Diagnostic modalities used to image the male pelvis

Plain radiography and contrast studies (Fig. 13.1)

• Plain radiography is generally not useful to examine the soft tissues of the male pelvis.

• Intravenous urography can normally delineate the ureters and bladder.

• Cystourethrography is used to image the male urethra.

Cross-sectional imaging

• Soft tissues of the pelvis can be demonstrated using ultrasound, CT and MRI.

• Ultrasound and MRI have the advantage of not using ionizing radiation.

Ultrasound

• First-line modality for assessment of the male genitourinary tract.

• Transabdominal ultrasound is used to examine the bladder, typically using a low-frequency curvilinear probe, and requires a full bladder to act as an acoustic window.

• Transrectal ultrasound is used to evaluate the prostate gland, especially to direct prostate biopsy.

• High-frequency linear probes are used to visualize the testes, penis and, less frequently, the urethra.

CT

• CT is generally not a first-line imaging test for evaluating male pelvic disorders, as radiation exposure to radiosensitive tissues (especially the testes) should be avoided. However, CT remains the best imaging study for the assessment of pelvic anatomy and pathology in the trauma setting.

• CT has lower contrast resolution than MRI, thus has a relatively limited role in the evaluation of soft tissue structures such as the prostate and penis.