Genitourinary, Obstetric and Breast Imaging

Urinary tract

• Renal colic: NCCT KUB (adults); US (pregnancy, children). Positive contrast hides stones.
• Calcium oxalate commonest; struvite = staghorn (Proteus); uric acid = X‑ray lucent, CT visible (DECT, dissolvable); cystine = ground glass; indinavir = CT invisible.
• Rim sign = ureteric stone; comet tail = phlebolith. Impaction: PUJ, pelvic brim, VUJ. Steinstrasse after ESWL.
• Obstructed infected kidney = emergency drainage. Medullary nephrocalcinosis: MSK, RTA type 1, HPT; cortical: cortical necrosis.
• Pyelonephritis: striated nephrogram. Emphysematous pyelonephritis: parenchymal gas, diabetics. XGP: staghorn + bear paw. Renal TB: moth‑eaten calyx, phantom calyx, Kerr kink, thimble bladder, putty kidney, beaded ureter.
• Bosniak 2019: I/II benign; IIF follow; III ~50%; IV enhancing nodule (surgery). AML = macroscopic fat (TS; bleed > 4 cm). RCC: enhancing, renal vein/IVC thrombus, VHL. Oncocytoma: central scar, spoke‑wheel. TCC: filling defect, goblet sign, stipple sign; CT urography. Wilms': claw sign, displaces vessels; neuroblastoma: calcified, encases vessels.
• Horseshoe: isthmus below IMA, anterior to aorta; PUJ obstruction, stones, Wilms'. Weigert–Meyer: upper moiety obstructs (inferomedial, ureterocele, ectopic, dribbling girl); lower moiety refluxes. Drooping lily. Cobra head = ureterocele. Reverse J = retrocaval ureter.
• CT urography for haematuria; MCU for VUR/PUV; RGU for anterior urethra (strictures, injury; before catheter if blood at meatus). VUR grades I–V (V: papillary impressions lost). PUV: dilated posterior urethra + shelf; antenatal keyhole.
• Bladder TCC: CTU + cystoscopy; VI‑RADS. Schistosomiasis: wall calcification, SCC. Christmas‑tree bladder = neurogenic. BPH: J‑shaped ureters.
• Prostate cancer: peripheral zone, mpMRI PI‑RADS v2.1 (DWI dominant PZ, T2 dominant TZ), sclerotic mets, PSMA PET.
• Scrotum: torsion = absent flow, whirlpool, operate first; epididymo‑orchitis = increased flow; intratesticular solid = malignant (seminoma); nodes drain to renal hilum; new right varicocele → retroperitoneal mass.

Obstetrics, gynaecology and breast

• TVS: sac ~5 wk, heartbeat ~6 wk; discriminatory β‑hCG ~1500–3500. CRL dates best. Failed pregnancy: CRL ≥ 7 mm no heartbeat or MSD ≥ 25 mm no embryo. Chorionicity: λ sign (DCDA) vs T sign (MC).
• NT 11–13⁺⁶ weeks (≥ 3.5 mm abnormal). Anomaly scan 18–22 weeks. Lemon + banana = spina bifida. Anencephaly earliest major anomaly. Gastroschisis (right, no membrane) vs omphalocele (midline, membrane, aneuploidy).
• Polyhydramnios: atresias, diabetes, anencephaly. Oligohydramnios: renal agenesis, PUV, ROM, FGR. Absent/reversed EDF = severe placental insufficiency. MCA PSV = fetal anaemia. Praevia: TVS. Accreta: previous caesarean, lacunae, lost clear zone.
• PC‑PNDT Act 1994/2003: sex determination/disclosure prohibited; register every machine; Form F for every pregnant woman; records 2 years; display board; imprisonment and deregistration.
• Haemorrhagic cyst = lace‑like; endometrioma = ground glass (T1 bright, T2 shading); dermoid = tip of the iceberg, dot‑dash, fat; malignant = solid with flow (O‑RADS); PCOS ≥ 20 follicles; torsion = enlarged ovary, peripheral follicles, whirlpool (flow may persist).
• Ectopic assessment: an empty uterus is non-diagnostic; look for adnexal ring (ring of fire), haemoperitoneum; pseudosac vs double decidual sign. Complete mole: snowstorm, no fetus, theca‑lutein cysts, very high β‑hCG.
• Fibroid T2 dark; adenomyosis JZ ≥ 12 mm, venetian blind; PMB endometrium > 4 mm → biopsy; cervical cancer staging MRI; HSG beaded tubes = TB.
• Breast: < 30 → US; ≥ 40 → mammography (CC + MLO); high risk → MRI. Spiculated mass most specific; fine linear branching calcification = DCIS; popcorn = fibroadenoma; taller‑than‑wide + shadowing = malignant. BI‑RADS 2025: 0 incomplete, 1 negative, 2 benign, 3 ≤ 2% (6‑month), 4 biopsy (A/B/C), 5 ≥ 95%, 6 proven.