Magnetic resonance imaging and diffusion tensor imaging of gray matter damage in multiple sclerosis / 中华放射学杂志

ABSTRACT

Objective To study MRI characteristics of the gray matter lesions in multiple sclerosis (MS) patients, and to investigate the occult damage in normal appearing gray matter (NAGM) by quantitative analysis using diffusion tensor imaging (DTI). Methods Conventional brain MRI and DTI were performed in 34 clinically defined MS patients and 25 non-MS healthy volunteers. Main signs of the GMlesions detected by conventional MRI were analyzed, including the distribution, numbers, shape, size,signal intensity and enhanced pattern. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values derived by DTI were measured in normal appearing deep gray matter for all participants and the differences between the two groups were compared. Results MRI examination revealed 83 lesions in cerebral gray matter, 18. 7% of the total 443 lesions. The GM lesions distributed over all brain lobes especially in frontal lobe, temporal lobe, and thalamus. Thirty-four, 60, 78, and 36 plaques were detected on T1WI, T,2WI, FLAIR, and reconstructed DWI images, respectively. Nine small lesions were identified on DWI more easily than on T2WI and FALIR. The ADC values of the head of caudatum (8. 0±0. 7) ×10-4mm2/s, t=-3.079, P<0.05), putamen (7.4±0.5)× 10-4mm2/s, t= -2.564, P<0.05),and thalamus (7.7± 0. 4) × 10-4mm<'2>/s, t = -2. 722, P < 0. 05) in MS group were significantly higher than those in healthy controls [ the ADC values of head of candatum (7.4 ± 0. 6) × 10-4 mm2/s, putamen(7.0±0.5) ×10-4 mm2/s,and thalamus(7.2±0.7)×10-4mm2/s]. Conclusions This study confirms the presence of GM damage in MS. It shows MRI characteristics of the macro-lesions, and combination of FLAIR and DWI can improve the detection of GM lesions. Occult micro-change in NAGM can be evaluated by using DTI quantitative analysis.