星形细胞瘤周围水肿区的磁共振弥散成像及氢质子波谱对肿瘤术前分级的综合评价

目的]通过对星形细胞瘤周围水肿区行磁共振弥散加权成像（diffusion - weighted imaging,DWI）和氢质子磁共振波谱（proton magnetic resonance spectroscopy,1H- MRS）检查,探讨周围水肿区的DWI和1H- MRS表现在星形细胞瘤术前分级的应用价值.方...

Pre-operation evaluation of edematous regions around astrocytoma by using of diffusion weighted imaging and proton MR spectroscopy

Objective] To investigate clinical value of DWI and 1H-MRS in diagnosing of astrocytomas grade by performing them in the peritumoral edematous regions.Methods] Twenty-eight patients proved of astrocytomas(9 cases of low-grade and 19 high-grade) underwent routine MR process,diffusion weighted imaging and 2D proton spectroscopic MR imaging.Apparent diffusion coefficient(ADC) and metabolic ratios including of Cho/NAA,Cho/Cr and NAA/Cr were calculated in the peritumoral edematous areas.Results] ADC value in the peritumoral edematous areas of low-grade astrocytomas(16.82±2.40) ×10-4 mm2/s was significantly higher than that of high-grade ones(12.95±1.59) ×10-4 mm2/s,P=0.014).A ADC threshold of 14.85×10-4 mm2/s in peritumoral area provided for sensitivity by 85.7%,specificity by 82.1% as well as accuracy by 71.4% in differentiation high-grade from low-grade astrocytomas.Significantly higher ratio of Cho/NAA was found in the peritumoral edematous area(2.13±0.74,P=0.02) of high grade gliomas compared with low grade ones(1.14±0.23).A threshold of Cho/NAA equal to 1.37 in peritumoral area was provided for differentiation high-grade from low-grade astrocytomas,and then sensitivity,specificity and accuracy were by 96.4%,75.0% and 78.6% respectively.Conclusion] ADC values and Cho/NAA quantification in the peritumoral edematous areas are useful complementary methods in diagnosing of astrocytomas grade.