定量动态增强MRI在乳腺癌中的研究进展

MRI具有良好的软组织分辨力,在乳腺良恶性肿瘤的鉴别以及早期评价乳腺癌治疗效果及预后中具有独特的优势,而动态增强MRI定量分析作为一种MR技术的新方法,可以准确地监测乳腺癌病灶内微血管灌注及渗透情况,并从细胞分子水平上反映出肿瘤的生物学行为。现就定量动态增强MRI的基本原理、数据采集方法、临床应用现状及技术上的局限性进行综述。     

Fibroadenomas of the breast: histopathological/dynamic contrast-enhanced MR correlation

A total of 22 women with fibroadenomas had preoperative dynamic MR study (T1-weighted images every 47 s after injection of Gd-DOTA). Their age, hormonal status, breast MR studies and histopathological slides were retrospectively reviewed. Eleven pre- (n = 2) or post-menopausal (n = 9) women showed no early contrast enhancement. The absence of early contrast enhancement correlated with hyalin stromal component. Eleven pre- (n = 7) or post-menopausal (n = 4) women showed focal (n = 9) or diffuse (n = 2) early contrast enhancement. Early focal contrast enhancement correlated with myxoid (n = 9), mixed hyalin/myxoid (n = 1) or hyalin (n = 1) fibroadenomas. Early diffuse contrast enhancement of the breast correlated with myxoid (n = 1) or hyalin (n = 1) stromal component associated with proliferative fibrocystic disease of the breast parenchyma. The presence of contrast enhancement correlated with myxoid fibroadenomas, whereas absence of contrast enhancement correlated with hyalin fibroadenomas. As hyalin fibroadenomas occurs in post-menopausal women, the diagnostic accuracy of dynamic MRI may be improved in this age group. Correspondence to: R. Gilles     

New subtraction algorithms for evaluation of lesions on dynamic contrast-enhanced MR mammography

We report new subtraction algorithms for the detection of lesions in dynamic contrast-enhanced MR mammography(CE MRM). Twenty-five patients with suspicious breast lesions underwent dynamic CE MRM using 3D fast low-angle shot. After the acquisition of the T1-weighted scout images, dynamic images were acquired six times after the bolus injection of contrast media. Serial subtractions, step-by-step subtractions, and reverse subtractions, were performed. Two radiologists attempted to differentiate benign from malignant lesion in consensus. The sensitivity, specificity, and accuracy of the method leading to the differentiation of malignant tumor from benign lesions were 85.7, 100, and 96%, respectively. Subtraction images allowed for better visualization of the enhancement as well as its temporal pattern than visual inspection of dynamic images alone. Our findings suggest that the new subtraction algorithm is adequate for screening malignant breast lesions and can potentially replace the time–intensity profile analysis on user-selected regions of interest. Electronic Publication     

Non-mass-like enhancement on contrast-enhanced breast MR imaging: Lesion characterization using combination of dynamic contrast-enhanced and diffusion-weighted MR images

Purpose

To evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) in characterization of lesions showing non-mass-like enhancement on breast MR imaging and to find the strongest discriminators between carcinoma and benignancy.

Materials and methods

We analyzed consecutive MR images in 45 lesions showing non-mass like enhancement in 41 patients. We analyzed lesion size, distribution, internal enhancement, kinetic curve pattern, and apparent diffusion coefficient (ADC) values. We applied univariate and multivariate analyses to find the strongest indicators for malignancy. In a validation study, 22 non-mass-like enhancement lesions in 21 patients were examined. We calculated diagnostic accuracy when we presume category 4b, 4c, and 5 lesions as malignant or high to moderate suspicion for malignancy, and category 4a and 3 as low suspicion for malignancy or benign.

Results

Segmental distribution (P = 0.018), clumped internal enhancement (P = 0.005), and ADC less than 1.3 × 10⁻³ mm²/s (P = 0.047) were the strongest MR indicators of malignancy. In a validation study, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 87% (13/15), 86% (6/7), 93% (13/14), 75% (6/8) and 86% (19/22), respectively.

Conclusion

The combination of DCE-MRI and DWI showed high diagnostic accuracy in characterization of non-mass-like enhancement lesions on breast MR images.     

乳腺癌MR动态增强扫描定量分析及其临床应用

对于乳腺癌的检出,乳腺MR成像被认为是一种具有高敏感性和较高特异性的检查方式.动态增强MRI定量分析可以通过Ktrans、kep、ve等多种参数的应用,量化评价肿瘤组织的血管内皮通透性和血流量.其较半定量分析能更为准确、客观地诊断肿瘤的良恶性及评价治疗疗效.就应用动态增强MRI定量分析乳腺癌的现状及目前所存在的问题作一综述.     

Detection of breast cancer with conventional mammography and contrast-enhanced MR imaging

The aim of this study was to compare the diagnostic performance of conventional mammography and dynamic contrast-enhanced fast 3D gradient-echo (GRE) MRI regarding the detection and characterization of breast lesions relative to histopathologic analysis and to assess the results of a combined evaluation of both methods. fifty consecutive patients with 63 histopathologically verified breast lesions underwent dynamic contrast-enhanced GRE MRI in addition to routine conventional mammography. All lesions were classified by both methods on a five-point scale as benign or malignant, and the results were correlated to histopathology. Conventional mammography and dynamic MRI yielded a sensitivity and specificity of 82 and 64 %, and 92 and 76 %, respectively. The difference between the results was statistically not significant (p > 0.05) with areas under the receiver-operating-characteristics curves of 0.807 for mammography and 0.906 for MR imaging. Combination of the results of both methods slightly increased the sensitivity for detection of breast cancer to 95 % but decreased specificity to 52 %. In this selected patient subset, including only patients referred for excisional biopsy, contrast-enhanced dynamic MRI proved more sensitive and specific than conventional mammography regarding the detection of malignancy. While a combination of both methods yields a slightly improved sensitivity, specificity is vastly reduced. Received 5 May 1997; Revision received 14 July 1997; Accepted 7 August 1997     

A case of pleomorphic adenoma of the breast on dynamic contrast-enhanced MR imaging

Pleomorphic adenoma commonly develops in the salivary gland, but rarely in the breast. The dynamic contrast-enhanced MR imaging findings of pleomorphic adenoma of the breast have not been well described. We report a 43-year-old woman with pleomorphic adenoma of the left breast. The imaging findings, including those on dynamic contrast-enhanced MR imaging, included an oval mass with a smooth margin, which consisted of solid and cystic components. The solid component was hypo-intense on T1-weighted imaging, hyper-intense on short tau inversion recovery imaging, with no apparent restricted diffusion, and had heterogeneous enhancement with dark internal septation and a fast/plateau dynamic contrast enhancement pattern. The cystic component was slightly hyper-intense on T1-weighted imaging, slightly hypo-intense on short tau inversion recovery imaging and had no apparent restricted diffusion or contrast enhancement. Together with its rarity, the similarities of imaging findings and the pathologic findings of pleomorphic adenoma of the breast to those of other tumors make accurate preoperative diagnosis difficult. Therefore, through this case report, awareness of pleomorphic adenoma of the breast on dynamic contrast-enhanced MR imaging will facilitate appropriate surgery and postoperative observation based on an accurate diagnosis.     

见微知著 感知精华 ——全超越全科研磁共振Ingenia CX

目的采用Meta分析评价动态增强MRI定量参数在乳腺癌新辅助化疗(NAC)疗效评估中的价值。方法检索Pub Med、PMC、OVID-MEDLINE、中国知网、万方和维普数据库中建库至2016年11月1日公开发表的有关动态增强MRI定量评估乳腺癌NAC疗效的中英文文献,提取文献中MRI定量评估乳腺癌化疗疗效的敏感度与特异度,用Meta-Di Sc1.4软件对评价疗效的敏感度、特异度进行Meta分析,绘制森林图和合并受试者操作特征(SROC)曲线。结果共纳入国内外文献17篇,乳腺癌总病灶数854例,以病理诊断为金标准判断NAC治疗有效255例,治疗无效599例;Meta分析结果显示14篇动态增强MRI定量参数(Ktrans、kep、ve)综合评估乳腺癌NAC疗效的敏感度为83.3%(95%CI:78.3%~87.6%),特异度为82.9%(95%CI:79.5%~85.6%),SROC曲线下面积为89.99%(95%CI:85.70%~94.28%)。4篇单独用容量转移常数(Ktrans)值评估NAC疗效的敏感度、特异度分别为83.6%(95%CI:71.2%~92.2%)、81.6%(95%CI:71.0%~89.5%),SROC曲线下面积为89.99%(95%CI:83.33%~96.65%)。结论动态增强MRI定量参数对乳腺癌NAC疗效的评价具有较高的敏感度和特异度。     

钼靶X线征象与不同类型乳腺癌关系的病理基础研究

目的:探讨不同类型乳腺癌的X线表现与其病理基础之间的关系。方法:经乳腺X线检查,手术、病理证实的乳腺癌36例,共36个病灶,包括浸润性导管癌26个,导管内癌及导管内癌伴微浸润7个,浸润性小叶癌2个,黏液腺癌伴浸润性导管癌1个。观察乳腺癌的X线表现,与病理分型对照。结果:①癌灶的X线表现有肿块者23个(63.9%),有钙化者18个(50%),有结构扭曲者3个(8.3%);②呈肿块表现的以浸润性导管癌为主,占87.9%;有钙化者易出现在导管内癌和浸润性导管癌中,分别占87.5%、42.3%,尤其单纯钙化多出现在导管内癌中(71.4%,5/7);结构扭曲可见于浸润性导管癌和导管内癌中,其它类型未见。结论:肿块、钙化和结构扭曲为乳腺癌的主要X线表现。浸润性导管癌占乳腺癌的大部分,除单纯钙化首先考虑导管内癌,其余征象均首先考虑浸润性导管癌;肿块改变尚要想到髓样癌和黏液腺癌的可能;结构扭曲也可出现在导管内癌中。     

乳腺肿块动态增强及高分辨MRI表现与病理相关性研究

目的:探讨动态增强和高分辨MRI中乳腺良、恶性病灶的形态学及血液动力学特点,并与病理结果对照,研究其相关性。方法:31例女性患者,年龄21~66岁,平均44.6岁。所有病例均行动态增强和高分辨MRI扫描,用高压注射器,注射速率2.5ml/s。评价病灶增强图像形态学特点,并进行血流动力学分析。结果:31例患者MRI共发现51个病灶。其中恶性12例20个病灶,良性19例31个病灶。以形态不规则、毛刺征、环形强化作为诊断乳腺癌标准,敏感性分别为60%、70%、80%,特异性83.9%、100%、93.5%,准确率74.5%、88.2%、88.2%。纤维腺瘤或纤维腺瘤样增生特征性表现有分叶状、压脂T2WI及增强后低信号分隔,敏感性分别为68%、60%、72%,特异性分别为92.3%、92%、96.2%,准确率80.4%、76.5%、84.3%。早期增强率和时间信号百分比曲线类型分布在良恶性病灶之间的差异有显著性意义(P<0.05)。以Ⅱ型、Ⅲ型曲线作为诊断乳腺癌的标准,敏感性90%,特异性86.6%,诊断准确率88%。结论:乳腺癌的特征性表现有形态不规则、环形强化和毛刺征。纤维腺瘤特征性表现有分叶状、T2WI及强化后可见低信号间隔。动态增强扫描中乳腺病变的时间-信号强度百分比曲线对鉴别良、恶性病变有较大意义,但是部分良、恶性病灶的曲线有重叠表现。     

乳腺癌动态增强MRI边缘强化与病理特征及VEGF表达相关性

目的：探讨乳腺癌动态增强MRI边缘强化、病理特征和VEGF表达的相关性。方法：搜集经病理和免疫组织化学染色证实的28例乳腺肿瘤病例,其中20例乳腺癌,8例纤维腺瘤。均行乳腺动态增强MRI检查．并分析边缘强化及其与病理学特征、VEGF表达和服窝淋巴结转移的相关性。结果：28例中10例(乳腺癌9例,纤维腺瘤1例)出现边缘强化征象。经病理和免疫组织化学分析发现边缘强化的乳腺癌病灶：①具备中心瘢痕形成、边缘高度纤维化和中心坏死等病理学特征;②病灶边缘VEGF表达水平和MVD值高于痛灶中心;③腋窝淋巴结转移发生率较高。结论：边缘强化的形成与乳腺癌病理学特征和肿瘤血管生成有关,并可在一定程度上预测乳腺癌的生物学行为和预后。     

Assessment of resectability of pancreatic cancer with dynamic contrast-enhanced MR imaging: technique, surgical correlation and patient outcome

The aim of our work was to investigate the use of a dynamic contrast-enhanced MR (DCEMR) technique for staging apparently localised pancreatic cancer, and to determine the patterns of tumour and vascular enhancement with this technique. Thirty-five consecutive patients were examined. The MR findings were correlated with surgical findings in 13 patients and with clinical outcome in 22 patients. Breath-hold gradient-echo fast low angle shot (TR = 100, TE = 4, flip angle 80 °) acquisitions were obtained at 10 and 40 s (right anterior coronal oblique plane) and at 90 s (axial plane) following intravenous gadolinium. Mean contrast-to-noise ratio was higher on the first than the second acquisition (p < 0.001) and higher on the second acquisition than the third (p < 0.005). Tumour conspicuity was greatest and arterial anatomy was best demonstrated on the first acquisition and the portal venous anatomy on the second. Small tumours were isointense by the third acquisition. Maximal intensity projections were helpful. The MR findings correctly predicted the surgical findings in 11 of 13 cases (85 %) and the clinical course in the other 22 patients. The DCEMR imaging technique is valuable in the staging of patients with pancreatic cancer. Capillary and portal venous phase images are both required for complete local staging. Received 5 November 1996; Revision received 24 March 1997; Accepted 21 April 1997     

Unusual malignant tumors of the breast: MRI features and pathologic correlation

Unusual malignant breast tumors are well-differentiated subtypes of invasive ductal carcinoma, including mucinous, tubular, medullary and papillary carcinomas, and account for about 10% of malignant breast tumors. They are increasingly being encountered during magnetic resonance imaging (MRI) examinations of the breast. Therefore, breast radiologists should be aware of their appearance on MRI.This review provides an overview of MRI characteristics of a range of unusual tumors (mucinous carcinoma, medullary carcinoma, tubular carcinoma, intraductal papillary carcinoma, intracystic papillary carcinoma and invasive papillary carcinoma), highlighting specific clues for diagnosis and correlating MRI and pathologic features. Many unusual breast tumors exhibit MRI features similar to those of benign or low suspicious lesions (oval shape, well-defined margins, high signal intensity on T2-weighted images, continuous increase kinetics, i.e. type I dynamic curve), leading to a possible misdiagnosis. Nevertheless, an understanding of pathologic features of these tumors, especially tissue content (mucinous, fibrous) and growth pattern, can help to define some specific clues for their diagnosis.     

Monitoring breast cancer response to neoadjuvant systemic chemotherapy using parametric contrast-enhanced MRI: a pilot study

RATIONALE AND OBJECTIVES: Neoadjuvant systemic therapy (NST) is the standard treatment for locally advanced breast cancer and a common option for primary operable disease. It is important to develop standardized imaging techniques that can monitor and quantify response to NST enabling treatment tailored to each individual patient, and facilitating surgical planning. Here we present a high spatial resolution, parametric method based on dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), which evaluates breast cancer response to NST. MATERIALS AND METHODS: DCE-MRI examinations were performed twice on 17 breast cancer patients, before and after treatment. Seven sets of axial breast images were sequentially recorded at 1.5 Tesla applying a three-dimensional, gradient echo at a spatial resolution approximately 2 x 1.2 x 0.6 mm(3) and temporal resolution approximately 2 minutes, using gadopentate dimeglumine (0.1 mmol/kg wt). Image analysis was based on a color-coded scheme related to physiologic perfusion parameters. RESULTS: A high Pearson correlation coefficient of 0.96 (P < .0001) was found between the histopathologic estimation of viable neoplastic tissue volume and the segmented volume of all the pixels demonstrating fast and steady state washout after NST (colored in light red and green). Segmentation of these pixels before and after NST indicated response in terms of reduced tumor volume and a parallel decrease in enhancement rate which reflects diminished transcapillary transfer of the contrast agent. CONCLUSIONS: The use of a parametric MRI technique provided a means to standardize segmentation and quantify changes in the perfusion of breast neoplastic tissue in response to NST. Whether this technique can serve to predict breast cancer recurrence and survival rates requires further clinical testing.     

3T磁共振高分辨动态增强诊断小乳癌的应用研究

目的:探讨磁共振高分辨动态增强检查对小乳腺癌诊断的临床应用价值。方法:回顾性分析病理证实的20例(21个病灶)小乳腺癌(最大径≤2cm)的MRI高分辨动态增强检查的形态学及血流动力学特征。结果:小乳腺癌的特征性表现为形态不规则或分叶、边缘不规则或者毛刺、不均匀环形强化的肿块样病变以及局灶、不均匀或簇集样强化的非肿块病变,时间-信号强度曲线:平台型7例(33.3%),流出型14例(66.7%)。对侧对称部位正常乳腺为逐渐轻度强化,时间-信号强度曲线均为持续型。结果显示小乳腺癌灶与正常乳腺组织之间的血流动力学变化有显著差异。结论:3T磁共振高分辨动态增强检查能够提供清晰、丰富的形态学及血流动力学信息,对小乳腺癌的诊断和鉴别诊断具有重要价值。     

胶质母细胞瘤的磁共振动态增强诊断

目的：探讨胶质母细胞瘤的MRI动态增强表现。方法：搜集67例胶质母细胞瘤患者的临床及影像资料,回顾性分析其磁共振动态增强表现特点。结果：67例胶质母细胞瘤中,单发者63例,多发者4例。MRI动态增强均呈明显不均质强化,其中28例呈花环样强化,15例呈环形强化,11例呈结节状强化,13例呈囊实性强化。时间-信号强度曲线20例（29.9%）呈缓升型,28例（42.0%）呈平台型,19例（28.4%）呈速升型。结论：胶质母细胞瘤的MRI动态增强具有一定的特征性,平台型时间-信号强度曲线有助于明确诊断。     

磁共振动态增强、扩散加权成像联合应用对乳腺病变的诊断价值

目的：探讨单一磁共振动态增强扫描诊断试验、扩散加权成像诊断试验及其联合应用对乳腺病变定性诊断的敏感性、特异性和阳性似然比、阴性似然比,比较其诊断效能。方法：对临床拟诊肿块的患者37例,同时进行动态增强扫描和扩散加权成像检查,均获得手术和病理证实,其中良性病灶18个,恶性病灶19个。对病变的边缘、形态特征、动态增强表现及时间一信号强度曲线采用评分法对病变性质分恶性、可疑恶性及良性三组进行判断。参照动态增强病变位置确定扩散图像病变所在,描记扩散图像上病变的感兴趣区,由软件计算获得表观扩散系数（ADC）值。对获取数据进行统计分析,采用t检验统计学方法进行良性和恶性ADC值比较。联合动态增强扫描和ADC值,采用评分法根据积分情况进行综合定性诊断。比较动态增强扫描、DWI ADC值及联合应用对乳腺病变定性诊断效能。结果：动态增强扫描（病灶边缘、形态学表现结合时间-信号强度曲线）诊断乳腺病变的敏感性、特异性和阳性似然比、阴性似然比分别为89．5％、72．2％和3．221、0．146。良性病变组ADC值1．474±0．441（×100^-3mm^2／s）,恶性病变组ADC值1．082±0．160（×10^-3mm^2／s）,两者间有显著统计学差异（P=0．002,〈0．05）。ADC值诊断敏感性、特异性和阳性似然比、阴性似然比分别为94．7％、66．7％和2．842、0．079。动态增强扫描和DWI-ADC值联合诊断的敏感性、特异性和阳性似然比、阴性似然比分别为94．7％、83．3％和5．684、0．063。结论：磁共振动态增强、扩散加权成像联合应用对乳腺病变的定性诊断敏感性、特异性、阳性似然比、阴性似然比均较单一动态增强扫描或扩散成像诊断效能强。     

乳腺癌X线毛刺征的病理学基础探讨

目的：探讨乳腺癌X线毛刺征形态学特点及其病理学基础。方法：回顾性分析51例具毛刺征的乳腺癌X线和病理学表现。所有病例均具备完整的X线摄片和病理切片资料。结果：X线上乳腺癌肿块具备长毛刺征6例，短毛刺征30例，星状影15例。病理学上，肿块毛刺成分均匀者23例．不均匀13例；而星状影则为5例、10例；肿块周边胶原纤维活性按低到中度和高度划分，长毛刺征为6例、0例，短毛刺组征为24例、6例，星状影为12例、3例；肿块周边呈浸润扩散改变，长毛刺征3例(50%)，短毛刺征27例(90%)，星状影12例(80％)。毛刺内伴钙化12例，均在癌浸润扩散基础上发生。结论：乳腺癌肿块边缘，癌浸润扩散是X线上毛刺征形成的主要病理学基础。毛刺内伴钙化是乳腺癌重要的恶性X线征象。     

The additional value of three time point color coding in dynamic contrast-enhanced MRI of the breast for inexperienced and experienced readers

Purpose

To evaluate the additional value of the color coding of dynamic data using the 3TP method in the evaluation of contrast-enhanced breast MRI for readers with different levels of experience.

Materials and methods

A total of 52 lesions were included in this study, 25 malignant and 27 benign. All lesions were evaluated by four readers on two different workstations for the evaluation of dynamic breast MRI; one displaying the subtracted images and relative enhancement versus time curves and one displaying the subtracted images together with the 3TP color coding projected onto pre-contrast T1 images. Readers with different levels of experience were used. The diagnostic performance of both workstations was evaluated using ROC curve analyses. Interobserver variations were evaluated using kappa statistics.

Results

All lesions were detected by all four readers on both workstations. The diagnostic performance found in the inexperienced readers improved significantly when using the 3TP evaluations (p = 0.04 and p = 0.03). No significant difference was found for the more experienced readers (p = 0.94 and p = 0.54). The level of agreement between the readers improved significantly when using the 3TP evaluation method (p = 0.01).

Conclusion

Even though the 3TP color coding did not improve the diagnostic performance of the more experienced readers, this study clearly shows its value for inexperienced readers. The use of 3TP color coding is therefore recommended for inexperienced readers.     

Invasive breast cancer: correlation of dynamic MR features with prognostic factors

The purpose of this exploratory study was to correlate kinetic and morphologic MR features with histologic prognostic factors in invasive breast cancer. Sixty-one women with invasive breast cancer underwent dynamic contrast-enhanced MR imaging at 1.5 T, using T1-weighted 3D fast low-angle shot technique. The MR characteristics were correlated with classical pathologic prognostic factors (tumor size, histologic type, grade and lymph node status) and immunohistochemically detected biomarkers [c-erbB-2, p53, Ki-67, and estrogen receptor (ER)]. Univariate and multivariate statistical analyses were performed. Presence of rim enhancement pattern, early maximal enhancement and washout phenomenon were independently associated with established predictors of poor prognosis (higher histologic grade, positive Ki-67, and negative ER status). Our results suggest that these MR signs are not only important in differentiating benign from malignant lesions, but may also be useful to noninvasively identify highly aggressive breast carcinomas.