The value of diffusion MR imaging in judging pathological changes of brain multiple sclerosis

Abstract

To analyze the findings of MR diffusion weighted imaging (DWI) and diffusion tensor Imaging (DTI) in patients with multiple sclerosis (MS), and to explore their role in reflecting the pathological changes of MR lesions. DWI and DTI were performed on 41 MS cases and 25 sub-acute brain infarct cases which used as control group. The appearances of ADC maps, EADC maps and FA maps in patients of both groups were analyzed. Quantitative analysis of the values of ADC, EADC and FA in the center and periphery of the lesions of acute MS, chronic MS and sub-acute brain infarct was carried out separately. In DWI, the small chronic lesions were iso-intensity, and the large acute MS lesions and the sub-acute-infarct lesions had a high signal intensity to various degrees. In the EADC map, only in 13 cases with acute MS around the peripheral zone of the lesions there was a high signal intensity, and all other cases, including the cases with chronic MS and brain infarct had no high signal lesions. The ADC values of chronic and infarct lesions were similar (P > 0.05), both of them had the highest ADC value which were higher than the signal intensity in the center (both P < 0.05) and the periphery (both P < 0.05) of the MS lesions. The FA values in the infarct lesions were the lowest, much more lower than that in the chronic MS lesions (P < 0.05). The FA value in the center of acute MS lesions was lower than that in the peripheral zone (P < 0.05), and higher than the FA value both in the chronic MS and infarct lesions (P < 0.05). The lowest ADC value outside the peripheral zone of acute MS lesions and the highest EADC value were found. The significance of DWI high signal in the diagnosis and differential diagnosis of MS is not reliable, so the patient's history and the findings found in the routine MRI must be conjugated when an imaging diagnosis is made. The EADC map is more accurate than ADC map for showing the diffusion restriction of water molecular in the MS lesions. The degree of increase of the ADC value and the degree of decease of the FA value are proportional to the degree of severity of the pathological changes of the MS lesions.