MR imaging of the breast.

The results of clinical investigation suggest that MR imaging can provide clinically important information that cannot be obtained with conventional imaging methods, and that this modality will, in the future, be an invaluable adjunctive breast imaging tool, just as breast imaging is today. MR imaging as a method to detect, diagnose, and stage breast cancer remains in the investigational stage, but is emerging as perhaps the most promising imaging modality for breast cancer detection.

MR imaging-guided interventions in the breast.

MR imaging of the breast has high sensitivity for the detection of invasive breast cancer. However, not all enhancing lesions are malignant. A needle localization or biopsy system is necessary to differentiate false positive benign enhancing lesions from the true carcinomas. In this article, the techniques, pitfalls, and potential clinical indications for MR imaging-guided needle localization and percutaneous biopsy are discussed.

Cyclosporin A-induced fibroadenomas of the breast: report of five cases.

Five female patients undergoing cyclosporin A therapy had newly developed breast masses. Masses were bilateral in three of the five patients and palpable in four patients. The imaging findings were suggestive of fibroadenomas, and biopsy results were used to confirm the diagnosis. With the development of new breast lesions in patients after transplantation surgery, the diagnosis of cyclosporin A-induced fibroadenomas should be considered.

A combined architectural and kinetic interpretation model for breast MR images.

RATIONALE AND OBJECTIVES: The purpose of this study was to integrate contrast material kinetic and architectural data from magnetic resonance (MR) images and to assess the improvement in diagnostic accuracy. MATERIALS AND METHODS: MR imaging data from a diagnostic cohort of 100 patients (50 malignant and 50 benign cases) were analyzed. RESULTS: Qualitative classification of the enhancement curve was the most predictive kinetic feature. Receiver operating characteristic (ROC) curves were calculated for the architectural model alone and for the architectural model combined with the qualitative kinetic classification. The results demonstrated a statistically significant increase in ROC area (P = .03) of the combined model compared with that of the architectural model alone. CONCLUSION: The addition of qualitative classification of the time-signal intensity curve to an architectural interpretation model results in significant improvement in model performance as measured by the area under the ROC curve.

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.

Diabetic mastopathy in men: imaging findings in two patients.

The classic imaging findings of diabetic mastopathy, an uncommon entity manifesting in patients with a history of long-standing insulin-dependent diabetes mellitus, have been reported in the literature in women but not, to the authors' knowledge, in men. Two men with diabetic mastopathy presented with palpable breast masses. The clinical histories of the men in whom this condition was diagnosed were similar to those reported for women with the condition. The mammographic findings in both men, at presentation, were suggestive of gynecomastia.

The impact of a multidisciplinary breast cancer center on recommendations for patient management: the University of Pennsylvania experience.

BACKGROUND: Advances in the diagnosis and treatment of breast carcinoma have led to a multidisciplinary approach to management for patients with breast carcinoma. To assess the effect of this approach, the authors performed an evaluation for a cohort of patients examined in a multidisciplinary breast cancer center. METHODS: An analysis was performed for the records of 75 consecutive women with 77 breast lesions examined in consultation in a multidisciplinary breast cancer center between January and June 1998. Each patient's case was evaluated by a panel consisting of a medical oncologist, surgical oncologist, radiation oncologist, pathologist, diagnostic radiologist, and, when indicated, plastic surgeon. A comprehensive history and physical examination was performed, and the relevant mammograms, pathology slides, and medical records were reviewed. Treatment recommendations made before this evaluation were compared with the consensus recommendations made by the panel. RESULTS: For the 75 patients, the multidisciplinary panel disagreed with the treatment recommendations from the outside physicians in 32 cases (43%), and agreed in 41 cases (55%). Two patients (3%) had no treatment recommendation before consultation. For the 32 patients with a disagreement, the treatment recommendations were breast-conservation treatment instead of mastectomy (n = 13; 41%) or reexcision (n = 2; 6%); further workup instead of immediate definitive treatment (n = 10; 31%); treatment based on major change in diagnosis on pathology review (n = 3; 9%); addition of postmastectomy radiation treatment (n = 3; 9%); or addition of hormonal therapy (n = 1; 3%). CONCLUSIONS: The multidisciplinary breast cancer evaluation program provided an integrated program in which individual patients were evaluated by a team of physicians and led to a change in treatment recommendation for 43% (32 of 75) of the patients examined. This multidisciplinary program provided important second opinions for many patients with breast carcinoma.

Update of breast MR imaging architectural interpretation model.

PURPOSE: To (a) validate a breast magnetic resonance (MR) interpretation model, (b) expand the tree-shaped prediction model to increase specificity without decreasing sensitivity, and (c) reevaluate the model's diagnostic performance. MATERIALS AND METHODS: Two hundred sixty-two new patients with palpable or mammographic abnormalities underwent MR imaging, and pathologic evaluation was performed. They were entered prospectively into the model, which yielded 454 patients in the construction (training) and validation (test) phases. Predictive values for previously published terminal nodes or branch points of the model were compared between the training and test data sets. Ductal enhancement morphology, regional enhancement micronodularity, regional enhancement degree, and focal mass T2 signal intensity were evaluated for model expansion. Diagnostic performance characteristics of the model were recalculated. RESULTS: For previously published nodes, absence of a lesion visible at MR imaging, smooth masses, lobulated masses with nonenhancing internal septations, and lobulated masses with minimal or no enhancement had negative predictive values (NPVs) for malignancy similar in both data sets (96% vs 99%, 100% vs 93%, 100% vs 98%, and 100% vs 100%). Irregular masses with internal septations (100% vs 0%) and spiculated masses with no or minimal enhancement (100% vs 50%) did not. Nonseptated enhancing lobulated masses with low T2 signal intensity were added as a benign terminal node (NPV, 100%). Mild regional enhancement (NPV, 92%) was added but not considered a terminal node. Sensitivity, specificity, NPV, positive predictive value, and accuracy of the expanded model were 96%, 80%, 96%, 78%, and 87%, respectively. CONCLUSION: Additional investigation yielded a slightly modified model, but the diagnostic performance characteristics remain high, similar to those originally published.

MR imaging of the breast in patients with invasive lobular carcinoma.

OBJECTIVE: Our objective was to assess the usefulness of MR imaging in patients diagnosed with invasive lobular carcinoma of the breast. MATERIALS AND METHODS: Between July 1993 and September 1999, 32 women (33 cases) diagnosed with pure invasive lobular carcinoma of the breast underwent contrast-enhanced MR imaging examination. One woman was excluded because of lack of follow-up. Correlation was made between the mammographic and sonographic findings, the MR imaging findings, and the final pathology results for the remaining 32 cases. RESULTS: In 18 women who did not undergo excisional biopsy before the MR imaging, MR imaging showed more extensive tumor burden or the detection of the primary lesion that was occult on conventional imaging in seven (38.9%) of 18 women. In nine (50%) of 18 women, MR imaging performed equally as well as mammography and sonography. In one case (5.6%), MR imaging and mammography underestimated disease extent. In another patient (5.6%), MR imaging overestimated tumor burden, although mammography failed to show the cancer. In 14 patients who had excisional biopsy before the MR imaging, residual tumor was shown in eight women (57.1%) with extensive tumor or additional separate foci in five of the eight patients. In two cases (14.3%) that were interpreted as equivocal, residual tumor was shown in both cases on reexcision. In three cases (21.4%), the MR imaging was interpreted as negative, but microscopic tumor was shown around seroma on reexcision. False-positive enhancement was seen in one case (7.1%). CONCLUSION: MR imaging showed more extensive tumor than conventional imaging and affected the clinical management in 16 (50%) of 32 patients with invasive lobular carcinoma.

Spectrum of US findings in pediatric and adolescent patients with palpable breast masses.

Palpable breast masses arising in pediatric and adolescent patients are uncommon. A careful physical examination should be performed first, followed by an ultrasonographic evaluation when a suspect mass is present. In this study population, palpable findings were all due to benign causes, which is concordant with the literature. Benign causes included gynecomastia, cyst, fibroadenoma, lymph node, galactocele, duct ectasia, and infection. Though extremely rare, breast malignancies do occur in the pediatric and adolescent population.

MR imaging of the breast.

The results of clinical investigation suggest that MR imaging can provide clinically important information that cannot be obtained with conventional imaging methods, and that this modality will, in the future, be an invaluable adjunctive breast imaging tool just as breast ultrasound is today. MR imaging appears to be the most accurate method for the detection of implant failure, and although it is the most costly of the available implant imaging techniques, it may be the study of choice when there is a question of implant integrity that cannot be answered with conventional methods. MR imaging as a method to detect, diagnose, and stage breast cancer remains in the investigational stage. The specificity of MR imaging appears limited because of the overlap in the enhancement kinetics and morphologic appearance of benign and malignant lesions. In selected cases, the identification of certain morphologic features, such as internal septations or the absence of enhancement, may be used to classify a lesion as benign, offering an alternative to percutaneous or excisional biopsy. MR imaging appears to be very sensitive for the visualization of both invasive carcinoma and DCIS. Perhaps most important, MR imaging can detect invasive and noninvasive breast carcinoma that is both mammographically and clinically occult, offering the potential for more accurate breast cancer staging and optimized treatment planning. MR imaging is emerging as perhaps the most promising imaging modality for breast cancer detection to date. Published results, however, are from studies with relatively small numbers of patients. The results of these studies should be validated in a large-scale clinical trial before MR imaging is implemented clinically, outside of research settings. This type of clinical investigation is needed to define the technical requirements for optimal imaging, to define interpretation criteria, to develop accurate MR imaging guided localization and biopsy systems, to define the clinical indications for which MR imaging should be used as an adjunct to conventional imaging methods, and to address the issue of cost-effectiveness. One such trial, an international, multi-institutional study funded by the National Cancer Institute, is presently underway.

MR imaging in patients with nipple discharge: initial experience.

PURPOSE: To investigate the potential of magnetic resonance (MR) imaging in patients with nipple discharge. MATERIALS AND METHODS: Between February 1992 and December 1998, 23 patients with nipple discharge underwent contrast material-enhanced MR imaging at 1.5 T. Mammographic findings were negative in 22 of 23 patients and revealed asymmetry in one patient. Galactography was attempted in two patients, with negative findings in one patient and no success in the other. Fifteen of 23 patients underwent excisional biopsy-seven of 15 with MR imaging-guided localization, and one of 15 with mammographic localization. Eight of 23 patients were followed up clinically (range, 7-24 months; mean, 20 months). RESULTS: In 11 of the 15 (73%) patients who underwent excisional biopsy, MR imaging findings correlated with histopathologic findings. MR imaging demonstrated four of six benign papillomas and one of two fibroadenomas as circumscribed, enhancing subareolar masses. Findings of one MR imaging examination were negative, and benign tissue was found at excisional biopsy. MR imaging findings were suspicious in six of the seven patients with excisional biopsy findings of malignancy (regional enhancement [n = 2], ductal enhancement [n = 2], peripherally enhancing mass [n = 1], and spiculated mass [n = 1]). In one of the seven patients, a benign-appearing intraductal mass was identified at MR imaging; excisional biopsy revealed a benign papilloma with an adjacent focus of DCIS. CONCLUSION: MR imaging can help identify both benign and malignant causes of nipple discharge. It potentially offers a noninvasive alternative to galactography.

Accuracy of sentinel lymph node biopsy in patients with large primary breast tumors.

BACKGROUND: Patients with large breast tumors are increasingly undergoing neoadjuvant treatment to downstage local disease; however, accurate staging of the axilla before the initiation of chemotherapy remains problematic. In the current study, the authors report on the accuracy of sentinel lymph node (SLN) biopsy in such patients to determine the feasibility of applying this technique before induction chemotherapy. METHODS: One hundred three patients with 104 tumors classified as American Joint Committee on Cancer (AJCC) T2 (tumor >/= 2 cm but /= 3 cm, 1 false-negative result (2% [95% exact CI, < 1-15%]) was identified, and the rate of lymph node metastasis was 62.5% (95% exact CI, 48. 5-75%) (35 of 56 tumors). Within 30 SLN positive patients with tumors >/= 3 cm and complete axillary lymph node dissection, 3 of 8 patients (37.5% [95% exact CI, 8.5-75.5%]) with micrometastasis ( 2 mm) to the SLN (P = 0.002). CONCLUSIONS: SLN biopsy for patients with large breast tumors is technically feasible and highly accurate. SLN biopsy should be considered for the staging of clinically negative axilla in patients scheduled to receive neoadjuvant chemotherapy.

Cost-effectiveness of MR imaging and core-needle biopsy in the preoperative work-up of suspicious breast lesions.

PURPOSE: To assess the clinical and economic consequences of the use of preoperative breast magnetic resonance (MR) imaging and core-needle biopsy (CNB) to avert excisional biopsy (EXB). MATERIALS AND METHODS: A decision-analytic Markov model was constructed to compare MR imaging, CNB, and EXB without preoperative testing in a woman with a suspicious breast lesion. Stage-specific cancer prevalence, tumor recurrence, progression rates, and MR imaging and CNB sensitivity and specificity were obtained from the literature. Cost estimates were obtained from the literature and from the Medicare fee schedule. RESULTS: EXB without preoperative testing was associated with the greatest quality-adjusted life expectancy, followed by MR imaging and CNB; life expectancies were 17.409, 17.405, and 17.398 years, respectively. EXB resulted in the greatest lifetime treatment cost ($31,438), followed by MR imaging ($29,072) and CNB ($28,573). Results were robust over a wide range of cancer prevalence, stage distribution, tumor progression rates, and procedure and treatment costs. Incremental cost-effectiveness ratios showed that preoperative testing was cost-effective, but the choice between MR imaging and CNB was highly dependent on the accuracy of each test and to patient preferences. CONCLUSION: Preoperative testing of most suspicious breast lesions was cost-effective. More precise estimates of MR imaging and CNB test performance characteristics are needed. Until those are available, patient preferences should inform individual decisions regarding preoperative testing.

Sentinel lymph node biopsy with metastasis: can axillary dissection be avoided in some patients with breast cancer?

PURPOSE: Recent studies have suggested that the sentinel lymph node (SLN) biopsy is an accurate alternative staging procedure for women with breast cancer. The goal of this study was to identify a subset of breast cancer patients in whom metastatic disease was confined only to the SLN. MATERIALS AND METHODS: From two institutions, we recruited 222 women with breast cancer for SLN biopsy. A SLN biopsy was performed in each patient, followed by an axillary dissection in 182 patients. Histologic and immunohistochemical cytokeratin stains were used on all SLNs. RESULTS: The SLN was identified in 220 (97. 8%) of the 225 biopsies. Evidence of metastatic breast cancer in the SLN was found in 60 (27.0%) of the 222 patients. Of these patients, 32 (53.3%) had evidence of tumor in the SLN only. By multivariate analysis, two factors were found to be significantly associated with a higher likelihood of tumor involvement in the non-SLNs: primary tumor size larger than 2.0 cm (P =.0004) and macrometastasis (> 2.0 mm) in the SLN (P =.002). Additional analysis revealed that none (0%; 95% confidence interval, 0% to 18.5%) of the 18 patients with primary tumors < or = 2.0 cm and micrometastasis to the SLN had remaining axillary lymph node involvement. CONCLUSION: The primary tumor size and metastasis size in the SLN are independent factors in predicting the incidence of tumor in the non-SLNs. Therefore, the SLN biopsy alone may be adequate for staging and/or therapy decision making in patients with primary breast tumors < or = 2.0 cm and micrometastasis in the SLN.

How experience and training influence mammography expertise.

RATIONALE AND OBJECTIVES: The authors evaluated the influence of perceptual and cognitive skills in mammography detection and interpretation by testing three groups representing different levels of mammography expertise in terms of experience, training, and talent with a mammography screening-diagnostic task. MATERIALS AND METHODS: One hundred fifty mammograms, composed of unilateral cranial-caudal and mediolateral oblique views, were displayed in pairs on a digital workstation to 19 radiology residents, three experienced mammographers, and nine mammography technologists. One-third of the mammograms showed malignant lesions; two-thirds were malignancy-free. Observers interacted with the display to indicate whether each image contained no malignant lesions or suspicious lesions indicating malignancy. Decision time was measured as the lesions were localized, classified, and rated for decision confidence. RESULTS: Compared with performance of experts, alternative free response operating characteristic performance for residents was significantly lower and equivalent to that of technologists. Analysis of overall performance showed that, as level of expertise decreased, false-positive results exerted a greater effect on overall decision accuracy over the time course of image perception. This defines the decision speed-accuracy relationship that characterizes mammography expertise. CONCLUSION: Differences in resident performance resulted primarily from lack of perceptual-learning experience during mammography training, which limited object recognition skills and made it difficult to determine differences between malignant lesions, benign lesions, and normal image perturbations. A proposed solution is systematic mentor-guided training that links image perception to feedback about the reasons underlying decision making.

Role of magnetic resonance imaging and magnetic resonance imaging--guided surgery in the evaluation of patients with early-stage breast cancer for breast conservation treatment.

Magnetic resonance imaging (MRI) may be more sensitive than mammography for detecting breast cancer and may have an adjunctive role in assessing patients with early-stage disease for breast conservation treatment. This study was performed to analyze the impact of breast MRI on the clinical management of 83 patients being considered for breast conservation treatment. Eighty-three consecutive cases of patients undergoing breast MRI during standard workup and evaluation for breast conservation treatment from 1993 to 1996 were retrospectively reviewed. Records were reviewed for patient and tumor characteristics, mammographic findings, MRI findings, timing of MRI study, findings from MRI-guided surgery (when done), and whether the patient underwent breast conservation treatment. MRI definitely altered management in 15 patients (18%), may have affected management in 4 patients (5%), and did not change management in 64 patients (77%). Thirteen patients underwent additional surgery because of MRI findings; the positive predictive value for MRI-guided surgery was 38% (5 of 13). Ultimately, 82% of the patients received breast conservation treatment. No predictive factor was identified to characterize the patients most likely to have management affected by MRI findings. These findings suggest that breast MRI may be useful in the evaluation of patients with early-stage breast cancer for breast conservation treatment. A larger study population and outcome data will be required to confirm these findings and to define those patients most likely to benefit from breast MRI.

Breast MR imaging in patients with axillary node metastases and unknown primary malignancy.

PURPOSE: To assess the usefulness of magnetic resonance (MR) imaging of the breast in patients with malignant axillary adenopathy and unknown primary malignancy. MATERIALS AND METHODS: Between October 1993 and December 1997, 38 women with malignant axillary adenopathy and negative mammographic and physical examination findings underwent contrast material-enhanced MR imaging. Sixteen patients were excluded due to axillary tail cancer (n = 7), lack of follow-up (n = 4), second primary malignancy (n = 3), or chemotherapy before MR imaging (n = 2). The study population comprised the remaining 22 patients. Histopathologic findings were available in 20 patients; follow-up MR imaging findings were available in two patients. RESULTS: MR imaging depicted a primary breast cancer in 19 patients (86%; identified at excisional biopsy or mastectomy in 17, resolved on follow-up MR images during treatment in two). MR imaging depicted 4-30-mm cancers (mean, 17 mm), which correlated closely with histopathologic size. Two patients (9%) had false-negative findings: (a) One had a 2-mm invasive ductal carcinoma, and (b) one had 17- and 20-mm invasive ductal carcinomas. Of the 19 patients, 11 underwent mastectomy, seven underwent breast-conservation therapy, and one did not undergo a surgical procedure. CONCLUSION: MR imaging is very sensitive for the detection of mammographically and clinically occult breast cancer in patients with malignant axillary adenopathy. In these patients, MR imaging offers potential not only for cancer detection but also for staging the cancer within the breast, which may be useful for treatment planning.

BI-RADS categorization as a predictor of malignancy.

PURPOSE: To determine the positive predictive value (PPV) of the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) categories 0, 2, 3, 4, and 5 by using BI-RADS terminology and by auditing data on needle localizations. MATERIALS AND METHODS: Between April 1991 and December 1996, 1,400 mammographically guided needle localizations were performed in 1,109 patients. Information entered into the mammographic database included where the initial mammography was performed (inside vs outside the institution), BI-RADS category, mammographic finding, and histopathologic findings. A recorded recommendation was available for 1,312 localizations in 1,097 patients, who composed the study population. RESULTS: The 1,312 localizations yielded 449 (34%) cancers (139 [31%] were ductal carcinoma in situ [DCIS]; 310 [69%] were invasive cancers) and 863 (66%) benign lesions. There were 15 (1%) category 0 lesions; the PPV was 13% (two of 15 lesions). There were 50 (4%) category 2 lesions; the PPV was 0% (0 of 40 lesions). There were 141 (11%) category 3 lesions; the PPV was 2% (three of 141 lesions). The three cancers in this group were all non-comedotype DCIS. There were 936 (71%) category 4 lesions; the PPV was 30% (279 of 936 lesions). There were 170 (13%) category 5 lesions; the PPV was 97% (165 of 170 lesions). CONCLUSION: Placing mammographic lesions into BI-RADS categories is useful for predicting the presence of malignancy. Perhaps, most important, a lesion placed into BI-RADS category 3 is highly predictive of benignity, and short-term interval follow-up as an alternative to biopsy would decrease the number of biopsies performed in benign lesions.