Doppler sonographic indices in diagnosing the nutcracker phenomenon in a hematuric adolescent.

Compression of the left renal vein between the aorta and the superior mesenteric artery, known as the nutcracker phenomenon, may cause gross or microscopic hematuria, pain in the flank, proteinuria, or a combination of these symptoms. We report the case of a hematuric adolescent diagnosed with a high index of suspicion by noninvasive Doppler sonography using the diagnostic indices of Doppler sonography established for adults with hematuria. Compression of the patient's left renal vein at the aortomesenteric portion and dilatation at the hilar portion were visualized by magnetic resonance angiography, which verified the diagnosis.