---

Summary of All Answers

---

Quick Reference - All 14 Answers (Already Written Above)

---

---

Q13. MRI Findings for Adnexal Lesions

Definition

MRI Technique

• T1W (T1-weighted): Identifies fat, blood, protein-rich fluid
• T2W (T2-weighted): Best for morphology, fluid characterization, ovarian stroma
• Fat suppression (STIR/Dixon/ChemSat): Confirms fat content (signal drops = fat)
• DWI (Diffusion-weighted imaging): Restricted diffusion (high signal DWI, low ADC) = malignancy
• DCE-MRI (Dynamic contrast-enhanced): Pattern, degree, and timing of enhancement
• Chemical shift MRI: Confirms intracellular fat (out-of-phase signal drop)

---

BENIGN ADNEXAL LESIONS

1. Simple Ovarian Cyst / Functional Cyst

• T1W: Hypointense (simple fluid - dark)
• T2W: Markedly hyperintense (water - bright)
• Post-contrast: No wall or internal enhancement
• Features: Thin wall (<3 mm), no septations, no solid components, no restricted diffusion
• Resolves spontaneously within 1-2 cycles
• O-RADS MRI 2: Almost certainly benign

---

2. Mature Cystic Teratoma (Dermoid Cyst)

• Most common ovarian tumor in reproductive age women (20-40 yrs)
• T1W: Markedly HYPERINTENSE (fat content - the brightest adnexal lesion on T1)
• T2W: Hyperintense fat component; Rokitansky protuberance (dermoid plug) appears as a solid nodule projecting into the cyst interior
• Fat suppression: Signal drops dramatically in fat areas - confirmatory finding
• Chemical shift (in-phase/out-of-phase): India ink artifact at fat-fluid interface (signal cancellation on out-of-phase = black rim)
• Calcification (teeth, bone): low signal on all sequences
• Sebaceous fluid: diffuse T1 high signal filling cyst
• Mature hair: low signal linear structures within fat
• Malignant transformation (1-2%): Enhancing solid component, rapid growth, local invasion

---

3. Endometrioma ("Chocolate Cyst")

• Ovarian cyst containing old menstrual blood (chronic hemorrhage)
• T1W: Markedly HYPERINTENSE (T1 bright - blood products shortening T1 relaxation) - classic "bright T1"
• T2W: HYPOINTENSE with "T2 shading" - the hallmark finding
  • T2 shading sign: gradual darkening from superior to inferior within cyst due to layering of different-aged blood products (deoxyhaemoglobin, methemoglobin)
  • Pathognomonic of endometrioma
• Post-contrast: No solid enhancing component (wall may mildly enhance)
• DWI: No restricted diffusion (unlike malignancy)
• May be bilateral; multiple "kissing ovaries" (bilateral endometriomas adherent in POD)
• Associated peritoneal endometriosis: T2 hypointense nodules on peritoneal surfaces, uterosacral ligaments, POD
• Distinction from hemorrhagic functional cyst: T2 shading + T1 bright + no resolution on follow-up = endometrioma

---

4. Ovarian Fibroma / Fibrothecoma

• Solid ovarian stromal tumor (sex cord-stromal origin)
• T1W: Hypointense (low signal - similar to muscle)
• T2W: Markedly HYPOINTENSE (very dark - key distinguishing feature due to dense fibrous stroma with low free water)
• Post-contrast: Minimal, gradual enhancement (fibrous tissue enhances slowly)
• DWI: May show mild restriction but ADC not as low as malignancy
• Well-defined, smooth margins; homogeneous
• Meigs Syndrome: Ovarian fibroma + ascites + right-sided pleural effusion (benign; resolves after tumor removal)
• Fibrothecoma: intermediate T2 signal (contains more cellular thecomatous elements)

---

5. Hydrosalpinx / Pyosalpinx

• T2W: Tubular, tortuous, folded C-shaped or S-shaped fluid-filled structure separate from ovary
• T1W: Hypointense (simple fluid)
• "Incomplete septations" - longitudinal mucosal folds create partial transverse folds on cross-section ("cogwheel" appearance on T2)
• No mural nodules, no enhancement
• Ipsilateral ovary identifiable separately

• T1W: Intermediate to high signal (protein-rich fluid)
• T2W: Intermediate signal with thick walls
• Post-contrast: thick enhancing wall
• DWI: restricted diffusion within lumen (high signal)
• Associated free pelvic fluid

---

6. Peritoneal Inclusion Cyst

• Seen in women with prior surgery/pelvic inflammatory disease
• Fluid trapped around normal ovary by adhesions
• T2W: Loculated fluid conforming to pelvic structures, surrounding normal ovary ("spider web" appearance)
• T1W: Hypointense
• Normal ovary visible within the collection
• No thick septa, no solid components

---

MALIGNANT ADNEXAL LESIONS

7. Epithelial Ovarian Carcinoma (Serous / Mucinous Cystadenocarcinoma)

• Most common ovarian malignancy; peak 50-70 yrs
• T2W: Complex cystic-solid mass; irregular thick septa (>3 mm); papillary projections (T2 intermediate signal); solid mural nodules
• T1W: Variable; hemorrhagic components may be T1 hyperintense
• Post-gadolinium: Solid components, papillary projections, and thick septations enhance - the key malignancy indicator
• DWI: Solid components show restricted diffusion; ADC value <1.0 × 10⁻³ mm²/s
• Staging findings on MRI:

• Peritoneal carcinomatosis: T2 intermediate enhancing nodules on peritoneum, omentum, bowel serosa
• Omental cake: Diffuse T2 intermediate thickening of omentum with enhancement
• Ascites: T2 bright free fluid in peritoneal cavity
• Lymphadenopathy: short axis >1 cm (para-aortic, pelvic nodes)

---

8. Borderline Serous Tumor (Low Malignant Potential)

• T2W: Multilocular cystic mass with fine septations + papillary projections (smaller than in carcinoma)
• Enhancement of papillary projections (mild to moderate)
• No restricted diffusion typically
• No peritoneal implants (usually Stage I)

---

9. Mucinous Cystadenoma / Cystadenocarcinoma

• Multilocular cystic mass - classically >10 locules ("stained glass" or "honeycomb" appearance)
• T1W: Variable signal in different locules (different mucinous concentrations - "signal stacking")
  • Some locules T1 bright (thick mucin), others T1 dark (watery mucin)
• T2W: Variable - high signal for watery mucin, intermediate/low for thick viscous mucin
• Malignant features: papillary projections, enhancing solid components, wall thickening

---

10. Tubo-Ovarian Abscess (TOA)

• Complex inflammatory mass merging tube and ovary
• T2W: Thick-walled cystic/complex mass; internal debris; loss of normal ovarian/tubal anatomy
• T1W: Low to intermediate signal; high T1 areas = hemorrhage or protein
• DWI: Restricted diffusion within abscess (high DWI signal, low ADC) - distinguishes pus from other fluid
• Post-contrast: Thick enhancing walls and septa; surrounding fat stranding (T2 bright fat signal = edema)
• Associated free pelvic fluid
• Gas within lesion (rare but diagnostic of abscess)

---

MRI Features That Suggest Malignancy (ADNEX MRI Criteria)

1. Solid enhancing components
2. Thick irregular septa (>3 mm) with enhancement
3. Papillary projections
4. Restricted diffusion in solid areas (ADC <1.0 × 10⁻³ mm²/s)
5. Peritoneal/omental deposits
6. Ascites
7. Lymphadenopathy (>1 cm)
8. Necrosis within solid components
9. Bilateral ovarian involvement (suggests metastatic/Krukenberg)

O-RADS MRI Classification

---

Q14. Draw the Cut Section of Kidney. Describe the Role of USG in Case of Painless Hematuria

Part A: Cut Section of Kidney

         ┌─────────────────────────────────────────┐
         │         FIBROUS CAPSULE (outer layer)   │
         │   ┌─────────────────────────────────┐   │
         │   │   CORTEX  (1.0 - 1.5 cm thick)  │   │
         │   │  • Renal corpuscles (glomeruli)  │   │
         │   │  • PCT, DCT                      │   │
         │   │  • Columns of Bertin ─────────┐  │   │
         │   │    (cortex dipping between     │  │   │
         │   │     medullary pyramids)        │  │   │
         │   ├────────────┬─────┬─────────────┤  │   │
         │   │  PYRAMID 1 │     │  PYRAMID 2  │  │   │
         │   │ (medulla)  │SINUS│  (medulla)  │  │   │
         │   │            │     │             │  │   │
         │   │  ↓ papilla │     │ papilla ↓   │  │   │
         │   │ Minor calyx│     │ Minor calyx │  │   │
         │   │     ↓      │     │     ↓       │  │   │
         │   │  Major calyx ←───→ Major calyx │  │   │
         │   │         ↓                      │  │   │
         │   │      RENAL PELVIS              │  │   │
         │   │         ↓                      │  │   │
         │   │       URETER (UPJ)             │  │   │
         │   └────────────────────────────────┘  │   │
         └─────────────────────────────────────────┘

Labeled Structures of the Cut Section:

---

Part B: Role of USG in Painless Hematuria

Significance of Painless Hematuria

• Bladder carcinoma (most common cause of gross painless hematuria in patients >50 years)
• Renal cell carcinoma (RCC)
• Urothelial carcinoma (renal pelvis, ureter)
• Angiomyolipoma (AML)
• IgA nephropathy (microscopic hematuria, young patients)

---

USG Technique

• Probe: Curved array 3.5-5 MHz (abdomen); Linear 7-15 MHz (superficial structures)
• Bladder must be full (250-300 ml) for optimal evaluation
• Scan: Both kidneys in longitudinal and transverse planes; bladder in two planes; post-void residual

---

USG Findings in Causes of Painless Hematuria

1. Bladder Carcinoma (Urothelial Carcinoma) - Most Important

• Echogenic mass projecting into the bladder lumen from the wall
• Papillary (polypoid): Pedunculated, frond-like echogenic mass; lower stage (superficial lamina propria)
• Sessile (flat/broad base): Focal wall thickening; higher stage (suggests muscle invasion)
• Bladder wall thickness >5 mm at the site of lesion
• Color Doppler: internal vascularity within the mass - distinguishes tumor from blood clot (clot = NO internal flow)
• Post-void: tumor remains fixed; clot may shift position
• Location: trigone and posterior wall most common; lateral walls and dome less common
• Large tumors: invasion into perivesical fat (irregular outer bladder contour)
• Limitation: Cannot detect flat carcinoma in situ (CIS), lesions <5 mm, lesions at dome/bladder neck

2. Renal Cell Carcinoma (RCC)

• Solid intrarenal mass: Variable echogenicity
  • Small RCC (<3 cm): often hyperechoic (similar to AML - requires CT differentiation)
  • Larger RCC: heterogeneous, iso- or hypoechoic; irregular margins
• Disruption of renal sinus fat (invasion)
• Cystic areas within mass: necrosis, hemorrhage
• Renal vein: Echogenic solid material = tumor thrombus (critical finding)
• IVC: Thrombus extending up to hepatic veins or right atrium
• Color Doppler: Internal arterial waveform within mass (tumor vascularity); distinguishes from simple cyst; renal vein patency
• Adrenal gland: Ipsilateral adrenal metastasis (separate mass above kidney)

3. Angiomyolipoma (AML)

• Highly echogenic (bright) well-defined intrarenal mass - characteristic appearance
• Fat content causes high echogenicity (similar to or brighter than renal sinus fat)
• Posterior acoustic shadowing in lesions >1.5 cm
• Well-defined margins; round or oval
• Color Doppler: internal vascularity (particularly in large AML - risk of spontaneous hemorrhage if >4 cm)
• Critical distinction from RCC: Both can be hyperechoic on USG; CT confirms fat density (<-30 HU) in AML
• Bilateral multiple AMLs: associated with tuberous sclerosis complex (TSC)

4. Renal Calculi

• Hyperechoic foci with posterior acoustic shadowing within renal parenchyma or collecting system
• Twinkling artifact on color Doppler: rapid color change behind stone = highly specific for calculi
• Obstructing stone: hydronephrosis (dilated pelvicalyceal system, dilated ureter)
• Ureteric stone: difficult to visualize directly; secondary hydronephrosis suggests obstruction
• Staghorn calculus: large echogenic cast of the renal pelvis + all calyces

5. Transitional Cell Carcinoma (TCC) of Renal Pelvis

• Echogenic non-shadowing soft tissue filling defect within dilated renal pelvis
• Hydronephrosis proximal to the lesion
• Color Doppler: internal vascularity distinguishes TCC from blood clot (avascular)
• Lower pole cortical thinning with preserved sinus (unlike RCC which replaces parenchyma)
• USG has very limited sensitivity for ureteric TCC (only 14%); CT Urography required

6. Hemorrhagic Renal Cyst

• Complex cyst with internal echoes (blood products)
• Thin wall; no Doppler flow within (distinguishes from cystic RCC which has flow in solid components)
• Thick wall / mural nodule / enhancing solid areas → Bosniak III or IV → suspicious for cystic RCC
• Simple hemorrhagic cyst: follow-up with USG or CT

7. Arteriovenous Malformation (AVM) / Renal AV Fistula

• Cause of hematuria without visible mass
• Gray-scale: May appear as small hypoechoic area or tubular structure
• Color Doppler: Focal area of intense color (mosaic pattern) due to turbulent high-velocity flow
• Pulsed wave Doppler: arterial waveform in a venous structure (arterialization of venous flow) = AV fistula
• Peak systolic velocity markedly elevated
• Confirms vascular etiology; refer for DSA and possible embolization

8. Polycystic Kidney Disease (ADPKD)

• Bilateral enlarged kidneys with multiple cysts of varying sizes
• Hematuria due to cyst hemorrhage or associated renal calculi
• Complex cysts (heterogeneous, echogenic content): intracystic hemorrhage
• Liver cysts often co-exist

---

Algorithm: USG Approach to Painless Hematuria

PAINLESS HEMATURIA
        ↓
Full bladder USG + Both kidneys
        ↓
 ┌──────────────────────────┬──────────────────────────┐
 │    POSITIVE FINDING      │     NEGATIVE FINDING     │
 ↓                          ↓                          ↓
Bladder mass               Renal mass             Proceed to:
→ CT staging               → CT characterization   • CT Urography
Renal stone                Hydronephrosis          • Cystoscopy
→ NCCT abdomen             → CTU/IVU               • Urine cytology
AML/RCC → CT
        ↓
Color Doppler:
• Flow in mass = tumor (not clot)
• Absent renal vein flow = thrombus
• Mosaic pattern = AVM

---

Limitations of USG in Painless Hematuria

---

When to Proceed Beyond USG

Key principle: A negative USG does NOT exclude bladder malignancy. Cystoscopy is always required when clinical suspicion is high, regardless of imaging findings. CT Urography remains the gold standard for complete upper and lower urinary tract evaluation in hematuria.