Isolated pelvic deep venous thrombosis: Relative frequency as detected with MR imaging

PURPOSE: To determine the relative frequency of deep venous thrombosis (DVT) isolated to the pelvic veins, as demonstrated with magnetic resonance (MR) imaging. MATERIALS AND METHODS: The reports of 769 MR examinations performed from lune 1993 through December 1999 in patients with suspected DVT were reviewed retrospectively. MR venography was performed by using a two-dimensional gradient-recalled-echo sequence (typically repetition time, 34 msec; echo time, 13 msec; flip angle, 60 degrees). The presence of DVT was categorized by location in the pelvis, thigh, or calf. RESULTS: DVT was identified in 167 (21.7%) of the 769 MR examinations. Thirty four (20.4%) of the 167 studies demonstrated DVT isolated to the pelvic veins. CONCLUSION: The relative frequency of isolated pelvic DVT detected with MR venography was higher than that reported in prior studies with ultrasonography (US) or ascending venography. MR venography should be performed in patients with suspected pelvic DVT or when clinical suspicion persists despite a negative US study.