In vivo quantitative whole-brain T1 rho MRI of multiple sclerosis.

ABSTRACT

BACKGROUND: To apply quantitative whole-brain T1 -rho (T1ρ ) and T2 imaging to the detection and quantification of brain changes resulting from multiple sclerosis (MS). METHODS: Twenty-three MS patients with clinically isolated syndrome (10) and relapsing remitting MS (13) phenotypes, compared with 24 age-matched healthy controls were imaged at 3 Tesla. An axial T1ρ -weighted three-dimensional turbo spin echo sequence with a variable flip angle and fluid suppression was used. Spin-lock times of 0, 20, 40, 60, 80, and 100 ms were used. Corresponding T2 maps were also acquired. RESULTS: Whole brain white matter (WM) T1ρ maps were elevated compared with controls (P = 0.002). WM lesion T1ρ and T2 values were highly correlated (r = 0.83), but T1ρ demonstrated 25% better contrast to noise ratio (P < 0.001). WM lesion T1ρ correlated with disease duration. Gray matter T1ρ was negatively correlated with the Expanded Disability Status Scale, r = -0.45, P = 0.03. Normal appearing gray matter and cortical gray matter lesions were negatively correlated on T1ρ , but not on T2 (rT1ρ = -0.63, pT1ρ = 0.03; rT2 = -0.17, pT2 = 0.6). CONCLUSION: T1ρ MRI demonstrates enhanced lesion contrast compared with T2 , and in some cases may provide complementary information. T1ρ may provide a useful measure of demyelinating processes in MS.