Pulmonary arteriovenous malformation and aortopulmonary collateral imaged by time resolved contrast enhanced magnetic resonance angiography

Objective: To evaluate clinically a new on line, automated technique to measure flow mediated dilatation (FMD) as a marker of endothelial function. Design: Prospective study. Patients: 12 healthy volunteers and 12 patients with significant, angiographically documented coronary artery disease. Interventions: Brachial arteries were imaged using a standard vascular ultrasound system with a 5-12 MHz linear transducer. Arterial diameter was measured on line (in real time) by connecting the ultrasound system to a personal computer equipped with a frame grabber and artery wall detection software (VIA) specially developed by the authors' group. By using this new technique, FMD was measured following 4.5 minutes of ischaemia of the proximal forearm in all subjects on two separate days.