Technetium-99m-RBC venography in the diagnosis of deep venous thrombosis of the lower extremity: a systematic review of the literature.

We systematically reviewed the six articles from the English-language medical literature, since 1979, which compared 99mTc-RBC venography with contrast venography for the diagnosis of deep venous thrombosis (DVT) of the lower extremity. The studies were generally small in size and poorly compliant with methodologic standards for diagnostic test research. There was considerable variation in both how the 99mTc-RBC venograms were performed and how they were interpreted. Sufficient clinical information on the patients was not provided. Although the overall sensitivities and specificities were high with a mean sensitivity of 0.89 and a mean specificity of 0.84, the small numbers of patients resulted in wide 95% confidence intervals. For distal disease, with only a total of 14 patients studied, the 95% confidence intervals were particularly broad. Although 99mTc-RBC venography is a promising technique, future studies with larger numbers of patients and closer adherence to methodologic standards are required.