Imaging description

A newborn baby boy presented with a broad flabby-appearing abdomen and apparent absence of the musculature of the abdomen. A radiograph of the chest and abdomen confirmed marked bulging of the bilateral flanks, flaring of the lower ribs, and flared iliac wings (Fig. 58.1). An ultrasound examination showed marked hydronephrosis and very dilated, tortuous ureters. The findings are characteristic for prune belly syndrome.

On ultrasound, the renal parenchyma is often dysplastic and hyperechoic, with small subcapsular cortical cysts. The calices are dilated and dysplastic. The ureters are markedly distended and tortuous. The bladder appears markedly dilated and trabeculated, with possible urachal remnants. The posterior urethra may appear dilated, with a prominent prostatic utricle (associated with hypoplastic or absent prostate). In addition, there is nearly always accompanying cryptorchidism (undescended testes).

Radiographs of the chest and abdomen typically demonstrate markedly bulging flanks, flaring of the lower ribs, and hypoplastic lungs (Fig. 58.2). Possible findings on voiding cystourethrogram (VCUG) include urethral stenosis or atresia, megalourethra, dilated prostatic utricle, dilated urinary bladder with trabeculated borders, bladder diverticula, patent urachus, vesicoureteral reflux, markedly tortuous hydroureters, and hydronephrosis. In addition, calcifications in the bladder or urachus may be present due to stasis of urine. A 99mTc DMSA (dimercaptosuccinic acid) scan can help to evaluate renal function.