Intracranial MR angiography: Application of magnetisation transfer contrast

Abstract

The purpose of the present study was to evaluate the effect of magnetisation transfer contrast (MTC) on three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA). All images were acquired with a 1.5-T system using a quadrature head coil. In 23 subjects, single volume 3D TOF MRA was performed with and without MTC preparation pulses using binomial on-resonance pulses. In 4 normal volunteers, influences of TR or flip angle were studied. By MTC pulses, signal intensity of white and grey matter was reduced by 43% and 35%, respectively. Signal intensity of basilar artery and superior sagittal sinuses decreased about 15% and 32%, respectively. Contrast between brain tissues and basilar or middle cerebral artery was improved by using MTC pulses, and the conspicuity of small vessels was improved with MTC. Reduction of signal intensity of brain tissue by MTC was slightly larger with shorter TRs and lower flip angles. However, the influences of TR and flip angles on vascular contrast remain to be evaluated. Use of MTC pulses can substantially enhance the quality of 3D TOF MRA of the brain.