[Usefulness of power Doppler sonography for the assessment of subpleural lesions].

We investigated the usefulness of color Doppler power mode imaging for the assessment of subpleural lesions in 48 patients (27 with pneumonia, 4 with pulmonary abscesses, 12 with primary lung cancer, and 5 with metastatic lung cancer). We classified the patterns obtained by color flow imaging of subpleural lesions into six groups: type 0, no color flow; type I, spotty color flow; type II, linear color flow; type III, branchy color flow; and type IV, tortuous color flow, with type IV-A, for partial tortuous flow and type IV-B, for general tortuous flow. The color Doppler power mode proved better than velocity mode in terms of ability to generate clear color flow patterns. Color flow patterns obtained in power mode on the patients with pneumonia differed significantly from the patterns obtained on the lung cancer patients. Although the color flow patterns observed in power mode differed significantly for the benign and malignant groups, no statistically significant differences were observed in velocity mode. These findings illustrated the usefulness of color Doppler power mode imaging as a means of diagnosing benign and malignant subpleural lesions.

Microangiographic assessment of collateral vessel formation following direct gene transfer of vascular endothelial growth factor in rats.

OBJECTIVE: The development of collateral microvessels following therapeutic angiogenesis with vascular endothelial growth factor (VEGF) was investigated using a new system of microangiography that employs monochromatic synchrotron radiation (SR) and a high definition video system to visualize arteries with a spatial resolution of 30 microns. METHODS: Ischemia was induced in the hindlimb of 20 rats by excision of the femoral artery, followed by transfection of the plasmid (400 micrograms) encoding VEGF or beta-galactosidase (control) into limb muscles. Microangiography was used to assess the development of collaterals in the ischemic limb four weeks after treatment. RESULTS: Gene transfer of VEGF produced morphologically similar, but significantly more extensive, collateral networks at the microvascular level as compared with the naturally occurring collateral arteries in the control animals (angiographic score: 0.88 +/- 0.08 versus 0.54 +/- 0.05, p < 0.01). No adverse vascular effects such as hemangiomas and/or arteriovenous (AV) fistulae were observed following VEGF treatment. The vasodilator effect of papaverine was evident in relatively large vessels in both groups. At the microvascular level (diameter < 100 microns), however, papaverine induced significant vasodilation in the VEGF-treated animals, and almost no vasodilation in the controls. CONCLUSIONS: SR microangiography allowed us to assess the development of small collateral arteries following VEGF-gene transfer. The information obtained may provide new insights regarding the collateral microcirculation and therapeutic angiogenesis.

Physiological assessment of augmented vascularity induced by VEGF in ischemic rabbit hindlimb.

This study was designed to assess the physiological consequences of augmented vascularity induced by administration of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, in a rabbit model of hindlimb ischemia. Ten days after excision of the common and superficial femoral arteries from one hindlimb of 24 New Zealand White rabbits, VEGF (n = 15) or saline (control; n = 9) was selectively injected into the ipsilateral internal iliac artery. Limb perfusion was evaluated immediately pre-VEGF (baseline) and again at days 10 and 30. A Doppler guide wire was advanced to the internal iliac artery to record flow velocity at rest and at maximum flow velocity provoked by intra-arterial injection of papaverine. At baseline and at day 10, no differences in flow parameters were observed between the control and the VEGF-treated animals. By day 30, however, flow at rest (P < 0.05), maximum flow velocity (P < 0.001), and maximum blood flow (P < 0.001) were all significantly higher in the VEGF-treated group. These physiological findings complement previous-anatomic studies by providing evidence that a single intra-arterial bolus of VEGF augments flow, particularly maximum flow, in the rabbit ischemic hindlimb. These data thus support the notion that VEGF administration represents a potential treatment strategy for certain patients with lower extremity ischemia.

Anomalous origin of the left coronary artery from the pulmonary artery: direct assessment of anomalous and collateral coronary flow by pulsed Doppler echocardiography.

We directly assessed the anomalous and collateral coronary flow profiles of a 58 year-old-man with Bland-White-Garland syndrome using pulsed Doppler echocardiography. Doppler recordings in this patient document the utility of pulsed Doppler echocardiography in the assessment of a cardiac shunt associated with a congenital coronary anomaly in an adult.