Imaging of venous thromboemboli with labeled platelets

Prevention and optimal treatment of venous thromboembolism requires techniques that can: (1) monitor patients at high risk; (2) promptly detect thromboemboli; (3) follow the course of patients during treatment. Multiple techniques have been introduced to assist in these tasks. Some have not been well validated. Others, while established as of substantial value, have limitations with respect to specificity, sensitivity, patient access, patient acceptability, or risk. The dynamic nature of venous thromboembolism makes it unlikely that any one procedure will satisfy all diagnostic needs. Platelets labeled with 111In (111In-P) have promise as a useful addition to the existing diagnostic armamentarium. Because 111In-P are incorporated into forming and growing thromboemboli, and can provide a gamma camera image, they offer certain potential advantages versus other techniques. However, to establish the clinical value and proper use of the 111In-P technique, additional investigations are needed to determine the impact of thrombus location, age, anticoagulant therapy, and imaging technique and timing upon in vivo visualization of thromboemboli.