T(2)-Weighted Whole-Brain Intracranial Vessel Wall Imaging at 3 Tesla With Cerebrospinal Fluid Suppression

BACKGROUND: T(2)-weighted (T(2)w) intracranial vessel wall imaging (IVWI) provides good contrast to differentiate intracranial vasculopathies and discriminate various important plaque components. However, the strong cerebrospinal fluid (CSF) signal in T(2)w images interferes with depicting the intracranial vessel wall. In this study, we propose a T(2)-prepared sequence for whole-brain IVWI at 3T with CSF suppression. METHODS: A preparation module that combines T(2) preparation and inversion recovery (T(2)IR) was used to suppress the CSF signal and was incorporated into the commercial three-dimensional (3D) turbo spin echo sequence-Sampling Perfection with Application optimized Contrast using different flip angle Evolution (SPACE). This new technique (hereafter called T(2)IR-SPACE) was evaluated on nine healthy volunteers and compared with two other commonly used 3D T(2)-weighted sequences: T(2)w-SPACE and FLAIR-SPACE (FLAIR: fluid-attenuated inversion recovery). The signal-to-noise ratios (SNRs) of the vessel wall (VW) and CSF and contrast-to-noise ratios (CNRs) between them were measured and compared among these three T(2)-weighted sequences. Subjective wall visualization of the three T(2)-weighted sequences was scored blindly and independently by two radiologists using a four-point scale followed by inter-rater reproducibility analysis. A pilot study of four stroke patients was performed to preliminarily evaluate the diagnostic value of this new sequence, which was compared with two conventional T(2)-weighted sequences. RESULTS: T(2)IR-SPACE had the highest CNR (11.01 ± 6.75) compared with FLAIR-SPACE (4.49 ± 3.15; p < 0.001) and T(2)w-SPACE (−56.16 ± 18.58; p < 0.001). The subjective wall visualization score of T(2)IR-SPACE was higher than those of FLAIR-SPACE and T(2)w-SPACE (T(2)IR-SPACE: 2.35 ± 0.59; FLAIR-SPACE: 0.52 ± 0.54; T(2)w-SPACE: 1.67 ± 0.58); the two radiologists’ scores showed excellent agreement (ICC = 0.883). CONCLUSION: The T(2)IR preparation module markedly suppressed the CSF signal without much SNR loss of the other tissues (i.e., vessel wall, white matter, and gray matter) compared with the IR pulse. Our results suggest that T(2)IR-SPACE is a potential alternative T(2)-weighted sequence for assessing intracranial vascular diseases.