Application of magnetization transfer at 3.0 T in three‐dimensional time‐of‐flight magnetic resonance angiography of the intracranial arteries

Abstract

Purpose To apply magnetization transfer (MT) at 3.0 T in three-dimensional time-of-flight magnetic resonance angiography of the intracranial arteries. Materials and Methods This study was performed on phantoms and seven volunteers to determine the effects of MT at 3.0 T. By using a modulated MT approach and an altered phase encode order, the specific absorption rate (SAR) was kept below 3 W/kg over any 8-second time period. Results For a 20-degree flip angle and 36 msec repetition time, the background suppression at 3.0 T was improved with MT by 52 ± 5% for white matter and 40 ± 8% for grey matter, making the distal intracranial vasculature significantly more discernible. Conclusions MT at 3.0 T can significantly improve background suppression in 3D time-of-flight magnetic resonance angiography (MRA) of the intracranial arteries without exceeding SAR guidelines. J. Magn. Reson. Imaging 2002;15:479–483.