脑肿瘤磁共振弥散与灌注成像的相关性

目的 探讨脑肿瘤磁共振弥散加权与灌注加权成像的相关性,提高脑肿瘤诊断的准确率.方法 回顾性分析东南大学医学院附属盐城医院2001年6月～2005年3月手术、病理及临床证实并行磁共振成像检查的100例脑肿瘤患者的弥散加权与灌注加权图像资料,对肿瘤感兴趣区的DWI与rCBV图的信号强度、ADC与QrCBV及rMTT值进行相关性研究. 结果 100例脑肿瘤中,33例为良性肿瘤,67例为恶性肿瘤.在DWI图上,90.9%的良性肿瘤呈高或等信号,65.7%的恶性肿瘤呈低信号.在rCBV图上,84.8%的良性肿瘤和79.1%的恶性肿瘤呈低信号,两者血流灌注量无显著性差异(P＞0.05).良性肿瘤的ADC平均值明显低于恶性肿瘤,差异有显著性(t=1.641,P＜0.05);但前者的QrCBV平均值和rMTT平均值明显高于后者,两者间差异均存在显著性(t=0.726,t=1.114,P＜0.05).良性脑肿瘤弥散与血流灌注呈反相关,而恶性肿瘤则呈正相关.良恶性肿瘤间的弥散和血流灌注均存在显著性差异(P＜0.05).结论 根据脑良恶性肿瘤间的磁共振弥散和血流灌注的相关性和显著性差异,可以推测肿瘤的生物学行为,有助于脑良恶性肿瘤的诊断和鉴别诊断,对进一步提高诊断准确率有着重要的临床价值.

Correlation between diffusion weighted imaging and perfilsion weighted imaging in brain tumors

Objective To evaluate correlation between diffusion weighted imaging (DWI) and perfusion weighted imaging (PWI) in diagnosing brain tumors, as well as to improve the diagnosis accuracy rate. Methods DWI and PWI data of 100 patients with brain tumors were reviewed. The patients were confirmed as some kinds of brain tumors by means of operation, pathological examinations and clinical data from June 2001 to March 2005. Several parameters were studied in order to probe their correlations. The intensities include DWI and relative cerebral blood volume (rCBV) map, the values of ADC. QrCBV and relative mean transit time (rMTT) in regions of interest (ROI) of brain tumors. Results Among the 100 patients, 33 were benign tumors and 67 malignant. On DWI, 90.9 percent of the benign tumors were hyperintensity or iso-intensity, 65.7 per cent of the malignant tumors were hypointensity. On rCBV, 84.8 percent of the benign tumors and 79.1 percent of the malignant tumors were hypointensity. There was no significant difference in the blood perfusion volume between the benign tumors and the malignant ones (P>0.05). The ADC averages of the benign tumors were significantly lower than that of the malignant ones (t =1.641, P <0.05), while the former had significantly higher QrCBV averages and rMTT averages than the latter (t = 0.726, t = 1.114, respectively,P < 0.05). PWI and DWI are negatively correlated in benign tumors and positively correlated in the malig- nant ones, and the both correlations were significant (P < 0.05). Conclusion Negative or positive correlations of DWI and PWI helps to estimate biological features of the tumors, conducive to give diagnosis and differential diagnosis to benign or malignant tumors and to improve diagnosis accuracy.