3．OT MRI定量动态对比增强对乳腺疾病的应用价值研究

目的 研究3.0T MRI动态对比增强定量参数对乳腺疾病的诊断价值.方法 采用3.0T MRI扫描仪和16通道乳腺相控阵线圈对45例怀疑乳腺肿瘤患者进行动态对比增强MRI检查,共发现病灶52个,其中5例为2个病灶（1例为双侧,4例为单侧）,1例为3个病灶（双侧）,所有2个以上病灶都取最大的病灶纳入研究.分别测量定量血流动力学参数,包括容量转移常数（volume transfer constant,Kttrans）和血管外细胞外间隙容积比（extravascular extracellular space distribute volume per unit tissue volume,Ve）.采用单因素方差分析比较乳腺癌、纤维瘤和其他良性病变的组间差异,受试者特性曲线（receiver operating characteristic curve,ROC）分析良、恶性病变的组间差异.结果 乳腺癌（n=23）的Ktrans和Ve均值分别为（10.18±2.65） min-1和7.64±1.20;良性病变（n=22）的Ktrans和Ve均值分别为（5.68±1.15）nind和8.44±2.01;良性病变中纤维瘤（n=12）的上述均值分别为（7.31±1.42） min1和11.25±2.75,其他良性病变（n=10）的上述均值分别为（3.73±0.83） min1和5.07±1.13.乳腺癌与良性病变间Ktrans的差异有统计学意义（F值为4.271,P值＜0.05）,Ve的差异无统计学意义（F值为1.553,P值＞0.05）；乳腺癌、乳腺纤维瘤与其他良性病变3组间Ktrans和Ve的差异均有统计学意义（F值分别为4.316和3.944,P值均＜0.05）.以最大约登指数为最佳诊断切点值,Ktrans和Ve判断乳腺良恶性病变的敏感度分别为87.5％和8l.3％；特异度分别为55.6％和38.9％.综合2个定量参数作为联合指标诊断良、恶性病变的敏感度、特异度和准确度分别为91..％（21/23）,77.3％ （17/22）和84.4％（38/45）.结论 3.0T MRI动态对比增强定量血流动力学参数Ktrans对乳腺良恶性病变的鉴别诊断具有很高的诊断价值,Ve对鉴别乳腺癌与纤维瘤具有一定的诊断价值.

3.0T quantitative dynamic contrast enhanced MRI in diagnosing breast tumor

Objective To evaluate the value of quantitative parameters of Dynamic Contrast Enhanced MRI （DCE MRI） in the diagnosis of breast tumors. Methods 45 patients suspected of breast tumour underwent DE-DCE MRI examination using 3.0 T whole-body MR scanner with a sixteen-channel phased-array breast coil. Quantitation of the pharmacokinetic parameters was measured including volume transfer constant （Ktrans）, extravascular extracellular space distribute volume per unit tissue volume （Ve）. The mean Ktrans and Ve of the breast cancer, fibroma and other benign lesions were calculated. One-way ANOVA and receiver operating characteristic curve （ROC） analysis were used for comparing the differences between malignant and benign lesions. Results The mean Ktrans and Ve of the lesions were as follows： breast cancer （n =23） ,（10.18±2.65） min^-1 , and 7.64±1.20; benign lesions （n=22）, （5.68±1.15） min^-1和 8.44±2.01. The mean Ktrans and Ve of fibroma （n=12） were （7.31±1.42） min^-1 , and 11. 254±2.75; The mean Ktrans and Ve of other benign lesions （n=10） were （3.73 ±0.83） min^-1 , and 5.07±1.13, respectively. There were significant differences between breast cancer and fibroma in Ktrans （ F = 4. 271, P〈0.05）. There were no significant differences between breast cancer and fibroma in Ve （ F=1. 553, P〉0.05）. There were significant differences among 3 groups of breast cancer, fibromain and other benign lesions in Ktrans and Ve （ F = 4. 316, 3. 944, respectively, P 〈0.05 in all intergroups）. The sensitivity of Ktrans and Ve were 87.5%, and 81.3% and the specificity of those were 55.6%, and 38.9%, respectively, for differential diagnosis of breast lesions with the maximum Youden＇ index as cut off. When combining with 2 quantitative parameters,the sensitivity, specificity and accuracy for differential diagnosis of breast tumors were 91.3% （21/23）, 77.3% （17/22） and 84.4%（38/45）, respectively. Conclusion The differential diagnosis of breast cancer from benign lesion by K derived from 3.0T DCE MRI is valuable. Ve can improve the diagnostic performance of breast MRI to differentiate breast cancer from fibroma.