兔VX2恶性骨肿瘤浸润范围的DWI与病理对照研究

目的:探讨PROPELLER序列扩散加权成像(DWI)对显示恶性骨肿瘤浸润范围的价值.方法:建立30只兔右侧胫骨恶性骨肿瘤模型,并行MRI常规序列及DWI(b=500 s/mm2)检查.DWI图像上测量肿瘤实性区、肿瘤坏死区、肌肉水肿、正常肌肉、骨髓水肿的平均表观扩散系数(ADC)值;于矢状位肿瘤最大层面分别测量DWI...

Comparative study of diffusion-weighted imaging and pathology of VX2 malignant bone tumor in rabbits

Objective:The purpose of this study was to analyze the manifestations of diffusion-weighted imaging(DWI)of PROPRLLER sequence and to explore its value in displaying the invasive range of malignant bone tumor in rabits.Methods:VX2 carcinomas were implanted into the tibia of 30 rabbits.MRI examinations,with sequences including sagittal PROPELLER DWI(b=500s/mm^2),FSE T 2WI,FS FSE T 2WI and STIR,were performed.Then histological examinations and MRI-pathologic correlation experiments were carried out.The mean ADC values,sensitivity and specificity were calculated.The regions of interest(ROI)contained viable tumor,tumor necrosis,peritumoral edema and normal muscle tissue.The range of the bone tumor was measured separately by MRI and histological methods and analyzed statistically.Results:The mean ADC of viable tumor,tumor necrosis,nearby muscle edema,distant muscle edema,normal muscle tissue and bone marrow edema were 1.16×10^-3 mm^2,1.81×10^-3 mm^2/s,2.20×10^-3 mm^2/s,2.33×10^-3 mm^2/s,1.86×10^-3 mm^2/s and 1.88×10^-3 mm^2/s,respectively.The above ADC values of ROI were all different from each other significantly(F=1146.78,P<0.001).The mean tumor size measured in T2WI,FSE T2WI+FS,STIR,ADC and the pathological section were(5.52±0.87)cm,(5.42±0.87)cm,(5.43±0.85)cm,(5.20±0.89)cm and(5.30±0.89)cm.There was no significantly difference among various MRI sequences and the pathological section.The sensitivity and specificity of different MRI sequences(T 2WI,FSE T 2WI+FS,STIR,PROPPLER DWI-ADC)for displaying the tumor margin were(53.3%,33.3%),(66.7%,53.3%),(60.0%,40.0%)and(93.3%,80.0%).Conclusion:DWI-ADC map can quantitatively distinguish different tissue compositions by ADC measurements,thus it can accurately and objectively determine the invasion scope of malignant bone tumor.Moreover,the sensitivity and specificity of DWI are better,than those of conventional sequences.