Value of MR mammography in the detection and exclusion of recurrent breast carcinoma

Breast MRI during pregnancy and lactation: clinical challenges and technical advances

The breast experiences substantial changes in morphology and function during pregnancy and lactation which affects its imaging properties and may reduce the visibility of a concurrent pathological process. The high incidence of benign gestational-related entities may further add complexity to the clinical and radiological evaluation of the breast during the period. Consequently, pregnancy-associated breast cancer (PABC) is often a delayed diagnosis and carries a poor prognosis. This state-of-the-art pictorial review illustrates how despite currently being underutilized, technical advances and new clinical evidence support the use of unenhanced breast MRI during pregnancy and both unenhanced and dynamic-contrast enhanced (DCE) during lactation, to serve as effective supplementary modalities in the diagnostic work-up of PABC.

Surveillance for second breast cancer events in women with a personal history of breast cancer using breast MRI: a systematic review and meta-analysis

PURPOSE

Women with personal history of breast cancer (PHBC) are currently recommended to receive annual mammography for surveillance of breast cancer recurrence or new primary. However, given issues in accuracy with mammography, there is a need for evolving evidence-based surveillance recommendations with supplemental imaging. In this systematic review, we compiled and compared existing studies that describe the test performance of surveillance breast MRI among women with PHBC.

METHODS

We searched PubMed and EMBASE using MeSH terms for studies (2000-2019) that described the diagnostic characteristics of breast MRI in women with PHBC. Search results were reviewed and included based on PICOTS criteria; quality of included articles was assessed using QUADAS-2. Meta-analysis of single proportions was conducted for diagnostic characteristics of breast MRI, including tests of heterogeneity.

RESULTS

Our review included 11 articles in which unique cohorts were studied, comprised of a total of 8338 women with PHBC and 12,335 breast MRI done for the purpose of surveillance. We predict intervals (PI) for cancer detection rate per 1000 examinations (PI 9-15; I² = 10%), recall rate (PI 5-31%; I² = 97%), sensitivity (PI 58-95%; I² = 47%), specificity (PI 76-97%; I² = 97%), and PPV3 (PI 16-40%; I² = 44%).

CONCLUSIONS

Studies addressing performance of breast MRI are variable and limited in population-based studies. The summary of evidence to date is insufficient to recommend for or against use of breast MRI for surveillance among women with PHBC.

The postconservation breast: part 2, Imaging findings of tumor recurrence and other long-term sequelae

OBJECTIVE

The objectives of this article are to highlight the imaging findings of tumor recurrence and other long-term potential sequelae after breast-conserving surgery and radiation therapy, including increased risk of infection and radiation-induced malignancies. The role of MRI as a problem-solving tool in evaluating the conservatively treated breast will also be discussed.

CONCLUSION

Imaging the treated breast presents challenges because of its limited compressibility and overlapping features of benign posttreatment alterations and tumor recurrence. After lumpectomy and radiation therapy, mammographic findings such as breast edema, skin thickening, fluid collections, architectural distortion, and calcifications have characteristic sequences of evolution toward stability. Changes in the imaging appearance after stability has been achieved--including increasing asymmetry, an enlarging mass, increasing edema or skin thickening, and the development of pleomorphic calcifications within or near the operative bed--should alert the radiologist to possible tumor recurrence. When mammography or sonography is indeterminate, MRI may be useful in excluding recurrence or providing a means for biopsy of a suspicious finding.

Surveillance mammography for detecting ipsilateral breast tumour recurrence and metachronous contralateral breast cancer: a systematic review

Objectives

To determine the diagnostic accuracy of surveillance mammography for detecting ipsilateral breast tumour recurrence and metachronous contralateral breast cancer in women previously treated for primary breast cancer.

Methods

A systematic review of surveillance mammography compared with ultrasound, magnetic resonance imaging (MRI), specialist-led clinical examination or unstructured primary care follow-up, using histopathological assessment for test positives and follow-up for test negatives as the reference standard.

Results

Nine studies met our inclusion criteria. Variations in study comparisons precluded meta-analysis. For routine ipsilateral breast tumour detection, surveillance mammography sensitivity ranged from 64–67% and specificity ranged from 85–97%. For MRI, sensitivity ranged from 86–100% and specificity was 93%. For non-routine ipsilateral breast tumour detection, sensitivity and specificity for surveillance mammography ranged from 50–83% and 57–75% and for MRI 93–100% and 88–96%. For routine metachronous contralateral breast cancer detection, one study reported sensitivity of 67% and specificity of 50% for both surveillance mammography and MRI.

Conclusion

Although mammography is associated with high sensitivity and specificity, MRI is the most accurate test for detecting ipsilateral breast tumour recurrence and metachronous contralateral breast cancer in women previously treated for primary breast cancer. Results should be interpreted with caution because of the limited evidence base.

Key Points

• Surveillance mammography is associated with high sensitivity and specificity

• Findings suggest that MRI is the most accurate test for detecting further breast cancer

• Robust conclusions cannot be made due to the limited evidence base

• Further research comparing surveillance mammography and other diagnostic tests is required

FDG-PET and other imaging modalities for the evaluation of breast cancer recurrence and metastases: a meta-analysis

Background and purpose

Breast carcinoma is the most common cancer in female patients with a propensity for recurrence and metastases. The accuracy of ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), scintimammography (SMM) and positron emission tomography (PET) in diagnosing the recurrent and/or breast cancer has never been systematically assessed, and present systematic review was aimed at this issue.

Methods

MEDLINE and EMBASE were searched for articles dealt with detection of recurrent and/or metastatic breast cancer by US, CT, MRI, SMM or PET whether interpreted with or without the use of CT. Histopathologic analysis and/or close clinical and imaging follow-up for at least 6 months were used as golden reference. We extracted data to calculate sensitivity, specificity, summary receiver operating characteristic curves and area under the curve and to test for heterogeneity.

Result

In 42 included studies, US and MRI had highest pooled specificity (0.962 and 0.929, respectively); MRI and PET had highest pooled sensitivity (0.9500 and 0.9530, respectively). The AUC of US, CT, MRI, SMM and PET was 0.9251, 0.8596, 0.9718, 0.9386 and 0.9604, respectively. Results of pairwise comparison between each modality demonstrated that AUC of MRI and PET was higher than that of US or CT, p < 0.05. No statistical significance was found between MRI and PET. There was heterogeneity among studies and evidence of publication bias.

Conclusion

In conclusion, MRI seemed to be a more useful supplement to current surveillance techniques to assess patients with suspected recurrent and/or metastatic breast cancer. If MRI shows an indeterminate or benign lesion or MRI was not applicable, FDG-PET could be performed in addition.

Typical atypical findings on dynamic MRI of the breast

Dynamic contrast enhanced magnetic resonance imaging (DCE MRI) of the breast has become an important tool to detect and characterize breast disease. The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS(®)) provides a standardized vocabulary for describing the morphologic features and contrast kinetics of breast lesions. However, some lesions may show morphologic and dynamic MR features not consistent with their histologic nature resulting in incorrect categorization as malignant or benign. Another cause of diagnostic problems is artifacts. Thus correct interpretation of dynamic MRI of the breast demands knowledge of the most common pitfalls encountered in clinical practice. A pictorial overview of these is presented, with particular reference to the differentiation of malignant tumors from benign lesions.

Magnetic resonance mammography in the evaluation of recurrence at the prior lumpectomy site after conservative surgery and radiotherapy

INTRODUCTION

The aim was to assess the value of magnetic resonance mammography (MRM) in the detection of recurrent breast cancer on the prior lumpectomy site in patients with previous conservative surgery and radiotherapy.

METHODS

Between April 1999 and July 2003, 93 consecutive patients with breast cancer treated with conservative surgery and radiotherapy underwent MRM, when a malignant lesion on the site of lumpectomy was suspected by ultrasound and/or mammography. MRM scans were evaluated by morphological and dynamic characteristics. MRM diagnosis was compared with histology or with a 36-month imaging follow-up. Enhancing areas independent of the prior lumpectomy site, incidentally detected during the MRM, were also evaluated.

RESULTS

MRM findings were compared with histology in 29 patients and with a 36-month follow-up in 64 patients. MRM showed 90% sensitivity, 91.6% specificity, 56.3% positive predictive value and 98.7% negative predictive value for detection of recurrence on the surgical scar. MRM detected 13 lesions remote from the scar. The overall sensitivity, specificity, positive predictive value and negative predictive value of MRM for detection of breast malignancy were 93.8%, 90%, 62.5% and 98.8%, respectively.

CONCLUSION

MRM is a sensitive method to differentiate recurrence from post-treatment changes at the prior lumpectomy site after conservative surgery and radiation therapy. The high negative predictive value of this technique can avoid unnecessary biopsies or surgical treatments.

The role of magnetic resonance imaging in diagnosis and management of breast cancer

A review of the literature on the current applications of breast magnetic resonance imaging (MRI) indications, their rationale and their place in diagnosis and management of breast cancer was given. Contrast-enhanced breast MRI is developing as a valuable adjunct to mammography and sonography. Its high sensitivity for invasive breast cancer establishes its superiority in evaluation of multifocality/multicentricity, tumor response to neoadjuvant chemotherapy, detection of recurrence, and staging. Emerging applications include spectroscopy, usage of new contrast agents, and MRI-guided interventions, including noninvasive treatment of breast cancer. Its potential benefit in screening high-risk women has yet to be established with prospective studies, particularly with regard to false positive results.

PET and functional anatomic fusion imaging in lung and breast cancers

Metabolic imaging with PET is an established adjunct to anatomic imaging methods in patients with bronchial and breast cancers. The functional anatomic fusion imaging with PET/CT can further improve staging and restaging of patients. PET/CT can influence the planning of a surgical intervention or radiation treatment at staging and in patients with suspected locoregional recurrence. The use of a PET/CT whole body imaging protocol may identify extended disease earlier than conventional imaging methods and thus influence treatment decisions.

Problem solving MR imaging of the breast

MR imaging is emerging as a valuable adjunct to mammography and ultrasound for the evaluation of the breast. Breast MR imaging has high sensitivity for the detection of breast cancer but suffers from a relatively low specificity. There is growing experience with this imaging modality as applied to breast diseases and more standardization in obtaining and interpreting these examinations is occurring, including the introduction ofa reporting lexicon similar to that for mammography. Breast MR imaging can be used for problem solving in determination of the local extent of disease in women with newly diagnosed breast cancer and for the evaluation of cases that remain inconclusive despite thorough mammographic and sonographic evaluation.

Improved artificial neural networks in prediction of malignancy of lesions in contrast-enhanced MR-mammography

The aim of this study was to evaluate the capability of improved artificial neural networks (ANN) and additional novel training methods in distinguishing between benign and malignant breast lesions in contrast-enhanced magnetic resonance-mammography (MRM). A total of 604 histologically proven cases of contrast-enhanced lesions of the female breast at MRI were analyzed. Morphological, dynamic and clinical parameters were collected and stored in a database. The data set was divided into several groups using random or experimental methods [Training & Testing (T&T) algorithm] to train and test different ANNs. An additional novel computer program for input variable selection was applied. Sensitivity and specificity were calculated and compared with a statistical method and an expert radiologist. After optimization of the distribution of cases among the training and testing sets by the T & T algorithm and the reduction of input variables by the Input Selection procedure a highly sophisticated ANN achieved a sensitivity of 93.6% and a specificity of 91.9% in predicting malignancy of lesions within an independent prediction sample set. The best statistical method reached a sensitivity of 90.5% and a specificity of 68.9%. An expert radiologist performed better than the statistical method but worse than the ANN (sensitivity 92.1%, specificity 85.6%). Features extracted out of dynamic contrast-enhanced MRM and additional clinical data can be successfully analyzed by advanced ANNs. The quality of the resulting network strongly depends on the training methods, which are improved by the use of novel training tools. The best results of an improved ANN outperform expert radiologists.

O uso da ressonância magnética na investigação do câncer mamário

Os métodos diagnósticos de imagem mamografia, ultra-sonografia e cintilografia são exames imprescindíveis no diagnóstico do câncer de mama e no acompanhamento após o procedimento cirúrgico, porém, todos apresentam limitações específicas. Atualmente, a ressonância magnética tem-se revelado um método diagnóstico promissor para avaliar mais detalhadamente lesões tumorais do parênquima mamário. Neste trabalho os autores descrevem as principais indicações e os achados da ressonância magnética no câncer de mama, bem como comparam o seu desempenho com o dos outros métodos de imagem - mamografia, ultra-sonografia e cintilografia -, incluindo as vantagens e limitações de cada modalidade.

Follow-up of women with breast cancer: comparison between MRI and FDG PET

The aim of this study was to compare MRI of the breast with (18)F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET) in patients with suspected local or regional breast cancer recurrence or suspected contralateral breast cancer. Thirty-two patients (mean age 57.2 years, age range 32-76 years) with suspected loco-regional recurrence ( n=19), chest wall recurrence ( n=5), and suspected secondary tumor of the contralateral breast ( n=8) underwent MRI of the breast and FDG PET of the whole body and breast region. Cytology/histology ( n=17) or a clinical follow-up examination ( n=15) with additional imaging served as the standard of reference. A McNemar test was performed to compare PET and MRI, and kappa was determined to quantify agreement of both methods. Sensitivity was 79 and 100%, specificity was 94 and 72%, and accuracy was 88 and 84% for MRI and PET, respectively. Additional metastases outside the field of view of MRI were found in PET in 5 patients. In this study both imaging methods had comparable accuracy. The detection of distant metastases with whole-body PET imaging can influence patient management.

Magnetic resonance imaging of induration in the irradiated breast

BACKGROUND

The causes of induration (hardness) in the breast many years after tumour excision and whole breast radiotherapy for early stage breast cancer are not well established. The purpose of this study is to describe morphological magnetic resonance imaging (MRI) appearances and MRI-derived microvascular functional characteristics of the indurated breast several years post-treatment.

PATIENTS AND METHODS

Fifteen women with moderate or marked induration at the electron boost site after breast preserving surgery and radiotherapy for early breast cancer (median 6 years; range, 2-15 years) underwent MRI, including 6/15 with very marked breast shrinkage and 8/15 with marked induration. Morphological T1- and T2-weighted and STIR images were obtained followed by a dynamic contrast medium enhanced sequence. The breast skin and underlying parenchyma of the irradiated breast were evaluated for thickening, oedema and the presence of enhancement compared to the contralateral breast. Particular note of boost site findings was made.

RESULTS

No evidence of tumour recurrence was seen. Fat necrosis was seen in 2/15 cases. Skin thickening and skin oedema not evident clinically were seen in 11/15 patients. Increased parenchymal oedema at the electron boost site was seen in 12/15 patients. The parenchymal oedema was not confined to the electron boost site, but was strongest in this location in 9/12 patients. Post-contrast images in 12/14 patients showed persistent parenchymal enhancement in nine (marked in three, who also had severe breast shrinkage and marked induration), a finding consistent with, but not diagnostic of tissue fibrosis.

CONCLUSIONS

Fat necrosis is not likely to contribute to breast induration several years after radiotherapy in more than a minority of patients. Increased fluid content in the breast parenchyma and skin oedema are likely to be more important contributors to palpable induration. Increased fluid content may be related to persistent capillary leakage even many years post-treatment, an expression of radiation-induced vascular injury. Fibrosis cannot be scored directly on MRI, but persistent parenchymal enhancement in a high proportion of post-contrast images is compatible with this pathology.

Silicone migration from silicone-injected breasts: magnetic resonance images

Injection of liquid silicone into the breast was performed illicitly in the 1950s to 1960s and was subsequently prohibited. Many complications arise from silicone injection, and liquid silicone migration is a complication that has not been widely reported. The authors present magnetic resonance images of a patient with liquid silicone migration from the breast to the upper chest and lower neck. Breast ultrasonographic and mammographic findings are also presented for correlation.

Magnetic resonance imaging of the breast

BACKGROUND

Magnetic resonance imaging (MRI) has the potential to become a useful adjunct in breast imaging. Contrast-enhanced breast MRI has demonstrated a high sensitivity in the detection of invasive breast cancer. In clinical studies, breast MRI has often altered the course of patient care. Although promising results have been generated, MRI of the breast is currently in a development stage.

METHODS

The authors reviewed the literature on the potential indications, sensitivity, specificity, and limitations of MRI of the breast.

RESULTS

Reported advantages of MRI of the breast over conventional imaging techniques include improved staging and treatment planning, enhanced evaluation of the augmented breast, better detection of recurrence, and improved screening of high-risk women. Contrast-enhanced breast MRI is a sensitive modality for detecting breast cancer, but its variable specificity is a major limitation.

CONCLUSIONS

MRI of the breast is emerging as a valuable adjunct to mammography and sonography for specific clinical indications. Additional clinical studies that define indications, interpretation criteria, imaging parameters, and cost effectiveness are needed. A multi-institutional study designed to address these issues is in progress.

MR imaging of the breast for the detection, diagnosis, and staging of breast cancer

With the introduction of contrast agents, advances in surface coil technology, and development of new imaging protocols, contrast agent-enhanced magnetic resonance (MR) imaging has emerged as a promising modality for detection, diagnosis, and staging of breast cancer. The reported sensitivity of MR imaging for the visualization of invasive cancer has approached 100%. There are many examples in the literature of MR imaging--demonstrated mammographically, sonographically, and clinically occult breast cancer. Often, breast cancer detected on MR images has resulted in a change in patient care. Despite these results, there are many unresolved issues, including no defined standard technique for contrast-enhanced breast MR imaging, no standard interpretation criteria for evaluating such studies, no consensus on what constitutes clinically important enhancement, and no clearly defined clinical indications for the use of MR imaging. Furthermore, this technology remains costly, and issues of cost-effectiveness and cost competition from percutaneous biopsy have yet to be fully addressed. These factors along with the lack of commercially available MR imaging--guided localization and biopsy systems have slowed the transfer of this imaging technology from research centers to clinical breast imaging practices. Technical requirements, potential clinical applications, and potential pitfalls and limitations of contrast-enhanced MR imaging as a method to help detect, diagnose, and stage breast cancer will be described.

Tumor vascularity of breast lesions: potentials and limits of contrast-enhanced Doppler sonography

OBJECTIVE

We investigated improving the evaluation of benignity in breast lesions using Doppler sonography with galactose palmitic acid-coated microbubbles.

SUBJECTS AND METHODS

In 77 patients with 84 breast tumors scheduled for surgical tumor removal, color-coded duplex sonography was performed before and after administration of Levovist. Of the 77 patients, 25 with 28 lesions had been treated for prior breast carcinoma. The parameters investigated were the following: degree of enhancement, number of tumor vessels, time to maximum enhancement, and the pattern of vascular morphology and course.

RESULTS

Findings in malignant tumors (n = 53) showed a greater number of vessels and a faster stronger enhancement after Levovist administration, whereas a definite partial overlap with results from benign tumors (n = 31) was found. The best distinction was produced by vascular morphology and course, with a sensitivity of 90% and a specificity of 81 %. In 23 of the 25 patients who previously underwent surgery, a clear distinction was possible between a postoperative scar (n = 11) and a tumor recurrence (n = 17).

CONCLUSION

Although administration of the contrast agent clearly improved evaluation of benign features on Doppler sonography, absolute certainty cannot be achieved. The feasibility of making an otherwise difficult distinction between a scar and tumor recurrence on sonography and mammography appears to be promising, but further studies are necessary.

MRI of the breast

MRI of the breast is rapidly evolving as a sensitive technique for the detection and staging of breast cancer. It has considerable benefits but is time consuming and expensive. The benefits and limitations of this technique are presented.

Mammographic findings after breast conservation therapy

Breast conservation therapy for breast cancer involves lumpectomy or segmental mastectomy followed by radiation therapy. Masses, fluid collections, architectural distortion, scarring, edema, skin thickening, and calcifications are posttreatment findings that may mimic or mask local tumor recurrence. Despite the overlap between posttreatment changes and tumor recurrence, the two entities can usually be distinguished by the characteristic mammographic appearances of posttreatment sequelae and by comparing interval findings on successive studies. Postoperative masses and fluid collections slowly diminish in size and usually resolve by 1 year after surgery. Radiation-induced edema gradually resolves; increasing edema may be due to recurrent cancer. Postsurgical scarring usually appears as a poorly marginated soft-tissue mass with interspersed radiolucent areas. Recurrent cancer is usually seen as a mass with no central radiolucent areas. Pleomorphic and granular microcalcifications are important markers for recurrent cancer and can usually be distinguished from the thick, calcified plaques and elongated dystrophic calcifications associated with scarring.

MRI in routine breast cancer follow-up: correlation with clinical outcome

AIM

Magnetic resonance imaging (MRI) of the breast has been shown to be useful as an additional imaging test in patients suspected of having recurrent disease, when clinical examination or mammography are equivocal. This study examines the utility of MRI as a routine test in the follow-up of treated breast cancer patients without equivocal clinical or imaging findings.

MATERIALS AND METHODS

Contrast-enhanced breast MRI was performed as part of routine breast cancer follow-up in 26 patients with equivocal clinical or mammographic findings and 33 control patients in whom clinical and imaging findings were consistent with post-treatment changes only. Clinical outcome was assessed at 3 years post MRI.

RESULTS

Four patients with equivocal clinical or mammographic findings had abnormal MRI: all MRI abnormalities were subsequently shown to represent benign disease. None of the equivocal group developed local recurrence, although two of 26 developed distant metastases. One of the control group had unsuspected distant metastases detected by MRI: the other 32 patients had no significant abnormality on MRI. Three patients subsequently developed local tumour recurrence.

CONCLUSION

A single normal breast MRI examination during follow-up is a poor predictor of subsequent local recurrence.

Characterization of N-ethyl-N-nitrosourea-induced malignant and benign breast tumors in rats by using three MR contrast agents

A carcinogen (N-ethyl-N-nitrosourea)-induced animal tumor model was established to grow malignant and benign breast tumors. In each tumor the pharmacokinetic characteristics were measured by using three contrast agents, gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA; <1 kD), Gadomer-17 (35 kD), and albumin-Gd-DTPA (70-90 kD). Infiltrating ductal carcinomas (IDC) with low, medium, and high Scarf-Bloom-Richardson grades and fibroadenomas (FA) were analyzed. We found that Gd-DTPA could differentiate between FA and malignant tumors, but not between malignant tumors of low and high grades. In contrast, the intermediate size agent Gadomer-17 could differentiate between high-grade and low-grade IDC, but not between low-grade IDC and FA due to their similar enhancement patterns (despite their different origins). The largest agent, albumin-Gd-DTPA, was capable of differentiating both, but the low contrast-to-noise ratio was its major technical concern. The results in this breast tumor model suggest that macromolecular agents provide useful information for differential diagnosis among IDCs of various grades, but they do not provide superior information than Gd-DTPA for differential diagnosis between IDC and FA.