| Part I Findings of conventional MRI of brain and spinal cord multiple sclerosis Objective: Analyze conventional MRI findings of brain and spinal cord MS, find the MRI signs which are meaningful in diagnosis and differential diagnosis. Materials and Methods: Analyze the MRI findings of 41 cases of clinical defined brain MS, 13 cases spinal cord MS, including numbers of lesions, distribution, size, shape, signal and enhancement. Result: Brain MS can happen singly and multiply with multiply happening more frequently. As to multiply happening, 4-15 lesions are observed most, with a few cases showing diffuse lesions and can not be counted accuratly. The distribution of lesions are observed most at the two sides of periventricular, followed by subcrotical, corpus callosum, brainstem, and only two cases of cerebrum. The size of lesions is from a couple of millimeter to 2cm, accounting for about 75% of total. Lesions with size above 2cm is seldom, with the biggest one of 6-7cm. According to the sharp and signal, lesions can be categorized in acute and chronic one. The acute lesions have a shape of oval or circle, feeling of swelling, low signal of T1WI, and isointensity or a slight higher signal edge on the circle. T2WI show high signal, with different increment and showing "core+lunar" sign. This kind of lesions show enhancement with the circle enhancement as the most typical one which has a complete circle or non-complete arc shape enhancement, even the lesions is big. The chronic lesions can also be divided into two categories: one is the quasi-symmetric lesions, with distribution along two sides of periventricular and shapes of small puncture or small patch, part of which merge into big patch. Another kind of lesions scatter sparsely at frontal pariatal lobes and two sides of periventricular, with shape of small patch. The chronic lesions have the feeling of shrinking, sharp edge, evensignals, and has no lunar circle phenomena and obvious enhancement. Spinal cord MS are most found in neck, thoracic spinal cord. The MRI has similar presentation: slightly to middle enlargement of spine cord, different size, continuous or non-continuous abnormal high signal lesions, few enhancement. Conclusion: Brain and spinal cord MS have different findings in conventional MRI respectively and can be used to support the clinical diagnosis.Part II Diffusion MR imaging techniques and presentation of brain multiplesclerosisObjective: Explore the diffusion weighted and diffusion tensor imaging methods and signals in brain MS, and analyze its value in evaluation the pathological changes of MS lesions. Material and Methods: Combine DWI and DTI scan of 41 brain MS and 11 cases of brain infarction with the former applying 3 diffusion graduates, the later 25 diffusion graduates, with b = 0 and 1000 s/mm2. Analyze the signal character of MS lesions on the DWI and of EADC map. Quantitatively analyze the value of ADC, EADC, FA in the center, rim of MS acute lesions, chronic MS lesions and infarction lesions to reflect biophysical changes in the underlying pathology of the demyelinating process. Result: Chronic, small lesions have isointensity in DWI. Acute and chronic bigger MS and infarction lesions have various extend high signal on the DWI. There are 13 high signal lesions in the EADC map, others with low signal. The ADC value of infarction lesions assemble to chronic MS (p>0.05) and increase most. The two >acute MS center lesions (p<0.05) >acute MS ring lesions (p<0.05 ); Infarction lesions have the lowest FA value, followed by chronic MS. The former is lower than later (p<0. 05) . The center of acute MS is lower than its rim, and both of them are lower than chronic MS and infarction (p<0.05). The lesions with13 lowest ADC and highest EADC values beyond the rim of acute MS lesions show the restricted diffusion change of water molecular in the tissue. Conclusion: It is more accurate to use EADC map's high signal to judge the restricted diffusion change in tissue than DWI. The increase of ADC and the decrease of FA value... |
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