypointensity", { x: 0.35, y: 1.4, w: 4.2, h: 1.15, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.3 });

s5.addShape(prs.ShapeType.rect, { x: 0.25, y: 2.8, w: 4.4, h: 1.8, fill: { color: "1A3050" }, line: { color: CYAN, width: 1 } });
s5.addText("Chronic Infarct", { x: 0.35, y: 2.85, w: 4.2, h: 0.45, fontSize: 14, bold: true, color: CYAN });
s5.addText("T2/FLAIR: Hyperintense encephalomalacia\nDWI: No restriction (T2 shine-through)\nT1: Hypointense (CSF-like)\nVolume loss and gliosis present\nEx vacuo dilatation of ventricles", { x: 0.35, y: 3.35, w: 4.2, h: 1.15, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.3 });

s5.addShape(prs.ShapeType.rect, { x: 5.0, y: 0.85, w: 4.7, h: 4.55, fill: { color: LIGHT_BG }, line: { color: NAVY, width: 1 } });
s5.addText("Time-Signal Evolution", { x: 5.1, y: 0.95, w: 4.5, h: 0.4, fontSize: 14, bold: true, color: NAVY });
s5.addTable([
  [{ text: "Time", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "DWI", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "ADC", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "FLAIR", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "T1", options: { bold: true, fill: NAVY, color: WHITE } }],
  ["0–6h", "↑↑ Bright", "↓↓ Dark", "Normal", "Normal"],
  ["6–24h", "↑↑ Bright", "↓↓ Dark", "↑ Bright", "Subtle ↓"],
  ["1–7d", "↑ Bright", "↓ Dark", "↑↑ Bright", "↓ Dark"],
  ["1–4wk", "Fading", "Normalizing", "↑ Bright", "↓ Dark"],
  [">4wk", "Normal/↓", "↑ (T2 shine)", "↑ FLAIR halo", "CSF-like ↓"],
], { x: 5.1, y: 1.4, w: 4.5, h: 3.0,
  colW: [0.9, 0.9, 0.9, 0.9, 0.9],
  rowH: [0.42, 0.42, 0.42, 0.42, 0.42, 0.42],
  border: { pt: 0.5, color: "D0D8E4" },
  fontSize: 10, color: "1A2B3C",
  autoPage: false,
});
s5.addShape(prs.ShapeType.rect, { x: 5.1, y: 4.5, w: 4.5, h: 0.65, fill: { color: AMBER } });
s5.addText("DWI-FLAIR mismatch: DWI bright + FLAIR normal → symptom onset <4.5h → thrombolysis candidate!", { x: 5.15, y: 4.52, w: 4.4, h: 0.6, fontSize: 10, bold: true, color: NAVY });

// SLIDE 6 - Brain Tumors Classification
const s6 = addContentSlide(prs, "Brain Tumors — WHO 2021 Classification Overview");
s6.addTable([
  [{ text: "Tumor Type", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "WHO Grade", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "T1 (Post-Gd)", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "T2/FLAIR", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "Key Feature", options: { bold: true, fill: NAVY, color: WHITE } }],
  ["Astrocytoma (IDH-mut)", "2–3", "No/minimal enhancement", "↑ T2", "IDH mutation, slow growth"],
  ["Glioblastoma (GBM)", "4", "Rim enhancement", "↑↑ T2", "Necrosis, mass effect, EDH"],
  ["Oligodendroglioma", "2–3", "Variable", "↑ T2", "1p/19q co-deletion, Ca²⁺"],
  ["Meningioma", "1–3", "Homogeneous enhance", "Iso-↑", "Dural tail, extra-axial"],
  ["Metastasis", "—", "Ring/solid enhance", "↑ T2 edema", "Multiple, corticomedullary junction"],
  ["Lymphoma (PCNSL)", "—", "Homogeneous, periventricle", "↑", "Restricted diffusion, DWI bright"],
  ["Ependymoma", "2–3", "Variable enhance", "↑ T2", "4th ventricle, CSF seeding"],
  ["Medulloblastoma", "4", "Enhance", "Variable", "Posterior fossa child, DWI bright"],
  ["Pituitary adenoma", "—", "Enhances (macroadenoma)", "Iso", "Sellar mass, suprasellar extension"],
], { x: 0.25, y: 0.82, w: 9.5, h: 4.6,
  colW: [2.2, 1.1, 1.9, 1.4, 2.9],
  rowH: [0.42, 0.42, 0.42, 0.42, 0.42, 0.42, 0.42, 0.42, 0.42, 0.42],
  border: { pt: 0.5, color: "D0D8E4" },
  fontSize: 10, color: "1A2B3C",
  autoPage: false,
});

// SLIDE 7 - GBM
const s7 = addContentSlide(prs, "Glioblastoma (GBM) — WHO Grade 4");
s7.addShape(prs.ShapeType.rect, { x: 0.25, y: 0.82, w: 4.5, h: 4.55, fill: { color: NAVY } });
s7.addText("MRI Hallmarks of GBM", { x: 0.35, y: 0.92, w: 4.3, h: 0.5, fontSize: 14, bold: true, color: CYAN });
s7.addText([
  { text: "• Heterogeneous ring-enhancing mass on post-Gd T1\n", options: {} },
  { text: "• Central necrosis (T1 dark, T2 bright core)\n", options: {} },
  { text: "• Vasogenic edema: extensive T2/FLAIR hyperintensity\n", options: {} },
  { text: "• Hemorrhagic foci (T2* GRE / SWI blooming)\n", options: {} },
  { text: "• Corpus callosum crossing → 'Butterfly GBM'\n", options: {} },
  { text: "• MR Spectroscopy: ↑ Choline, ↓ NAA, ↑ Cho/Cr ratio\n", options: {} },
  { text: "• MR Perfusion (DSC): ↑ rCBV in enhancing rim\n", options: {} },
  { text: "• DWI: Restricted diffusion in cellular areas\n", options: {} },
  { text: "• Multifocal in 5–10%; crosses midline\n", options: {} },
], { x: 0.35, y: 1.5, w: 4.3, h: 3.7, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.35 });

s7.addShape(prs.ShapeType.rect, { x: 5.0, y: 0.82, w: 4.7, h: 2.1, fill: { color: RED } });
s7.addText("Diagnosis & Prognosis", { x: 5.1, y: 0.9, w: 4.5, h: 0.4, fontSize: 13, bold: true, color: WHITE });
s7.addText("Median survival: 14–16 months (MGMT-methylated) vs 9–12 months (unmethylated)\nIDH-wildtype = most aggressive; IDH-mutant = slightly better prognosis\nTERMBP criteria for pseudoprogression vs true progression", { x: 5.1, y: 1.35, w: 4.5, h: 1.4, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.3 });

s7.addShape(prs.ShapeType.rect, { x: 5.0, y: 3.1, w: 4.7, h: 2.27, fill: { color: "1A3050" }, line: { color: CYAN, width: 1 } });
s7.addText("RANO Criteria — Response Assessment", { x: 5.1, y: 3.18, w: 4.5, h: 0.4, fontSize: 12, bold: true, color: CYAN });
s7.addText("Complete Response: No enhancement, no FLAIR change, off steroids\nPartial Response: ≥50% ↓ enhancement\nStable Disease: <50% ↓ to <25% ↑\nProgression: ≥25% ↑ enhancement or new lesion\nPseudoprogression: ↑ enhancement at 1–3mo post-RT (treatment effect)", { x: 5.1, y: 3.65, w: 4.5, h: 1.55, fontSize: 10, color: WHITE, lineSpacingMultiple: 1.3 });

// SLIDE 8 - Meningioma & Metastases
const s8 = addContentSlide(prs, "Meningioma & Brain Metastases");
s8.addText("Meningioma", { x: 0.25, y: 0.82, w: 4.4, h: 0.4, fontSize: 15, bold: true, color: NAVY });
s8.addText([
  { text: "• Extra-axial dural-based mass\n", options: {} },
  { text: "• T1: Isointense to grey matter\n", options: {} },
  { text: "• T2: Iso to slightly hyperintense\n", options: {} },
  { text: "• Post-Gd: Intense homogeneous enhancement\n", options: {} },
  { text: "• DURAL TAIL: pathognomonic\n", options: { bold: true } },
  { text: "• Calcification: T2*/SWI blooming\n", options: {} },
  { text: "• WHO Grade 1 (benign) — most common\n", options: {} },
  { text: "• Grade 2 (atypical) / Grade 3 (anaplastic): invasion\n", options: {} },
  { text: "• Sites: parasagittal, sphenoid wing, olfactory groove, CPA\n", options: {} },
], { x: 0.25, y: 1.3, w: 4.4, h: 3.8, fontSize: 11, color: "1A2B3C", lineSpacingMultiple: 1.35 });

s8.addShape(prs.ShapeType.rect, { x: 4.85, y: 0.82, w: 4.9, h: 4.55, fill: { color: "1A2030" } });
s8.addText("Brain Metastases", { x: 4.95, y: 0.92, w: 4.7, h: 0.4, fontSize: 15, bold: true, color: AMBER });
s8.addText([
  { text: "• Most common adult brain tumors\n", options: {} },
  { text: "• Location: corticomedullary junction (junction zone)\n", options: {} },
  { text: "• T2: Hyperintense with surrounding vasogenic edema\n", options: {} },
  { text: "• Post-Gd T1: Ring or solid enhancement\n", options: {} },
  { text: "• DWI: Variable (high in lymphoma, variable in mets)\n", options: {} },
  { text: "• SWI: Hemorrhagic mets (melanoma, RCC, thyroid, choriocarcinoma)\n", options: {} },
], { x: 4.95, y: 1.45, w: 4.7, h: 2.0, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.35 });
s8.addTable([
  [{ text: "Primary", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "% Brain Mets", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "Appearance", options: { bold: true, fill: NAVY, color: WHITE } }],
  ["Lung (NSCLC)", "~40%", "Solid/ring, multiple"],
  ["Breast", "~15%", "Leptomeningeal spread"],
  ["Melanoma", "~10%", "Hemorrhagic, T1 bright"],
  ["RCC", "~7%", "Vascular, hemorrhagic"],
  ["Colorectal", "~5%", "Cystic ring-enhancing"],
], { x: 4.95, y: 3.55, w: 4.7, h: 1.75,
  colW: [1.5, 1.3, 1.9],
  rowH: [0.32, 0.32, 0.32, 0.32, 0.32, 0.32],
  border: { pt: 0.5, color: "2E4A6A" },
  fontSize: 10, color: WHITE, fill: "1A3050",
  autoPage: false,
});

// SLIDE 9 - Multiple Sclerosis
const s9 = addContentSlide(prs, "Multiple Sclerosis — MRI Criteria");
s9.addShape(prs.ShapeType.rect, { x: 0.25, y: 0.82, w: 9.5, h: 0.5, fill: { color: CYAN } });
s9.addText("McDonald 2017 Criteria: DIS = Dissemination in Space | DIT = Dissemination in Time", { x: 0.3, y: 0.87, w: 9.4, h: 0.4, fontSize: 12, bold: true, color: NAVY });
s9.addTable([
  [{ text: "Location", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "Min Lesions for DIS", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "MRI Characteristics", options: { bold: true, fill: NAVY, color: WHITE } }],
  ["Periventricular", "≥1 lesion", "Dawson fingers: perpendicular to ventricles on sagittal FLAIR"],
  ["Cortical / Juxtacortical", "≥1 lesion", "Leukocortical, intracortical lesions; best on DIR"],
  ["Infratentorial", "≥1 lesion", "Brainstem, cerebellum, middle cerebellar peduncle"],
  ["Spinal cord", "≥1 lesion", "<2 vertebral segments, peripheral, partial cord involvement"],
  ["Optic nerve", "≥1 lesion", "T2 hyperintense optic nerve; seen in 70% of MS patients"],
], { x: 0.25, y: 1.4, w: 9.5, h: 2.5,
  colW: [2.2, 2.2, 5.1],
  rowH: [0.42, 0.42, 0.42, 0.42, 0.42, 0.42],
  border: { pt: 0.5, color: "D0D8E4" },
  fontSize: 10, color: "1A2B3C",
  autoPage: false,
});
s9.addShape(prs.ShapeType.rect, { x: 0.25, y: 4.0, w: 4.6, h: 1.4, fill: { color: NAVY }, line: { color: AMBER, width: 1.5 } });
s9.addText("Active Lesion (DIT)", { x: 0.35, y: 4.08, w: 4.4, h: 0.4, fontSize: 12, bold: true, color: AMBER });
s9.addText("Post-Gd enhancing lesion OR new T2 lesion compared to prior scan (without need for Gd if prior scan exists)", { x: 0.35, y: 4.55, w: 4.4, h: 0.75, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.3 });
s9.addShape(prs.ShapeType.rect, { x: 5.1, y: 4.0, w: 4.6, h: 1.4, fill: { color: NAVY }, line: { color: GREEN, width: 1.5 } });
s9.addText("Black Holes (T1 Hypointense)", { x: 5.2, y: 4.08, w: 4.4, h: 0.4, fontSize: 12, bold: true, color: GREEN });
s9.addText("Chronic irreversible axonal loss. T1 dark lesions correlate with disability. More common in progressive MS forms.", { x: 5.2, y: 4.55, w: 4.4, h: 0.75, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.3 });

// SLIDE 10 - CNS Infections
const s10 = addContentSlide(prs, "CNS Infections — Brain Abscess, Encephalitis & Meningitis");
s10.addTable([
  [{ text: "Condition", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "T1 Post-Gd", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "T2/FLAIR", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "DWI", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "Key Feature", options: { bold: true, fill: NAVY, color: WHITE } }],
  ["Pyogenic Abscess", "Rim enhancement (thin, smooth)", "↑↑ surrounding edema", "Bright centre (restricted)", "Low ADC in pus cavity"],
  ["Toxoplasma", "Ring enhance; target sign", "↑ edema", "Variable", "Eccentric nodule (HIV)"],
  ["Viral Encephalitis (HSV)", "No/late enhancement", "↑ temporal/insular FLAIR", "Restricted early", "Temporal lobe involvement"],
  ["Tuberculous", "Thick ring/nodular enhance", "↑ T2, basilar meningitis", "Variable", "Basal meningeal enhance"],
  ["Cryptococcus", "Gelatinous pseudocysts", "↑ T2 basal ganglia", "Normal", "Perivascular (Virchow-Robin) dilation"],
  ["Bacterial Meningitis", "Leptomeningeal enhance", "↑ subarachnoid FLAIR", "Cortical ribbon DWI", "Post-Gd FLAIR most sensitive"],
  ["PML (JC virus)", "No enhancement", "↑↑ T2 white matter", "Variable centre", "No mass effect, HIV/immunosuppressed"],
], { x: 0.25, y: 0.82, w: 9.5, h: 4.6,
  colW: [2.0, 2.1, 1.8, 1.5, 2.1],
  rowH: [0.42, 0.52, 0.52, 0.52, 0.52, 0.52, 0.52, 0.52],
  border: { pt: 0.5, color: "D0D8E4" },
  fontSize: 10, color: "1A2B3C",
  autoPage: false,
});

// SLIDE 11 - Hydrocephalus
const s11 = addContentSlide(prs, "Hydrocephalus — MRI Classification & Features");
s11.addShape(prs.ShapeType.rect, { x: 0.25, y: 0.82, w: 4.5, h: 4.55, fill: { color: LIGHT_BG }, line: { color: NAVY, width: 1 } });
s11.addText("Types of Hydrocephalus", { x: 0.35, y: 0.9, w: 4.3, h: 0.4, fontSize: 14, bold: true, color: NAVY });
s11.addText([
  { text: "Obstructive (Non-communicating):\n", options: { bold: true, color: CYAN } },
  { text: "• Aqueduct stenosis (Sylvian)\n• Tectal plate glioma\n• Colloid cyst (3rd ventricle)\n• Dandy-Walker malformation\n\n", options: { color: "1A2B3C" } },
  { text: "Communicating:\n", options: { bold: true, color: CYAN } },
  { text: "• Post-SAH / meningitis (adhesions)\n• Normal Pressure Hydrocephalus (NPH)\n• Choroid plexus papilloma (↑ CSF)\n\n", options: { color: "1A2B3C" } },
  { text: "Ex Vacuo Dilatation:\n", options: { bold: true, color: AMBER } },
  { text: "• Parenchymal loss, NOT true hydrocephalus", options: { color: "1A2B3C" } },
], { x: 0.35, y: 1.35, w: 4.3, h: 3.8, fontSize: 11, lineSpacingMultiple: 1.35 });

s11.addShape(prs.ShapeType.rect, { x: 5.0, y: 0.82, w: 4.7, h: 4.55, fill: { color: NAVY } });
s11.addText("MRI Signs of Hydrocephalus", { x: 5.1, y: 0.92, w: 4.5, h: 0.4, fontSize: 14, bold: true, color: CYAN });
s11.addText([
  { text: "• Enlarged ventricles (Evan's index >0.3)\n", options: {} },
  { text: "• Periventricular FLAIR hyperintensity (transependymal oedema)\n", options: {} },
  { text: "• Dilated temporal horns (early and sensitive)\n", options: {} },
  { text: "• Upward bowing of corpus callosum\n", options: {} },
  { text: "• Third ventricle rounding and expansion\n", options: {} },
  { text: "• Aqueductal flow void on T2 (normal CSF jet)\n", options: {} },
  { text: "• PC-MRI: CSF flow quantification at aqueduct\n", options: {} },
  { text: "\nNPH Triad: Gait apraxia, urinary incontinence, dementia\n", options: { bold: true, color: AMBER } },
  { text: "MRI: Dilated ventricles, tight sulci at vertex, DESH pattern", options: { color: "8ECAE6" } },
], { x: 5.1, y: 1.4, w: 4.5, h: 3.8, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.35 });

// SLIDE 12 - TBI
const s12 = addContentSlide(prs, "Traumatic Brain Injury (TBI) on MRI");
s12.addTable([
  [{ text: "Injury Type", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "Location", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "T2/FLAIR", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "SWI/T2*", options: { bold: true, fill: NAVY, color: WHITE } }, { text: "DWI", options: { bold: true, fill: NAVY, color: WHITE } }],
  ["Cortical Contusion", "Frontotemporal (coup-contrecoup)", "↑ T2", "Blooming hemorrhage", "Restricted edges"],
  ["DAI (Grade 1)", "WM at grey-white junction", "↑ T2/FLAIR", "No hemorrhage", "Restricted diffusion"],
  ["DAI (Grade 2)", "Corpus callosum splenium", "↑ T2/FLAIR", "+/- hemorrhage", "Restricted diffusion"],
  ["DAI (Grade 3)", "Dorsal brainstem", "↑ T2/FLAIR", "Hemorrhagic", "Restricted diffusion"],
  ["Epidural Hematoma", "Biconvex, temporal", "Variable", "Hypointense acute blood", "N/A"],
  ["Subdural Hematoma", "Crescent, mixed stages", "Variable age", "Mixed signal", "N/A"],
  ["Subarachnoid Hemorrhage", "Cisterns, sulci", "FLAIR bright", "T2* blooming", "N/A"],
], { x: 0.25, y: 0.82, w: 9.5, h: 4.2,
  colW: [2.2, 2.0, 1.7, 1.9, 1.7],
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s12.addText("SWI is the most sensitive sequence for DAI detection — identifies microhemorrhages invisible on CT and conventional MRI", { x: 0.3, y: 5.12, w: 9.4, h: 0.3, fontSize: 10, bold: true, color: NAVY });

// SLIDE 13 - Epilepsy
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s13.addText("Epilepsy MRI Protocol", { x: 0.35, y: 0.92, w: 4.3, h: 0.4, fontSize: 14, bold: true, color: CYAN });
s13.addText([
  { text: "3T preferred over 1.5T\n\n", options: { color: AMBER } },
  { text: "Sequences:\n", options: { bold: true, color: CYAN } },
  { text: "• Axial FLAIR (3mm)\n• Coronal T2 perpendicular to hippocampus\n• Coronal FLAIR (3mm)\n• 3D T1 MPRAGE (1mm isotropic)\n• Axial DWI (post-ictal)\n• Axial SWI/GRE (cavernoma)\n• Post-Gd T1 (tumor/FCD)\n\n", options: { color: WHITE } },
  { text: "Volumetry & VBM for subtle MCD", options: { color: "8ECAE6" } },
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s13.addText("Hippocampal Sclerosis (HS) — Most Common", { x: 5.1, y: 0.9, w: 4.5, h: 0.45, fontSize: 12, bold: true, color: NAVY });
s13.addText([
  { text: "MRI Signs:\n", options: { bold: true, color: NAVY } },
  { text: "• T2/FLAIR hyperintensity in hippocampus\n• Hippocampal atrophy (volume loss)\n• Loss of internal architecture (striation)\n• Ipsilateral temporal lobe atrophy\n• Contralateral compensatory hypertrophy\n\n", options: { color: "1A2B3C" } },
  { text: "Other Causes:\n", options: { bold: true, color: NAVY } },
  { text: "• Focal cortical dysplasia (FCD): blurring of grey-white junction, FLAIR bright\n• Cortical tubers (TSC): T2 bright, calcify with age\n• Cavernoma: SWI blooming (popcorn)\n• DNET / ganglioglioma: T2 cystic, cortical", options: { color: "1A2B3C" } },
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// SLIDE 14 - Cerebrovascular Malformations
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  ["AVM", "Flow voids", "Flow voids ('bag of worms')", "Prominent vessels", "Yes", "Arterial feeders, venous drainage, nidus"],
  ["Cavernoma", "Mixed (blood products)", "Popcorn: mixed core", "↓↓ Blooming halo (hemosiderin)", "None", "Epilepsy, best seen on SWI"],
  ["DVA (Developmental Venous Anomaly)", "Normal", "Normal or subtle", "+/- Cavernoma", "Caput medusae sign", "Benign, do not resect"],
  ["Capillary Telangiectasia", "Normal", "Normal", "Subtle blooming", "Faint brush-like", "Pontine, benign, incidental"],
  ["DAVF (Dural AV Fistula)", "Engorged veins", "Flow voids in WM", "Cortical veins", "Arterial feeders", "Cortical venous HTN, Cognard/Borden"],
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  { text: "• Adenohypophysis (anterior): isointense T1\n• Neurohypophysis (posterior): T1 bright spot (normal)\n• Height: <8mm women, <6mm men (10mm in adolescence/pregnancy)\n• Enhancement: homogeneous and early\n• Infundibulum: midline, <3mm thick at base\n• Pituitary stalk deviation: suggests microadenoma\n\nDynamic MRI Protocol (microadenoma):\n• Rapid coronal T1 post-Gd at 30s, 60s, 90s, 120s\n• Adenoma: hypoenhancing early, fills in late\n• Cut-off: <1cm micro, ≥1cm macro", options: { color: "1A2B3C" } }
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s15.addText("Pituitary & Sellar Pathology", { x: 5.1, y: 0.92, w: 4.5, h: 0.4, fontSize: 14, bold: true, color: CYAN });
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  ["Microadenoma", "Iso/hypo T1", "Hypo early, fills late"],
  ["Macroadenoma", "Iso T1, ↑ T2", "Heterogeneous"],
  ["Craniopharyngioma", "T1 bright cyst (cholesterol)", "Rim + solid"],
  ["Rathke's cleft cyst", "T1 bright (proteinaceous)", "None"],
  ["Meningioma (sellar)", "Iso T1/T2", "Homogeneous, dural tail"],
  ["Germinoma", "Iso", "Homogeneous"],
  ["Pituitary apoplexy", "T1 bright (blood)", "Peripheral ring"],
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// SLIDE 16 - Posterior Fossa & Pediatric
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  ["Medulloblastoma", "Children (<10y)", "Midline cerebellum / 4th V", "DWI bright, homogeneous enhance"],
  ["Pilocytic Astrocytoma", "Children", "Cerebellar hemisphere", "Cyst + mural nodule, T2 bright"],
  ["Ependymoma", "Children (4th V) / Adults (lateral)", "4th ventricle, plastic", "Heterogeneous; CSF seeding"],
  ["Hemangioblastoma", "Adults (VHL)", "Cerebellar hemisphere", "Cyst + vascular nodule; prominent flow voids"],
  ["Metastasis", "Adults (>45y)", "Cerebellar hemisphere", "Multiple, ring enhance, junction zone"],
  ["DNET/Ganglioglioma", "Young adults", "Cortical temporal/cerebellum", "T2 cystic cortical lesion, no oedema"],
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s16.addText("Pediatric Brain MRI Note: Myelination progresses from posterior→anterior, inferior→superior. T1 bright myelination by 12 months in most regions. Unmyelinated white matter appears T2 bright — do not mistake for pathology in neonates.", { x: 0.3, y: 4.57, w: 9.4, h: 0.76, fontSize: 10, color: NAVY });

// SLIDE 17 - Key Takeaways
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last.addText("Key Takeaways", { x: 0.7, y: 0.3, w: 9, h: 1.1, fontSize: 36, bold: true, color: WHITE });
last.addText([
  { text: "1. DWI-FLAIR mismatch is the key MRI marker for thrombolysis eligibility in wake-up stroke\n", options: {} },
  { text: "2. GBM: ring enhancement + necrosis + T2 edema + crossingCC = butterfly pattern\n", options: {} },
  { text: "3. MS lesions: Dawson fingers on sagittal FLAIR; periventricular, juxtacortical, infratentorial, cord\n", options: {} },
  { text: "4. Brain abscess: DWI bright (restricted pus) differentiates from necrotic tumor (not restricted)\n", options: {} },
  { text: "5. SWI is the most sensitive sequence for DAI microhemorrhages in TBI\n", options: {} },
  { text: "6. Hippocampal sclerosis: T2 bright + volume loss + loss of striation on coronal MRI\n", options: {} },
  { text: "7. Cavernoma: popcorn on T2, hemosiderin halo on SWI — best appreciated at high field", options: {} },
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prs.writeFile({ fileName: "/home/daytona/workspace/mri-radiology-teaching/03_Brain_Neuro_MRI.pptx" })
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prs.title = "Spine MRI";

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// SLIDE 1 - Title
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t.addText("Spine MRI", { x: 0.8, y: 0.9, w: 8.8, h: 1.6, fontSize: 48, bold: true, color: WHITE });
t.addText("MRI Radiology Teaching Series — Module 4", { x: 0.8, y: 3.1, w: 8.8, h: 0.6, fontSize: 18, color: CYAN });
t.addText("Disc Disease • Cord Pathology • Infections • Tumors • Post-Op", { x: 0.8, y: 3.8, w: 8.8, h: 0.5, fontSize: 13, color: "8ECAE6" });
t.addText("Radiology Department | 2026", { x: 0.8, y: 4.7, w: 8.8, h: 0.4, fontSize: 12, color: "4A7A9B" });

// SLIDE 2 - TOC
const toc = cs(prs, "Table of Contents");
toc.addText([
  {text:"1.  Indications & Standard Protocol",options:{breakLine:true}},
  {text:"2.  Normal Spine Anatomy on MRI",options:{breakLine:true}},
  {text:"3.  Disc Nomenclature & Herniation Types",options:{breakLine:true}},
  {text:"4.  Cervical Spine — Cord Compression",options:{breakLine:true}},
  {text:"5.  Lumbar Spine — Disc Disease",options:{breakLine:true}},
  {text:"6.  Spinal Stenosis Grading",options:{breakLine:true}},
  {text:"7.  Modic Changes",options:{breakLine:true}},
  {text:"8.  Spondylolisthesis",options:{breakLine:true}},
  {text:"9.  Spinal Cord Pathology",options:{breakLine:true}},
  {text:"10. Spinal Infections",options:{breakLine:true}},
  {text:"11. Spinal Tumors",options:{breakLine:true}},
  {text:"12. Post-Operative Spine MRI",options:{breakLine:true}},
  {text:"13. Cauda Equina Syndrome",options:{breakLine:true}},
  {text:"14. Key Takeaways"}
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toc.addText("Spine MRI at a Glance", { x: 5.2, y: 0.95, w: 4.4, h: 0.5, fontSize: 14, bold: true, color: CYAN });
toc.addText("Most common clinical indication for MRI worldwide\n\n3 regions: Cervical (C) / Thoracic (T) / Lumbar (L)\n\nKey sequences:\n• Sagittal T1, Sagittal T2, Axial T2\n• STIR for marrow edema / infection\n• Post-Gd T1 for tumor / infection\n• DWI for cord ischemia\n• GRE/SWI for hemorrhage", 
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// SLIDE 3 - Normal Anatomy
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  [{text:"Structure",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T1 Signal",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T2 Signal",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Notes",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Vertebral body (adult)","Bright (fatty marrow)","Intermediate","Marrow fat replaces red marrow in adults"],
  ["Cortical bone","Dark","Dark","Signal void on all sequences"],
  ["Intervertebral disc — Nucleus","Iso","Bright (hydrated)","T2 bright from water; lost in degeneration"],
  ["Intervertebral disc — Annulus","Iso","Dark","Fibrocartilagenous, low water content"],
  ["Spinal cord","Iso (grey>white)","Slightly ↑","Grey matter butterfly; central canal"],
  ["CSF","Dark","Bright","T2 myelographic effect"],
  ["Conus medullaris","Iso","Iso","Ends at L1-L2 in adults"],
  ["Cauda equina nerve roots","Iso","Iso","Floating in bright CSF on T2"],
  ["Ligamentum flavum","Dark","Dark","Thickens in stenosis (>5mm)"],
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// SLIDE 4 - Disc Nomenclature
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  [{text:"Term",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Definition",options:{bold:true,fill:NAVY,color:WHITE}},{text:"MRI Appearance",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Disc Bulge","Generalised disc extension >50% circumference (not herniation)","Diffuse symmetric contour beyond disc margin"],
  ["Protrusion","Focal herniation; base > dome width; annulus intact","Focal disc material, base wider than height"],
  ["Extrusion","Base < dome; annulus disrupted; nucleus through AF","Sub-ligamentous or trans-ligamentous displacement"],
  ["Sequestration (Free Fragment)","Extruded disc loses continuity with parent disc","Migrated fragment, may be distant from disc level"],
  ["Disc Degeneration","Loss of T2 signal in nucleus (desiccation)","Dark nucleus on T2 (Pfirrmann grading I-V)"],
  ["Schmorl's Node","Intravertebral herniation through end plate","T2 bright disc material within vertebral body"],
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s4.addText("Location Classification: Central | Paracentral (most common) | Foraminal | Far-lateral (extraforaminal)\nLeft vs Right: Document side, affected nerve root, level (e.g. L4/5 right paracentral — L5 root compression)", 
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// SLIDE 5 - Cervical Spine
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s5.addText("Cervical Myelopathy Signs", { x: 0.35, y: 0.92, w: 4.3, h: 0.4, fontSize: 14, bold: true, color: CYAN });
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  {text:"CORD COMPRESSION:\n",options:{bold:true,color:AMBER}},
  {text:"• Canal diameter <10mm = critical stenosis\n• Cord flattened / deformed on axial T2\n• Cord signal change: T2 hyperintensity = myelopathy\n• T1 hypointense cord signal = myelomalacia (irreversible)\n\n",options:{color:WHITE}},
  {text:"CAUSATIVE PATHOLOGY:\n",options:{bold:true,color:CYAN}},
  {text:"• Disc herniation: C5/6 most common\n• Spondylotic osteophyte bars\n• Ossification of PLL (OPLL): T1 dark, behind vertebral body\n• Ligamentum flavum hypertrophy\n• Atlantoaxial instability (RA): ADI >3mm\n• Epidural hematoma / abscess",options:{color:WHITE}},
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s5.addText("Cord Signal Change — Grading", { x: 5.1, y: 0.9, w: 4.5, h: 0.4, fontSize: 13, bold: true, color: NAVY });
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  ["0 — Normal","No cord signal change","Excellent post-op recovery"],
  ["1 — T2 only","T2 hyperintense only","Good recovery"],
  ["2 — T2+T1","T2 hyper + T1 hypointense","Moderate; irreversible component"],
  ["3 — Cavitation","Syrinx / cystic change","Poor; permanent deficit"],
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s5.addText("Important levels:\nC3/4 — Phrenic nerve (diaphragm)\nC5/6 — Most common disc herniation\nC6/7 — Second most common\nAtlanto-axial: C1/2 — Dens fractures, RA pannus", 
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// SLIDE 6 - Lumbar Spine
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s6.addText("Most common levels: L4/5 and L5/S1", { x: 0.25, y: 0.82, w: 9.5, h: 0.4, fontSize: 12, bold: true, color: NAVY });
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  [{text:"Level",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Root",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Pain Distribution",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Motor Deficit",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Reflex",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["L3/4","L4","Anterior thigh, medial leg","Quadriceps weakness","↓ Knee jerk"],
  ["L4/5","L5","Posterior thigh, lateral leg, dorsum foot","EHL weakness (dorsiflexion)","None usually"],
  ["L5/S1","S1","Posterior thigh, leg, lateral foot","Plantar flexion weakness","↓ Ankle jerk"],
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s6.addText("Pfirrmann Disc Grading (T2 Signal)", { x: 0.35, y: 3.48, w: 4.3, h: 0.4, fontSize: 12, bold: true, color: CYAN });
s6.addText("I: Bright white nucleus, clear AF boundary\nII: Inhomogeneous nucleus, clear AF boundary\nIII: Grey nucleus, unclear AF boundary\nIV: Dark grey nucleus, annulus loss\nV: Black disc, no nucleus/annulus distinction", 
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s6.addText("Red Flags — Surgical Emergency", { x: 5.1, y: 3.48, w: 4.5, h: 0.4, fontSize: 12, bold: true, color: AMBER });
s6.addText("• Cauda equina syndrome: bilateral radiculopathy + sphincter dysfunction\n• Saddle anaesthesia\n• Progressive neurological deficit\n→ URGENT MRI within 4 hours", 
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// SLIDE 7 - Stenosis
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s7.addTable([
  [{text:"Grade",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Description",options:{bold:true,fill:NAVY,color:WHITE}},{text:"CSF on T2",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Canal Area (ap) / Notes",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["0 — Normal","No stenosis","CSF visible all around cord",">10mm AP diameter (cervical)"],
  ["1 — Mild","Slight reduction","CSF visible around roots","<10% reduction in cross-sectional area"],
  ["2 — Moderate","Significant reduction","CSF partially absent","Obliteration of part of thecal sac"],
  ["3 — Severe","Critical stenosis","No CSF visible","Complete obliteration; cord deformed"],
], { x: 0.25, y: 0.85, w: 9.5, h: 2.2,
  colW: [2.0, 2.5, 2.0, 3.0],
  rowH: [0.42, 0.48, 0.48, 0.48, 0.48],
  border: { pt: 0.5, color: "D0D8E4" }, fontSize: 11, color: "1A2B3C", autoPage: false });

s7.addShape(prs.ShapeType.rect, { x: 0.25, y: 3.15, w: 4.5, h: 2.2, fill: { color: LIGHT_BG }, line: { color: NAVY, width: 1 } });
s7.addText("Causes of Stenosis", { x: 0.35, y: 3.23, w: 4.3, h: 0.4, fontSize: 13, bold: true, color: NAVY });
s7.addText("• Disc herniation / osteophytes (central)\n• Facet joint hypertrophy\n• Ligamentum flavum thickening\n• Spondylolisthesis\n• Congenital (short pedicles)\n• Post-operative epidural fibrosis", 
  { x: 0.35, y: 3.7, w: 4.3, h: 1.55, fontSize: 11, color: "1A2B3C", lineSpacingMultiple: 1.3 });

s7.addShape(prs.ShapeType.rect, { x: 5.0, y: 3.15, w: 4.7, h: 2.2, fill: { color: NAVY } });
s7.addText("Lateral Recess & Foraminal Stenosis", { x: 5.1, y: 3.23, w: 4.5, h: 0.4, fontSize: 13, bold: true, color: CYAN });
s7.addText("Lateral Recess Stenosis:\n• Normal height >3mm; stenotic <2mm\n• Axial T2: nerve root compressed by facet / disc\n\nForaminal Stenosis:\n• Parasagittal T2 shows nerve root compression\n• Grade 0–3 on sagittal images (Lee classification)\n• Far lateral disc herniations affect exiting root", 
  { x: 5.1, y: 3.7, w: 4.5, h: 1.55, fontSize: 11, color: WHITE, lineSpacingMultiple: 1.3 });

// SLIDE 8 - Modic Changes
const s8 = cs(prs, "Modic Changes — Vertebral End Plate Signal Patterns");
s8.addTable([
  [{text:"Type",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T1 Signal",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T2 Signal",options:{bold:true,fill:NAVY,color:WHITE}},{text:"STIR",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Pathology",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Clinical",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Type 1","↓ Hypointense","↑ Hyperintense","↑ Bright","Vascular fibrous tissue, inflammation, oedema","Active, painful; may respond to treatment"],
  ["Type 2","↑ Hyperintense","↑ Hyperintense","Normal/↓","Fatty marrow replacement of end plate","Chronic, stable; often asymptomatic"],
  ["Type 3","↓ Hypointense","↓ Hypointense","↓","Subchondral bone sclerosis","Chronic, quiescent; correlates with osteosclerosis"],
], { x: 0.25, y: 0.85, w: 9.5, h: 2.5,
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s8.addShape(prs.ShapeType.rect, { x: 0.25, y: 3.5, w: 9.5, h: 1.85, fill: { color: CYAN } });
s8.addText("Clinical Significance & Differential Diagnosis", { x: 0.35, y: 3.58, w: 9.3, h: 0.4, fontSize: 13, bold: true, color: NAVY });
s8.addText("Type 1 Modic: can mimic discitis/osteomyelitis — KEY DIFFERENTIATOR: infection has disc T2 signal loss + disc height loss + clinical fever + elevated CRP/ESR\nMixed types occur; Type 1→2 conversion over time common. Type 1 associated with axial low back pain and Modic-targeted therapy trials.", 
  { x: 0.35, y: 4.05, w: 9.3, h: 1.2, fontSize: 11, color: NAVY, lineSpacingMultiple: 1.35 });

// SLIDE 9 - Spondylolisthesis
const s9 = cs(prs, "Spondylolisthesis — Classification & MRI Grading");
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s9.addText("Meyerding Grading (Slip %)", { x: 0.35, y: 0.9, w: 4.3, h: 0.4, fontSize: 13, bold: true, color: NAVY });
s9.addTable([
  [{text:"Grade",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Slip",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Management",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["I","<25%","Conservative"],
  ["II","25–50%","Conservative/surgical"],
  ["III","50–75%","Surgical"],
  ["IV",">75%","Surgical"],
  ["V (Spondyloptosis)","100% (complete)","Surgical emergency"],
], { x: 0.35, y: 1.35, w: 4.3, h: 2.3,
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  rowH: [0.38, 0.38, 0.38, 0.38, 0.38, 0.38],
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s9.addText("MRI Findings:\n• Anterior displacement of vertebral body\n• Sagittal T2: step deformity at affected level\n• Associated disc degeneration\n• Posterior element: pars defect (T1, STIR)\n• Secondary stenosis at affected level", 
  { x: 0.35, y: 3.75, w: 4.3, h: 1.55, fontSize: 11, color: "1A2B3C", lineSpacingMultiple: 1.35 });

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s9.addText("Etiological Classification (Wiltse)", { x: 5.1, y: 0.92, w: 4.5, h: 0.4, fontSize: 13, bold: true, color: CYAN });
s9.addText([
  {text:"Type I — Dysplastic:\n",options:{bold:true,color:AMBER}},
  {text:"Congenital deficiency of sacral facets\n\n",options:{color:WHITE}},
  {text:"Type II — Isthmic (MOST COMMON):\n",options:{bold:true,color:AMBER}},
  {text:"Pars interarticularis fracture/elongation (L5/S1)\n\n",options:{color:WHITE}},
  {text:"Type III — Degenerative:\n",options:{bold:true,color:AMBER}},
  {text:"Disc + facet degeneration (common in adults, L4/5)\n\n",options:{color:WHITE}},
  {text:"Type IV — Traumatic / Type V — Pathologic\n",options:{bold:true,color:CYAN}},
  {text:"(Lytic lesion, fracture)\n\nIsthmic: STIR/T1 fat-sat for pars oedema",options:{color:WHITE}},
], { x: 5.1, y: 1.4, w: 4.5, h: 3.8, fontSize: 11, lineSpacingMultiple: 1.35 });

// SLIDE 10 - Cord Pathology
const s10 = cs(prs, "Spinal Cord Pathology — Myelopathy Differential");
s10.addTable([
  [{text:"Condition",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T1",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T2",options:{bold:true,fill:NAVY,color:WHITE}},{text:"STIR",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Post-Gd",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Key Feature",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["MS Cord Lesion","Iso","Focal ↑ T2, peripheral, <2 segments","↑","Transient Gd enhance","<50% cord cross-section; dorsal columns"],
  ["NMOSD (Neuromyelitis Optica)","Iso","↑ T2, central, ≥3 segments","↑↑","Yes, ring/central","Central cord, H-sign on axial, bright spot on T1"],
  ["Spondylotic Myelopathy","Iso","↑ T2, pencil-like, at compression","↑","Absent","Adjacent disc/osteophyte; T1 hypo = myelomalacia"],
  ["Spinal Cord Infarction","Iso","↑ T2 anterior cord","↑","Variable","DWI restricted (owl eyes on axial); vascular distribution"],
  ["Syringomyelia","Dark (CSF)","Bright, central cavity","CSF-like","None","Associated with Chiari, tethered cord, post-traumatic"],
  ["Ependymoma (cord)","Iso","↑ T2, central, sausage-shaped","↑","Homogeneous","Cap sign (hemosiderin); widening cord"],
  ["Astrocytoma (cord)","Iso/↓","↑ T2, infiltrative, eccentric","↑","Heterogeneous","Infiltrative, no clear margin, children"],
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  rowH: [0.42, 0.52, 0.52, 0.52, 0.52, 0.52, 0.52, 0.52],
  border: { pt: 0.5, color: "D0D8E4" }, fontSize: 9.5, color: "1A2B3C", autoPage: false });

// SLIDE 11 - Spinal Infections
const s11 = cs(prs, "Spinal Infections — Discitis, Osteomyelitis & Epidural Abscess");
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s11.addText("KEY: MRI is the gold standard for early diagnosis — changes precede X-ray and CT by 2–3 weeks", { x: 0.3, y: 0.85, w: 9.4, h: 0.38, fontSize: 11, bold: true, color: WHITE });
s11.addTable([
  [{text:"Feature",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Discitis/Osteomyelitis",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Epidural Abscess",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Tuberculous (Pott's)",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["T1","↓ Disc + endplates (loss of normal T1)","Iso to ↓","↓ Vertebral bodies (may span disc)"],
  ["T2","↑ Disc + endplates (bright)","↑ (fluid/phlegmon)","↑ Vertebral, discs relatively preserved early"],
  ["STIR","↑↑ Bright endplates","↑↑","↑↑"],
  ["Post-Gd T1","Diffuse disc + endplate enhancement","Rim-enhancing collection","Rim-enhance; paraspinal abscess"],
  ["Disc Height","Reduced or lost","Preserved","Preserved until late (disc spared early)"],
  ["Location","Any level","Posterior epidural space","Thoracic most common; skip lesions possible"],
  ["Organism","S. aureus (pyogenic)","S. aureus","Mycobacterium tuberculosis"],
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s11.addText("Epidural abscess: SURGICAL EMERGENCY if neurological deficit — requires urgent decompression within 24 hours", { x: 0.3, y: 5.0, w: 9.4, h: 0.38, fontSize: 10.5, bold: true, color: NAVY });

// SLIDE 12 - Spinal Tumors
const s12 = cs(prs, "Spinal Tumors — Classification by Compartment");
s12.addTable([
  [{text:"Compartment",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Common Tumors",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T1",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T2",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Enhancement",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Clue",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Extradural","Metastasis (most common), lymphoma, plasmacytoma","↓ (replaces marrow)","↑ STIR","Avid","Pedicular destruction; skip lesions"],
  ["Extradural","Chordoma (clivus/sacrum)","↓/iso","↑↑","Heterogeneous","Midline sacral destructive lesion"],
  ["Intradural-Extramedullary","Meningioma (thoracic)","Iso","Iso","Homogeneous","Dural attachment, calcify"],
  ["Intradural-Extramedullary","Schwannoma / Neurofibroma","Iso","↑","Homogeneous, may have cyst","Dumbbell shape through foramen"],
  ["Intradural-Extramedullary","Myxopapillary ependymoma","Iso/↓","↑↑","Homogeneous","Conus/filum terminale"],
  ["Intramedullary","Ependymoma (adult)","Iso","↑↑ central","Homogeneous","Cap sign, expands cord, central"],
  ["Intramedullary","Astrocytoma (child/young)","↓","↑↑ eccentric","Heterogeneous","Infiltrative, no cap sign"],
  ["Intramedullary","Hemangioblastoma (VHL)","Iso","Cyst + nodule","Vivid nodule","Associated syrinx, VHL syndrome"],
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// SLIDE 13 - Post-Op Spine
const s13 = cs(prs, "Post-Operative Spine MRI");
s13.addShape(prs.ShapeType.rect, { x: 0.25, y: 0.82, w: 4.5, h: 4.55, fill: { color: NAVY } });
s13.addText("Normal Post-Op Changes", { x: 0.35, y: 0.92, w: 4.3, h: 0.4, fontSize: 13, bold: true, color: CYAN });
s13.addText("Within 6 months of surgery:\n• Epidural enhancement (granulation tissue) — normal\n• Disc space enhancement — normal up to 6 months\n• Scar tissue: T1 iso, T2 variable, enhances\n\nPost-Op Protocol (Gd-enhanced MRI):\n• T1 pre and post Gd mandatory\n• Fat-saturated T1 post-Gd\n\nScar vs Residual Disc:\n• Scar: enhances homogeneously, immediate post-Gd\n• Disc fragment: NO enhancement on early post-Gd\n  (peripheral enhancement on delayed 30-min scan)\n  — Gold standard: early + late T1 post-Gd", 
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s13.addText("Post-Op Complications", { x: 5.1, y: 0.9, w: 4.5, h: 0.4, fontSize: 13, bold: true, color: NAVY });
s13.addText([
  {text:"Adjacent Segment Disease:\n",options:{bold:true,color:NAVY}},
  {text:"• Accelerated degeneration at level above/below fusion\n• T2 disc signal loss, new herniation\n\n",options:{color:"1A2B3C"}},
  {text:"Pseudomeningocele:\n",options:{bold:true,color:NAVY}},
  {text:"• CSF leak post-dural tear; T2 bright paravertebral collection\n\n",options:{color:"1A2B3C"}},
  {text:"Epidural Hematoma / Abscess:\n",options:{bold:true,color:RED}},
  {text:"• Post-op ring-enhancing collection, cord compression\n\n",options:{color:"1A2B3C"}},
  {text:"Hardware Assessment:\n",options:{bold:true,color:NAVY}},
  {text:"• Use metal artifact reduction sequences (MARS, SEMAC, MAVRIC)\n• T1: screw loosening = halo around pedicle screw",options:{color:"1A2B3C"}},
], { x: 5.1, y: 1.4, w: 4.5, h: 3.8, fontSize: 11, lineSpacingMultiple: 1.35 });

// SLIDE 14 - Key Takeaways
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last.addShape(prs.ShapeType.rect, { x: 0.5, y: 1.55, w: 9.5, h: 0.06, fill: { color: AMBER } });
last.addText("Key Takeaways", { x: 0.7, y: 0.3, w: 9, h: 1.1, fontSize: 36, bold: true, color: WHITE });
last.addText([
  {text:"1. Extrusion/sequestration: annulus disrupted; base < dome — requires urgent clinical correlation\n",options:{}},
  {text:"2. Modic Type 1 (T1↓ / T2↑) mimics infection — use clinical + lab context to differentiate\n",options:{}},
  {text:"3. Cord signal change: T2 only = reversible; T1 hypo = myelomalacia = irreversible damage\n",options:{}},
  {text:"4. Spinal infection MRI: disc T2 bright + endplate T1 dark + enhancement = discitis/osteomyelitis\n",options:{}},
  {text:"5. Post-op: early Gd enhancement = scar (no enhancement = residual disc fragment)\n",options:{}},
  {text:"6. Intramedullary tumors: ependymoma (adult, central, cap sign) vs astrocytoma (child, eccentric)\n",options:{}},
  {text:"7. Cauda equina syndrome: bilateral radiculopathy + sphincter dysfunction → EMERGENCY MRI",options:{}},
], { x: 0.7, y: 1.75, w: 9.0, h: 3.65, fontSize: 13, color: WHITE, lineSpacingMultiple: 1.45 });

prs.writeFile({ fileName: "/home/daytona/workspace/mri-radiology-teaching/04_Spine_MRI.pptx" })
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  .catch(err => console.error("ERROR:", err));

const pptxgen = require("pptxgenjs");
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prs.layout = "LAYOUT_16x9";
prs.title = "MSK & Joint MRI";
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t.addText("MSK & Joint MRI",{x:0.8,y:0.9,w:8.8,h:1.6,fontSize:44,bold:true,color:WHITE});
t.addText("MRI Radiology Teaching Series — Module 5",{x:0.8,y:3.1,w:8.8,h:0.6,fontSize:18,color:CYAN});
t.addText("Knee • Shoulder • Hip • Ankle • Wrist • Bone Tumors",{x:0.8,y:3.8,w:8.8,h:0.5,fontSize:13,color:"8ECAE6"});
t.addText("Radiology Department | 2026",{x:0.8,y:4.7,w:8.8,h:0.4,fontSize:12,color:"4A7A9B"});

// Slide 2 TOC
const toc=cs(prs,"Table of Contents");
toc.addText([{text:"1.  MSK MRI Protocol Overview",options:{breakLine:true}},{text:"2.  Knee MRI — Meniscus",options:{breakLine:true}},{text:"3.  Knee MRI — Ligaments & Cartilage",options:{breakLine:true}},{text:"4.  Shoulder MRI — Rotator Cuff",options:{breakLine:true}},{text:"5.  Shoulder MRI — Labrum",options:{breakLine:true}},{text:"6.  Hip MRI — FAI & Labral Tears",options:{breakLine:true}},{text:"7.  Hip MRI — AVN",options:{breakLine:true}},{text:"8.  Ankle & Foot MRI",options:{breakLine:true}},{text:"9.  Wrist MRI — TFCC & Scaphoid",options:{breakLine:true}},{text:"10. Bone Marrow & Soft Tissue Tumors",options:{breakLine:true}},{text:"11. Muscle Injuries",options:{breakLine:true}},{text:"12. Key Takeaways"}],{x:0.3,y:0.85,w:4.5,h:4.6,fontSize:11.5,color:"1A2B3C",lineSpacingMultiple:1.35});
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toc.addText("MSK MRI Protocols",{x:5.2,y:0.95,w:4.4,h:0.5,fontSize:14,bold:true,color:CYAN});
toc.addText("Standard Knee Protocol:\n• Sagittal PD fat-sat (meniscus/ligaments)\n• Coronal PD fat-sat (medial/lateral structures)\n• Axial PD fat-sat (patellofemoral)\n• Sagittal T1 (bone marrow)\n• Optional: 3D WATSc for cartilage\n\nMRI Arthrography (MR-A):\nDilute Gd intra-articular injection\n→ Best for labral tears (hip/shoulder)\n→ Improves labral detachment detection",{x:5.2,y:1.55,w:4.4,h:3.7,fontSize:11,color:WHITE,lineSpacingMultiple:1.35});

// Slide 3 - Meniscus
const s3=cs(prs,"Knee MRI — Meniscal Tears");
s3.addTable([
  [{text:"Grade",options:{bold:true,fill:NAVY,color:WHITE}},{text:"MRI Finding",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Pathology",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Clinical",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Grade 1","Globular intrameniscal T2/PD signal, NOT reaching surface","Mucoid degeneration, intact","Asymptomatic, no surgery"],
  ["Grade 2","Linear intrameniscal signal, NOT reaching surface","Intrasubstance degeneration","Asymptomatic variant, conservative"],
  ["Grade 3","Signal reaching articular surface","True tear — surgical significance","Meniscectomy / repair"],
  ["Complex","Multiple orientations, fragmented","Maceration","Partial/total meniscectomy"],
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s3.addText("Tear Patterns",{x:0.25,y:3.05,w:4.5,h:0.4,fontSize:13,bold:true,color:NAVY});
s3.addText("• Vertical longitudinal (bucket-handle): flipped fragment in intercondylar notch\n• Horizontal (cleavage): older patients, degenerative\n• Radial: perpendicular to long axis; disrupts circumferential fibers\n• Root tear: posterior horn insertion; key on coronal MRI\n• Oblique (flap/parrot beak): combination",{x:0.25,y:3.5,w:4.5,h:1.85,fontSize:11,color:"1A2B3C",lineSpacingMultiple:1.35});
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s3.addText("Bucket-Handle Tear Signs",{x:5.1,y:3.08,w:4.5,h:0.4,fontSize:13,bold:true,color:CYAN});
s3.addText("• Double PCL sign: flipped fragment anterior to PCL on sagittal\n• Fragment in intercondylar notch on coronal\n• Absent bow-tie (only 1 bow-tie on sagittal instead of 2)\n• Truncated 'blunted' posterior horn on sagittal",{x:5.1,y:3.55,w:4.5,h:1.65,fontSize:11,color:WHITE,lineSpacingMultiple:1.35});

// Slide 4 - Ligaments & Cartilage
const s4=cs(prs,"Knee MRI — Ligaments & Cartilage");
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s4.addText("ACL Tear MRI Signs",{x:0.35,y:0.92,w:4.3,h:0.4,fontSize:14,bold:true,color:CYAN});
s4.addText("Primary Signs:\n• Non-visualization / disrupted ACL fibers\n• Abnormal ACL orientation (>45° = lax/torn)\n• Wavy, irregular ACL signal on sagittal PD\n\nSecondary Signs (bone bruise pattern):\n• Lateral femoral condyle posterolateral bruise\n• Posterior tibial plateau anterolateral bruise\n• 'Kissing contusions' — pivot-shift mechanism\n\nAssociated Injuries:\n• PCL laxity/avulsion (posterior capsule)\n• Lateral compartment bone bruise\n• Medial meniscus tears (O'Donoghue triad)\n• MCL sprain (medial collateral)\n• Segond fracture (avulsion lateral tibial plateau)",{x:0.35,y:1.4,w:4.3,h:3.8,fontSize:10.5,color:WHITE,lineSpacingMultiple:1.35});
s4.addShape(prs.ShapeType.rect,{x:5.0,y:0.82,w:4.7,h:4.55,fill:{color:LIGHT_BG},line:{color:NAVY,width:1}});
s4.addText("Cartilage — ICRS Grading",{x:5.1,y:0.9,w:4.5,h:0.4,fontSize:13,bold:true,color:NAVY});
s4.addTable([
  [{text:"Grade",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Description",options:{bold:true,fill:NAVY,color:WHITE}},{text:"MRI Finding",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["0 — Normal","Intact","Normal cartilage"],
  ["1 — Softening","Superficial defect <50% depth","T2 bright zone in cartilage"],
  ["2 — Partial","Defect 50–75% depth","Focal thinning, surface irregularity"],
  ["3 — Deep","Defect >75% depth","Near full-thickness loss"],
  ["4 — Full-thickness","Down to bone","Exposed subchondral bone, bone edema"],
],[{x:5.1,y:1.35,w:4.5,h:2.2,colW:[1.4,1.5,1.6],rowH:[0.38,0.38,0.38,0.38,0.38,0.38],border:{pt:0.5,color:"D0D8E4"},fontSize:10,color:"1A2B3C",autoPage:false}]);
s4.addText("Best Cartilage Sequences:\n• 3D GRE (VIBE/DESS/WATSc) — isotropic 1mm\n• dGEMRIC: delayed Gd-enhanced — proteoglycan mapping\n• T2 mapping: collagen integrity, early OA detection\n• T1-rho: early degeneration before structural loss",{x:5.1,y:3.65,w:4.5,h:1.65,fontSize:11,color:"1A2B3C",lineSpacingMultiple:1.35});

// Slide 5 - Rotator Cuff
const s5=cs(prs,"Shoulder MRI — Rotator Cuff Tears");
s5.addTable([
  [{text:"Tear Type",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Definition",options:{bold:true,fill:NAVY,color:WHITE}},{text:"MRI Finding",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Management",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Partial Articular (PASTA)","<50% thickness, articular surface","T2 bright focal defect, articular side","Conservative/arthroscopic debridement"],
  ["Partial Bursal","Bursal surface involvement","T2 bright, bursal side","Conservative"],
  ["Full Thickness","Complete tendon discontinuity","Fluid gap through tendon on coronal PD","Surgical repair"],
  ["Massive Tear","≥2 tendons torn","Large fluid-filled defect, retraction, atrophy","Complex repair / tendon transfer"],
],[{x:0.25,y:0.82,w:9.5,h:2.1,colW:[2.0,2.5,2.7,2.3],rowH:[0.42,0.48,0.42,0.42,0.42],border:{pt:0.5,color:"D0D8E4"},fontSize:10.5,color:"1A2B3C",autoPage:false}]);
s5.addShape(prs.ShapeType.rect,{x:0.25,y:3.05,w:4.5,h:2.3,fill:{color:NAVY}});
s5.addText("Supraspinatus Tear Assessment",{x:0.35,y:3.13,w:4.3,h:0.4,fontSize:12,bold:true,color:CYAN});
s5.addText("• Coronal PD fat-sat: primary plane\n• Gap in tendon substance = full-thickness\n• Retraction: measured from footprint to torn end\n• Critical zone: 1cm from insertion (avascular)\n• Fatty infiltration: Goutallier grade 0–4 (MRI equivalent)\n• Grade 3–4: poor surgical outcome",{x:0.35,y:3.6,w:4.3,h:1.6,fontSize:11,color:WHITE,lineSpacingMultiple:1.35});
s5.addShape(prs.ShapeType.rect,{x:5.0,y:3.05,w:4.7,h:2.3,fill:{color:LIGHT_BG},line:{color:CYAN,width:1}});
s5.addText("Rotator Cuff Muscles",{x:5.1,y:3.13,w:4.5,h:0.4,fontSize:12,bold:true,color:NAVY});
s5.addText("SItS — Supraspinatus, Infraspinatus, teres minor, Subscapularis\n\n• Supraspinatus: abduction (most commonly torn)\n• Infraspinatus: external rotation (posterior tears)\n• Subscapularis: internal rotation; tear = Lesser tuberosity avulsion, biceps instability\n• Teres minor: least commonly torn",{x:5.1,y:3.6,w:4.5,h:1.6,fontSize:11,color:"1A2B3C",lineSpacingMultiple:1.35});

// Slide 6 - Shoulder Labrum
const s6=cs(prs,"Shoulder MRI — Labral Tears (SLAP & Bankart)");
s6.addShape(prs.ShapeType.rect,{x:0.25,y:0.82,w:4.5,h:4.55,fill:{color:LIGHT_BG},line:{color:NAVY,width:1}});
s6.addText("SLAP Lesions (Superior Labrum Anterior-Posterior)",{x:0.35,y:0.9,w:4.3,h:0.5,fontSize:12,bold:true,color:NAVY});
s6.addTable([
  [{text:"Type",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Description",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["I","Fraying of superior labrum, intact biceps anchor"],
  ["II (Most common)","Detachment of superior labrum + biceps anchor"],
  ["III","Bucket-handle superior labrum tear, biceps intact"],
  ["IV","Bucket-handle + biceps tendon involvement"],
],[{x:0.35,y:1.45,w:4.3,h:1.8,colW:[0.7,3.6],rowH:[0.38,0.42,0.42,0.42,0.42],border:{pt:0.5,color:"D0D8E4"},fontSize:10.5,color:"1A2B3C",autoPage:false}]);
s6.addText("MRI-Arthrography (MR-A):\n• Best for labral pathology\n• Intra-articular Gd distends capsule\n• SLAP II: contrast undermining superior labrum\n• Pitfall: sublabral recess (normal variant at 11-1 o'clock)",{x:0.35,y:3.35,w:4.3,h:1.9,fontSize:11,color:"1A2B3C",lineSpacingMultiple:1.35});
s6.addShape(prs.ShapeType.rect,{x:5.0,y:0.82,w:4.7,h:4.55,fill:{color:NAVY}});
s6.addText("Bankart Lesions (Anterior Instability)",{x:5.1,y:0.92,w:4.5,h:0.4,fontSize:13,bold:true,color:CYAN});
s6.addText([
  {text:"Classic Bankart:\n",options:{bold:true,color:AMBER}},
  {text:"Avulsion of anterior-inferior labrum from glenoid rim\nMRI: detached/absent anterior-inferior labrum, J-sign\nAssociated: anterior capsular laxity, Hill-Sachs (posterior humeral head impression)\n\n",options:{color:WHITE}},
  {text:"Bony Bankart:\n",options:{bold:true,color:AMBER}},
  {text:"Glenoid rim fracture + labral detachment\nCT more sensitive for bone loss\n\n",options:{color:WHITE}},
  {text:"Hill-Sachs Lesion:\n",options:{bold:true,color:CYAN}},
  {text:"Posterolateral humeral head impaction fracture\nGolf-club deformity on axial imaging\nEngaging vs non-engaging — surgical significance",options:{color:WHITE}},
],{x:5.1,y:1.4,w:4.5,h:3.8,fontSize:11,lineSpacingMultiple:1.35});

// Slide 7 - Hip MRI
const s7=cs(prs,"Hip MRI — FAI, Labral Tears & AVN");
s7.addShape(prs.ShapeType.rect,{x:0.25,y:0.82,w:4.5,h:4.55,fill:{color:NAVY}});
s7.addText("Femoroacetabular Impingement (FAI)",{x:0.35,y:0.92,w:4.3,h:0.45,fontSize:13,bold:true,color:CYAN});
s7.addText([
  {text:"Cam-type FAI:\n",options:{bold:true,color:AMBER}},
  {text:"• Abnormal femoral head-neck junction\n• Alpha angle >55° on radial MRI\n• Asphericity of femoral head\n• Labral tear: anterosuperior labrum\n\n",options:{color:WHITE}},
  {text:"Pincer-type FAI:\n",options:{bold:true,color:AMBER}},
  {text:"• Overcoverage of acetabulum\n• Coxa profunda / protrusio acetabuli\n• Lateral CEA >40° (normal 25–35°)\n• Labral crush + ossification\n\n",options:{color:WHITE}},
  {text:"MR Arthrography (1.5ml Gd dilute):\n",options:{bold:true,color:CYAN}},
  {text:"Best for labral tears — 87% sensitivity\nRadial imaging: 12 orientations around femoral neck",options:{color:WHITE}},
],{x:0.35,y:1.45,w:4.3,h:3.8,fontSize:11,lineSpacingMultiple:1.35});
s7.addShape(prs.ShapeType.rect,{x:5.0,y:0.82,w:4.7,h:4.55,fill:{color:LIGHT_BG},line:{color:NAVY,width:1}});
s7.addText("Avascular Necrosis (AVN) — Ficat Staging",{x:5.1,y:0.9,w:4.5,h:0.45,fontSize:13,bold:true,color:NAVY});
s7.addTable([
  [{text:"Stage",options:{bold:true,fill:NAVY,color:WHITE}},{text:"MRI",options:{bold:true,fill:NAVY,color:WHITE}},{text:"X-Ray",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["0","Normal or subtle marrow edema","Normal"],
  ["I","T1 dark band / T2 double line (pathognomonic)","Normal"],
  ["II","Sclerosis/cystic, no collapse","Sclerosis/cysts"],
  ["III","Subchondral fracture (crescent sign)","Crescent on X-ray"],
  ["IV","Articular collapse, secondary OA","Collapse, OA"],
],[{x:5.1,y:1.4,w:4.5,h:2.2,colW:[0.9,2.3,1.3],rowH:[0.38,0.38,0.38,0.38,0.38,0.38],border:{pt:0.5,color:"D0D8E4"},fontSize:10.5,color:"1A2B3C",autoPage:false}]);
s7.addText("Double Line Sign (AVN):\nOuter low T2 signal (sclerosis) + inner high T2 signal (granulation tissue/hyperemia)\nPathognomonic for AVN on MRI\n\nRisk Factors: Steroids, alcohol, trauma, sickle cell, Gaucher's, diving (dysbarism), HIV therapy",{x:5.1,y:3.7,w:4.5,h:1.55,fontSize:11,color:"1A2B3C",lineSpacingMultiple:1.35});

// Slide 8 - Ankle & Foot
const s8=cs(prs,"Ankle & Foot MRI — Tendons & Ligaments");
s8.addTable([
  [{text:"Structure",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Normal MRI",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Pathology",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Key Features",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Achilles tendon","Dark T1/T2, 6mm","Tendinopathy → T2 bright intratendinous","Critical zone 2-6cm above insertion; partial vs complete tear"],
  ["Posterior tibial (PT)","Dark, posteromedial","PT tendinopathy / tear — flatfoot","Type I: partial; II: longitudinal split; III: complete"],
  ["Peroneal tendons","Dark, lateral ankle","Peroneal split tear; subluxation","SPR injury; os peroneum fracture"],
  ["Anterior talofibular (ATFL)","Thin band, anterolateral","Sprain vs complete tear","Most commonly injured ankle ligament (inversion)"],
  ["Spring ligament","Medial arch support","Tear → acquired flatfoot deformity","Associated with PT tendon tears"],
  ["Plantar fascia","Thick band at calcaneus","Plantar fasciitis: T2 bright thickening",">4mm at origin; T2 edema at calcaneal insertion"],
],[{x:0.25,y:0.82,w:9.5,h:4.6,colW:[2.0,1.9,2.4,3.2],rowH:[0.42,0.52,0.52,0.52,0.42,0.52,0.52],border:{pt:0.5,color:"D0D8E4"},fontSize:10,color:"1A2B3C",autoPage:false}]);

// Slide 9 - Wrist
const s9=cs(prs,"Wrist MRI — TFCC & Scaphoid");
s9.addShape(prs.ShapeType.rect,{x:0.25,y:0.82,w:4.5,h:4.55,fill:{color:NAVY}});
s9.addText("TFCC — Triangular Fibrocartilage Complex",{x:0.35,y:0.92,w:4.3,h:0.45,fontSize:13,bold:true,color:CYAN});
s9.addText("Components:\n• Articular disc (central)\n• Dorsal & volar radioulnar ligaments\n• Ulnocarpal ligaments (meniscus homolog)\n• Extensor carpi ulnaris tendon sheath\n\nPalmer Classification:\nType 1 Traumatic: 1A (central disc), 1B (ulnar avulsion — most common), 1C (distal avulsion), 1D (radial avulsion)\nType 2 Degenerative: 2A–2E (progressive ulnar impaction)\n\nMRI: 3T preferred; 3D PD fat-sat; 1mm coronal\nTear: T2 bright defect in disc; fluid through disc on MR-A",{x:0.35,y:1.45,w:4.3,h:3.8,fontSize:11,color:WHITE,lineSpacingMultiple:1.35});
s9.addShape(prs.ShapeType.rect,{x:5.0,y:0.82,w:4.7,h:4.55,fill:{color:LIGHT_BG},line:{color:CYAN,width:1}});
s9.addText("Scaphoid Fractures on MRI",{x:5.1,y:0.9,w:4.5,h:0.4,fontSize:13,bold:true,color:NAVY});
s9.addText([
  {text:"Why MRI?\n",options:{bold:true,color:NAVY}},
  {text:"X-ray: 20% false negative for occult fractures\nMRI: 100% sensitivity at 24-48h post-injury\n\n",options:{color:"1A2B3C"}},
  {text:"MRI Findings:\n",options:{bold:true,color:NAVY}},
  {text:"• T1: linear hypointense fracture line\n• STIR/T2 fat-sat: bone marrow edema (bright)\n• Identify incomplete vs complete fracture\n• Assess for AVN: proximal pole T1 signal\n\n",options:{color:"1A2B3C"}},
  {text:"AVN of Scaphoid:\n",options:{bold:true,color:RED}},
  {text:"• Proximal pole T1 hypointense (absent marrow fat signal)\n• Poor blood supply from distal to proximal\n• Occurs in 30-40% of untreated fractures",options:{color:"1A2B3C"}},
],{x:5.1,y:1.4,w:4.5,h:3.8,fontSize:11,lineSpacingMultiple:1.35});

// Slide 10 - Bone & Soft Tissue Tumors
const s10=cs(prs,"Bone Marrow, Soft Tissue & Bone Tumors on MRI");
s10.addTable([
  [{text:"Feature",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Benign",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Malignant",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Margins","Well-defined, sclerotic rim","Ill-defined, permeative"],
  ["T2 signal","Bright (lipoma, cyst, hemangioma)","Heterogeneous intermediate"],
  ["Peritumoral edema","Absent or minimal","Present and extensive"],
  ["Enhancement pattern","None or peripheral (cyst)","Avid, heterogeneous, nodular"],
  ["Size","<5cm usually benign",">5cm, deep to fascia = suspicious"],
  ["Cortical involvement","None","Cortical destruction, periosteal reaction"],
  ["Bone marrow","Normal adjacent marrow","T1 dark replacement, STIR bright"],
],[{x:0.25,y:0.82,w:9.5,h:3.6,colW:[2.5,3.4,3.6],rowH:[0.42,0.42,0.42,0.42,0.42,0.42,0.42,0.42],border:{pt:0.5,color:"D0D8E4"},fontSize:10.5,color:"1A2B3C",autoPage:false}]);
s10.addShape(prs.ShapeType.rect,{x:0.25,y:4.52,w:4.5,h:0.82,fill:{color:CYAN}});
s10.addText("Lipoma: T1 bright, follows fat on all sequences, loss of signal on fat-sat — no enhancement (benign)",{x:0.3,y:4.55,w:4.4,h:0.76,fontSize:10.5,color:NAVY,bold:true});
s10.addShape(prs.ShapeType.rect,{x:5.0,y:4.52,w:4.7,h:0.82,fill:{color:RED}});
s10.addText("Rule: Deep, >5cm, intermediate T2, heterogeneous enhancement → BIOPSY (MRI-guided or US-guided)",{x:5.05,y:4.55,w:4.6,h:0.76,fontSize:10.5,color:WHITE,bold:true});

// Slide 11 - Muscle Injuries
const s11=cs(prs,"Muscle Injuries — MRI Grading & Classification");
s11.addTable([
  [{text:"Grade",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Severity",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T2/STIR MRI",options:{bold:true,fill:NAVY,color:WHITE}},{text:"T1 MRI",options:{bold:true,fill:NAVY,color:WHITE}},{text:"Return to Play",options:{bold:true,fill:NAVY,color:WHITE}}],
  ["Grade 0","Normal (neural — not MRI visible)","Normal","Normal","Variable"],
  ["Grade 1 (Mild)","Micro-tears, <10% fibers","T2 bright edema, feathery pattern","Normal","Days–2 weeks"],
  ["Grade 2 (Moderate)","Partial tear (10–50%)","T2 bright + fluid gap partial","T1 normal","3–6 weeks"],
  ["Grade 3 (Severe)","Partial tear (>50%)","Extensive fluid + hematoma","T1 dark (hematoma)","6–12 weeks"],
  ["Grade 4 (Complete)","Complete rupture","Full muscle discontinuity","Retracted muscle belly","Surgery/months"],
],[{x:0.25,y:0.82,w:9.5,h:2.7,colW:[1.4,2.0,2.5,1.7,1.9],rowH:[0.42,0.42,0.42,0.42,0.42,0.42],border:{pt:0.5,color:"D0D8E4"},fontSize:10.5,color:"1A2B3C",autoPage:false}]);
s11.addShape(prs.ShapeType.rect,{x:0.25,y:3.65,w:9.5,h:1.7,fill:{color:NAVY}});
s11.addText("Important Muscle Injury Patterns",{x:0.35,y:3.73,w:9.3,h:0.4,fontSize:13,bold:true,color:CYAN});
s11.addText("• Proximal hamstring avulsion: complete avulsion from ischial tuberosity — T2 bright hematoma at ischium\n• Myositis ossificans: T1 bright peripheral rim 4-6 weeks (maturing ossification); NOT to be confused with sarcoma\n• Compartment syndrome: post-injury compartment diffusely T2 bright, muscular swelling; clinical correlation essential\n• Denervation oedema: increased T2 signal in muscle supplied by compressed nerve — helps localise compression level",{x:0.35,y:4.2,w:9.3,h:1.05,fontSize:10.5,color:WHITE,lineSpacingMultiple:1.3});

// Slide 12 - Key Takeaways
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last.addShape(prs.ShapeType.rect,{x:0,y:0,w:0.5,h:5.625,fill:{color:CYAN}});
last.addShape(prs.ShapeType.rect,{x:0.5,y:1.55,w:9.5,h:0.06,fill:{color:AMBER}});
last.addText("Key Takeaways",{x:0.7,y:0.3,w:9,h:1.1,fontSize:36,bold:true,color:WHITE});
last.addText([
  {text:"1. Meniscal Grade 3 signal (reaching surface) = true tear; Grades 1–2 are intrasubstance and NOT surgically significant\n",options:{}},
  {text:"2. ACL tear: look for pivot-shift bone bruise pattern — lateral femoral condyle + posterolateral tibial plateau\n",options:{}},
  {text:"3. AVN hip: Double-line sign on T2 is pathognomonic; T1 dark proximal pole scaphoid = proximal AVN\n",options:{}},
  {text:"4. Cam FAI: alpha angle >55° + anterosuperior labral tear on radial MR arthrography\n",options:{}},
  {text:"5. Soft tissue rule: deep location + >5cm + intermediate T2 = assume malignant until proven otherwise\n",options:{}},
  {text:"6. Muscle injury: feathery T2 edema = Grade 1; fluid gap = Grade 2+; retraction = complete rupture\n",options:{}},
  {text:"7. Post-op MRI: use MARS (metal artifact reduction) sequences for implant assessment",options:{}},
],{x:0.7,y:1.75,w:9.0,h:3.65,fontSize:13,color:WHITE,lineSpacingMultiple:1.45});

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