The clinical application of forearm and hand blood flow measurements using a gamma camera.

A new method of measuring blood flow to forearms and hands during reactive hyperemia is described. Subjects are positioned with forearms and hands over a gamma camera, and the circulation below the elbows is isolated for 4 minutes with pneumatic cuffs. The remaining blood pool is labeled with technetium-99m-labeled human serum albumin given via a vein in the dorsum of the foot. The rate of rise of activity in the arms after cuff release is measured from the gradient of time activity curves, and these are calibrated for flow by counting a sample of venous blood. Blood flow per unit volume is obtained from measurements of the limb volume, done by water displacement. Results for eight normal control subjects showed a mean flow per unit volume to forearm plus hand of 32.9 +/- 6.4 ml/100 ml/min and to hand alone 36.5 +/- 6.9 ml/100 ml/min. Case studies of patients with a variety of large- and small-vessel diseases are presented, illustrating the use of the technique to aid diagnosis and measure response to treatment.