Doppler waveform parvus and tardus. A sign of proximal flow obstruction.

The Doppler linear flow velocity versus time spectrum obtained in an arterial flow system in which there is proximal occlusive disease with or without collateral formation has a tardus-parvus waveform. The conditions that cause this Doppler sign are due to a poststenotic pressure drop.

Doppler diagnosis of partial vertebral/subclavian steals convertible to full steals with physiologic maneuvers.

Subclavian steal syndrome has been classically described as a unidirectional phenomenon in which retrograde flow occurs in the ipsilateral vertebral artery in cases of high-grade proximal subclavian stenosis. Pulsed Doppler examination in cases of subclavian stenosis shows that partial steals with to-and-fro flow do occur. A model based on fluctuating pressure gradients to explain the partial steal phenomenon is discussed. The usefulness of physiologic maneuvers such as ipsilateral arm exercise and postocclusive hyperemia in converting partial steals to full steals is demonstrated. In cases in which surgical bypass to correct partial steals is carried out, a relative steal can be demonstrated by Doppler examination before and after physiologic maneuvers.

Sonography of autonomous follicular ovarian cysts in precocious pseudopuberty.

Isolated follicular cysts of the ovary without elevated gonadotropin levels can occur as the primary source of early pubertal changes in young girls. To date, cyst excision or oophorectomy have been the treatments of choice. We studied three girls aged 5 to 8 7/12 years who presented with sexual precocity and revealed autonomous functioning ovarian cysts (2.2 to 5.5 cm). Clinical signs subsided following resection of the cyst in one case and after regression of the cyst documented by ultrasonography in the other two cases. On the basis of these three cases, we believe ultrasonography can be valuable in the workup of sexual precocity caused by primary ovarian cysts. Given that the spontaneous resolution of such cysts is possible, close clinical follow-up of unequivocally benign-appearing large ovarian cysts in young girls with pubertal changes deserves consideration.

Doppler sonographic demonstration of the progressive spontaneous thrombosis of pseudoaneurysms.

In three patients with diagnosed pseudoaneurysms, surgical intervention was delayed because of the patients' clinical condition. In successive follow-up examinations in one patient, development of a new lobe to the previously single-lobed pseudoaneurysm was noted with progressive centripetal thrombus formation in each lobe leading to the eventual complete thrombosis of the pseudoaneurysm without surgical intervention. The sequence of steps leading to the complete thrombosis of the pseudoaneurysm as seen by color Doppler and pulsed Doppler examination is described. In two other patients with a single-lobed and a multilobed pseudoaneurysm, respectively, follow-up examinations without surgical management revealed complete thrombosis of the pseudoaneurysms. Whereas traditional teaching holds that pseudoaneurysms require surgical repair, this short series of cases suggests that, when progressive centripetal thrombus formation is observed, the pseudoaneurysms can go on to complete thrombosis. Follow-up for up to 4 months reveals no sonographic evidence of rebleeding or other evidence of weakness in the arterial wall at the site of the previous pseudoaneurysms.

Popliteal vein compression due to popliteal artery aneurysm: effects of aneurysm size.

Unlike the venous compression associated with larger popliteal artery aneurysms, which frequently is associated with deep vein thrombosis, the venous compression caused by the moderate sized (greater than 2 cm and less than 3 cm) aneurysms in the reported cases is not associated with thrombosis. The extrinsic compressive effect of these moderate sized popliteal artery aneurysms on the adjacent vein is shown to vary with the patient's leg position. Three of the four patients with unilateral leg swelling discussed here had bilateral popliteal artery aneurysms. In these cases, the contralateral leg had a small popliteal aneurysm (less than 2 cm) and no leg swelling was present. The cases suggest that popliteal artery aneurysm size is an important factor in determining the type of venous obstruction that results from the extrinsic compression of the ipsilateral popliteal vein. The described phenomenon of a popliteal artery aneurysm having the effect of restricting flow in the ipsilateral popliteal vein must be included as a differential diagnosis among the causes of unilateral leg swelling in the absence of deep vein thrombosis.