Genitourinary and Pelvic Imaging
Genitourinary and Pelvic Imaging tests renal mass and stone assessment, prostate and gynaecological MRI reporting systems, and obstetric safety.
Renal masses
Bosniak classification applies to cystic renal masses on CT or MRI: I simple, II benign, IIF follow-up, III surgical, IV clearly malignant. Thick irregular enhancing walls or nodular enhancement upgrade the lesion. Solid enhancing masses are staged, not Bosniak-graded.
Stones and obstruction
Non-contrast CT KUB is first line for suspected ureteric colic. Look for the stone, hydronephrosis, perinephric stranding and the soft tissue rim sign. Ultrasound is preferred in pregnancy and children.
Prostate and pelvis
PI-RADS v2.1 scores lesions on a 1-5 scale, with DWI dominant in the peripheral zone and T2 in the transition zone; a score of 3 or more usually prompts targeted biopsy. O-RADS stratifies adnexal lesions on ultrasound and MRI. Ovarian torsion is a clinical diagnosis: normal Doppler flow does not exclude it.
Worked example
A 55-year-old has a 4 cm left renal cyst with smooth enhancing septa measuring 3 mm and no nodularity. This is Bosniak III because of measurable enhancement of a thick septum, so surgical excision is advised; Bosniak IIF would require follow-up rather than surgery.
Traps
Applying Bosniak to solid masses; ignoring pseudoenhancement of small cysts on CT; relying on Doppler to exclude torsion; under-staging prostate cancer when MRI is degraded by artefact; scanning pregnant patients without justification.