【作者】 刘超；

【导师】 刘佩芳；

【作者基本信息】 天津医科大学 ， 影像医学与核医学， 2011， 硕士

【摘要】 目的：本课题旨在分析乳腺非肿块性病变中最常见的导管性及段性强化病变的MRI表现,探讨乳腺MRI对此类病变的诊断及鉴别诊断价值,以期为临床制订个体化诊疗方案提供可靠的影像学参考。资料与方法：回顾性分析112例经手术病理证实的、在乳腺MRI上表现为导管性及段性强化的患者资料,对MRI图像分析依据美国放射学会提出的乳腺影像报告和数据系统MRI (BI-RADS-MRI)标准,包括病变的形态学表现、内部强化特征、时间-信号强度曲线类型、脂肪抑制T2WI与正常乳腺组织相比较的信号强度和DWI上的ADC值表现。病理诊断依据WHO乳腺肿瘤分类(2003)标准。将MRI表现与相应的组织病理学表现进行对照分析。MRI检查均在GE 1.5T Signa Infinity EXCITEⅡ磁共振扫描仪上进行,应用4通道乳腺专用相控阵表面线圈,所有数据测量及图像处理在GEAW4.2工作站上利用FunctoolⅡ软件完成。对所测数据应用SPSS16.0软件包进行如下统计学分析：(1)b值为1000s/mm2,计算导管性及段性强化病变中良、恶性病变的平均ADC值,采用独立样本t检验比较其差异是否具有统计学意义；(2)时间-信号强度曲线类型(ⅠⅡ、Ⅲ型)、内部强化方式(均匀、不均匀)、脂肪抑制T2WI信号强度(等、高)的比较采用χ2检验。以P<0.05认为差异具有统计学意义。对导管性和段性强化病变计算其阳性预测值。结果：112例乳腺MRI表现为导管性及段性强化的患者中,37例表现为导管性强化,75例表现为段性强化；恶性病变95例(85%),良性病变17例(15%)。37例表现为导管性强化病变包括恶性病变29例(非特殊型浸润性导管癌16例,导管原位癌11例,浸润性微乳头状癌1例,混合型粘液腺癌1例),其中导管原位癌或以导管原位癌成分为主的病变占38%；良性病变8例(囊性增生病伴乳头状瘤病3例,导管上皮增生2例,不典型增生1例,慢性炎症1例,腺管型腺病1例)。在b值为1000 s/mm2的DWI图上37例导管性强化病变均呈稍高或高信号,良性病变和恶性病变的平均ADC值分别为(1.24±0.21)×10-3mm2/s和(1.33±0.26)×10-3mm2/s,两者之间的差异无统计学意义(t=1.653,P=0.105)。37例导管性强化病变中27例TIC表现为Ⅰ型(73%),其中20例为恶性病变,7例为良性病变；5例TIC表现为II型(13.5%),其中4例为恶性病变,1例为良性病变；5例TIC表现为III型(13.5%),全部为恶性病变。良、恶性病变的时间-信号强度曲线类型的差异无统计学意义(x2=0.564,P=0.56)。关于内部强化特征,37例导管性强化病变中25例表现为病变内部强化信号均匀,其中恶性病变21例,良性病变4例；12例表现为不均匀强化,其中恶性病变8例,良性病变4例,良、恶性病变的内部强化特征差异无统计学意义(x2=0.394,P=0.39)。37例导管性强化病变中22例在脂肪抑制T2WI上表现为等信号,其中17例为恶性病变,5例为良性病变；15例表现为高信号,其中12例为恶性病变,3例为良性病变,良、恶性病变的脂肪抑制T2WI信号强度的差异无统计学意义(x2=1.0,P=1.0)。75例乳腺MRI表现为段性强化病变包括恶性病变66例,其中非特殊型浸润性导管癌37例(4例以导管原位癌成分为主,2例伴浸润性微乳头状癌)、导管原位癌23例(5例伴微浸润)、乳头状瘤癌变2例(1例局限于导管内)、浸润性小叶癌2例(其中1例伴导管原位癌成分)、浸润性筛状癌1例(伴导管原位癌成分),浸润性微乳头状癌1例,导管原位癌或以导管原位癌成分为主的病变占45%；良性病变9例,其中慢性炎症4例,囊性增生病3例,大汗腺化生1例,腺病1例。在b值为1000 s/mm2的DWI图上75例段性强化病变均呈稍高或高信号,良性病变(9例)和恶性病变(66例)的平均ADC值分别为(1.26±0.21)×103mm2/s和(1.28±0.31)×10-3mm2/s,两者之间的差异无统计学意义(t=1.245,P=1.115)。75例段性强化病变中,41例TIC表现为I型(54.6%),其中35例为恶性病变,6例为良性病变；17例TIC表现为II型(22.7%),其中16例为恶性病变,1例为良性病变；17例TIC表现为III型(22.7%),其中15例为恶性病变,2例为良性病变,良、恶性病变时间-信号强度曲线类型的差异无统计学意义(x2=1.0,P=0.81)。75例段性强化病变中9例内部强化信号均匀,其中恶性病变8例,良性病变1例；66例内部强化信号不均匀,其中恶性病变58例,良性病变8例。良、恶性病变内部强化特征的差异无统计学意义(x2=1.0,P=1.0)。在75例乳腺MRI表现为段性强化病变中,38例于脂肪抑制T2WI呈等信号,其中恶性病变32例,良性病变6例；37例呈高信号,其中恶性病变34例,良性病变3例,良、恶性病变的脂肪抑制T2WI信号强度的差异无统计学意义(x2=0.481,P=0.46)关于乳腺MRI表现为导管性和段性强化病变提示恶性病变的阳性预测值方面,本研究结果表明段性强化征象较导管性强化更具有较高的阳性预测值,它们分别为88%和78%。结论：乳腺MRI表现为导管性和段性强化的非肿块性病变是乳腺MRI诊断难点,依据对肿块性病变的MRI诊断原则(如时间-信号强度曲线和ADC值指标)不能对其进行良恶性鉴别诊断,而形态学表现即沿导管或段性强化较其他诊断指标更具有意义。本研究结果表明乳腺MRI表现为导管性或段性强化的非肿块性病变多见于恶性病变(112例乳腺MRI表现为导管性或段性强化的患者中,恶性病变为95例,占85%),其中导管原位癌或伴有导管原位癌成分的乳腺癌占所有恶性病变的43.1%；而导管性和段性强化病变对乳腺癌阳性预测值方面的两者比较结果,则提示段性强化征象较导管性强化更具有较高的阳性预测值。更多还原

【Abstract】 Objective:To characterize the ductal enhancement and segmental enhancement lesions on breast MRI, the usual nonmass-like lesions, correlate with histopathology and differ from benign and malignant breast lesions.Materials and Methods:The MRI findings of 112 ductal and segmental enhancement lesions proved by pathology were restrospectively analyzed, according to the lexicon of Breast Imaging Reporting and Data System-Magnetic Resonance Imaging(BI-RADS-MRI) designed by American College of Radiology(ACR), including morphology, internal structure after enhancement, kinetic curve pattern on dynamic study, signal intensity on fat-suppression T2WI before enhancement, and the mean value of apparent diffusion coefficients (ADC) on DWI. The pathologic diagnosis was made according to the standard of the World Health Organization Classification of Tumors (2003), characterize the correlation between MRI findings and histopathology. MRI imaging of the breast was performed on 1.5 Tesla scanner (Signa Infinity, GE), application of 4-channel phased array dedicated breast surface coil, all of the data measurement and imaging observation were collected with FunctoolⅡsoftware in GE AW 4.2 work station. SPSS16.0 software was used to make the following statistic analysis:(1) b value=1000 s/mm2, the t-test was used for testing the difference of ADC between malignant and benign breast lesions in two groups. (2) Grouping three parameters of both ductal enhancement and segmental enhancement lesions:Time-signal intense curve(typeⅠ, typeⅡ, typeⅢ), internal structure after enhancement(homogeneous/heterogeneous), fat-suppression T2WI signal intensity (isointense/hyperintense),χ2-test was used for testing the difference of each group.Results:All 112 cases included 37 ductal enhancement and 75 segmental enhancement, and malignant and benign lesions accounted for 85%(95/112) and 15% (17/112), respectively.Histopathological diagnosis in 37 ductal enhancement lesions were 8 benign, including 3 cystic hyperplasia with multiple papilloma, 2 ductal hyperplasia, 1 atypical ductal hyperplasia, and chronic inflammation in one and 29 malignant lesions including invasive ductal carcinoma (IDC) in 16, ductal carcinoma in situ (DCIS) in 11 (including one with lobular carcinoma in situ), invasive micropapillary carcinoma in one, and mixed mucinous adenocarcinoma in one.37 patients with lesions in the b value=1000 s/mm2 DWI imaging shown higher or as high signal, the average ADC values of 8 cases of benign lesions and 29 cases of malignant lesions were (1.24±0.21)×10-3mm2/s and (1.33±0.26)×10-3mm2/s, there were no significant differences for the mean ADC values between benign and malignant lesions (t=1.653, P= 0.105). TIC type:The group of 27 cases in the TIC showed typeⅠ(73%), of which 20 were malignant lesions,7 were benign.5 cases in the TIC showed typeⅡ(13.5%), of which 4 were malignant lesions,1 were benign and 5 cases in the TIC showed typeⅢ(13.5%), all malignant lesions (χ2=0.564, P=0.56). Internal enhancement characteristic:The lesions were 25 cases of lesions showed homogeneous enhancement, with 21 cases of malignant lesions, benign lesions in 4.12cases of lesions showed heterogeneous enhancement, including malignant lesions in 8 cases,4 cases of benign lesions(χ2= 0.394, P=0.39). Fat-suppression T2WI signal strength: The group of lesions were 22 cases in FS T2WI imaging showed isointense signal, of which 17 were malignant lesions,5 cases of benign lesions.15 cases showed high signal, of which 12 were malignant lesions,3 cases of benign lesions (χ2=1.0, P= 1.0).Segmental enhancement accounted for 75 of 112 nonmass-like lesions. Pathological finding in these 75 lesions were 9 benign lesions including chronic inflammation in four, cystic hyperplasia in three (one with multiple papilloma), apocrine metaplasia in one, adenosis in one and 66 malignant lesions including invasive ductal carcinoma (IDC) in 37 (four mainly composed of DCIS and two with invasive micropapillary carcinoma), ductal carcinoma in situ (DCIS) in 23 (five with microinvasive component and one with lobular carcinoma in situ), papilloma canceration in two(one limited intraduct), invasive lobular carcinoma in two (one with DCIS), invasive cribriform carcinoma (with DCIS) and invasive micropapillary carcinoma in one.75 patients with lesions in the b value=1000 s/mm2 DWI imaging shown higher or as high signal, the average ADC values of 9 cases of benign lesions and 66 cases of malignant lesions were (1.26±0.21)×10-3mm2/s and (1.28±0.31)×10-3mm2/s, there were no significant differences for the mean ADC values between benign and malignant lesions (t=1.245, P=1.115). TIC type:The group of 41 cases in the TIC showedⅠtype (54.6%), of which 35 were malignant lesions,6 were benign.17 cases in the TIC showedⅡtype (22.7%), of which 16 were malignant lesions,1 were benign.17 cases in the TIC showedⅢtype (22.7%),15 malignant lesions and 2 benign lesions (χ2=1.0, P=0.81). Internal enhancement characteristic: The lesions were 9 cases of lesions showed homogeneous enhancement, with 8 cases of malignant lesions, benign lesions in 1.66 cases of lesions showed heterogeneous enhancement, including malignant lesions in 58 cases,8 cases of benign lesions (χ2 =1.0, P=1.0). Fat-suppression T2WI signal strength: The group of lesions were 38 cases in FS T2WI imaging showed isointense signal, of which 32 were malignant lesions,6 cases of benign lesions.37 cases showed high signal, of which 34 were malignant lesions,3 cases of benign lesions (χ2=0.481, P=0.46).Both breast ductal and segmental enhancement had high positive predictive value for malignant lesions, about 78% and 88%, respectively.Conclusion:The wide used diagnostic principle of mass lesions, such as time-signal intense curve types (TIC) or ADC value, could not be used to distinguish benign from malignant lesions for ductal or segmental enhancement lesions on breast MRI. Whereas, the morphology of ductal or segmental enhancement is of more usefulness. Our study showed ductal or segmental enhancement more potentially suggestting malignant lesions (95 malignancy in all 112 cases), and DCIS accounted for 43.1% of all malignant lesions. The PPV of segmental enhancement was higher than ductal enhancement lesions for predicting malignancy.更多还原