Breast Magnetic Resonance Imaging Studies Research Articles

High-Temporal/High-Spatial Resolution Breast Magnetic Resonance Imaging Improves Diagnostic Accuracy Compared With Standard Breast Magnetic Resonance Imaging in Patients With High Background Parenchymal Enhancement.

To compare breast magnetic resonance imaging (MRI) diagnostic performance using a standard high-spatial resolution protocol versus a simultaneous high-temporal/high-spatial resolution (HTHS) protocol in women with high levels of background parenchymal enhancement (BPE). We conducted a retrospective study of contrast-enhanced breast MRIs performed at our institution before and after the introduction of the HTHS protocol. We compared diagnostic performance of the HTHS and standard protocol by comparing cancer detection rate (CDR) and positive predictive value of biopsy (PPV3) among women with high BPE (ie, marked or moderate). Among women with high BPE, the HTHS protocol demonstrated increased CDR (23.6 per 1,000 patients v 7.9 per 1,000 patients; P = 0. 013) and increased PPV3 (16.0% v 6.3%; P = .021) compared with the standard protocol. This corresponded to a 9.8% (95% CI, 1.29 to 18.3) decrease in the proportion of unnecessary biopsies among high-BPE patients and an additional cancer yield of 15.7 per 1,000 patients (95% CI, 1.3 to 18.3). Among women with high BPE, HTHS MRI improved diagnostic performance, leading to an additional cancer yield of 15.7 cancers per 1,000 women and concomitantly decreasing unnecessary biopsies by 9.8%. A multisite prospective trial is warranted to confirm these findings and to pave the way for more widespread clinical implementation.

Can breast MRI predict pathologic response following neoadjuvant chemotherapy for breast cancer? A retrospective cohort study

PurposeFor patients treated with neoadjuvant chemotherapy (NAC) for breast cancer, it is standard of care to perform pre- and post-NAC imaging to evaluate response to therapy prior to surgery. In this study we assess outcome metrics of magnetic resonance imaging (MRI) following NAC. MethodsWe conducted a retrospective analysis of patients with invasive breast cancer who underwent a breast MRI before and after NAC between 2016 and 2021 at a single, multisite academic institution. All breast MRI studies were characterized as either radiologic complete response (rCR) or non-rCR. Corresponding surgical pathology reports were reviewed and categorized as pathologic complete response (pCR) or non-pCR. We defined a positive test as having residual enhancement on MRI (non-rCR) and a positive outcome as having residual disease on final surgical pathology (non-pCR). ResultsThere were 225 patients included in the study (mean age 52 ± 12 years). Breast cancer receptor distribution was HR+/HER2− (n = 71, 32%), HR+/HER2+ (n = 51, 23%), HR−/HER2− (n = 72, 32%), and HR−/HER2+ (n = 31, 14%). In total, 78 (35%) had rCR and 77 (34%) had pCR; 43 (19%) had both rCR and pCR. The overall accuracy rate was 69% (156/225), sensitivity 76% (113/148), specificity 56% (43/77), positive predictive value 77% (113/147), and negative predictive value 55% (43/78). The PPV was significantly associated with receptor status (p = 0.004). No patient or imaging characteristics were associated with sensitivity. ConclusionBreast MRI only moderately predicts pathologic response for invasive breast cancer treated with NAC (overall accuracy 69%). PPV is significantly associated with receptor status.

A new scoring system for differentiating malignant from benign “second-look” breast lesions detected by MRI in patients with known breast cancer

To propose a scoring system made of reproducible and objective criteria to aid in differentiating malignant from benign "second-look" breast lesions detected at magnetic resonance imaging (MRI). Data were collected retrospectively for "second-look" lesions identified on breast MRI studies performed at the University Hospitals of Leicester NHS Trust breast unit over a 2-year period (from January 2020 to January 2022). Ninety-five "second look" MRI-detected lesions were included in this retrospective study. Lesions were assessed according to margins, T2 signal, internal enhancement patterns, contrast kinetics, and diffusion-weighted imaging (DWI) patterns. Fifty-two per cent of the included lesions were confirmed at histopathology to be malignant. The most common contrast kinetics identified in malignant lesions was the plateau pattern followed by the washout pattern while the most common pattern in benign lesions was the progressive pattern. The apparent diffusion coefficient (ADC) cut-off value for separating benign and malignant lesions at the unit was found to be 1.1×10-3 mm2/s. Based on the MRI features described above, a scoring system is suggested to help differentiate benign from malignant "second-look" lesions. According to the present results, setting a score of 2 or more points as an indication for biopsy was 100% reliable in identifying malignant lesions and avoiding biopsies in >30% of lesions. The suggested scoring system could avoid biopsy of >30% of the "second-look" lesions detected by MRI without missing any malignant lesions.

The Utility of Short-Interval Follow-Up for Baseline High-Risk Screening Breast MRI.

Patients with a high lifetime risk of developing breast cancer undergo annual screening magnetic resonance imaging (MRI) starting at age 30. A proportion of these patients are subsequently required to undergo short-interval follow-up MRI 6 months after their baseline examination. The purpose of this study was to evaluate the utility and outcome of these short-interval follow-up examinations in this population. A retrospective review was performed of 523 patients who received their baseline high-risk breast screening MRI at our institution between 2013 and 2017. The proportion of patients who received a short-interval follow-up MRI at 6 months was recorded. The findings at baseline and follow-up MRI were recorded, as well as the outcomes and results of any interventions performed. Ninety-six (17.6%) patients (age range: 25-67, mean age: 41) received a short-interval follow-up MRI following their baseline screening examination. Indications for follow-up included moderate to marked background parenchymal enhancement, nonmass enhancement, and likely benign enhancing mass. Of the 92 patients, 5 (5.4%) went on to have a biopsy, with none revealing a malignant pathology. The remainder either returned to routine screening (91.3%) or received further imaging in the form of ultrasound or additional follow-up MRI (3.3%). Short-interval follow-up breast MRI in high-risk patients after a baseline screening study with likely benign findings is unlikely to yield clinically significant findings. This retrospective study can be considered a starting point for additional future work looking at the rate, indications, and yield of short-interval follow-up following baseline high-risk screening breast MRI studies.

Comparative study of automatic breast volume scanner and MRI in the diagnosis of breast masses

Objective To compare the value of automatic breast volume scanner (ABVS) with enhanced magnetic resonance imaging(MRI) in the diagnosis of breast masses. Methods Seventy-four patients with 80 breast masses underwent preoperative ultrasound examinations including ABVS and MRI. The values of ABVS and MRI in the diagnosis of breast masses were comparatively analyzed. Results Among the 80 breast masses that were surgically removed, 37 masses were benign and 43 masses were malignant.The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of ABVS in the diagnosis of breast malignant masses were 94.6%, 79.1%, 86.3%, 79.5% and 94.4%, respectively, those of MRI were 94.6%, 86.0%, 90.0%, 85.4% and 94.9%, respectively, and those of the combination of ABVS and MRI were 94.6%, 93.0%, 93.8%, 92.1%, and 95.2%, respectively. The sensitivity and specificity were not significant difference between ABVS and MRI in the diagnosis of breast malignant masses(P>0.05). The specificity of the combination ABVS and MRI in the diagnosis of breast malignant masses were significantly higher than that of ABVS (χ2=4.17, P=0.04). The sensitivity, specificity and accuracy of convergence sign in the diagnosis of breast malignant masses were 64.9%, 97.7% and 82.5%, respectively. Conclusions ABVS and MRI are both valuable in the diagnosis of breast masses, and the combination of ABVS and MRI is the most valuable due to high specificity. Key words: Ultrasonography, mammary; Breast diseases; Automatic breast volume scanner; Magnetic resonance imaging; Convergent sign

Prevalence and clinical significance of incidental extra-mammary findings in breast magnetic resonance imaging: A retrospective study of 1070 patients

PurposeThe purpose of this study was to analyze the prevalence of extra-mammary findings in magnetic resonance imaging (MRI). Materials and methodsData from 1070 consecutive breast MRI studies was analyzed. MR-BI-RADS (Breast Imaging Reporting and Data System) was used to classify the risk category. ResultsAccording to MR-BI-RADS, 915 (85.5%) of 1070 women were classified into MR-BI-RADS categories 1–3, and 155 (14.5%) into MR-BI-RADS categories 4–5. MR-BI-RADS categories 4–5 had a 10-times higher risk for major extra-mammary findings (odds ratio 10.1, P<0.01). ConclusionExtra-mammary findings are common and may have important clinical consequences.

B1 Field Correction of T1 Estimation Should Be Considered for Breast Dynamic Contrast-enhanced MR Imaging Even at 1.5 T.

Purpose To prospectively quantify the effect of T1 estimation in fat by B1 correction in breast magnetic resonance (MR) imaging at 1.5 T and to examine the subsequent quantitative dynamic contrast material-enhanced parameters in breast cancer with and without B1 correction. Materials and Methods This study had institutional review board approval, and informed consent was obtained from 72 patients with breast cancer before breast MR imaging studies were performed between January and July 2015. B1+ field and variable flip angle (FA) mapping were included in the dynamic contrast-enhanced breast MR imaging protocol with a 1.5-T MR imaging system. Precontrast T1 relaxation in fat and breast tumors was computed with and without B1 correction. The pharmacokinetic parameters of breast cancer were calculated by using the Tofts model with T1 values before and after B1 correction. The Mann-Whitney U test and linear regression model were used for statistical analysis. Results The FA was 19% higher in the left breast and 3% lower in the right breast than the prescribed value. This 22% average FA difference created a 43% T1 estimation bias in fat between the breasts. The T1 variation in fat was reduced to 0.96% after B1 correction. There was a 50% overestimation and a 7% underestimation of tumor T1 in the left breast and the right, respectively, associated with B1 error. Assuming T1 after B1 correction represents the true tumor T1, 41% underestimation in the left breast and 10% overestimation in the right without B1 correction were seen in the dynamic contrast-enhanced parameters (including the volume transfer constant, or Ktrans, fraction of extracellular extravascular space, or ve, and blood normalized initial area under the gadolinium concentration curve to 90 seconds, or IAUGCBN90). Conclusion B1 correction for more accurate T1 values should be considered for quantitative dynamic contrast-enhanced breast MR imaging, even at 1.5 T, to offset significant systemic error. © RSNA, 2016.

Magnetic resonance imaging in the preoperative setting for breast cancer patients with undetected additional disease

ObjectiveThe last few years have witnessed a significant increase in the preoperative use of Magnetic Resonance Imaging (MRI) for staging purposes in breast cancer (BC) patients. Many studies have confirmed the improvement that MRI can provide in terms of diagnostic assessment, especially with regard to additional disease foci. In the present study, we address the advantages and disadvantages of MRI in the preoperative setting for BC patients. Patients and methodsThere were 1513 consecutive breast MRI studies performed in patients with either primary or recurrent BC, who were scheduled for surgery. ResultsBeyond the primary lesion, 10.4% of our cases had additional disease at the final histological assessment. MRI overall sensitivity, when considering tumour size and additional foci together, was 74.3%, and 80.3% when considering additional foci exclusively. MRI specificity for additional disease was 95.3%, positive predictive value was 77.4%, and negative predictive value was 94.6%. Nevertheless, 5% of cases had additional tumours that were missed by MRI or, conversely, had additional foci on MRI that were not confirmed by histology. Age (p=0.020) and lobular carcinomas (p=0.030) showed significance in the multivariate analysis by logistic regression, using the presence of additional foci diagnosed by MRI as a dependent variable. ConclusionPreoperative MRI seems to have a role in preoperative tumour staging for breast cancer patients, as it discloses additional disease foci in some patients, including contralateral involvement. However, given the lack of absolute accuracy, core-needle biopsy cannot be neglected in the diagnosis of such additional malignant foci, which could result in a change in surgical treatment.

How I report breast magnetic resonance imaging studies for breast cancer staging and screening.

Magnetic resonance imaging (MRI) of the breast is the most sensitive imaging technique for the diagnosis and local staging of primary breast cancer and yet, despite the fact that it has been in use for 20 years, there is little evidence that its widespread uncritical adoption has had a positive impact on patient-related outcomes.This has been attributed previously to the low specificity that might be expected with such a sensitive modality, but with modern techniques and protocols, the specificity and positive predictive value for malignancy can exceed that of breast ultrasound and mammography. A more likely explanation is that historically, clinicians have acted on MRI findings and altered surgical plans without prior histological confirmation. Furthermore, modern adjuvant therapy for breast cancer has improved so much that it has become a very tall order to show a an improvement in outcomes such as local recurrence rates.In order to obtain clinically useful information, it is necessary to understand the strengths and weaknesses of the technique and the physiological processes reflected in breast MRI. An appropriate indication for the scan, proper patient preparation and good scan technique, with rigorous quality assurance, are all essential prerequisites for a diagnostically relevant study.The use of recognised descriptors from a standardised lexicon is helpful, since assessment can then dictate subsequent recommendations for management, as in the American College of Radiology BI-RADS (Breast Imaging Reporting and Data System) lexicon (Morris et al., ACR BI-RADS® Atlas, Breast Imaging Reporting and Data System, 2013). It also enables audit of the service. However, perhaps the most critical factor in the generation of a meaningful report is for the reporting radiologist to have a thorough understanding of the clinical question and of the findings that will influence management. This has never been more important than at present, when we are in the throes of a remarkable paradigm shift in the treatment of both early stage and locally advanced breast cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s40644-016-0078-0) contains supplementary material, which is available to authorized users.

A Cost Analysis of Preoperative Breast MRI Use for Patients with Invasive Lobular Cancer

Whereas the impact of magnetic resonance imaging (MRI) of the breast on the surgical management of breast cancer patients is well documented, less is known about its effect on health care costs. This study aimed to evaluate whether MRI use for women with invasive lobular carcinoma (ILC) significantly changes the cost of care. Patients with ILC were recruited to a prospective registry study of breast MRI. Women who met the same inclusion criteria but had not undergone breast MRI were retrospectively identified for comparison. A micro-costing analysis using institutional billing records was conducted. Nonparametric bootstrapping was used to compare the unadjusted cost differences between the patients receiving MRI and those receiving no MRI. Of the patients in this study, 51 had preoperative MRI, and 60 did not. Method of diagnostic biopsy, disease stage, oncologic procedure, and rates of contralateral prophylactic mastectomy were similar between the two groups. The patients in the MRI group were younger (median age 55 vs. 64 years; p = 0.01) and more likely to undergo reconstruction (45.1 vs. 25 %; p = 0.03). The median costs of care were significantly higher in the MRI group ($24,781 vs. $18,921; p < 0.01). After adjustment for clinical factors, MRI remained significantly associated with increased cost (p = 0.03). Other factors associated with increased cost included type of oncologic procedure (mastectomy vs. lumpectomy; p < 0.01), number of operations required to achieve negative margins (1 vs. >1; p < 0.01), and use of reconstruction (p < 0.01). Preoperative breast MRI increases the median total cost of care per patient. However, the contribution to the overall cost of care is modest compared with the cost of other interventions.

Breast Shape Change Associated with Aging: A Study Using Prone Breast Magnetic Resonance Imaging.

Background:Objective assessments of the shapes of various parts of the body can be made using images acquired with multidetector row computed tomography or magnetic resonance imaging. These images can be useful for understanding the changes in body shape that accompany aging.Methods:Data from our previous bilateral prone breast magnetic resonance imaging studies between March and August 2013 were analyzed. Breast size and volume were measured using these images. All the patients included in the study were divided into a younger group (54 years or younger) and an older group (55 years or older). The values were compared between the 2 groups using paired t tests. Regarding variables that were shown to have a significant difference between the 2 groups, the relationships between age and the values of the variables were evaluated using the Pearson correlation coefficient.Results:A total of 90 breasts, 45 breasts in the younger group and 45 breasts in the older group, were used for analysis. There was a significant correlation between age and craniocaudal nipple deviation (R = −0.38; P < 0.001) and between age and the measured breast volume (R = 0.26; P < 0.05). There was also a significant correlation between the measured breast volume and the craniocaudal nipple deviation (R = −0.48; P < 0.001).Conclusions:A caudal deviation of the nipple and an increase in volume were age-related changes in breast shape. These 2 variables were also correlated.

Computerized Image Analysis for Identifying Triple-Negative Breast Cancers and Differentiating Them from Other Molecular Subtypes of Breast Cancer on Dynamic Contrast-enhanced MR Images: A Feasibility Study

To determine the feasibility of using a computer-aided diagnosis (CAD) system to differentiate among triple-negative breast cancer, estrogen receptor (ER)-positive cancer, human epidermal growth factor receptor type 2 (HER2)-positive cancer, and benign fibroadenoma lesions on dynamic contrast material-enhanced (DCE) magnetic resonance (MR) images. This is a retrospective study of prospectively acquired breast MR imaging data collected from an institutional review board-approved, HIPAA-compliant study between 2002 and 2007. Written informed consent was obtained from all patients. The authors collected DCE MR images from 65 women with 76 breast lesions who had been recruited into a larger study of breast MR imaging. The women had triple-negative (n = 21), ER-positive (n = 25), HER2-positive (n = 18), or fibroadenoma (n = 12) lesions. All lesions were classified as Breast Imaging Reporting and Data System category 4 or higher on the basis of previous imaging. Images were subject to quantitative feature extraction, feed-forward feature selection by means of linear discriminant analysis, and lesion classification by using a support vector machine classifier. The area under the receiver operating characteristic curve (Az) was calculated for each of five lesion classification tasks involving triple-negative breast cancers. For each pair-wise lesion type comparison, linear discriminant analysis helped identify the most discriminatory features, which in conjunction with a support vector machine classifier yielded an Az of 0.73 (95% confidence interval [CI]: 0.59, 0.87) for triple-negative cancer versus all non-triple-negative lesions, 0.74 (95% CI: 0.60, 0.88) for triple-negative cancer versus ER- and HER2-positive cancer, 0.77 (95% CI: 0.63, 0.91) for triple-negative versus ER-positive cancer, 0.74 (95% CI: 0.58, 0.89) for triple-negative versus HER2-positive cancer, and 0.97 (95% CI: 0.91, 1.00) for triple-negative cancer versus fibroadenoma. Triple-negative cancers possess certain characteristic features on DCE MR images that can be captured and quantified with CAD, enabling good discrimination of triple-negative cancers from non-triple-negative cancers, as well as between triple-negative cancers and benign fibroadenomas. Such CAD algorithms may provide added diagnostic benefit in identifying the highly aggressive triple-negative cancer phenotype with DCE MR imaging in high-risk women.

High-resolution diffusion-weighted imaging for the separation of benign from malignant BI-RADS 4/5 lesions found on breast MRI at 3T

To determine whether readout-segmented echo-planar diffusion imaging (RESOLVE) improves separation of malignant versus benign lesions compared to standard single-shot echo-planar imaging (ss-EPI) on BI-RADS 4/5 lesions detected on breast magnetic resonance imaging (MRI). Consecutive 3T breast MRI studies with BI-RADS 4/5 designation and subsequent biopsy or benign mastectomy were retrospectively identified. Freehand regions of interest (ROIs) were drawn on lesions and also on normal background fibroglandular tissue for comparison. Lesion-to-background contrast was evaluated by normalizing signal intensity of the lesion ROI by the normal background tissue ROI at b = 800. Statistical analysis used the Mann-Whitney/Wilcoxon rank-sum test for unpaired and Wilcoxon signed-rank for paired comparisons. Of 38 lesions in 32 patients, 10 were malignant. Lesion-to-background contrast was higher on RESOLVE than ss-EPI (1.80 ± 0.71 vs. 1.62 ± 0.63, P = 0.03). Mean apparent diffusion coefficient (ADC) was the same or lower on RESOLVE than ss-EPI, and this effect was largest in malignant lesions (RESOLVE 0.90 ± 0.13; ss-EPI 1.00 ± 0.13; median difference -0.10 (95% confidence interval [CI]: -0.17, -0.02) × 10(-3) mm(2) /sec; P = 0.014). By either diffusion method, there was a statistically significant difference between benign and malignant mean ADC (P < 0.001). Increased lesion-to-background contrast and improved separation of benign from malignant lesions by RESOLVE compared to standard diffusion suggests that RESOLVE may show promise as an adjunct to clinical breast MRI.

Automated Extraction of BI-RADS Final Assessment Categories from Radiology Reports with Natural Language Processing

The objective of this study is to evaluate a natural language processing (NLP) algorithm that determines American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) final assessment categories from radiology reports. This HIPAA-compliant study was granted institutional review board approval with waiver of informed consent. This cross-sectional study involved 1,165 breast imaging reports in the electronic medical record (EMR) from a tertiary care academic breast imaging center from 2009. Reports included screening mammography, diagnostic mammography, breast ultrasound, combined diagnostic mammography and breast ultrasound, and breast magnetic resonance imaging studies. Over 220 reports were included from each study type. The recall (sensitivity) and precision (positive predictive value) of a NLP algorithm to collect BI-RADS final assessment categories stated in the report final text was evaluated against a manual human review standard reference. For all breast imaging reports, the NLP algorithm demonstrated a recall of 100.0 % (95 % confidence interval (CI), 99.7, 100.0 %) and a precision of 96.6 % (95 % CI, 95.4, 97.5 %) for correct identification of BI-RADS final assessment categories. The NLP algorithm demonstrated high recall and precision for extraction of BI-RADS final assessment categories from the free text of breast imaging reports. NLP may provide an accurate, scalable data extraction mechanism from reports within EMRs to create databases to track breast imaging performance measures and facilitate optimal breast cancer population management strategies.

Optimization of apparent diffusion coefficient measured by diffusion-weighted MRI for diagnosis of breast lesions presenting as mass and non-mass-like enhancement

The purpose of this study was to investigate the diagnostic value of the apparent diffusion coefficient (ADC), measured by diffusion-weighted magnetic resonance imaging (MRI), for the diagnosis of breast lesions presenting as mass and non-mass-like enhancement (NMLE). The breast MRI studies of 174 patients were reviewed retrospectively. A total of 188 histologically confirmed lesions were analyzed and classified into 127 mass enhancement (86 malignant and 41 benign) and 61 NMLE (42 malignant and 19 benign). The ADC values were measured using a spin-echo echo-planner-imaging (SE-EPI) sequence with b=1,000 s/mm(2). Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis. The mean ADC was 0.99 ± 0.22 × 10(-3)mm(2)/s for invasive cancer, 1.23 ± 0.33 × 10(-3)mm(2)/s for ductal carcinoma in situ (DCIS), and 1.52 ± 0.35 × 10(-3)mm(2)/s for benign adenosis. The mean ADC of all NMLE lesions was 1.44 ± 0.41 × 10(-3)mm(2)/s, which is higher than the mean ADC of all mass lesions, 1.12 ± 0.33 × 10(-3)mm(2)/s. In the ROC analysis, the optimal cutoff ADC value for differentiating benign from malignant lesions was 1.05 × 10(-3)mm(2)/s for mass lesions and 1.35 × 10(-3)mm(2)/s for NMLE. In conclusion, ADC values can be used for the diagnosis of invasive and DCIS as well as benign tumors. The NMLE lesions tend to have higher ADC values than mass lesions; therefore, the morphological appearance of a lesion needs to be considered when using the ADC value for diagnosis.

Is There a Role for Magnetic Resonance Imaging in Diagnosing Palpable Breast Masses When Mammogram and Ultrasound Are Negative?

The use of breast magnetic resonance imaging (MRI) for screening high-risk patients is well established. However, the role of MRI as a diagnostic problem-solving tool is less well studied. With the increasing availability of MRI, its use for problem solving has increased. This small retrospective study examines the use and utility of breast MRI in evaluating palpable breast masses with negative diagnostic mammogram and ultrasound studies. We reviewed our breast MRI database, selecting breast MRI studies performed to assess palpable abnormalities with negative mammogram and ultrasound findings. Evidence of cancer was determined by biopsy. Seventy-seven studies were included, comprising 1.3% of all breast MRI studies performed at our institution during the study period (2005-2011). Twenty-two patients underwent biopsy, and 55 were followed clinically without biopsy. Approximately half (27 of 55) of the patients without biopsy were lost to follow-up after negative MRI, and the rest had no evidence of cancer on imaging or clinical examination at 1 year. Of the 22 patients who underwent biopsy, 2 were diagnosed with cancer, both with positive MRI studies. Sensitivity of MRI when compared to tissue diagnosis was 100%, and specificity was 70%. Positive and negative predictive values were 25% and 100%, respectively. When used for evaluation of a palpable breast mass with negative traditional imaging, breast MRI likely offers low yield of cancer diagnosis and low specificity. Negative MRI results may cause a low compliance rate for recommended follow-up. Because a biopsy is indicated for persistent palpable masses, the addition of diagnostic MRI only adds another step, with associated costs and burdens.

Updated breast MRI lexicon

The American College of Radiology (ACR) BI-RADS Breast Imaging Lexicon was developed over a 5 year period, initially organized in 1999 by a Breast MRI “Lesion Diagnosis Working Group” and later by the ACR. This work resulted in a lexicon (dictionary) of terms to describe breast lesions on contrast-enhanced breast magnetic resonance imaging studies. The first publication was developed when breast MRI was first being used and referencing the little data available to produce the lexicon of terms in describing lesions seen on breast MRI. Even though the ACR Lexicon has proved robust for the most part, since its publication there have been technical advances in breast MRI hardware, coils and pulse sequences, resulting in new information on breast cancer morphology and kinetic behavior. Publication on MRI studies using the new hardware and software resulted in increases in cancer sensitivity and specificity in published literature. As a result, information is now available on technical parameters required to obtain both high spatial and temporal resolution on breast MRI scans that resulted in high sensitivity and specificity. These advances and scientific data were used in developing and updating the new Lexicon. The new breast MRI Lexicon is chaired by Elizabeth A Morris, M.D and is expected to be published in the fall of 2012. The new ACR Lexicon includes a web-based format (hardcopy is also available), recommends mammography/US/MRI correlation, and has evidence based information with hyperlinks to references. The Lexicon also includes sections on Quality Assessment with technical parameters and kinetic/functional considerations that influence MRI images. There is a new section on audit recommendations. The ACR also lists a separate ACR Breast MRI Accreditation Program that accredits breast MRI facilities in the United States with technical, outcome and personnel credentialing criteria. Breast MRI Lexicon recommendations include adding T2weighted non-contrast sequences, and combined reporting of MRI with mammographic and ultrasound findings. Finally, simultaneous bilateral MRI scans are recommended and are considered standard of care. There is a new section on breast implants, with a lexicon describing the implant type, location, and findings commonly seen in intact and ruptured implants. In silicone breast implant studies, imaging terms include normal radial folds, subcapsular line, linguine and keyhole/teardrop. Importantly, there is a new section describing background parenchymal enhancement (BPE) that describes how much of the normal breast parenchyma enhances, which in turn can influence the sensitivity of breast MRI to detect cancer. The BPE can be described as none, minimal, mild, moderate or marked. Terms that previously were used to describe findings seen on breast MRI such as “diffuse stippled enhancement” may actually represent moderate BPE, which is a normal finding. As before, both morphology and kinetic information is considered important. There are no changes to the kinetic terminology. Morphology terms in the lexicon have been added or deleted, adding terms that were commonly used, and deleting those that were not used in the scientific literature. Deleted terms include central and septal enhancement, and enhancing septations. Morphology additions include clustered ring enhancement in contrast-enhanced studies. Morphology terms that have been revised include “non-masslike” to “non-mass” enhancement, and “irregular” mass margins to “uneven” mass margins in masses that have an irregular shape. Last, the Lexicon recommends a final BIRADS assessment including BIRADS codes 0 – Incomplete, Need Additional Imaging Evaluation, 1 – Negative, 2 – Benign, 3 – Probably Benign, 4 – Suspicious, 5 – Highly Suggestive of Malignancy, and 6 – Known Biopsy Proven Malignancy. The ACR Breast MRI Lexicon publication also includes an atlas that illustrates the key findings described in the lexicon. Because the contributors to the atlas were based both in the USA and around the world, there are a wide variety of techniques and pulse sequences that were used to generate the images. Variability in the examples include axial, sagittal, multi-planar reconstructions, fatsuppressed and non-fat-suppressed images chosen as state-of-theart, providing the reader with the rare chance to view MRI studies of specific findings using high-quality, varying techniques.

Diffusion-weighted magnetic resonance imaging in patients with known or suspected breast malignancy: Correlation between apparent diffusion coefficient and histopathologic diagnoses.

65 Background: Magnetic resonance imaging (MRI) is an important imaging modality for evaluating patients at high risk for breast malignancy. However, the role and utility of diffusion-weighted imaging (DWI) in breast MRI has not been fully elucidated. This study was designed to investigate the relationship between apparent diffusion coefficient (ADC) values and histopathologic diagnoses in benign and malignant breast pathologies as well as to assess the relative diagnostic value of this parameter. Methods: We searched our database for patients who received breast MRI studies from February 2010 through March 2011. We then identified those patients who had either known or suspected breast malignancy and who had also undergone DWI. Breast abnormalities were identified through a review of the short tau inversion recovery (STIR) and T1-weighted pre- and post-contrast images. DWI images were evaluated and the corresponding ADC values were calculated. These lesions were correlated with histopathologic results when available. Results: A total of 174 patient MRI studies were evaluated. Single dominant lesions were assessed and included biopsy-proven infiltrating ductal carcinoma (IDC), biopsy-proven ductal carcinoma in situ (DCIS), and benign lesions including cysts. The median ADC value for IDC was 118 x 10-5 mm2 s-1. The median ADC value for DCIS was 123 x 10-5 mm2 s-1. Finally, the median ADC value for breast cysts was 217 x 10-5 mm2 s-1. Conclusions: As the role of MRI continues to evolve in the evaluation of breast pathology, the addition of DWI may increase diagnostic confidence for breast cancer, allowing for further differentiation from benign lesions. DWI is feasible to implement in many clinical practices and correlates with imaging features of breast cancer. The DWI images are acquired rapidly and without intravenous contrast. This method of imaging could be used in short intervals to assess treatment response to therapies such as biologic inhibitors or radiation therapy.

Utility of second-look ultrasound in the management of incidental enhancing lesions detected by breast MR imaging

To assess the utility of second-look ultrasound (US) for identifying and characterising incidental enhancing lesions detected by breast magnetic resonance imaging (MRI). From among 655 consecutive breast MRI studies, 62 lesions (MRI visible, nonpalpable, occult at first-look US and mammography) were recommended for second-look US. MRI enhancement of lesions was mass-like in 59 cases (95%) and non-mass-like in three (5%). Forty-two lesions (68%) were ≤10 mm; only three lesions (5%) were >20 mm. Of all lesions, the Breast Imaging Reporting and Data System (BI-RADS) MRI category was highly suggestive of malignancy in six cases (10%), suspicious abnormality in 33 (53%) and probably benign in 23 (37%). The correlation between MRI lesion appearance, lesion size, histopathology findings and detection rate at second-look US were analysed. The reference standard was histopathology and/or follow-up (range 18-24 months). Statistical analysis was performed with the Fisher exact test. Second-look US identified 44 out of 62 (71%) lesions depicted at MRI. The detection rate at second-look US was higher for mass-like MRI lesions (75%) than non-mass-like lesions (0%), for lesion size >10mm (90%) and for BI-RADS 4 lesions (88%). Second-look US-guided biopsy detected 12 out of 17 (71%) malignant lesions. There was no correlation between the likelihood of carcinoma and the presence of a sonographic correlate. Second-look US is a reliable problem-solving tool in identifying and characterising most incidental MRI findings. It contributes to accurately selecting the cases in which MRI-guided biopsy is required.

Development, standardization, and testing of a lexicon for reporting contrast‐enhanced breast magnetic resonance imaging studies

The purpose of this study was to develop, standardize, and test reproducibility of a lexicon for reporting contrast-enhanced breast magnetic resonance imaging (MRI) examinations. To standardize breast MRI lesion description and reporting, seven radiologists with extensive breast MRI experience developed consensus on technical detail, clinical history, and terminology reporting to describe kinetic and architectural features of lesions detected on contrast-enhanced breast MR images. This lexicon adapted American College of Radiology Breast Imaging and Data Reporting System terminology for breast MRI reporting, including recommendations for reporting clinical history, technical parameters for breast MRI, descriptions for general breast composition, morphologic and kinetic characteristics of mass lesions or regions of abnormal enhancement, and overall impression and management recommendations. To test morphology reproducibility, seven radiologists assessed morphology characteristics of 85 contrast-enhanced breast MRI studies. Data from each independent reader were used to compute weighted and unweighted kappa (kappa) statistics for interobserver agreement among readers. The MR lexicon differentiates two lesion types, mass and non-mass-like enhancement based on morphology and geographical distribution, with descriptors of shape, margin, and internal enhancement. Lexicon testing showed substantial agreement for breast density (kappa = 0.63) and moderate agreement for lesion type (kappa = 0.57), mass margins (kappa = 0.55), and mass shape (kappa = 0.42). Agreement was fair for internal enhancement characteristics. Unweighted kappa statistics showed highest agreement for the terms dense in the breast composition category, mass in lesion type, spiculated and smooth in mass margins, irregular in mass shape, and both dark septations and rim enhancement for internal enhancement characteristics within a mass. The newly developed breast MR lexicon demonstrated moderate interobserver agreement. While breast density and lesion type appear reproducible, other terms require further refinement and testing to lead to a uniform standard language and reporting system for breast MRI. J. Magn. Reson. Imaging 2001;13:889-895.