Visualization of venous systems by time-of-flight magnetic resonance angiography

Background and purpose: Time-of-flight (TOF) imaging technique depicts strong signal from fresh unsaturated magnetization that moves fast into the imaging region, and TOF magnetic resonance angiography (MRA) visualizes the arterial system using saturation pulse and band. However, TOF MRA can visualize the venous system when the flow direction is reversed. Methods and patients: We consecutively enrolled patients between June 2002 and February 2003 with an internal jugular vein (IJV) and sigmoid sinus (SS) visualized by TOF MRA. Carotid Duplex ultrasonography was performed on all patients to check IJV flow directions. Gadolinium (Gd)-enhanced MRA and conventional digital subtraction angiography were performed in selected patients. Results: The IJVs and SSs of eight patients (left = 7, right = 1) were observed by TOF MRA. In these 8 patients, Duplex ultrasonography confirmed a reversed direction in IJVs. Four of the patients underwent Gd-enhanced MRA, which showed proximal innominate vein steno-occlusion. Conclusions: This is the first description of IJV and SS visualization by TOF MRA. Clinical implications are discussed.