MR灌注成像在鉴别单发脑转移瘤与高级别胶质瘤中的价值

Value of perfusion MR imaging in the differential diagnosis between single brain metastasis and high grade gliomas

目的探讨MR灌注成像在鉴别单发脑转移瘤与高级别胶质瘤中的作用及价值。方法对10例单发脑转移瘤和15例高级别胶质瘤患者行手术前MR灌注成像扫描。分析其MR灌注曲线及伪彩图像,测量肿瘤实质部分及瘤周水肿区最大相对脑血容积(rCBV)值及相应部位相对平均通过时间(rMTT)数值并将所测值进行t检验。结果单发脑转移瘤的MR灌注曲线形态和伪彩图像中的色彩特点与高级别胶质瘤有明显区别。单发脑转移瘤与高级别胶质瘤肿瘤实质部分的最大rCBV值分别为3.70±2.34、6.01±2.17,瘤周水肿区则分别为0.80±0.28、1.77±1.19。单发脑转移瘤与高级别胶质瘤肿瘤实质相应部位的rMTT值分别为1.17±0.39、1.11±0.18,瘤周水肿区则分别为1.17±0.38、1.02±0.20。两者肿瘤实质部分和瘤周水肿区的rCBV值均数之间差异有统计学意义(P<0.05),而相应的rMTT值均数之间差异没有统计学意义(P>0.05)。结论MR灌注成像对术前鉴别单发脑转移瘤与高级别胶质瘤有临床实用价值。

Objective To evaluate the value of dynamic susceptibility-contrast MR perfusion imaging in the per-operative differential diagnosis between single brain metastasis and high grade gliomas. Methods MR imaging was performed on a 1.5 T scanner in 10 single brain metastasis and 15 high grade gliomas by using a first-pass Gd-DTPA T2 ^＊ echo-planar perfusion sequence followed by conventional imaging. The patients＇ data were transferred to on-line workstation and processed to obtain time-signal intensity curves, color perfusion maps and relative perfnsion values. The perfusion maps were compared with conventional images and perfnsion values were calculated in a personal computer by using t-test and P 〈 0. 05 showed a significant difference. Results The time-signal intensity curves of single metastasis had similar shape to those of normal grey matter. On CBV color images, perfusion color of most brain metastases showed equal to those of normal grey matter in parenchyma of tumors, and showed low perfnsion in peri-tumor edema. All high grade gliomas had high perfusion color （red） in their parenchyma The means of maximum rCBV values of high-grade gliomas and metastases were 6. 01 ± 2. 17 and 3.70 ± 2. 34 in the parenchyma part and 1.77 ± 1.19 and 0. 80 ± 0. 28 in the peritumoral region. The differences were statistically significant （ P 〈 0. 05） in both. The means of the corresponding rMTT values of high-grade gliomas and metastases were 1.11 ±0. 18 and 1.17 ±0.39 in the parenchyma part and 1.02 ±0.20 and 1.17 ±0.38 in peritumoral region. The differences of means of rMTT values between brain metastases and high-grade gliomas showed no statistically significance （P 〉 0. 05 ） in both the parenchyma part of tumor and the peritumoral region. Condusion DSC MR perfusion imaging can provide useful vascular information of brain metastasis and high grade gliomas, it is useful in the preoperative differential diagnosis between single brain metastasis and high-grade gliomas.