Differential diagnosis of intra- and perivesical abnormalities using bladder air/CO2 contrast sonography.

Sonographic air/CO2 contrast studies of the urinary bladder allow identification of abnormal peri- and intravesical low-echogenic structures and can differentiate between those that communicate with the bladder (refluxing ureters, bladder diverticula, patent urachus) from others that do not communicate (cysts of ovarian/enteric origin, urachus cyst). Ureteroceles with a refluxing/obstructed ureter can be more clearly delineated using gas contrast than with plain ultrasound. In a group of 217 children examined by bladder contrast sonography, 19 showed pathological peri- and intravesical findings, 17 of which were definitely evaluated by bladder contrast sonography. On the other hand, only 10 abnormalities of these 19 could be detected, and in not more than 8 was the final diagnosis made by plain sonography alone.