The application of a new method of limb blood flow measurement using a radioactive isotope and a gamma camera.

To evaluate a new method for limb blood flow measurement using a radioactive isotope and a gamma camera, blood flow measurements have ben made on 108 patients with peripheral vascular disease. Thirty-six patients had ischaemic rest pain, of whom two had previously undergone unilateral amputation. Five had bilateral symptoms, giving 29 asymptomatic limbs and 41 limbs with critical ischaemia. In 72 patients with intermittent claudication a series of exercise tests were attempted, in 33 these were unsatisfactory; 13 patients had a greater than 20% variability in the maximum walking distance between four tests and in 20 walking distance was limited by factors other than claudication. In these 33 patients the limb blood flow to the symptomatic leg was 3.95 (1.36-11.08) ml/100 ml of tissue/minute. This is not significantly different from the limb blood flow to the symptomatic leg of the 39 patients who satisfactorily completed four exercise tests, 3.75 (1.08-8.25) ml/100 ml of tissue/minute. In these 39 patients the mean pain-free walking distance was 40 metres and the mean maximum walking distance was 63 metres. The limb blood flow to the 41 symptomatic limbs of 36 patients with rest pain was 1.90 (0.90-4.49) ml/100 ml of tissue/minute, which is significantly less than that obtained in claudicants. There was a wide range of blood flow values found in the asymptomatic limbs of all the patients and in many cases the flow was markedly reduced from normal. This method of limb blood flow measurement is accurate and reproducible and may be recommended for assessment of peripheral vascular disease.