CT Venography for Deep Venous Thrombosis: Continuous Images Versus Reformatted Discontinuous Images Using PIOPED II Data

OBJECTIVE. This study was designed to determine whether discontinuous CT of the lower extremities for the detection of deep venous thrombosis (DVT) yields results similar to those of complete helical imaging using cases from the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II).MATERIALS AND METHODS. In PIOPED II, CT venography followed CT angiography (CTA) to detect pulmonary embolus, using 7.5-mm continuous helical imaging from the iliac crest to the tibial plateau. DVT was detected in 105 of 737 patients (14.2%). We randomly chose 54 positive cases and 96 negative cases for our study. The continuous helical images were reformatted as 7.5-mm images and two of every three images were deleted. These images (7.5 mm; skip = 15 mm) were then sent—without identifying information—to the original reviewers. From 1 to 3.5 years had elapsed since the original interpretations. The results of the new interpretations were compared with the original CT venography consensus interpretations of PI...