This film was taken during the voiding phase, the bladder wall appears to be irregular. Notice the bulging on the upper right portion of the image. This is an indication of detrusor muscle hypertrophy caused by bladder outlet obstruction. Just as cariac muscles thicken with an increased work load, bladder muscles hypertrophy when the urethra is obstructed. The prostatic urethra (the most proximal portion of the urethra) is dilated. Notice the thin lines by the label. These are posterior urethral valves, tissue flaps that obstruct flow or urine out of the bladder. Some children with posterior urethral valves also have reflux.
