抄録
Detection of thrombi by scintiphotography and measurement of platelet survival with 111In-oxide labeled autologous platelets were carried out in patients with thrombosis. Platelets were separated using differential centrifugation from 44ml of venous blood obtained in 6ml ACD solution from a subject. They were suspended in 3ml ACD-saline solution (pH 6.5). Three hundred μCi of 111In-oxide were added to the platelet suspension, and then the mixture was incubated for 20 minutes at room temperature. One hundred and fifty μCi of labeled platelets resuspended in autologous plasma were injected to the patient. Imaging by scintillation camera on the body and detection of platelet radioactivity in the blood were done following the course of time.
A normal subject (case 1) and four patients suspected of thrombi (cases 2-5) were studied. Cases 2 and 3 had been implanted Dacron-graft 6 and 4 years before respectively, because of abdominal aortic aneurysm. Case 4 who had old myocardial infarction with left ventricular aneurysm and case 5 who suffered from mitral stenosis have been suspected of intracardiac thrombi by two dimensional echocardiography. In normal case, radioactivity on the spleen and liver and also cardiac blood pool was observed at 1 hour after the injection of 111In-labeled platelets. At 5 days after, the radioactivity on the cardiac blood pool was decreased, whereas that of the liver and the spleen were increased. Unusual platelet depositions on the Dacron-graft were observed in case 2 and 3. The accumulation of labeled platelets to thrombus at the left ventricular aneurysm in case 4 and to left atrial thrombus in case 5 was cleary detected as the camera images. Mean platelet survival time was normal in case 1 (8.6 days), shortened in case 2 (3.4 days) and case 3 (3.7 days), and slightly shortened in case 4 (6.9 days) and case 5 (5.6 days).
Imaging of thrombi and measurement of platelet survival using 111In-oxine labeled platelets are considered to be an excellent method for the diagnosis and decision of treatment on various disorders with thrombi.
