Thrombus-related uptake and vascular clearance of 131 I-fibrin des-AABB as compared to 125 I-fibrinogen in patients with established venous thrombosis.
Thrombus-related uptake of 131 I-fibrin des-AABB has been compared to that of 125 I-fibrinogen in 13 patients with established venous thrombosis. Both tracers originated from a common pool of beta-alanine precipitated fibrinogen. Scan-recordings were performed as a radiofibrin (ogen) uptake test. Uptake characteristics of des-AABB fibrin were similar to those of fibrinogen, when measured as percentage of concomitant radioactivity over the heart. Due to its longer circulation time, fibrinogen was superior to fibrin des-AABB for the detection of venous thrombi. Circulating des-AABB fibrin was cleared biphasically, with an initial rapid decline followed by a gradual exponential decrease. Mean half-lives were 5.5 +/- SD 3.5 hr and 10 +/- SD 3.5 hr, respectively. The elimination rates were uninfluenced by thrombus activity, as judged by the fibrin(ogen) uptake test. Metabolic half-life of fibrinogen in the total material was 62 +/- SD 19 hr. Dissociation of fibrinogen and soluble des-AABB fibrin clearance rates was evident, describing their own, independent elimination patterns, probably reflecting different clearing mechanisms.
D005337:Fibrin / Q000097:blood / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D007457:Iodine Radioisotopes; D008657:Metabolic Clearance Rate; D011877:Radionuclide Imaging; D013924:Thrombophlebitis / Q000097:blood / Q000000981:diagnostic imaging*
D007457:Iodine Radioisotopes; D005337:Fibrin; D005340:Fibrinogen