3-T magnetic resonance angiography in primary angiitis of the central nervous system.

OBJECTIVE: Primary angiitis of the central nervous system (PACNS) is a rare disease characterized by an inflammatory process of intracranial vessels. Magnetic resonance angiography (MRA) (3 T) offers increased signal-to-noise ratio and background suppression, leading to better depiction of the intracranial vessels. The aim of our work was to compare the sensitivity of 3-T MRA to that of 1.5-T MRA in the diagnosis of PACNS. METHODS: Eight patients with PACNS and signs of angiitis at digital subtraction angiography (DSA) underwent MRA at 1.5 and 3 T. Magnetic resonance angiograms obtained with time-of-flight (TOF) technique were evaluated for the presence of stenosis with respect to DSA. RESULTS: In PACNS patients, DSA identified 827 intracranial stenoses. Sensitivity for vessel stenosis of 3-T TOF MRA was 47% and 14% for 1.5-T TOF. CONCLUSIONS: Time-of-flight MRA at 3 T improved the sensitivity of MRA in the noninvasive preliminary evaluation of patients with PACNS.