Segmentation of gray matter, white matter, and CSF with fluid and white matter suppression using MP2RAGE

Background: MP2RAGE can generate uniform T₁ -weighted images, which have been used for brain segmentation. However, there remain concerns about carrying out fast brain segmentation.

Purpose: To propose an acquisition-based method for fast segmentation of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) of healthy human brains with fluid and white matter suppression (FLAWS) using MP2RAGE.

Study type: Prospective.

Subjects: 12 volunteers (23-28 years, seven subjects; 51-62 years, five subjects).

Field strength/sequences: 3T/3D MPRAGE and FLAWS.

Assessment: The proposed method was evaluated by calculating tissue volumes and the spatial overlap with the segmentation results from FSL and SPM12. The processing time was recorded.

Statistical tests: A paired t-test was used to compare the tissue volumes of the proposed method with those from other segmentation methods RESULTS: For the 12 subjects, the tissue volume difference between the proposed and SPM12 were 3.2 ± 2.8%, 4.2 ± 2.5%, 18.2 ± 13.1% for GM, WM, and CSF, respectively. The relative difference between the proposed and FSL was over 14% for all tissue classes. The spatial overlap between the proposed and other methods were 87-94% for GM and WM and less than 80% for CSF. The GM and WM volumes of the proposed method were not significantly different from those of SPM12 using MPRAGE as the input (P = 0.5540 and P = 0.3115, respectively). The rest of the comparisons all showed significant differences between the proposed and other methods. Statistical analysis of the two subgroups yielded similar results. The mean processing time of one subject was 6.5, 185, and 165 seconds for the proposed method, FSL, and SPM12, respectively.

Data conclusion: Our method may be accurate for the segmentation of most brain structures using FLAWS. In addition, the proposed method is fast and applicable to the two distinct age ranges.

Level of evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;48:1540-1550.