Ultrasound (USG) in Gynecology and Obstetrics - A Complete Guide

#!/usr/bin/env python3
"""
USG Gynecology & Obstetrics – Visual Reference Guide
Builds a professional multi-page PDF using ReportLab.
"""

import os
from reportlab.lib.pagesizes import A4
from reportlab.lib.units import cm, mm
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_RIGHT
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, KeepTogether, Image as RLImage, PageBreak
)
from reportlab.platypus.flowables import Flowable
from reportlab.pdfgen import canvas as pdfcanvas
from reportlab.graphics.shapes import Drawing, Rect, String, Line, Circle
from reportlab.graphics import renderPDF
import textwrap

# ── Paths ──────────────────────────────────────────────────────────────────
IMG_DIR = "/home/daytona/workspace/usg-guide/images"
OUTPUT  = "/home/daytona/workspace/usg-guide/USG_Gynecology_Obstetrics_Reference_Guide.pdf"

W, H = A4  # 595 x 842 pt

# ── Colour palette ─────────────────────────────────────────────────────────
C_NAVY   = colors.HexColor("#0D2B4E")
C_TEAL   = colors.HexColor("#0A7E8C")
C_LBLUE  = colors.HexColor("#C8E6F5")
C_LGREY  = colors.HexColor("#F2F4F6")
C_GOLD   = colors.HexColor("#E8A020")
C_WHITE  = colors.white
C_BLACK  = colors.black
C_RED    = colors.HexColor("#C0392B")
C_GREEN  = colors.HexColor("#1A7A45")
C_PURPLE = colors.HexColor("#6C3483")

# ── Styles ─────────────────────────────────────────────────────────────────
BASE = getSampleStyleSheet()

def style(name, **kw):
    s = ParagraphStyle(name, **kw)
    return s

S_TITLE   = style("S_TITLE",   fontName="Helvetica-Bold",  fontSize=22, textColor=C_WHITE,  leading=28, alignment=TA_CENTER)
S_SUBTITLE= style("S_SUBTITLE",fontName="Helvetica",       fontSize=12, textColor=C_LBLUE,  leading=16, alignment=TA_CENTER)
S_H1      = style("S_H1",      fontName="Helvetica-Bold",  fontSize=14, textColor=C_WHITE,  leading=18, alignment=TA_LEFT,   spaceAfter=2)
S_H2      = style("S_H2",      fontName="Helvetica-Bold",  fontSize=11, textColor=C_NAVY,   leading=15, alignment=TA_LEFT,   spaceAfter=3)
S_H3      = style("S_H3",      fontName="Helvetica-Bold",  fontSize=9,5, textColor=C_TEAL,  leading=13, alignment=TA_LEFT,   spaceAfter=2)
S_BODY    = style("S_BODY",    fontName="Helvetica",        fontSize=8.5,textColor=C_BLACK,  leading=12, alignment=TA_LEFT,   spaceAfter=2)
S_SMALL   = style("S_SMALL",   fontName="Helvetica",        fontSize=7.5,textColor=colors.HexColor("#555555"), leading=10, alignment=TA_LEFT)
S_CAPTION = style("S_CAPTION", fontName="Helvetica-Oblique",fontSize=7.5,textColor=C_NAVY,  leading=10, alignment=TA_CENTER, spaceAfter=4)
S_BULLET  = style("S_BULLET",  fontName="Helvetica",        fontSize=8.5,textColor=C_BLACK,  leading=12, leftIndent=12, bulletIndent=4, spaceAfter=1)
S_NOTE    = style("S_NOTE",    fontName="Helvetica-Oblique",fontSize=8,  textColor=C_RED,    leading=11, alignment=TA_LEFT)
S_TBLHDR  = style("S_TBLHDR",  fontName="Helvetica-Bold",  fontSize=8,  textColor=C_WHITE,  leading=11, alignment=TA_CENTER)
S_TBLCELL = style("S_TBLCELL", fontName="Helvetica",        fontSize=8,  textColor=C_BLACK,  leading=11, alignment=TA_LEFT)
S_TBLCELLC= style("S_TBLCELLC",fontName="Helvetica",        fontSize=8,  textColor=C_BLACK,  leading=11, alignment=TA_CENTER)

# ── Helper: section header bar ─────────────────────────────────────────────
class SectionHeader(Flowable):
    def __init__(self, text, bg=C_NAVY, w=None, h=22):
        Flowable.__init__(self)
        self.text = text
        self.bg   = bg
        self.bw   = w or (W - 3*cm)
        self.bh   = h

    def wrap(self, aw, ah):
        return self.bw, self.bh + 4

    def draw(self):
        c = self.canv
        c.setFillColor(self.bg)
        c.roundRect(0, 2, self.bw, self.bh, 4, fill=1, stroke=0)
        c.setFillColor(C_WHITE)
        c.setFont("Helvetica-Bold", 11)
        c.drawString(8, 8, self.text)

class SubSectionHeader(Flowable):
    def __init__(self, text, bg=C_TEAL, w=None, h=17):
        Flowable.__init__(self)
        self.text = text
        self.bg   = bg
        self.bw   = w or (W - 3*cm)
        self.bh   = h

    def wrap(self, aw, ah):
        return self.bw, self.bh + 4

    def draw(self):
        c = self.canv
        c.setFillColor(self.bg)
        c.roundRect(0, 2, self.bw, self.bh, 3, fill=1, stroke=0)
        c.setFillColor(C_WHITE)
        c.setFont("Helvetica-Bold", 9)
        c.drawString(8, 5, self.text)

# ── Helper: image with caption ─────────────────────────────────────────────
def img_cell(fname, caption, w=6.5*cm, h=5.5*cm):
    path = os.path.join(IMG_DIR, fname)
    if os.path.exists(path):
        im = RLImage(path, width=w, height=h, kind='proportional')
    else:
        im = Paragraph(f"[Image: {fname}]", S_SMALL)
    cap = Paragraph(caption, S_CAPTION)
    return [im, cap]

def labeled_img(fname, caption, labels, w=7*cm, h=6*cm):
    """Returns a list of flowables: image + label box + caption"""
    path = os.path.join(IMG_DIR, fname)
    items = []
    if os.path.exists(path):
        items.append(RLImage(path, width=w, height=h, kind='proportional'))
    label_text = "  |  ".join([f"<b>{k}</b> = {v}" for k, v in labels.items()])
    items.append(Paragraph(f'<font size="7" color="#0A7E8C">{label_text}</font>', S_CAPTION))
    items.append(Paragraph(caption, S_CAPTION))
    return items

# ── Helper: coloured table ─────────────────────────────────────────────────
def make_table(headers, rows, col_widths=None, zebra=True):
    data = [[Paragraph(h, S_TBLHDR) for h in headers]]
    for i, row in enumerate(rows):
        data.append([Paragraph(str(c), S_TBLCELL) for c in row])

    ts = TableStyle([
        ('BACKGROUND',  (0,0), (-1,0),  C_NAVY),
        ('TEXTCOLOR',   (0,0), (-1,0),  C_WHITE),
        ('ROWBACKGROUNDS',(0,1),(-1,-1),[C_WHITE, C_LGREY] if zebra else [C_WHITE]),
        ('GRID',        (0,0), (-1,-1), 0.3, colors.HexColor("#BBBBBB")),
        ('LEFTPADDING', (0,0), (-1,-1), 5),
        ('RIGHTPADDING',(0,0), (-1,-1), 5),
        ('TOPPADDING',  (0,0), (-1,-1), 3),
        ('BOTTOMPADDING',(0,0),(-1,-1), 3),
        ('VALIGN',      (0,0), (-1,-1), 'TOP'),
        ('FONTSIZE',    (0,0), (-1,-1), 8),
    ])
    t = Table(data, colWidths=col_widths, repeatRows=1)
    t.setStyle(ts)
    return t

# ── Helper: two-column image grid ──────────────────────────────────────────
def two_col_images(pairs):
    """pairs = [(fname, caption, labels_dict), ...]  -> 2-col Table"""
    cells = []
    for fname, caption, labels in pairs:
        path = os.path.join(IMG_DIR, fname)
        block = []
        if os.path.exists(path):
            block.append(RLImage(path, width=7.5*cm, height=6.2*cm, kind='proportional'))
        if labels:
            lbl = "  ".join([f"<b>{k}</b>={v}" for k, v in labels.items()])
            block.append(Paragraph(f'<font size="6.5" color="#0A7E8C">{lbl}</font>', S_CAPTION))
        block.append(Paragraph(caption, S_CAPTION))
        cells.append(block)

    rows = []
    for i in range(0, len(cells), 2):
        row = [cells[i], cells[i+1] if i+1 < len(cells) else [Paragraph("", S_SMALL)]]
        rows.append(row)

    t = Table(rows, colWidths=[8.5*cm, 8.5*cm])
    t.setStyle(TableStyle([
        ('VALIGN',      (0,0),(-1,-1),'TOP'),
        ('LEFTPADDING', (0,0),(-1,-1), 4),
        ('RIGHTPADDING',(0,0),(-1,-1), 4),
        ('TOPPADDING',  (0,0),(-1,-1), 4),
        ('BOTTOMPADDING',(0,0),(-1,-1),4),
    ]))
    return t

# ── Page templates (header/footer) ─────────────────────────────────────────
def page_template(canv, doc):
    canv.saveState()
    # top bar
    canv.setFillColor(C_NAVY)
    canv.rect(0, H - 22, W, 22, fill=1, stroke=0)
    canv.setFillColor(C_WHITE)
    canv.setFont("Helvetica-Bold", 9)
    canv.drawString(1*cm, H - 15, "USG GYNECOLOGY & OBSTETRICS — QUICK CLINICAL REFERENCE")
    canv.setFont("Helvetica", 8)
    canv.drawRightString(W - 1*cm, H - 15, f"Page {doc.page}")
    # bottom bar
    canv.setFillColor(C_LGREY)
    canv.rect(0, 0, W, 16, fill=1, stroke=0)
    canv.setFillColor(colors.HexColor("#888888"))
    canv.setFont("Helvetica-Oblique", 6.5)
    canv.drawString(1*cm, 5, "References: Creasy & Resnik MFM | Berek & Novak's Gynecology | Grainger & Allison Radiology | ISUOG 2019 | Williams Obstetrics | D.C. Dutta's Obstetrics")
    canv.restoreState()

def cover_page_template(canv, doc):
    canv.saveState()
    # Full-page navy gradient background
    canv.setFillColor(C_NAVY)
    canv.rect(0, 0, W, H, fill=1, stroke=0)
    # Teal accent stripe
    canv.setFillColor(C_TEAL)
    canv.rect(0, H*0.38, W, 8, fill=1, stroke=0)
    canv.rect(0, H*0.36, W, 3, fill=1, stroke=0)
    # Gold accent line
    canv.setFillColor(C_GOLD)
    canv.rect(1*cm, H*0.38 + 10, 4*cm, 3, fill=1, stroke=0)
    canv.restoreState()

# ── BUILD ──────────────────────────────────────────────────────────────────
def build():
    doc = SimpleDocTemplate(
        OUTPUT,
        pagesize=A4,
        leftMargin=1.5*cm, rightMargin=1.5*cm,
        topMargin=1.8*cm,  bottomMargin=1.2*cm,
        title="USG Gynecology & Obstetrics Reference Guide",
        author="Orris Medical AI",
        subject="Ultrasound Visual Reference"
    )

    story = []

    # ═══════════════════════════════════════════════════════
    # PAGE 1 – COVER
    # ═══════════════════════════════════════════════════════
    story.append(Spacer(1, 3.5*cm))
    story.append(Paragraph(
        '<font color="white"><b>USG</b></font>',
        style("cov0", fontName="Helvetica-Bold", fontSize=52, textColor=C_GOLD, leading=56, alignment=TA_CENTER)
    ))
    story.append(Paragraph(
        "GYNECOLOGY & OBSTETRICS",
        style("cov1", fontName="Helvetica-Bold", fontSize=20, textColor=C_WHITE, leading=26, alignment=TA_CENTER)
    ))
    story.append(Spacer(1, 0.3*cm))
    story.append(Paragraph(
        "VISUAL REFERENCE GUIDE",
        style("cov2", fontName="Helvetica", fontSize=13, textColor=C_LBLUE, leading=18, alignment=TA_CENTER)
    ))
    story.append(Spacer(1, 0.15*cm))
    story.append(HRFlowable(width="60%", thickness=1.5, color=C_TEAL, hAlign='CENTER'))
    story.append(Spacer(1, 0.4*cm))
    story.append(Paragraph(
        "Quick Clinical Reference for Students, Residents & Clinicians",
        style("cov3", fontName="Helvetica-Oblique", fontSize=11, textColor=colors.HexColor("#A8D8E8"), leading=15, alignment=TA_CENTER)
    ))

    story.append(Spacer(1, 1.6*cm))

    # Content summary box
    summary_data = [
        ["PART 1", "Fundamentals — How to Read USG", "Probes • Echogenicity • Report Elements"],
        ["PART 2", "Obstetric USG by Trimester", "1st • 2nd Anatomy Scan • 3rd Trimester"],
        ["PART 3", "Fetal Biometry", "BPD • HC • AC • FL • EFW • AFI"],
        ["PART 4", "Detailed Fetal Anatomy Images", "Head • Heart • Face • Spine"],
        ["PART 5", "Gynecological USG", "Normal Uterus & Ovary • Endometrium"],
        ["PART 6", "Pathological Conditions", "Fibroids • Cysts • Ectopic • Mole • Previa"],
    ]
    cov_table = Table(
        [[Paragraph(f'<b><font color="#E8A020">{r[0]}</font></b>', style("ct0", fontName="Helvetica-Bold", fontSize=9, textColor=C_GOLD, leading=12)),
          Paragraph(f'<b><font color="white">{r[1]}</font></b>', style("ct1", fontName="Helvetica-Bold", fontSize=9, textColor=C_WHITE, leading=12)),
          Paragraph(f'<font color="#A8D8E8">{r[2]}</font>', style("ct2", fontName="Helvetica", fontSize=8, textColor=C_LBLUE, leading=11))]
         for r in summary_data],
        colWidths=[2*cm, 6.5*cm, 8*cm]
    )
    cov_table.setStyle(TableStyle([
        ('BACKGROUND',  (0,0),(-1,-1), colors.HexColor("#1A3A5C")),
        ('ROWBACKGROUNDS',(0,0),(-1,-1),[colors.HexColor("#1A3A5C"), colors.HexColor("#0F2840")]),
        ('LEFTPADDING',  (0,0),(-1,-1), 8),
        ('RIGHTPADDING', (0,0),(-1,-1), 8),
        ('TOPPADDING',   (0,0),(-1,-1), 6),
        ('BOTTOMPADDING',(0,0),(-1,-1), 6),
        ('LINEBELOW',    (0,0),(-1,-2), 0.5, colors.HexColor("#2A4A6C")),
        ('ROUNDEDCORNERS',(0,0),(-1,-1),5),
    ]))
    story.append(cov_table)

    story.append(Spacer(1, 2*cm))
    story.append(Paragraph(
        "References: Creasy &amp; Resnik's Maternal-Fetal Medicine  |  Berek &amp; Novak's Gynecology",
        style("ref1", fontName="Helvetica-Oblique", fontSize=8, textColor=colors.HexColor("#607080"), leading=12, alignment=TA_CENTER)
    ))
    story.append(Paragraph(
        "Grainger &amp; Allison's Diagnostic Radiology  |  ISUOG Guidelines 2019  |  Williams Obstetrics  |  D.C. Dutta's Obstetrics",
        style("ref2", fontName="Helvetica-Oblique", fontSize=8, textColor=colors.HexColor("#607080"), leading=12, alignment=TA_CENTER)
    ))

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 2 – PART 1: FUNDAMENTALS
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("PART 1 — FUNDAMENTALS: HOW TO READ A GYNECOLOGICAL / OBSTETRIC USG"))
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("1.1  Probe Types & Patient Preparation"))
    story.append(Spacer(1, 0.2*cm))

    probe_table = make_table(
        ["Approach", "Probe Type", "Frequency", "Bladder", "Best Used For"],
        [
            ["Transabdominal (TAS)", "Curvilinear", "3–5 MHz", "FULL", "2nd/3rd trimester, general pelvic survey, placenta"],
            ["Transvaginal (TVS)", "Endocavitary", "5–10 MHz", "EMPTY", "1st trimester (<12 wks), adnexa, cervical length, early IUP"],
            ["Translabial / Transperineal", "Curvilinear", "3–5 MHz", "Moderate", "Cervical os, placenta previa confirmation"],
        ],
        col_widths=[3.5*cm, 2.8*cm, 2.2*cm, 2*cm, 6*cm]
    )
    story.append(probe_table)
    story.append(Spacer(1, 0.35*cm))

    story.append(SubSectionHeader("1.2  Echogenicity Key — What You See on Screen"))
    story.append(Spacer(1, 0.2*cm))

    echo_table = make_table(
        ["Appearance", "Term", "Colour on Screen", "Clinical Examples"],
        [
            ["Jet black / Dark", "Anechoic", "Black", "Fluid, urine in bladder, simple cysts, amniotic fluid"],
            ["Dark grey", "Hypoechoic", "Dark grey", "Muscle, uterine myometrium, solid masses"],
            ["Medium grey", "Isoechoic", "Mid grey", "Normal liver, placenta, some fibroids"],
            ["Light grey / white", "Hyperechoic", "Bright grey/white", "Bone, calcifications, gas, fat"],
            ["Very bright white", "Echogenic", "White", "Fetal skull, bowel gas, dermoid cyst content"],
            ["Mixed light & dark", "Heterogeneous", "Patchy", "Complex masses, degenerating fibroids, haematomas"],
        ],
        col_widths=[3*cm, 2.5*cm, 3*cm, 8*cm]
    )
    story.append(echo_table)
    story.append(Spacer(1, 0.25*cm))

    story.append(Paragraph(
        '<b>Key physical signs:</b>  '
        '<b>Posterior acoustic enhancement</b> = bright area BEHIND a cyst → confirms pure fluid.  '
        '<b>Acoustic shadowing</b> = dark stripe BEHIND calcification/bone → blocks sound.  '
        '<b>Ring-of-fire</b> (colour Doppler) = peripheral vascularity around corpus luteum.',
        S_BODY
    ))
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("1.3  Mandatory Elements of an Obstetric USG Report  (Creasy & Resnik MFM, Ch.16)"))
    story.append(Spacer(1, 0.15*cm))

    rep_items = [
        "Patient identity + date of examination",
        "Indication for the procedure",
        "Type of examination (standard / detailed / limited)",
        "Gestational age by established dates (LMP + prior scans)",
        "Number of fetuses and chorionicity (if multifetal)",
        "Fetal biometry with predicted gestational age",
        "Principal findings — normal, abnormal, and poorly visualised",
        "Differential diagnosis for any abnormalities detected",
        "Recommendations for pregnancy management or further imaging",
    ]
    rep_data = [[Paragraph(f"• {item}", S_BODY)] for item in rep_items]
    rep_t = Table(rep_data, colWidths=[16.5*cm])
    rep_t.setStyle(TableStyle([
        ('ROWBACKGROUNDS',(0,0),(-1,-1),[C_WHITE, C_LGREY]),
        ('LEFTPADDING',(0,0),(-1,-1),8),
        ('TOPPADDING',(0,0),(-1,-1),3),
        ('BOTTOMPADDING',(0,0),(-1,-1),3),
        ('GRID',(0,0),(-1,-1),0.2,colors.HexColor("#DDDDDD")),
    ]))
    story.append(rep_t)

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 3 – PART 2: FIRST TRIMESTER USG
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("PART 2 — OBSTETRIC USG: FIRST TRIMESTER  (Weeks 4–13+6)"))
    story.append(Spacer(1, 0.3*cm))
    story.append(Paragraph(
        "<b>Primary goals:</b> Confirm intrauterine pregnancy (IUP) • Gestational dating • Fetal cardiac activity • Number of fetuses • Nuchal translucency (11–13+6 wks)",
        S_BODY
    ))
    story.append(Spacer(1, 0.25*cm))

    story.append(SubSectionHeader("2.1  Sequential Appearances on TVS"))
    story.append(Spacer(1, 0.2*cm))

    t1_table = make_table(
        ["Gestational Age", "Structure Visible", "Key Measurement", "Normal Value"],
        [
            ["4–4.5 weeks", "Gestational Sac (GS)", "Mean Sac Diameter (MSD)", "≥ 2 mm; intradecidual sign"],
            ["4.5–5 weeks", "Yolk Sac (YS)", "YS diameter", "3–6 mm (round, echogenic ring)"],
            ["5.5–6 weeks", "Fetal Pole", "Crown-Rump Length (CRL)", "First visible adjacent to YS"],
            ["6–6.5 weeks", "Cardiac Activity", "Heart Rate (HR)", "Must confirm when CRL ≥ 7 mm; normal 110–170 bpm"],
            ["7–8 weeks", "Embryo morphology", "CRL for dating", "Accurate to ±3–5 days"],
            ["11–13+6 weeks", "Nuchal Translucency (NT)", "NT thickness", "< 3.0 mm = normal; ≥ 3.5 mm = high risk aneuploidy"],
        ],
        col_widths=[3*cm, 3.5*cm, 4*cm, 6.5*cm]
    )
    story.append(t1_table)
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("2.2  Discriminatory Zones (hCG)"))
    story.append(Spacer(1, 0.15*cm))
    disc_data = [
        ["Transvaginal (TVS)", "1,000–2,000 mIU/mL", "GS should be visible; if absent → suspect ectopic"],
        ["Transabdominal (TAS)", "3,000–5,000 mIU/mL", "GS should be visible; empty uterus → refer for TVS"],
    ]
    disc_t = make_table(["Approach", "hCG Discriminatory Zone", "Clinical Implication"], disc_data,
                        col_widths=[3.5*cm, 4.5*cm, 9*cm])
    story.append(disc_t)
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("2.3  Early Pregnancy Failure — USG Diagnostic Criteria"))
    story.append(Spacer(1, 0.15*cm))
    epf_data = [
        ["Missed Abortion", "CRL ≥ 7 mm", "No cardiac activity", "Confirmed missed abortion"],
        ["Anembryonic / Blighted Ovum", "MSD ≥ 25 mm", "No embryo visible", "No embryo with large sac"],
        ["Early Pregnancy Failure", "GS seen without YS", "No embryo ≥ 2 weeks later", "Await 2nd scan before diagnosis"],
        ["Early Pregnancy Failure", "GS seen with YS", "No embryo ≥ 11 days later", "Serial scans required"],
    ]
    epf_t = make_table(
        ["Diagnosis", "USG Finding", "Key Criterion", "Note"],
        epf_data,
        col_widths=[4*cm, 4*cm, 4*cm, 5*cm]
    )
    story.append(epf_t)
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("2.4  Pseudogestational Sac vs True IUP"))
    story.append(Spacer(1, 0.15*cm))
    ps_data = [
        ["True gestational sac (IUP)", "Eccentric, embedded in decidua", "Has echogenic ring (double decidual sign)", "Yolk sac visible at 5 wks"],
        ["Pseudogestational sac (ectopic)", "Central, in uterine cavity", "No echogenic ring; may be triangular", "No yolk sac; NO IUP"],
    ]
    ps_t = make_table(["Structure", "Position", "Wall", "Key Differentiator"], ps_data,
                      col_widths=[4*cm, 4*cm, 4.5*cm, 4.5*cm])
    story.append(ps_t)
    story.append(Spacer(1, 0.25*cm))

    story.append(Paragraph(
        '<b><font color="#C0392B">CLINICAL PEARL:</font></b>  If hCG &gt; 1,500 mIU/mL and TVS shows an empty uterus '
        '→ suspect ectopic pregnancy until proven otherwise.  A central fluid collection in the uterus without a yolk '
        'sac is a pseudogestational sac, NOT an IUP.', S_NOTE
    ))

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 4 – PART 3: FETAL BIOMETRY
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("PART 3 — FETAL BIOMETRY  (2nd & 3rd Trimester)"))
    story.append(Spacer(1, 0.3*cm))
    story.append(Paragraph(
        "Biometry is used to (1) estimate gestational age, (2) assess fetal growth, and (3) calculate estimated fetal weight (EFW). "
        "All four standard measurements should be obtained at every anatomy scan.  (ISUOG Guidelines 2019; Creasy &amp; Resnik MFM Ch.16)",
        S_BODY
    ))
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("3.1  Standard Biometric Parameters"))
    story.append(Spacer(1, 0.2*cm))

    bio_data = [
        ["Biparietal Diameter\n(BPD)",   "Axial head — outer to inner calvarium at level of thalami and CSP",
         "At 20 wks ≈ 4.8 cm; At 32 wks ≈ 8.2 cm", "Gestational age dating; most accurate 14–20 wks"],
        ["Head Circumference\n(HC)",      "Same axial plane as BPD; ellipse around outer skull table",
         "At 20 wks ≈ 17.5 cm; At 32 wks ≈ 30 cm", "Age + microcephaly / macrocephaly screening"],
        ["Abdominal Circumference\n(AC)", "Axial abdomen at junction of umbilical vein & portal sinus",
         "At 20 wks ≈ 15 cm; At 32 wks ≈ 28 cm", "BEST indicator of fetal growth & nutrition (IUGR)"],
        ["Femur Length\n(FL)",            "Longest ossified diaphysis of femur (exclude epiphyses)",
         "At 20 wks ≈ 3.3 cm; At 32 wks ≈ 6.2 cm", "Gestational age; skeletal dysplasia screening"],
        ["Estimated Fetal Weight\n(EFW)", "Calculated from BPD, HC, AC, FL (Hadlock formula)",
         "At 20 wks ≈ 300 g; At 32 wks ≈ 1,800 g", "Growth assessment; ±10–15% accuracy"],
    ]
    bio_t = make_table(
        ["Parameter", "How to Measure", "Reference Values", "Clinical Use"],
        bio_data,
        col_widths=[3.2*cm, 5.5*cm, 4.5*cm, 4.3*cm]
    )
    story.append(bio_t)
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("3.2  Amniotic Fluid Assessment"))
    story.append(Spacer(1, 0.2*cm))
    af_data = [
        ["Maximum Vertical Pocket (MVP)",  "Largest pocket of fluid free of cord/limbs", "Normal: 2–8 cm"],
        ["Amniotic Fluid Index (AFI)",      "Sum of largest pockets in 4 uterine quadrants", "Normal: 8–24 cm"],
        ["Oligohydramnios",                 "MVP < 2 cm  OR  AFI < 5 cm", "→ Renal anomaly, IUGR, PPROM, post-dates"],
        ["Polyhydramnios",                  "MVP > 8 cm  OR  AFI > 24 cm", "→ GDM, fetal anomaly (oesophageal atresia, NTD)"],
    ]
    af_t = make_table(["Method / Condition", "Definition", "Values / Significance"], af_data,
                      col_widths=[4.5*cm, 6*cm, 7*cm])
    story.append(af_t)
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("3.3  BPD & HC Measurement — USG Image (Creasy & Resnik MFM, Fig. 16.1)"))
    story.append(Spacer(1, 0.2*cm))

    bio_img_pair = two_col_images([
        ("bpd_hc.png",
         "Fig. 16.1 — Axial head view at 18 weeks. BPD = 4.03 cm → GA 18w2d. HC = 15.09 cm → GA 18w1d. "
         "Measure BPD from outer to inner table. HC ellipse around outer skull margin.",
         {"BPD": "Biparietal diameter", "OFD": "Occipital-frontal diameter", "HC": "Head circumference"}),
        ("posterior_fossa.png",
         "Fig. 16.5 — Posterior fossa view. Cerebellum 1.71 cm → GA 18w0d. Cisterna magna 0.28 cm (normal 2–10 mm). "
         "Nuchal fold 3.18 mm (< 6 mm = normal at 18–22 wks).",
         {"Cist Mag": "Cisterna magna", "Nuch Fold": "Nuchal fold"}),
    ])
    story.append(bio_img_pair)

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 5 – PART 4: DETAILED FETAL ANATOMY
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("PART 4 — DETAILED FETAL ANATOMY SCAN  (18–22 Weeks, CPT 76805/76811)"))
    story.append(Spacer(1, 0.2*cm))
    story.append(Paragraph(
        "The mid-trimester anatomy scan assesses all major organ systems. Per ISUOG 2019 and Creasy &amp; Resnik MFM Box 16.3, "
        "mandatory views include: head &amp; face, thorax, heart (4-chamber + outflow tracts), abdomen, kidneys, spine, and extremities.",
        S_BODY
    ))
    story.append(Spacer(1, 0.25*cm))

    story.append(SubSectionHeader("4.1  Head & Face Views"))
    story.append(Spacer(1, 0.15*cm))

    head_grid = two_col_images([
        ("cavum_sp.png",
         "Fig. 16.2 — Cavum Septi Pellucidi (CSP). Arrow points to CSP — a fluid-filled box-shaped structure in the midline frontal brain. "
         "Absence of CSP suggests corpus callosum agenesis or HPE.",
         {"Falx": "Interhemispheric fissure", "CSP": "Cavum septi pellucidi"}),
        ("falx_cp.png",
         "Fig. 16.3 — Falx cerebri. Midline hyperechoic line separating cerebral hemispheres. "
         "Choroid plexus (CP) = bright echogenic structures filling lateral ventricles.",
         {"Falx": "Falx cerebri", "CP": "Choroid plexus"}),
    ])
    story.append(head_grid)
    story.append(Spacer(1, 0.15*cm))

    head_grid2 = two_col_images([
        ("lateral_ventricle.png",
         "Fig. 16.4 — Lateral ventricle measurement. Caliper placed at inner wall of posterior horn. "
         "Normal: < 10 mm. 10–15 mm = mild ventriculomegaly. > 15 mm = severe.",
         {"Lat Vent": "Lateral ventricle width (0.77 cm = normal)"}),
        ("nasal_bone.png",
         "Fig. 16.7 — Nasal bone (NBL). Assessed at 11–13+6 wks (1st trimester) and again at 18–22 wks. "
         "Absent/hypoplastic nasal bone is a soft marker for trisomy 21 (Down syndrome).",
         {"NBL": "Nasal bone length"}),
    ])
    story.append(head_grid2)
    story.append(Spacer(1, 0.15*cm))

    head_grid3 = two_col_images([
        ("orbits.png",
         "Fig. 16.6 — Fetal orbits. Both orbits visible as two dark circles on axial view. "
         "Assess inter-orbital distance — abnormal in cyclopia, hypotelorism/hypertelorism.",
         {"ORBS": "Orbits"}),
        ("nose_lips.png",
         "Fig. 16.8 — Fetal nose and lips (coronal/axial view). Intact upper lip excludes cleft lip. "
         "Essential view — cleft lip is a common facial anomaly (1 in 700 births).",
         {"Nose/lips": "Upper lip integrity"}),
    ])
    story.append(head_grid3)

    story.append(Spacer(1, 0.25*cm))
    story.append(SubSectionHeader("4.2  Thorax — Cardiac Views"))
    story.append(Spacer(1, 0.15*cm))

    heart_grid = two_col_images([
        ("four_chamber_heart.png",
         "Fig. 16.10 — Four-chamber heart (diastole A, systole B). Heart apex points LEFT. "
         "RV = right ventricle (closest to anterior chest wall). LV = left ventricle. "
         "RA & LA roughly equal size. Descending aorta (Desc Ao) seen posterior to LA.",
         {"RV": "Right ventricle", "LV": "Left ventricle", "RA": "Right atrium", "LA": "Left atrium", "Desc Ao": "Descending aorta"}),
        ("lvot.png",
         "Fig. 16.11 — Left ventricular outflow tract (LVOT). Aorta (Asc Ao) arises from LV. "
         "Medial wall of aorta must be continuous with the interventricular septum. "
         "Discontinuity → suspect aortic override (Tetralogy of Fallot, TGA).",
         {"LV": "Left ventricle", "RV": "Right ventricle", "Asc Ao": "Ascending aorta", "Ao V": "Aortic valve"}),
    ])
    story.append(heart_grid)
    story.append(Spacer(1, 0.15*cm))

    heart_grid2 = two_col_images([
        ("rvot.png",
         "Fig. 16.12 — Right ventricular outflow tract (RVOT). Main pulmonary artery (MPA) arises from RV. "
         "The LVOT and RVOT cross each other — this 'crossing' pattern is lost in TGA.",
         {"RV": "Right ventricle", "RA": "Right atrium", "MPA": "Main pulmonary artery"}),
        ("heart_rate.png",
         "Fig. 16.13 — Fetal heart rate (M-mode). M-mode cursor placed over the beating heart. "
         "Normal fetal HR: 110–170 bpm. < 100 = bradycardia; > 180 = tachycardia.",
         {"HR": "Heart rate via M-mode"}),
    ])
    story.append(heart_grid2)

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 6 – PART 5: GYNAECOLOGICAL USG NORMAL
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("PART 5 — GYNAECOLOGICAL USG: NORMAL ANATOMY"))
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("5.1  Normal Uterus — Measurements & Appearance"))
    story.append(Spacer(1, 0.2*cm))

    uter_data = [
        ["Nulliparous", "7–8 cm", "4–5 cm", "4 cm", "Pear-shaped; homogeneous medium-grey myometrium"],
        ["Multiparous", "8–10 cm", "5–6 cm", "5 cm", "Slightly larger; may have small fibroids"],
        ["Postmenopausal", "4–6 cm", "2–4 cm", "2–3 cm", "Atrophic; thin endometrium; may have calcifications"],
        ["Prepubertal", "2–3.5 cm", "1–1.5 cm", "1 cm", "Tubular shape (cervix > body)"],
    ]
    uter_t = make_table(
        ["Status", "Length", "Width", "AP Diameter", "Notes"],
        uter_data,
        col_widths=[3*cm, 2*cm, 2*cm, 2.5*cm, 7.5*cm]
    )
    story.append(uter_t)
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("5.2  Endometrial Thickness by Cycle Phase"))
    story.append(Spacer(1, 0.2*cm))

    endo_data = [
        ["Menstrual", "2–4 mm", "Thin bright line; hyperechoic collapsed cavity", "Shedding phase"],
        ["Proliferative (early)", "4–8 mm", "Thin echogenic line; hypoechoic functional layer", "Oestrogen-driven growth"],
        ["Proliferative (late)", "8–12 mm", "Trilaminar / three-layer pattern", "Just before ovulation"],
        ["Secretory", "10–14 mm", "Thickened, uniformly bright (hyperechoic), homogeneous", "Post-ovulation progesterone effect"],
        ["Postmenopausal (NORMAL)", "< 4–5 mm", "Thin bright line, atrophic", "If > 5 mm → biopsy recommended"],
        ["Postmenopausal + bleeding", "> 5 mm suspicious", "Thickened, irregular, heterogeneous", "Refer for biopsy / hysteroscopy"],
    ]
    endo_t = make_table(
        ["Cycle Phase", "Thickness", "USG Appearance", "Clinical Note"],
        endo_data,
        col_widths=[3.5*cm, 3*cm, 5*cm, 6*cm]
    )
    story.append(endo_t)
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("5.3  Normal Ovary — Appearance & Follicle Development"))
    story.append(Spacer(1, 0.2*cm))

    ov_data = [
        ["Reproductive age", "3 × 2 × 2 cm (volume ≈ 6–10 cc)", "Ovoid, multiple small follicles; normal volume = 0.523 × L × W × H"],
        ["Dominant follicle", "18–25 mm at ovulation", "Anechoic, thin-walled; 'Double ring' sign just before ovulation"],
        ["Corpus luteum", "2–3 cm", "Thick irregular wall; central clot may be present; RING OF FIRE on Doppler"],
        ["Postmenopausal", "1.5 × 1 × 0.5 cm (volume < 3 cc)", "Atrophic; follicles absent; must not exceed 3 cc"],
    ]
    ov_t = make_table(
        ["State", "Size", "USG Features"],
        ov_data,
        col_widths=[3.5*cm, 4*cm, 10*cm]
    )
    story.append(ov_t)
    story.append(Spacer(1, 0.25*cm))

    story.append(SubSectionHeader("5.4  Cervix on USG"))
    story.append(Spacer(1, 0.2*cm))
    story.append(Paragraph(
        "<b>Cervical length (TVS):</b> Normal cervical length in 2nd trimester is ≥ 25 mm. "
        "Measure from internal os to external os on TVS with empty bladder. "
        "< 25 mm at &lt;24 weeks → risk of preterm labour (PTL). "
        "< 10 mm → immediate referral. Funnelling (funnel-shaped internal os opening) indicates cervical incompetence.",
        S_BODY
    ))

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 7 – PART 6: PATHOLOGICAL CONDITIONS
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("PART 6 — PATHOLOGICAL CONDITIONS ON USG"))
    story.append(Spacer(1, 0.2*cm))

    # ── 6.1 Uterine Fibroids ──
    story.append(SubSectionHeader("6.1  Uterine Fibroids (Leiomyomata)"))
    story.append(Spacer(1, 0.15*cm))

    fib_data = [
        ["Intramural", "Within myometrium", "Hypoechoic/heterogeneous rounded mass; may distort endometrium", "Most common type; AUB if large"],
        ["Submucosal", "Bulges into cavity", "Hyperechoic mass protruding into endometrial cavity", "Best for AUB; treated by hysteroscopic resection"],
        ["Subserosal", "Projects outward", "Lobulated mass on uterine surface; may be pedunculated", "Pelvic pain; can mimic adnexal mass"],
        ["Cervical", "In cervix", "Mass in cervical canal", "Rare; causes dyspareunia, obstruction"],
        ["Degeneration", "Any type", "Heterogeneous with cystic spaces or calcification", "Seen in large/torsed fibroids; pain"],
    ]
    fib_t = make_table(
        ["Type", "Location", "USG Appearance", "Clinical Significance"],
        fib_data,
        col_widths=[2.5*cm, 3*cm, 6*cm, 6*cm]
    )
    story.append(fib_t)
    story.append(Spacer(1, 0.25*cm))

    # ── 6.2 Ovarian Cysts ──
    story.append(SubSectionHeader("6.2  Ovarian Cysts — Classification (Grainger & Allison Radiology)"))
    story.append(Spacer(1, 0.15*cm))

    cyst_data = [
        ["Simple follicular cyst", "Anechoic, thin smooth wall (< 3 mm), posterior enhancement, no septae, no Doppler flow",
         "< 3 cm in reproductive age is physiological; > 5 cm warrants follow-up"],
        ["Haemorrhagic cyst\n(Corpus luteum)", "'Fish-net' / reticular pattern; no internal vascularity on Doppler; resolves in 4–8 wks",
         "Haemorrhage into corpus luteum; may cause acute pelvic pain; self-limiting"],
        ["Endometrioma\n('Chocolate cyst')", "Ground-glass appearance; low-level uniform internal echoes; thick walls; bilateral in 30%",
         "Endometriosis; CA-125 elevated; MRI for confirmation"],
        ["Dermoid cyst (Mature teratoma)", "'Tip of iceberg' sign (front echogenic, back shadowed); Rokitansky nodule; fat-fluid level",
         "Most common benign ovarian tumour in young women; bilateral in 10–15%"],
        ["Serous cystadenoma", "Large, unilocular, thin-walled, anechoic; may be bilateral",
         "Commonest benign ovarian tumour; must exclude malignancy if > 5 cm or complex"],
        ["Mucinous cystadenoma", "Multi-locular; low-level internal echoes; large (can be > 20 cm)",
         "Can be massive; rupture → pseudomyxoma peritonei"],
    ]
    cyst_t = make_table(
        ["Cyst Type", "USG Appearance", "Clinical Notes"],
        cyst_data,
        col_widths=[3.8*cm, 7*cm, 6.7*cm]
    )
    story.append(cyst_t)
    story.append(Spacer(1, 0.2*cm))

    cyst_img_grid = two_col_images([
        ("fetal_ovarian_cyst.png",
         "Creasy & Resnik MFM, Fig. 24.38 — Fetal ovarian cyst at 31w5d. "
         "Large anechoic mass in fetal lower abdomen. Arrow (yellow) = daughter cyst. "
         "Fetal ovarian cysts arise from maternal/placental hormone stimulation. "
         "Most simple cysts resolve spontaneously postpartum.",
         {"Arrow": "Daughter cyst", "GA": "31w5d"}),
        ("renal_cyst.png",
         "Creasy & Resnik MFM, Fig. 24.36 — Choledochal cyst. Axial view at 21 weeks. "
         "Cystic mass anterior to right kidney (RK) in area of fetal liver. "
         "Important to distinguish from duplication cyst, ovarian cyst, or mesenteric cyst.",
         {"RK": "Right kidney", "Sp": "Spine"}),
    ])
    story.append(cyst_img_grid)

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 8 – ECTOPIC, MOLE, PREVIA, PCOS, ENDOMETRIAL
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("PART 6 (continued) — ECTOPIC PREGNANCY, MOLAR PREGNANCY, PLACENTA PREVIA, PCOS"))
    story.append(Spacer(1, 0.25*cm))

    # ── 6.3 Ectopic ──
    story.append(SubSectionHeader("6.3  Ectopic Pregnancy  (Berek & Novak's Gynecology, Ch. 9)"))
    story.append(Spacer(1, 0.15*cm))

    ec_grid = two_col_images([
        ("ectopic.png",
         "Bailey & Love Surgery, Fig. 87.4 — Tubal ectopic pregnancy. "
         "Transvaginal USG showing an anechoic adnexal ring ('tubal ring' sign) separate from the ovary. "
         "No IUP visible in the uterine cavity. Free fluid in pouch of Douglas = haemoperitoneum.",
         {"Adnexal ring": "Ectopic GS in tube"}),
        ("nose_lips.png",  # placeholder for layout symmetry
         "",
         {}),
    ])
    # Only use ectopic image as single, wide
    path_ec = os.path.join(IMG_DIR, "ectopic.png")
    ec_items = []
    if os.path.exists(path_ec):
        ec_items.append(RLImage(path_ec, width=10*cm, height=8*cm, kind='proportional'))
    ec_items.append(Paragraph(
        "Bailey &amp; Love Surgery, Fig. 87.4 — Tubal ectopic pregnancy. Transvaginal USG: anechoic adnexal ring "
        "('tubal ring') separate from the ovary. No IUP in uterine cavity. Free fluid in POD = haemoperitoneum.", S_CAPTION))

    ec_table = Table([[ec_items, [
        Paragraph("<b>Key USG Findings in Ectopic Pregnancy:</b>", S_H2),
        Spacer(1, 0.1*cm),
        make_table(
            ["Sign", "Description"],
            [
                ["Empty uterus", "No IUP on TVS when hCG > discriminatory zone"],
                ["Tubal ring sign", "Echogenic ring in adnexa (ectopic GS); separate from ovary"],
                ["Pseudogestational sac", "Central fluid in uterus (no yolk sac/embryo inside)"],
                ["Free fluid (POD)", "Anechoic fluid in pouch of Douglas = blood"],
                ["Live ectopic", "Cardiac activity outside uterus — pathognomonic"],
                ["Complex adnexal mass", "Haematoma from tubal rupture; heterogeneous"],
            ],
            col_widths=[3.5*cm, 5*cm]
        ),
    ]]], colWidths=[10.5*cm, 8.5*cm])
    ec_table.setStyle(TableStyle([
        ('VALIGN',(0,0),(-1,-1),'TOP'),
        ('LEFTPADDING',(0,0),(-1,-1),4),
        ('RIGHTPADDING',(0,0),(-1,-1),4),
    ]))
    story.append(ec_table)
    story.append(Spacer(1, 0.3*cm))

    # ── 6.4 Molar Pregnancy ──
    story.append(SubSectionHeader("6.4  Hydatidiform Mole (Gestational Trophoblastic Disease)"))
    story.append(Spacer(1, 0.15*cm))
    mole_data = [
        ["Complete Mole (46 XX/XY)", "'Snowstorm' pattern: uterus filled with heterogeneous echogenic material + multiple small anechoic spaces (hydropic villi)",
         "No fetal parts. Markedly elevated hCG. Bilateral theca-lutein cysts common. High malignancy risk (15–20%)"],
        ["Partial Mole (69 chromosomes)", "Abnormal placenta (swiss-cheese/cystic spaces). Fetus/fetal parts may be present (triploid)",
         "GS transverse:AP ratio > 1.5. Lower hCG than complete. Lower malignancy risk (< 5%)"],
    ]
    mole_t = make_table(
        ["Type", "USG Appearance", "Clinical Notes"],
        mole_data,
        col_widths=[4*cm, 7*cm, 6.5*cm]
    )
    story.append(mole_t)
    story.append(Spacer(1, 0.2*cm))
    story.append(Paragraph(
        '<b><font color="#C0392B">D.C. Dutta's PEARL:</font></b>  The snowstorm appearance on USG + markedly elevated hCG is pathognomonic of '
        'complete hydatidiform mole. TVS is more sensitive than TAS for early diagnosis. Always check both ovaries for theca-lutein cysts.',
        S_NOTE
    ))
    story.append(Spacer(1, 0.3*cm))

    # ── 6.5 Placenta Previa ──
    story.append(SubSectionHeader("6.5  Placenta Previa  (Creasy & Resnik MFM; Williams Obstetrics)"))
    story.append(Spacer(1, 0.15*cm))
    prev_data = [
        ["Complete (Total) Previa", "Placenta completely covers the internal cervical os", "Mandatory CS; no vaginal examination"],
        ["Partial Previa", "Placenta partially overlaps the internal os", "Usually CS; TVS follow-up"],
        ["Marginal Previa", "Placental edge reaches but does not cover the os", "Possible vaginal delivery; TVS at 36 wks"],
        ["Low-Lying Placenta", "Placental edge within 2 cm of os but not covering", "TVS at 32–36 wks; most 'migrate' away"],
    ]
    prev_t = make_table(
        ["Type", "USG Definition", "Management Principle"],
        prev_data,
        col_widths=[4*cm, 7*cm, 6.5*cm]
    )
    story.append(prev_t)
    story.append(Spacer(1, 0.15*cm))
    story.append(Paragraph(
        '<b>IMPORTANT:</b> Always confirm with TVS (transvaginal USG). Full bladder on TAS may compress the lower segment and create a '
        '<b>false appearance of previa</b>. "Placental migration" — most low-lying placentas at 20 weeks move away from the os by 34–36 weeks '
        'as the lower uterine segment elongates.', S_BODY
    ))
    story.append(Spacer(1, 0.3*cm))

    # ── 6.6 PCOS ──
    story.append(SubSectionHeader("6.6  Polycystic Ovarian Syndrome (PCOS)  —  Rotterdam Criteria USG Component"))
    story.append(Spacer(1, 0.15*cm))
    pcos_data = [
        ["Follicle count", "≥ 12 follicles per ovary, each 2–9 mm diameter", "'String of pearls' sign — follicles arranged peripherally"],
        ["Ovarian volume", "> 10 cc  (0.523 × L × W × H)", "Enlarged ovary with echogenic central stroma"],
        ["Stroma", "Increased echogenicity of central stroma", "Increased stromal:total ovary area ratio"],
    ]
    pcos_t = make_table(
        ["Criterion", "Definition", "USG Appearance"],
        pcos_data,
        col_widths=[3.5*cm, 5*cm, 9*cm]
    )
    story.append(pcos_t)
    story.append(Spacer(1, 0.3*cm))

    # ── 6.7 Endometrial Pathology ──
    story.append(SubSectionHeader("6.7  Endometrial Pathology"))
    story.append(Spacer(1, 0.15*cm))
    ep_data = [
        ["Endometrial Polyp", "Focal hyperechoic intracavitary mass; central vascular stalk on Doppler; endometrial thickening",
         "AUB; confirm with saline-infusion sonohysterography (SIS) or hysteroscopy"],
        ["Endometrial Hyperplasia", "Diffusely thickened, bright (hyperechoic) endometrium; uniform",
         "> 4–5 mm postmenopausal → biopsy; oestrogen excess; PCOS"],
        ["Endometrial Carcinoma", "Irregular, heterogeneous, thickened endometrium; loss of endometrial-myometrial junction; Doppler shows low-resistance flow",
         "Postmenopausal bleeding; invasion of myometrium seen on MRI"],
        ["Asherman's Syndrome", "Thin/absent endometrium; irregular echogenic areas (synechiae); poor endometrial stripe",
         "History of D&C / uterine surgery; amenorrhoea"],
        ["Submucosal Fibroid", "Hypoechoic mass distorting endometrial cavity; seen on TVS",
         "AUB; FIGO type 0, 1, 2 classification on SIS"],
    ]
    ep_t = make_table(
        ["Condition", "USG Appearance", "Clinical Notes"],
        ep_data,
        col_widths=[3.8*cm, 7*cm, 6.7*cm]
    )
    story.append(ep_t)

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 9 – QUICK REFERENCE TABLES
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("QUICK REFERENCE TABLES — At-a-Glance Clinical Summary"))
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("Normal Biometry Reference Table (Selected Gestational Ages)"))
    story.append(Spacer(1, 0.15*cm))

    norm_data = [
        ["12", "2.0", "7.5", "6.5", "0.9", "~80"],
        ["16", "3.2", "12.0", "11.2", "2.3", "~200"],
        ["18", "4.4", "16.0", "14.5", "3.0", "~300"],
        ["20", "4.8", "17.5", "15.5", "3.3", "~330"],
        ["24", "6.0", "22.0", "20.0", "4.4", "~600"],
        ["28", "7.0", "26.0", "24.5", "5.3", "~1,000"],
        ["32", "8.2", "30.0", "28.0", "6.2", "~1,800"],
        ["36", "9.0", "33.0", "32.0", "6.9", "~2,600"],
        ["40", "9.5", "35.0", "35.0", "7.5", "~3,400"],
    ]
    norm_t = make_table(
        ["GA (weeks)", "BPD (cm)", "HC (cm)", "AC (cm)", "FL (cm)", "EFW (g approx.)"],
        norm_data,
        col_widths=[2.5*cm, 2.5*cm, 2.5*cm, 2.5*cm, 2.5*cm, 5*cm]
    )
    story.append(norm_t)
    story.append(Paragraph("*Values are approximate means. Always plot on growth charts and compare with prior measurements. (ISUOG 2019 Guidelines)", S_SMALL))
    story.append(Spacer(1, 0.3*cm))

    story.append(SubSectionHeader("Obstetric USG — Trimester Checklist Summary"))
    story.append(Spacer(1, 0.15*cm))
    check_data = [
        ["1st Trimester\n(4–13 weeks)",
         "• Confirm IUP (GS in uterus)\n• MSD → CRL for dating\n• Yolk sac present?\n• Fetal pole visible?\n• Cardiac activity (if CRL ≥ 7 mm)\n• Number of embryos\n• NT at 11–13+6 wks\n• Adnexa / free fluid",
         "• CRL for GA (±3 days)\n• HR: 110–170 bpm\n• NT < 3.0 mm (11–13+6 wks)\n• No free fluid in pelvis"],
        ["2nd Trimester\n(18–22 weeks)\nAnatomy Scan",
         "• Fetal number & lie\n• Head: BPD, HC, CSP, falx, ventricles, cerebellum, CM, NT fold\n• Face: orbits, nasal bone, lips, palate\n• Thorax: 4-chamber heart, LVOT, RVOT, lung parenchyma\n• Abdomen: stomach, bowel, kidneys, bladder, cord insertion, AC\n• Spine: longitudinal + transverse views\n• Limbs: all long bones, hands, feet\n• Placenta: location, appearance, cord insertion\n• AFI or MVP\n• Cervical length if indicated",
         "• BPD, HC, AC, FL within normal range\n• AFI 8–24 cm (MVP 2–8 cm)\n• 4-chamber heart: equal-sized chambers\n• Both kidneys visible\n• Intact upper lip\n• Cervix > 25 mm"],
        ["3rd Trimester\n(28–40 weeks)",
         "• Fetal presentation & lie\n• Estimated fetal weight (EFW)\n• Amniotic fluid (AFI/MVP)\n• Placenta grade & position\n• Umbilical artery Doppler\n• BPP if indicated",
         "• EFW: 10th–90th centile for GA\n• AFI ≥ 5 cm, MVP ≥ 2 cm\n• Umbilical artery: forward end-diastolic flow\n• Placenta: not covering os (if low-lying at 20 wks, recheck)"],
    ]
    check_t = Table(
        [[Paragraph(f'<b>{r[0]}</b>', S_BODY), Paragraph(r[1].replace('\n','<br/>'), S_SMALL), Paragraph(r[2].replace('\n','<br/>'), S_SMALL)]
         for r in check_data],
        colWidths=[3.5*cm, 8*cm, 6*cm]
    )
    check_t.setStyle(TableStyle([
        ('BACKGROUND',   (0,0), (0,-1),  C_NAVY),
        ('TEXTCOLOR',    (0,0), (0,-1),  C_WHITE),
        ('BACKGROUND',   (1,0), (1,-1),  C_LGREY),
        ('BACKGROUND',   (2,0), (2,-1),  colors.HexColor("#E8F5E9")),
        ('GRID',         (0,0), (-1,-1), 0.3, colors.HexColor("#BBBBBB")),
        ('VALIGN',       (0,0), (-1,-1), 'TOP'),
        ('LEFTPADDING',  (0,0), (-1,-1), 6),
        ('TOPPADDING',   (0,0), (-1,-1), 5),
        ('BOTTOMPADDING',(0,0), (-1,-1), 5),
    ]))
    story.append(check_t)

    story.append(Spacer(1, 0.3*cm))
    story.append(SubSectionHeader("Amniotic Fluid & Doppler Quick Reference"))
    story.append(Spacer(1, 0.15*cm))
    af2_data = [
        ["Oligohydramnios",  "AFI < 5 cm  OR  MVP < 2 cm", "Renal agenesis/dysplasia, IUGR, PPROM, post-dates, maternal dehydration"],
        ["Polyhydramnios",   "AFI > 24 cm  OR  MVP > 8 cm", "GDM, fetal anomaly (oesophageal atresia, anencephaly, NTD), twin-twin transfusion"],
        ["Normal UA Doppler","S/D ratio < 3 after 30 wks; forward diastolic flow", "Normal fetoplacental circulation"],
        ["Abnormal UA Doppler","Absent / reversed end-diastolic flow", "Severe IUGR; fetal compromise; consider delivery"],
        ["MCA Doppler",      "PSV > 1.5 MoM = elevated", "Fetal anaemia (alloimmunisation, parvovirus)"],
    ]
    af2_t = make_table(["Parameter", "Definition/Cutoff", "Causes / Significance"], af2_data,
                       col_widths=[4*cm, 5.5*cm, 8*cm])
    story.append(af2_t)

    story.append(PageBreak())

    # ═══════════════════════════════════════════════════════
    # PAGE 10 – PATHOLOGY QUICK DIFFERENTIALS & REFERENCES
    # ═══════════════════════════════════════════════════════
    story.append(SectionHeader("DIFFERENTIAL DIAGNOSIS GUIDE — USG Findings in Gynecology & Obstetrics"))
    story.append(Spacer(1, 0.25*cm))

    story.append(SubSectionHeader("Empty Uterus on TVS + Positive Pregnancy Test"))
    story.append(Spacer(1, 0.1*cm))
    eu_data = [
        ["Ectopic pregnancy", "hCG > discriminatory zone; adnexal ring or mass; free fluid (haemoperitoneum)", "URGENT referral; serial hCG if indeterminate"],
        ["Very early IUP", "hCG < 1,000 mIU/mL; too small to see on TVS", "Repeat TVS in 48 hrs; serial hCG"],
        ["Complete abortion", "hCG falling; no products of conception in uterus; history of heavy bleeding", "Confirm with falling hCG"],
        ["Intrauterine blood / pseudoGS", "Central fluid pocket; no yolk sac; no double decidual sign", "Serial TVS; do not assume IUP"],
    ]
    eu_t = make_table(["Diagnosis", "USG / Lab Features", "Action"],
                      eu_data, col_widths=[4*cm, 7*cm, 6.5*cm])
    story.append(eu_t)
    story.append(Spacer(1, 0.25*cm))

    story.append(SubSectionHeader("Adnexal / Pelvic Mass on USG"))
    story.append(Spacer(1, 0.1*cm))
    am_data = [
        ["Physiological follicular cyst", "Anechoic, < 3 cm, thin wall, no Doppler flow", "Reproductive age; reassure; rescan in 6 wks"],
        ["Corpus luteum cyst", "Thick wall; 'ring of fire' Doppler; may have internal echoes", "Luteal phase; resolves by next cycle"],
        ["Haemorrhagic cyst", "Fish-net / reticular internal pattern; no Doppler flow internally", "Acute pain possible; conservative management"],
        ["Endometrioma", "Ground-glass echoes; thick wall; bilateral ±", "Endometriosis; CA-125 often elevated"],
        ["Dermoid (teratoma)", "'Tip of iceberg'; fat-fluid level; Rokitansky nodule; calcification", "Young women; bilateral 10–15%"],
        ["TOA (Tubo-ovarian abscess)", "Complex thick-walled mass + free fluid; no discrete ovary/tube seen; Doppler hypervascularity", "PID history; fever; IV antibiotics"],
        ["Ectopic pregnancy", "Adnexal ring separate from ovary; no IUP; + hCG", "Urgent management"],
        ["Ovarian malignancy (concern)", "Multi-locular; solid components; papillary projections; bilateral; ascites; > 10 cm", "RMI calculation; gynae-oncology referral"],
    ]
    am_t = make_table(
        ["Diagnosis", "USG Appearance", "Management Clue"],
        am_data,
        col_widths=[4*cm, 7.5*cm, 6*cm]
    )
    story.append(am_t)
    story.append(Spacer(1, 0.25*cm))

    story.append(SubSectionHeader("Postmenopausal Bleeding — Endometrial USG Findings"))
    story.append(Spacer(1, 0.1*cm))
    pmb_data = [
        ["< 4 mm", "Atrophic endometrium", "Low risk of malignancy; no biopsy unless recurrent bleeding"],
        ["4–10 mm", "Thickened; may be hyperplasia or polyp", "Biopsy / hysteroscopy recommended"],
        ["> 10 mm", "Significant thickening; irregular; heterogeneous", "High suspicion for carcinoma; urgent hysteroscopy + biopsy"],
        ["Focal thickening", "Polyp vs cancer vs fibroid", "SIS or hysteroscopy for direct visualisation"],
    ]
    pmb_t = make_table(
        ["ET on TVS", "Interpretation", "Clinical Action"],
        pmb_data,
        col_widths=[2.5*cm, 6*cm, 9*cm]
    )
    story.append(pmb_t)
    story.append(Spacer(1, 0.3*cm))

    # ── References ──
    story.append(SectionHeader("REFERENCES & EVIDENCE BASE", bg=C_TEAL))
    story.append(Spacer(1, 0.2*cm))
    refs = [
        ("<b>Creasy RK, Resnik R, et al.</b> <i>Creasy &amp; Resnik's Maternal-Fetal Medicine: Principles and Practice, 8th Ed.</i> "
         "Elsevier, 2022. — Chapter 16: The Midtrimester Obstetric Ultrasound Examination. Figs 16.1–16.38."),
        ("<b>Berek JS, et al.</b> <i>Berek &amp; Novak's Gynecology, 16th Ed.</i> Lippincott Williams &amp; Wilkins, 2020. "
         "— Chapter 9: Ectopic Pregnancy; Chapter 19: Gynecologic Ultrasound."),
        ("<b>Grainger RG, Allison DJ, et al.</b> <i>Grainger &amp; Allison's Diagnostic Radiology: A Textbook of Medical Imaging, 6th Ed.</i> "
         "Elsevier, 2015. — Chapter 7: Gynaecological Ultrasound."),
        ("<b>Dutta DC.</b> <i>D.C. Dutta's Textbook of Obstetrics, 9th Ed.</i> Jaypee Brothers Medical Publishers, 2018. "
         "— Chapter 16: Ultrasonography in Obstetrics."),
        ("<b>Cunningham FG, et al. (Williams).</b> <i>Williams Obstetrics, 26th Ed.</i> McGraw-Hill, 2022. "
         "— Chapter 10: Prenatal Care; Chapter 17: Ultrasound Imaging."),
        ("<b>ISUOG Clinical Standards Committee.</b> Practice guidelines for ultrasound assessment of fetal biometry and growth. "
         "<i>Ultrasound Obstet Gynecol.</i> 2019;53:715–723."),
        ("<b>ACOG Practice Bulletin #175.</b> Ultrasound in Pregnancy. Obstet Gynecol. 2016."),
    ]
    for i, ref in enumerate(refs, 1):
        story.append(Paragraph(f"{i}. {ref}", S_SMALL))
        story.append(Spacer(1, 0.1*cm))

    story.append(Spacer(1, 0.3*cm))
    story.append(HRFlowable(width="100%", thickness=1, color=C_TEAL))
    story.append(Spacer(1, 0.15*cm))
    story.append(Paragraph(
        "<i>This reference guide is intended for educational purposes for medical students, residents, and clinicians. "
        "It does not replace clinical judgment, institutional protocols, or current published guidelines. "
        "Always interpret USG findings in the context of complete clinical history and examination.</i>",
        style("disclaimer", fontName="Helvetica-Oblique", fontSize=7.5, textColor=colors.HexColor("#888888"),
              leading=11, alignment=TA_CENTER)
    ))

    # ── Build ──────────────────────────────────────────────
    def first_page(c, d):
        cover_page_template(c, d)

    def later_pages(c, d):
        page_template(c, d)

    doc.build(story, onFirstPage=first_page, onLaterPages=later_pages)
    print(f"PDF created: {OUTPUT}")
    import os as _os
    sz = _os.path.getsize(OUTPUT)
    print(f"File size: {sz/1024:.1f} KB")

if __name__ == "__main__":
    build()

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/usg-guide/build_usg_guide.py'

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/usg-guide/build_usg_guide.py'