Meningioma Subtypes Mr And Pathologic Findings,

Objective: To study the relationship between MR imaging features of meningioma and its pathological subtypes, improving the level of diagnosis of the subtypes of meningioma on MRI. Material and Methods: To analyze MR imagings in 95 patients who have been proved by surgically and pathologically with meningioma correlated with the pathological findings. MR imaging was performed with a 0.5-T MR imager and brain-array coil. SE T1WI and SE high-weighted T2WI were obtained with a matrix of 179× 256, and a section thickness of 0.6cm in all cases. SE T1WI after contrast enhanced were obtained also in 50 patients of them. MR scan with axial and sagittal sections was conducted in every case. Coronal sections performed necessarily in part of them. The subtypes of meningioma were classified according to the criteria of the WHO classification about meningioma. The features of meningioma in MR imagings had been analyzed, including the visually signal intensity in T1-weighted and T2-weighted sequence, homogeneity of tumor, secondary features (cyst, calcification, hemorrhage), peritumoral brain edema, and enhanced degree in contrast-enhanced T1-weighted imagings. These features were scored according to their criteria. The data were compared with the pathological subtypes, sex and age in the statistical analysis system. Results: 95 cases included syncytial group (31 cases), fibrous group (38 cases), transitional group (8 cases), angiomatous group (8 cases), psammomatous group (4 cases) and malignant group (6 cases). The cases of syncytial and fibrous subtypes were 72.6% in the total cases and had significant difference in the proportion of sex (females are more). There was not significant difference in the other benign subtypes in sex. All cases were males in the malignant group (6.3% in all cases). The performance of meningioma in MR imagings is highly related to its pathological subtype. Significant difference in T1WI signal intensity was found among syncytial subtype group, fibrous subtype group and psammomatous subtype group. Syncytial group had higher signal intensitythan the others; psammomstous group had the lowest signal intensity in all subtypes groups. Significant difference in T2WI signal intensity was found in the benign subtypes groups, but not found between benign group and nonbenign group. There is no significant difference among the subtype groups in the secondary features, including cyst, calcification and hemorrhage, but they could affect the homogeneity of the tumor. Homogeneity in the subtype groups had significant difference. In our data syncytial group is the most homogeneous, and then angiomatous, psammomatous and malignant subtypes were lower homogeneous. Angiomatous, malignant subtypes were associated with heavier peritumoral brain edema than were the other subtypes in the statistics analysis. Significant difference on contrast enhanced T1-weighted imagings had been found. Angiomatous subtype had the highest degree of signal intensity in contrast-enhanced T1WI imagings, and malignant, syncytial subtypes had higher degree of contrast-enhanced. Fibrous subtype had the lowest enhanced degree. Conclusion: the performance of meningioma on MRI is highly related to its pathological subtypes. The subtypes of meningioma can be strongly suspected if MR images reflect the above features.