乳腺癌的MRI诊断

MRI是乳腺癌的一种新的、重要的检查方法。增强MRI对侵袭性乳腺癌具有很高的敏感性。MRI对乳腺癌手术方案的制订、鉴别复发起到重要作用。就MRI和其他检查方法在乳腺癌诊断方面的应用比较予以综述。     

The current status of positron emission mammography in breast cancer diagnosis

Mammography is currently the standard breast cancer screening procedure, even though it is constrained by low specificity in the detection of malignancy and low sensitivity in women with dense breast tissue. Modern imaging modalities, such as magnetic resonance imaging (MRI), have been developed in an effort to replace or complement mammography, because the early detection of breast cancer is critical for efficient treatment and long-term survival of patients. Nuclear medicine imaging technology has been introduced in the field of oncology with the development of positron emission tomography (PET), positron emission tomography/computed tomography (PET/CT) and, ultimately, positron emission mammography (PEM). PET offers the advantage of precise diagnosis, by measuring metabolism with the use of a radiotracer and identifying changes at the cellular level. PET/CT imaging allows for a more accurate assessment by merging the anatomic localization to the functional image. However, both techniques have not yet been established as diagnostic tools in early breast cancer detection, primarily because of low sensitivity, especially for sub-centimeter and low-grade tumors. PEM, a breast-specific device with increased spatial resolution, has been developed in order to overcome these limitations. It has demonstrated higher detectability than PET/CT and comparable or better sensitivity than MRI. The ability to target the lesions visible in PEM with PEM-guided breast biopsy systems adds to its usability in the early diagnosis of breast cancer. The results from recent studies summarized in this review indicate that PEM may prove to be a useful first-line diagnostic tool, although further evaluation and improvement are required.     

Magnetic resonance imaging in the evaluation of ductal carcinoma in situ

Before 2000, breast magnetic resonance imaging (MRI) was considered a relatively poor imaging tool for ductal carcinoma in situ (DCIS), as a high percentage of false-negative magnetic resonance examinations were cases of DCIS. Three specific shifts in breast MRI occurred, which changed this assessment: 1) a shift from high temporal to high spatial imaging, revealing specific morphological features on MRI suspicious for DCIS; 2) a shift from diagnostic studies of patients with cancers identified on mammography to screening studies of high-risk patients, allowing more accurate comparisons of mammography vs MRI in detecting the full spectrum of breast cancers regardless of appearance on mammography; and 3) a shift from emphasis on masses to improved understanding of features of non-mass-like malignant lesions, distinct from benign background parenchymal enhancement patterns. Over the last decade, research has confirmed that of all imaging tools, MRI has the highest sensitivity in detection of DCIS (compared with mammography and ultrasound). Future studies are needed to clarify how best to use this tool for improved patient outcomes.     

Status of scintimammography and its relationship to other detection methods for breast cancer

Breast cancer is the most important malignancy for women of the world's industrialized nations. It is second only to lung cancer in cancer-related mortality. Early detection is the best means of improving survival; the cornerstone of early diagnosis is mammography. Given the endemic nature of breast cancer, screening mammography has secured a routine place in health maintenance for women, although it is less than perfect. To aid in the diagnosis of malignant breast disease, other imaging modalities have evolved: ultrasound, magnetic resonance imaging (MRI), positron emission tomography (PET), and SMM. Scintimammography (SMM) is rapidly with a variety of applications for the management of breast disease. This technology has become a complementary modality to other conventional methods of breast imaging. This review will focus on the science behind SMM and how it is currently used in the management of breast lesions.     

MRI compared to conventional diagnostic work-up in the detection and evaluation of invasive lobular carcinoma of the breast: a review of existing literature

Purpose The clinical diagnosis and management of invasive lobular carcinoma (ILC) of the breast presents difficulties. Magnetic resonance imaging (MRI) has been proposed as the imaging modality of choice for the evaluation of ILC. Small studies addressing different aspects of MRI in ILC have been presented but no large series to date. To address the usefulness of MRI in the work-up of ILC, we performed a review of the currently published literature. Materials and methods We performed a literature search using the query “lobular AND (MRI OR MR OR MRT OR magnetic)” in the Cochrane library, PubMed and scholar.google.com, to retrieve all articles that dealt with the use of MRI in patients with ILC. We addressed sensitivity, morphologic appearance, correlation with pathology, detection of additional lesions, and impact of MRI on surgery as different endpoints. Whenever possible we performed meta-analysis of the pooled data. Results Sensitivity is 93.3% and equal to overall sensitivity of MRI for malignancy in the breast. Morphologic appearance is highly heterogeneous and probably heavily influenced by interreader variability. Correlation with pathology ranges from 0.81 to 0.97; overestimation of lesion size occurs but is rare. In 32% of patients, additional ipsilateral lesions are detected and in 7% contralateral lesions are only detected by MRI. Consequently, MRI induces change in surgical management in 28.3% of cases. Conclusion This analysis indicates MRI to be valuable in the work-up of ILC. It provides additional knowledge that cannot be obtained by conventional imaging modalities which can be helpful in patient treatment.     

Diagnostic Performance of Breast MRI in the Evaluation of Contralateral Breast in Patients with Diagnosed Breast Cancer

Aims: The purpose of our study was to evaluate the diagnostic performance of breast magnetic resonance imaging (MRI) in the evaluation of contralateral breast  in patients with diagnosed breast cancer. A secondary objective was to determine accuracy of breast MRI in diagnosing multi-focal and multicentric lesions in the ipsilateral breast. Materials and Methods: Using a non-probability convenience sampling technique, patients with histopathologically diagnosed breast cancer with MRI of breast performed to exclude additional lesions were included. MRI findings were correlated with histopathology. In addition, follow-up imaging with mammography and ultrasound was also assessed for establishing stability of negative findings and for the detected of benign lesions. Results: Out of 157 MRI breast conducted during the period of 2008 to 2013, 49 were performed for patients with diagnosed breast cancer. The sample comprised of all females with mean age 50.7±11.0 years. The patient follow-up imaging was available for a period of 2-5 years. The sensitivity, specificity, and positive and negative predictive values of MRI in the detection of multifocal/multicenteric lesions was 85.7%, 88.8%, 60% and 96.6% respectively and for the detection of lesions in the contralateral breast were 100%, 97%, 83.3% and 100% respectively. Conclusions: Our study highlights the diagnostic performance and the added value of MRI in the detection of multifocal /multicenteric and contralateral malignant lesions. In patients with diagnosed breast cancer having dense breast parenchyma and with infiltrating lobular carcinoma as the index lesion MRI is particularly useful with excellent negative predictive value in the exclusion of additional malignant foci in the ipsilateral and contralateral breasts.     

MRI-guided Wire Localization Open Biopsy is Safe and Effective for Suspicious Cancer on Breast MRI

Background: Magnetic resonance imaging of breast, reported to be a high sensitivity of 94% to 100%, is themost sensitive method for detection of breast cancer. The purpose of this study was to investigate our clinicalexperience in MRI-guided breast lesion wire localization in Chinese women. Materials and Methods: A total of44 patients with 46 lesions undergoing MRI-guided breast lesion localization were prospectively entered intothis study between November 2013 and September 2014. Samples were collected using a 1.5-T magnet with aspecial MR biopsy positioning frame device. We evaluated clinical lesion characteristics on pre-biopsy MRI,pathologic results, and dynamic curve type baseline analysis. Results: Of the total of 46 wire localization excisionbiopsied lesions carried out in 44 female patients, pathology revealed fourteen malignancies (14/46, 30.4%) andthirty-two benign lesions (32/46, 69.6%). All lesions were successfully localized followed by excision biopsy andassessed for morphologic features highly suggestive of malignancy according to the American College of RadiologyBreast Imaging Reporting and Data System (BI-RADS) category of MRI (C4a=18, C4b=17, C4c=8,C5=3). Of46 lesions, 37 were masses and 9 were non-mass enhancement lesions. Thirty-two lesions showed a continuouskinetics curve, 11 were plateau and 3 were washout. Conclusions: Our study showed success in MRI-guidedbreast lesion wire localization with a satisfactory cancer diagnosis rate of 30.4%. MRI-guided wire localizationbreast lesion open biopsy is a safe and effective tool for the workup of suspicious lesions seen on breast MRIalone without major complications. This may contribute to increasing the diagnosis rate of early breast cancerand improve the prognosis in Chinese women.     

Utility of magnetic resonance imaging in the management of breast cancer: evidence for improved preoperative staging.

PURPOSE: The staging and treatment for breast cancer are changing; there is an increase in the incidence of ductal carcinoma-in-situ, the use of fine-needle aspiration and stereotactic biopsy for diagnosis, and the use of neoadjuvant chemotherapy. Thus, there is a need for a tool to assess more precisely the extent of cancer in the breast before surgery. To better plan surgical and chemotherapeutic interventions, we evaluated high-resolution magnetic resonance imaging (MRI) as such a tool. PATIENTS AND METHODS: Fifty-seven patients with 58 cases of breast cancer were evaluated preoperatively with MRI using a technique called the triple-acquisition rapid gradient echo technique to maximize anatomic detail. Imaging results were compared with mammography and subsequent pathology results. RESULTS: Magnetic resonance imaging correctly identified residual or primary cancer in 55 of 58 cases and accurately predicted the extent of the cancer in 54 of 58 cases. The anatomic extent was more accurately defined with MRI compared with mammography (98% v 55%). Magnetic resonance imaging added the greatest value in cases of multifocal disease. CONCLUSION: By applying MRI selectively to patients with a known diagnosis of cancer and focusing on defining the extent of malignant lesions, we were able to obtain clear and accurate anatomic information. Our results suggest that MRI could provide very valuable information for preoperative planning and single-stage resection in breast cancer. Based on preliminary data from our series, MRI would be valuable as a staging tool in the preoperative setting even if the cost is in the range of $1,300 to $2,000. It is already significantly less than the target cost, so it is reasonable to refine this technique for clinical use to help plan the most appropriate surgical intervention and possibly reduce costs as well. A careful prospective study is warranted to validate our findings.     

Role of MRI in screening, diagnosis and management of breast cancer

Screening and early diagnosis has an important role in reducing the morbidity and mortality associated with breast cancer. Mammography has an established role and has been approved for routine screening. MRI is an emerging tool and has the highest sensitivity of current breast imaging techniques. Although low specificity and high cost of MRI restricted its use in routine screening, it has been increasingly used in the screening of high-risk individuals, diagnosing occult cases, staging and assessing the response to chemotherapy. MRI-guided techniques, including needle-localization biopsy and vacuum-assisted breast biopsy, have a special role in diagnosis and management. This article focuses on the role of MRI in diagnosis, screening and management of breast cancer, and reviews the current indications for breast MRI.     

Role of MRI in screening,diagnosis and management of breast cancer

Screening and early diagnosis has an important role in reducing the morbidity and mortality associated with breast cancer. Mammography has an established role and has been approved for routine screening. MRI is an emerging tool and has the highest sensitivity of current breast imaging techniques. Although low specificity and high cost of MRI restricted its use in routine screening, it has been increasingly used in the screening of high-risk individuals, diagnosing occult cases, staging and assessing the response to chemotherapy. MRI-guided techniques, including needle-localization biopsy and vacuum-assisted breast biopsy, have a special role in diagnosis and management. This article focuses on the role of MRI in diagnosis, screening and management of breast cancer, and reviews the current indications for breast MRI.     

Magnetic resonance imaging in breast cancer: A literature review and future perspectives

Early detection and diagnosis of breast cancer are essential for successful treatment. Currently mammography and ultrasound are the basic imaging techniques for the detection and localization of breast tumors. The low sensitivity and specificity of these imaging tools resulted in a demand for new imaging modalities and breast magnetic resonance imaging (MRI) has become increasingly important in the detection and delineation of breast cancer in daily practice. However, the clinical benefits of the use of pre-operative MRI in women with newly diagnosed breast cancer is still a matter of debate. The main additional diagnostic value of MRI relies on specific situations such as detecting multifocal, multicentric or contralateral disease unrecognized on conventional assessment (particularly in patients diagnosed with invasive lobular carcinoma), assessing the response to neoadjuvant chemotherapy, detection of cancer in dense breast tissue, recognition of an occult primary breast cancer in patients presenting with cancer metastasis in axillary lymph nodes, among others. Nevertheless, the development of new MRI technologies such as diffusion-weighted imaging, proton spectroscopy and higher field strength 7.0 T imaging offer a new perspective in providing additional information in breast abnormalities. We conducted an expert literature review on the value of breast MRI in diagnosing and staging breast cancer, as well as the future potentials of new MRI technologies.     

Advanced Breast MRI Techniques: Helpful for Screening Breast Cancer?

Breast magnetic resonance imaging (MRI) is increasingly used in conjunction with mammography as a screening tool to detect breast cancers in asymptomatic high-risk women. Conventional dynamic contrast-enhanced (DCE) breast MRI has a high sensitivity but only moderate specificity for the detection of breast cancer. The primary goal of developing and applying advanced breast MRI techniques that can assess tissue biology is to improve lesion specificity. This review provides a summary of the advances in DCE-MRI techniques and the use of diffusion-weighted imaging and magnetic resonance spectroscopy for breast cancer detection. Publications on the use of these advanced MRI techniques are largely single-institution studies with small numbers of patients, which limits the generalization of this data to a wider screening population. In their current forms, these adjunctive techniques require further research, incorporating an expanded patient population, to validate their utility for breast cancer screening.     

The application of breast MRI in staging and screening for breast cancer

Contrast-enhanced breast magnetic resonance imaging (MRI) is a relatively new but increasingly used modality for the detection of breast cancer. MRI has demonstrated utility in identifying additional tumor foci and extent of disease in patients with known breast cancer. This is especially useful with invasive lobular carcinoma, which is difficult to evaluate on mammography. MRI has been found to identify the primary tumor in 70% to 86% of cases of occult breast cancer. Contrast-enhanced breast MRI has shown some usefulness in the detection of residual cancer following surgery but is limited by postoperative changes. In patients who have undergone neoadjuvant chemotherapy, breast MRI is most accurate in those patients in whom there is little or no response to chemotherapy. The use of contrast-enhanced breast MRlfor breast cancer screening is controversial. It has only been used in afew small studies of high-risk patients. The limitations of breast MRI include uptake in benign lesions and normal tissue, sensitivity for ductal carcinoma in situ, cost, and availability. This paper will discuss the uses, benefits, and limitations of contrast-enhanced breast MRI in the staging and screening of breast cancer.     

MRI联合钼靶及超声对乳腺占位性病变的定性诊断价值

目的:探讨MRI联合钼靶及超声对乳腺占位性病变的定性诊断价值。方法:以回顾性研究法和随机抽样法展开研究,选取从2016年1月到2017年3月在我院就诊的80例乳腺占位性病变患者作为研究对象,病理诊断为恶性乳腺占位性病变20例(恶性组)和良性乳腺占位性病变60例(良性组),记录所有患者的多模态MRI、钼靶、超声诊断特点,并进行鉴别诊断分析。结果:相对于良性组,恶性组钼靶特征主要表现为形态不规则、钙化和毛刺多,对比差异都有统计学意义(P＜0.05)。恶性组超声造影评分为（3.54±0.14）分,良性组超声造影评分为（1.56±0.24）分,恶性组高于良性组(P＜0.05)。恶性组MRI峰值时间低于良性组(P＜0.05),信号增强比率高于良性组(P＜0.05)。多模态MRI、钼靶、超声鉴别诊断乳腺占位性病变的敏感性与特异性分别为100.0%、90.0%、95.0%和100.0%、100.0%和100.0%。结论:MRI联合钼靶及超声对乳腺占位性病变的定性诊断应用都有很好的影像学特征,诊断敏感性与特异性都比较高,在临床上可借鉴性合理选择使用。     

Breast MRI Screening: Benefits and Limitations

Multiple studies have demonstrated screening mammography’s ability to decrease mortality in average risk women. It is also recognized that women at high risk for breast cancer who choose surveillance benefit from additional imaging strategies for cancer detection in addition to mammography alone. Contrast-enhanced breast MRI has become a standard and accepted tool in the screening evaluation of women with a high risk of breast cancer. However, despite recognition of MRI’s ability to detect breast cancer in the screening setting in a high-risk population, there are still questions surrounding the use of breast MRI in the screening environment. This chapter will provide an overview of breast screening MRI indications and current guidelines and will also review the evidence supporting the use of screening breast MRI.     

Bildgebende Diagnostik in der Schwangerschaft

Due to hormone-induced physiological changes the diagnosis of breast cancer during pregnancy is challenging even for experienced radiologists. Sonography is the first choice procedure as the initial imaging modality for evaluating clinically symptomatic breasts during pregnancy. Mammography is an essential complementary imaging modality and is not regarded as an absolute contraindication in pregnancy. Image-guided percutaneous biopsy should be performed for immediate histological diagnosis of suspicious and unclear lesions. Contrast-enhanced magnetic resonance imaging (MRI) of the breast is of limited value in pregnancy. In cases of proven breast cancer complete local staging is recommended. If there is a high risk of distant metastases chest X-ray, ultrasound of the abdomen and plain MRI of the skeleton are recommended. Preoperative sentinel lymph node biopsy should be performed if indicated. Due to increased radiation exposure methods, such as bone scintigraphy and PET/CT should be avoided during pregnancy.     

乳腺肿瘤MRI检查的临床应用

随着MRI设备的更新和软件技术的发展,乳腺MRI在乳腺肿瘤诊断、治疗等方面都有其独特的实用价值。MRI诊断乳腺肿瘤的准确率大大提高,对可疑病灶能在MRI引导下行穿刺活检。乳腺MRI可为手术治疗,尤其是保留乳房的手术治疗提供理想的影像学支持;此外MRI可对乳腺肿瘤行导向治疗。乳腺MRI亦可评价肿瘤手术治疗、放疗、化疗的治疗效果。     

Imaging in breast cancer: Magnetic resonance imaging

Over the past 5 years there has been a marked increase in the use of magnetic resonance imaging (MRI) of the breast. Multiple research studies have confirmed improved cancer detection, diagnosis, and evaluation of response to therapy with breast MRI compared with mammography and ultrasound. As this exciting new technology advances, focused work in optimal scan protocols, appropriate clinical applications, and image interpretation are needed. Both the potential benefits and harms need to be evaluated to guide optimal use of this imaging modality in select patient populations.     

Ultrasonographic findings of missed breast cancer: pitfalls and pearls

Breast ultrasonography (US) is an indispensable tool for diagnosis of palpable and non-palpable breast masses and can facilitate good patient care for breast cancer. However, it is of limited value in cases of isoechoic lesions surrounded by fat, heterogeneous echoic lesions surrounded by a heterogeneous background, deep lesions in huge breasts, subareolar lesions, and lesions caused by poor and underdeveloped operator skills. Some breast tumors such as ductal carcinoma in situ and invasive lobular carcinoma are easily missed on US because of the nature of the lesions. Recent studies have emphasized the use of tools complementary to B-mode US, including real-time elastography and Doppler imaging, in the evaluation of breast lesions missed on US. Radiologists can take a number of steps that will enhance the accuracy of US image interpretation and decrease the rate of false-negative findings. These steps include reviewing clinicopathological data, using mammography and MRI to help assess breast lesions missed on US, strictly adhering to positioning and technical requirements, being alert to subtle features of missed breast lesions, and judging a lesion by its most malignant feature.     

MRI技术在乳腺癌诊断中的应用进展

乳腺癌作为女性恶性肿瘤的常见病，其发病率和发病人数表现出逐年递增趋势。伴随诊治技术及方案的改进，乳腺癌的诊治方式、疗效监督及预后评估等各方面都有了显著提升，从而也对乳腺癌临床早期诊断的检出率及分期的准确率有了较高的要求。医学影像技术尤其是 MRI检查在乳腺疾病诊治方面不断取得新突破和新应用，乳腺MRI检查技术的角色和作用显得越发重要。MRI基础及功能序列扫描等多种辅助检查，多角度、全方位提供病灶相关解剖、血流动力学、功能及代谢等信息。因而需要全方面熟悉MRI检查技术在乳腺癌诊治中的应用现状，才能使之合理高效的运用于临床诊断、术前分期、治疗方案选取及疗效评估等各方面。