Serial ultrasonographic evaluation of neonatal vein of Galen malformations to assess the efficacy of interventional neuroradiological procedures. Two-dimensional echocardiography complemented with color-flow imaging and pulsed Doppler ultrasound was used to evaluate one fetus and five neonates with a vein of Galen malformation who had severe high-output congestive heart failure and cranial bruits at birth. Intracranial blood flow through the vein of Galen malformations, cardiac status, and direction of aortic blood flow were assessed before and after staged interventional neuroradiological treatment with transarterial and transvenous embolization procedures. Color-flow imaging in each infant displayed the major vascular anatomy including feeding vessels and the patterns of filling of the vein of Galen malformations. Pulsed Doppler ultrasound performed on the descending aorta above the diaphragm showed the degree of diastolic flow reversal indicative of runoff into the vein of Galen malformations. A reduction in blood flow through the vein of Galen malformation was seen on color-flow imaging in four patients treated successfully by embolic procedures. The ratio of diastolic retrograde flow velocity in the descending aorta to systolic antegrade velocity decreased from 0.51 +/- 0.15 (mean +/- standard deviation) to 0.15 +/- 0.20 (P less than 0.05). Color-flow imaging and pulsed Doppler ultrasonography provided anatomical and pathophysiological information regarding cardiac hemodynamics and intracranial blood flow; with the patient's clinical status, these methods provided a reliable, noninvasive means to evaluate the effectiveness of therapy and the need for further treatment in neonates with vein of Galen malformations. 