【作者】 郑春红；

【导师】 陈正挺；

【作者基本信息】 福建医科大学 ， 医学影像与核医学， 2008， 硕士

【摘要】 目的:探讨磁共振扩散加权及单体素质子波谱成像检查对乳腺良恶性病变诊断的价值和限度方法:对自2007年8月至2008年3月期间于我院行乳腺MR检查并经病理证实的60例乳腺疾病患者的资料进行回顾性分析。患者年龄24～60岁,平均年龄44.0岁。以上病例均行常规MR平扫检查,所有病例均行扩散加权成像(b=100s/mm2、600 s/mm2、1000 s/mm2)及单体素1H MRS检查。应用GE 1.5 Signa INFINITY TWINSPEED 1.5T超导型双梯度磁共振仪,配有质子波谱后处理软件包。应用双侧乳腺相控阵线圈。扩散加权成像采用单次激发回波平面技术,分别测量b值为100s/mm2、600 s/mm2、1000 s/mm2时正常腺体及良恶性病变的平均ADC值。单体素质子波谱成像采用GE公司针对乳腺肿瘤研究开发的SS-PRESS序列,以在3.2ppm出现胆碱峰作为诊断恶性病变的标准。用SPSS统计软件以及ROC曲线(Receive operating charateristic curve)分析软件处理以确定不同b值下鉴别诊断乳腺良恶性病变的最佳界值,并对不同b值对乳腺肿瘤的诊断能力进行统计学分析。对不同b值对乳腺病变诊断能力采用敏感性、特异性及准确性参数进行评价。结果:在经病理结果证实的60个病例中,乳腺恶性肿瘤30例,良性肿瘤30例,病灶直径约0.7cm～12.0cm,平均3.8cm。在DWI上,b值越大,乳腺良恶性病变ADC值越小,对病变的诊断准确性越高,但相应图像质量越差,信噪比低。本研究结果表明b值为100 s/mm2时诊断良恶性病变的最佳ADC界值为1.60×10-3mm2/s,其对应的敏感性和特异性分别约为38%和83%;当b值为600 s/mm2诊断良恶性病变的最佳ADC界值为1.32×10-3mm2/s,其对应的敏感性和特异性分别约为80%和93%;当b值为1000 s/mm2时诊断良恶性病变的最佳ADC界值为1.08×10-3mm2/s,其对应的敏感性和特异性分别约为97%和77%。利用配对t检验证明b为100 s/mm2时,良恶性病变ADC值差异无显著统计学意义;当b值为600 s/mm2、1000 s/mm2时良恶性病变ADC值差异具有统计学意义。在MRS上,以在3.2ppm出现胆碱峰为恶性病变诊断指标,MRS对乳腺病变诊断的敏感性和特异性为53.3%和93.3%。结论:DWI检查时间短,无需对比剂,采用高b值下ADC值对乳腺病变诊断的准确性较高,有助于检出病变,可作为乳腺常规检查序列之一。MRS可提高对乳腺肿瘤诊断的特异性,但对机器性能要求较高,受病灶体积大小及良恶性肿瘤本身生物学特性影响较大,对病变检出的敏感性相对较低,因此需与其他MR检查方法联合使用。将乳腺DWI和MRS相结合可增加乳腺MRI诊断的敏感性和特异性,有效减少不必要的活检。更多还原

【Abstract】 Objective: To evaluate the diagnostic effectiveness of MR diffusion-weighted imaging (DWI),and single-voxel1H MR spectroscopy (MRS) in patients with breast tumor.Methods:60 patients with breast lesions detected by physical examination or mammography underwent MR examination on a 1.5T scanner (GE,Signa INFINITY) pre-operatively. MR examinations included DWI with b value of 100s/mm2,600s/ mm2 and 1000s/mm2 by single-shot EPI sequence,and single-voxel 1H MRS by Spectral Spatial PRESS.The mean apparent diffusion coefficients (ADC) of the lesions were calculatede on DWI with both b value of 100s/mm2,500s/mm2 and 1000s/mm2.Lesions presenting a dectectable Choline single in their spetra at 3.2ppm were diagnsoed as malignant.The sensitivity,specificity,and accuracy of DWI,and single-voxel 1H MRS regarding the diagnosis of breast lesions were determined respectively.Results:Among 60 patients,pathology revealed 30 malignant and 30 benign lesions. We selected the ADCcutoff value of 1.08×10-3mm2/s for b=1000s/mm2 , 1.32×10-3mm2/s for b=600s/mm2 and 1.60×10-3mm2/s for b=600s/mm2 .At the cutoff values ,sensitivity and specificity were 97% and 77% for b=1000 ,80% and 93% for b=600s/mm2,38% and 83% for b=100s/mm2. The difference of the accuracy among the DWI for b=600 s/mm2 and b=1000 s/mm2 showed statistical significance but the differenc of the accuracy among the DWI for b=100 s/mm2showed however no statistical significance . For MRS, the sensitivity and specificity were 53.3% and 93.3%.Conclusion: DWI and MRS can provide the functional and cytologic information of breast tumor.Due to its short scan time and no need of contrast agent ,DWI is an easy and effective method for breast cancer diagnosis compared with MRS.The accuracy of ADC with high b-value (b=1000s/mm2) is promising. MR spectroscopy could complement MR imaging fingdings to improve the specificity, but limited by technics and the pathologic types of tumors.DWI and MRS have effective value in the diagnosis of breast tumor.Combination of DWI and single-voxel 1H MRS could give more information in differentiating breast lesions and reduce the number of unnecessary biopsies.更多还原