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Objective To investigate the value of MR diffusion weighted imaging (DWI) in the pathological grading of glioma. Methods Thirty patients who were confirmed pathologically with glioma were examined by MR DWI. The values of apparent diffusion coefficient (ADC) and relative ADC (rADC) were measured. All those values were analyzed statistically. Results The 30 glioma patients were divided into lower-grade and higher-grade glioma groups. The lower-grade glioma group included 14 cases (1 case of WHO Ⅰ, tricholeukocyte astrocytoma; 13 cases of WHO Ⅱ, 11 astrocytomas with 1 case of post-operative reenrrence, 1 ependymoma, 1 oligodendroglioma); the higher-grade group included 16 cases (! I cases of WHOm, anaplastic astrocytoma with 1 case of post-operative recurrence; 5 cases of WHO Ⅳ, 4 multiforme glioblastomas, 1 ependymoma). The ADC and rADC values of lower-grade gliomas were (1.36±0.16)×10-3 mm2/s and 1.76±0.23, and the values of higher-grade glioma were (1.08±0.10)×10-3 mm2/s and 1.36±0.16, respectively. The values of ADC and rADC were significantly different between the 2 groups (P<0.05). The accuracy rates were 86.7% and 83.3% when the thresholds of ADC and rADC were 1.20×10-3 mm2/s and 1.53. Conclusion The values of ADC and rADC have high accuracy for pathological grading of the glioma.
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Objective To investigate the value of perfusion-weighted magnetic resonanceimaging (MRI) in the grading ofgliomas. Methods Thirty patients with pathologically confirmedglioma underwent perfusion-weighted MRI. Of the 30 glioma patients, 14 patients had low-grade and 16had high-grade gliomas. The low-grade glioma patients included 1 with WHO grade Ⅰ glioma (pilocyticastroeytoma) and 13 with WHO grade Ⅱ gliomas; in the WHO grade Ⅱ patients, 11 had astrocytomaincluding I with postoperative recurrence, 1 with epeudymoma, and 1 with oligodendroglioma. Of the 16patients with high-grade gliomas, 11 had WHO grade Ⅲ gliomas identified as anaplastic astrocytoma(including 1 with postoperative recurrence) and 5 had WHO Ⅳ gliomas (including 4 with glioblastomamultiforme and 1 with ependymoma). The relative cerebral blood volume (rCBV), rMSD and relativemean transit time (rMTT) were measured and statistically analyzed in these patients. Results TherCBV, rMSD and rMTT were 1.99±1.0, 1.83±0.78, and 1.10±0.08 in the patients with low-grade gliomas,as compared to those in the high-grade giioma patients of 4.95±2.04, 3.59±1.13, and 1.03±0.61,respectively, showing significant differences in the rCBV and rMSD between the two groups (P<0.05).The diagnostic accuracy of rCBV and rMSD was 83.3% and 80% for the gliomas using their upper limits(2.99 and 2.61, respectively) as the diagnostic thresholds. Conclusion The values ofrCBV and rMSDhave high accuracy in the grading of brain gliomas.
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Objective To demonstrate the diffusion tensor imaging(DTI)characteristics of multiple sclerosis(MS)plaques,periplaque white matter regions and normal appearing white matter (NAWM)regions in patients with MS,and to evaluate the clinical values of DTI and three-dimensional brain fiber tracking for the diagnosis of MS.Methods Conventional MRI and DTI were performed in 32 patients with MS and 32 age-matched control subjects.Fractional anisotropy(FA)and apparent diffusion coefficient(ADC)maps were generated and coregistered with T_2-weighted MR images,FA and ADC values were calculated in regions of interest in plaques,periplaque white matter regions,NAWM regions and white matter regions in control subjects.And three-dimensional brain fiber tracking maps were generated by using the DTI.Results TheADCwas(1.233?0.119)?10~(-3)mm~2/s in MS plaques,(0.973?0.098)?10~(-3) mm~2/s in periplaque white matter regions,(0.748?0.089)?10~(-3)mm~2/s in NAWM,and(0.620? 0.094)?10~(-3)mm~2/s in control subjects.The FA was 0.225?0.052 in MS plaques,0.311?0.050 in perip]aque white matter regions,0.421?0.070 in NAWM,and 0.476?0.069 in control subjects. Significant differences in FA and ADC values were observed among all white matter regions(P