MR angiography of the cerebral perforating arteries with magnetization prepared anatomical reference at 7 T: comparison with time-of-flight

Abstract

Purpose: To develop a magnetic resonance imaging (MRI) protocol that visualizes both the perforating arteries and the related anatomy in a single acquisition at 7 T.

Material and methods: T(1)-weighted magnetization prepared imaging (MPRAGE) was empirically modified for use as angiography method at 7 T. The resulting sequence depicts the vasculature simultaneously with the surrounding anatomical structures, and is referred to as "magnetization prepared anatomical reference MRA" (MPARE-MRA). The method was compared to time-of-flight (TOF) MRA in seven healthy subjects. The conspicuity of the perforating arteries and the contrast between gray and white matter were evaluated both quantitatively by contrast-to-noise (CNR) measurements, and qualitatively by two radiologists who scored the images.

Results: The contrast-to-noise ratio (CNR) between blood and background was 28 +/- 9 for MPARE-MRA and 35 +/- 16 for TOF-MRA, indicating good conspicuity of the vessels. CNR values were: internal capsule (IC) vs. caudate head (CH): 4.2 +/- 0.7; IC vs. putamen: 3.5 +/- 0.6; white matter vs. gray matter: 9.7 +/- 2.5.

Conclusion: The benefits of ultra-high-field MRI can transform MPRAGE into a new angiography method to image small vessels and associated parenchyma at the same time. This technique can be used to study the correlation between tissue damage and vascular pathology.