Arteriovenous malformations of the kidneys: diagnosis and follow-up with color Doppler sonography in six patients.

We performed color Doppler sonography in six patients with arteriovenous malformations of the kidneys. The diagnosis was established by angiography in all patients. Color Doppler sonograms were obtained at a large Doppler frequency-shift range (55 cm/sec of maximal average flow velocity at zero Doppler angle) to depict high-velocity blood flow in the malformation. In all patients, the malformations were seen as focal areas of flow, portrayed as a mixing of lighter colors. These were reflected by a rapid flow rate and marked tortuosity of the vessels. The sonograms showed a small peripheral malformation that was indistinct on selective renal angiography. However, flow in normal vessels grouped in the hilum obscured lighter-color flow of a small central malformation. In three patients who had total or partial ablation of the malformations with alcohol, follow-up color Doppler sonograms showed that the focal areas of flow, represented as mixing of lighter colors, disappeared or became smaller. This study shows that color Doppler sonography is a useful noninvasive procedure for diagnosing arteriovenous malformations of the kidney.