Whole-brain intracranial vessel wall imaging at 3 Tesla using cerebrospinal fluid–attenuated T1-weighted 3D turbo spin echo
Although three-dimensional (3D) turbo spin echo (TSE) with variable flip angles has proven to be useful for intracranial vessel wall imaging, it is associated with inadequate suppression of cerebrospinal fluid (CSF) signals and limited spatial coverage at 3 Tesla (T). This work aimed to modify the sequence and develop a protocol to achieve whole-brain, CSF-attenuated T1-weighted vessel wall imaging.
Nonselective excitation and a flip-down radiofrequency pulse module were incorporated into a commercial 3D TSE sequence. A protocol based on the sequence was designed to achieve T1-weighted vessel wall imaging with whole-brain spatial coverage, enhanced CSF-signal suppression, and isotropic 0.5-mm resolution. Human volunteer and pilot patient studies were performed to qualitatively and quantitatively demonstrate the advantages of the sequence.
Compared with the original sequence, the modified sequence significantly improved the T1-weighted image contrast score (2.07 ± 0.19 versus 3.00 ± 0.00, P = 0.011), vessel wall-to-CSF contrast ratio (0.14 ± 0.16 versus 0.52 ± 0.30, P = 0.007) and contrast-to-noise ratio (1.69 ± 2.18 versus 4.26 ± 2.30, P = 0.022). Significant improvement in vessel wall outer boundary sharpness was observed in several major arterial segments.
The new 3D TSE sequence allows for high-quality T1-weighted intracranial vessel wall imaging at 3 T. It may potentially aid in depicting small arteries and revealing T1-mediated high-signal wall abnormalities. Magn Reson Med, 2016. © 2016 Wiley Periodicals, Inc.