Applicable Study Of DWI And PWI In Cerebral Tumors

Purpose:Our aim was to evaluate the role of diffusion-weighted imaging (DWI) andperfusion- weighted imaging (PWI) in the differentiation of these cerebral tumors.Material and methods:1.Using a 1.5T MRI unit, we examined 49 patients with histologically verified or clinically diagnosed brain tumors[11 gliomas(grade3-4), 9 gliomas(gradel-2),9 meningiomas,7 metastatictumors,7 acoustics chwannomas,and 6 lymphomas] .ADC values were calculated on an ADW4.0 workstation and ADC map was reconstructed automatically. We measured ADC values both in the solid portion of the tumors,Apparent diffusion were calculated. Statistical software SPSS 11.5 for windows was used to analysis the diferences of ADC among different groups of the brain tumors.2.Study of PWI involved 36 patients(11 high-grade gliomas, 9 low-grade gliomas,9 meningiomas and 7metastatictum)who were identified as having histopathologieally proven gliomas. MR perfusion imaging and MR conventional imaging were performed preoperatively in them. PWI was applied using dynamic susceptibility contrast technique ,perfusion dada were changed to get a signal-time curve and a color map of CBV. Maximum relative cerebral blood volume (rCBV_max) was calculated from each tumor given in ratio with Contralateral normal white matterResults:1.The results of DWI calculated by one-way-ANOVA showed statistic difference between glioma (grade3-4) and glioma (grade 1-2).ADC in glioma (grade3-4), glioma (gradel-2) and schwannoma are statistically higher than meningioma. It also has indicated a statistically significant difference between lymphoma and other cerebral tumors in ADC value.2.The results of PWI calculated by one-way-ANOVA showed statistic difference between the rCBVmax of high-grade gliomas and meningiomas and high and low-grade gliomas, while there Was no significant difference between metastases and other cerebral tumors, but the signal-time curve in the mass of gliomas meningiomas and metastases was characteristicConclusion:Although conventional MR imaging characteristics of brain tumors may be similar,DWI and PWI may be helpful to distinguish them properatively on the basis of their information.