Diagnostic imaging of lower urinary tract disease.

Diagnostic imaging is routinely performed in small animals with lower urinary tract disease. Survey radiographs allow identification of radiopaque calculi, gas within the urinary tract, and lymph node or bone metastases. Cystography and urethrography remain useful in the evaluation of bladder or urethral rupture, abnormal communication with other organs, and lesions of the pelvic or penile urethra. Ultrasonography is the modality of choice for the diagnosis of most disorders. Computed tomography and magnetic resonance imaging are useful in evaluating the ureterovesical junction and intrapelvic lesions, monitoring the size of lesions, and evaluating lymph nodes and osseous structures for metastases.