Dilated Ureter 2 (UTI/VUR)

Bilateral retrograde pyelography in a 1-month-old infant. The terminal ureter has an abnormal configuration which looks like a snake's head. In addition, a pelvicocaliceal dilatation is present which is more distinct on the left side. The diagnosis is bilateral obstructive megaureter. The contrast excretion lags behind on the left side, and the upper urinary tract is still dilated. In addition to the shape of the terminal ureter, the degree (strong peristalsis), type (retroperistalsis), and effect of peristalsis (residual contrast) is useful in the differential diagnosis 'obstructive' versus 'non-obstructive megaureter'.