Mixed-Methods Study to Predict Upstaging of DCIS to Invasive Disease on Mammography.

BACKGROUND. The incidence of ductal carcinoma in situ (DCIS) has steadily increased, as have concerns regarding overtreatment. Active surveillance is a novel treatment strategy that avoids surgical excision, but identifying patients with occult invasive disease who should be excluded from active surveillance is challenging. Radiologists are not typically expected to predict the upstaging of DCIS to invasive disease, though they might be trained to perform this task. OBJECTIVE. The purpose of this study was to determine whether a mixed-methods two-stage observer study can improve radiologists' ability to predict upstaging of DCIS to invasive disease on mammography. METHODS. All cases of DCIS calcifications that underwent stereotactic biopsy between 2010 and 2015 were identified. Two cohorts were randomly generated, each containing 150 cases (120 pure DCIS cases and 30 DCIS cases upstaged to invasive disease at surgery). Nine breast radiologists reviewed the mammograms in the first cohort in a blinded fashion and scored the probability of upstaging to invasive disease. The radiologists then reviewed the cases and results collectively in a focus group to develop consensus criteria that could improve their ability to predict upstaging. The radiologists reviewed the mammograms from the second cohort in a blinded fashion and again scored the probability of upstaging. Statistical analysis compared the performances between rounds 1 and 2. RESULTS. The mean AUC for reader performance in predicting upstaging in round 1 was 0.623 (range, 0.514-0.684). In the focus group, radiologists agreed that upstaging was better predicted when an associated mass, asymmetry, or architectural distortion was present; when densely packed calcifications extended over a larger area; and when the most suspicious features were focused on rather than the most common features. Additionally, radiologists agreed that BI-RADS descriptors do not adequately characterize risk of invasion, and that microinvasive disease and smaller areas of DCIS will have poor prediction estimates. Reader performance significantly improved in round 2 (mean AUC, 0.765; range, 0.617-0.852; p = .045). CONCLUSION. A mixed-methods two-stage observer study identified factors that helped radiologists significantly improve their ability to predict upstaging of DCIS to invasive disease. CLINICAL IMPACT. Breast radiologists can be trained to better predict upstaging of DCIS to invasive disease, which may facilitate discussions with patients and referring providers.

Abnormalities of the Fetal Central Nervous System: Prenatal US Diagnosis with Postnatal Correlation.

Fetal central nervous system (CNS) abnormalities are second only to cardiac malformations in their frequency of occurrence. Early and accurate diagnosis at prenatal US is therefore essential, allowing improved prenatal counseling and facilitating appropriate referral. Thorough knowledge of normal intracranial anatomy and adoption of a logical sonographic approach can improve depiction of abnormal findings, leading to a more accurate differential diagnosis earlier in pregnancy. Four standard recommended views-transventricular, falx, cavum, and posterior fossa or transcerebellar views-provide an overview of fetal intracranial anatomy during the second trimester anatomy scan. Essential elements surveyed in the head and neck include the lateral cerebral ventricles, choroid plexus, midline falx, cavum septi pellucidi, cerebellum, cisterna magna, upper lip, and nuchal fold. CNS abnormalities can be organized into six main categories at prenatal US. Developmental anomalies include neural tube defects and neuronal migration disorders. Posterior fossa disorders include Dandy-Walker malformation variants and Chiari II malformation. Ventricular anomalies include aqueductal stenosis. Midline disorders include those on the spectrum of holoprosencephaly, agenesis of the corpus callosum, and septo-optic dysplasia. Vascular anomalies include vein of Galen malformations. Miscellaneous disorders include hydranencephaly, porencephaly, tumors, and intracranial hemorrhage. Correlation with postnatal MRI is helpful for confirmation and clarification of suspected diagnoses after birth. The authors discuss a standard US imaging approach to the fetal CNS and review cases in all categories of CNS malformations, providing postnatal MRI correlation when available.©RSNA, 2020.

Machine learning-based prediction of future breast cancer using algorithmically measured background parenchymal enhancement on high-risk screening MRI.

BACKGROUND: Preliminary work has demonstrated that background parenchymal enhancement (BPE) assessed by radiologists is predictive of future breast cancer in women undergoing high-risk screening MRI. Algorithmically assessed measures of BPE offer a more precise and reproducible means of measuring BPE than human readers and thus might improve the predictive performance of future cancer development. PURPOSE: To determine if algorithmically extracted imaging features of BPE on screening breast MRI in high-risk women are associated with subsequent development of cancer. STUDY TYPE: Case-control study. POPULATION: In all, 133 women at high risk for developing breast cancer; 46 of these patients developed breast cancer subsequently over a follow-up period of 2 years. FIELD STRENGTH/SEQUENCE: 5 T or 3.0 T T1 -weighted precontrast fat-saturated and nonfat-saturated sequences and postcontrast nonfat-saturated sequences. ASSESSMENT: Automatic features of BPE were extracted with a computer algorithm. Subjective BPE scores from five breast radiologists (blinded to clinical outcomes) were also available. STATISTICAL TESTS: Leave-one-out crossvalidation for a multivariate logistic regression model developed using the automatic features and receiver operating characteristic (ROC) analysis were performed to calculate the area under the curve (AUC). Comparison of automatic features and subjective features was performed using a generalized regression model and the P-value was obtained. Odds ratios for automatic and subjective features were compared. RESULTS: The multivariate model discriminated patients who developed cancer from the patients who did not, with an AUC of 0.70 (95% confidence interval: 0.60-0.79, P < 0.001). The imaging features remained independently predictive of subsequent development of cancer (P < 0.003) when compared with the subjective BPE assessment of the readers. DATA CONCLUSION: Automatically extracted BPE measurements may potentially be used to further stratify risk in patients undergoing high-risk screening MRI. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:456-464.

A machine learning approach to radiogenomics of breast cancer: a study of 922 subjects and 529 DCE-MRI features.

BACKGROUND: Recent studies showed preliminary data on associations of MRI-based imaging phenotypes of breast tumours with breast cancer molecular, genomic, and related characteristics. In this study, we present a comprehensive analysis of this relationship. METHODS: We analysed a set of 922 patients with invasive breast cancer and pre-operative MRI. The MRIs were analysed by a computer algorithm to extract 529 features of the tumour and the surrounding tissue. Machine-learning-based models based on the imaging features were trained using a portion of the data (461 patients) to predict the following molecular, genomic, and proliferation characteristics: tumour surrogate molecular subtype, oestrogen receptor, progesterone receptor and human epidermal growth factor status, as well as a tumour proliferation marker (Ki-67). Trained models were evaluated on the set of the remaining 461 patients. RESULTS: Multivariate models were predictive of Luminal A subtype with AUC = 0.697 (95% CI: 0.647-0.746, p < .0001), triple negative breast cancer with AUC = 0.654 (95% CI: 0.589-0.727, p < .0001), ER status with AUC = 0.649 (95% CI: 0.591-0.705, p < .001), and PR status with AUC = 0.622 (95% CI: 0.569-0.674, p < .0001). Associations between individual features and subtypes we also found. CONCLUSIONS: There is a moderate association between tumour molecular biomarkers and algorithmically assessed imaging features.

Suspicious breast calcifications undergoing stereotactic biopsy in women ages 70 and over: Breast cancer incidence by BI-RADS descriptors.

OBJECTIVES: To determine the malignancy rate overall and for specific BI-RADS descriptors in women ≥70 years who undergo stereotactic biopsy for calcifications. METHODS: We retrospectively reviewed 14,577 consecutive mammogram reports in 6839 women ≥70 years to collect 231 stereotactic biopsies of calcifications in 215 women. Cases with missing images or histopathology and calcifications associated with masses, distortion, or asymmetries were excluded. Three breast radiologists determined BI-RADS descriptors by majority. Histology, hormone receptor status, and lymph node status were correlated with BI-RADS descriptors. RESULTS: There were 131 (57 %) benign, 22 (10 %) atypia/lobular carcinomas in situ, 55 (24 %) ductal carcinomas in situ (DCIS), and 23 (10 %) invasive diagnoses. Twenty-seven (51 %) DCIS cases were high-grade. Five (22 %) invasive cases were high-grade, two (9 %) were triple-negative, and three (12 %) were node-positive. Malignancy was found in 49 % (50/103) of fine pleomorphic, 50 % (14/28) of fine linear, 25 % (10/40) of amorphous, 20 % (3/15) of round, 3 % (1/36) of coarse heterogeneous, and 0 % (0/9) of dystrophic calcifications. CONCLUSIONS: Among women ≥70 years that underwent stereotactic biopsy for calcifications only, we observed a high rate of malignancy. Additionally, coarse heterogeneous calcifications may warrant a probable benign designation. KEY POINTS: • Cancer rates of biopsied calcifications in women ≥70 years are high • Radiologists should not dismiss suspicious calcifications in older women • Coarse heterogeneous calcifications may warrant a probable benign designation.

Impact of Breast Density Notification Legislation on Radiologists' Practices of Reporting Breast Density: A Multi-State Study.

Purpose To evaluate the impact of breast density notification legislation on breast density reporting by radiologists nationally. Materials and Methods The institutional review board exempted this HIPAA-compliant retrospective study from the requirement for informed consent. State-level data over a 5-year period on breast density categorization and breast cancer detection rate were collected from the National Mammography Database (NMD). Z tests were used to calculate differences in proportions. Results Facilities in 13 of 17 states that had breast density notification legislation as of 2014 submitted data to the NMD before and after law enactment. A total of 1 333 541 mammographic studies (hereafter called "mammograms") over a 30-month period, beginning 20 months before and continuing 10 months after law enactment, were included in the analysis. There was a small but statistically significant decrease in the percentage of mammograms reported as showing dense breast tissue (hereafter called "dense mammograms") in the month before law enactment compared with the month after (43.0% [22 338 of 52 000] vs 40.0% [18 604 of 46 464], P < .001). There was no statistically significant difference in the percentage of mammograms reported as dense in the month before law enactment compared with the 10th month after (43.0% [22 338 of 52 000] vs 42.8% [15 835 of 36 991], P = .65). There were no significant differences in the breast cancer detection rate between the month before and the month after law enactment (3.9 vs 3.8 cancers per 1000 mammograms, P = .79) or between the month before law enactment and the 10th month after (3.9 vs 4.2 cancers per 1000 mammograms, P = .55). In 21 analyzed states without breast density notification legislation, the percentage of mammograms reported as dense did not decrease below 42.8% (43 363 of 101 394) from 2010 to 2014, in contrast to 13 analyzed states with breast density notification legislation, which reached a nadir of 39.3% (20 965 of 53 360) (P < .001). Conclusion The percentage of mammograms reported as dense slightly decreased immediately after enactment of breast density notification legislation but then returned to prelegislation percentages within 10 months. (©) RSNA, 2016.

Evaluation of Pathologic Nipple Discharge: What is the Added Diagnostic Value of MRI?

PURPOSE: To determine the diagnostic value of magnetic resonance imaging (MRI) for the evaluation of patients with pathologic nipple discharge. METHODS: We performed a retrospective review of women with nipple discharge who underwent breast MRI between January 1, 2004, and December 31, 2013. Radiographic findings, pathology results, and clinical notes were reviewed. Sensitivity, specificity, positive predictive value, and negative predictive value of MRI were calculated. RESULTS: Over a 10-year period, 103 women (mean age 46 years, range 25-72 years) underwent MRI for evaluation of nipple discharge. Ninety-one patients (88 %) underwent surgical excision or had clinical and/or radiographic follow-up at least 2 years after presentation and thus comprise the study population. Eleven (30 %) of 37 patients with MRIs coded as American College of Radiology Breast Imaging-Reporting and Data System (BI-RADS) 4 of 5 were diagnosed with ductal carcinoma in situ (n = 6) or invasive adenocarcinoma (n = 5). Seven (64 %) of 11 patients diagnosed with malignancy had a negative mammographic and sonographic workup. None of the patients with MRIs coded as BI-RADS 1, 2, or 3 was diagnosed with malignancy immediately after presentation or during the 2-year follow-up period. The sensitivity and specificity of MRI for the detection of malignancy were 100 % (11 of 11) and 68 % (54 of 80), respectively. The positive predictive value and negative predictive value were 37 and 100 %, respectively. CONCLUSIONS: MRI is a valuable additional diagnostic tool for the evaluation of pathologic nipple discharge when conventional imaging is negative. A negative MRI in this symptomatic population may obviate the need for duct exploration and excision.

Architectural Distortion on Mammography: Correlation With Pathologic Outcomes and Predictors of Malignancy.

OBJECTIVE: The objective of our study was to determine the risk of malignancy associated with architectural distortion and to evaluate the imaging and clinical features that may contribute to the prediction of malignancy in the setting of architectural distortion. MATERIALS AND METHODS: We performed a retrospective review of architectural distortion cases from January 1, 2004, to December 31, 2013. Imaging findings and pathology outcomes were reviewed. RESULTS: Over the 10-year study period, architectural distortion that was considered to be suspicious for or highly suggestive of malignancy was present in 435 of 231,051 (0.2%) mammographic examinations. Cases were excluded if the main finding described was a mass with an associated feature of architectural distortion (n = 62) or if no pathology results were available (n = 4). Two hundred seventy-five cases of invasive adenocarcinoma or ductal carcinoma in situ (DCIS) were identified; the positive predictive value (PPV) was therefore 74.5% (275/369). DCIS alone was identified in only 4.1% (15/369). The most common benign finding on pathology was a radial scar or complex sclerosing lesion (27/369, 7.3%). Architectural distortion was less likely to represent malignancy on screening mammography than on diagnostic mammography (67.0% vs 83.1%, respectively; p < 0.001). Architectural distortion without a sonographic correlate was less likely to represent malignancy than architectural distortion with a correlate (27.9% vs 82.9%, respectively; p < 0.001). There was no statistically significant difference in the malignancy rate between pure architectural distortion and architectural distortion with calcifications or asymmetries (73.0% vs 78.8%; p = 0.26). CONCLUSION: The PPV of architectural distortion for malignancy is 74.5%. Architectural distortion is less likely to represent malignancy if detected on screening mammography than on diagnostic mammography or if there is no sonographic correlate.

Diagnostic Value of Ultrasound in Female Patients With Nipple Discharge.

OBJECTIVE: The purpose of this study was to assess the contribution of ultrasound to the evaluation of patients with pathologic nipple discharge. MATERIALS AND METHODS: A retrospective review was conducted of the records of females who presented with nipple discharge between January 1, 2009, and December 31, 2011. Pathologic nipple discharge was defined as discharge with one or more of the following features: unilateral, clear or bloody, and spontaneous. Patients underwent bilateral mammography followed by ultrasound directed at the subareolar portion of the affected breast. Radiologic findings and pathologic results were reviewed. RESULTS: Over a 3-year period, 327 females (mean age, 48 years; range, 13-88 years) presented with nipple discharge. Among these patients, 273 (83%) underwent surgical excision or clinical or radiographic follow-up at least 2 years after presentation and composed the study population. Among the 273 patients, 262 (96%) underwent mammography and 246 (90%) underwent sonography. Among 252 patients who had at least one pathologic feature of nipple discharge and underwent surgical excision or at least 2 years of follow-up, a total of 20 (8%) cases of ductal carcinoma in situ (DCIS) or invasive adenocarcinoma were diagnosed. DCIS or invasive adenocarcinoma was diagnosed in eight patients with normal sonographic findings. For the detection of DCIS and invasive adenocarcinoma, the sensitivity and specificity of ultrasound were 56% (10/18) and 75% (170/228); the sensitivity and specificity of mammography were 15% (3/20) and 98% (237/242). CONCLUSION: For females presenting with pathologic nipple discharge, ultrasound is a useful diagnostic tool and may be worth including in the routine evaluation.

Frequency of Malignancy and Imaging Characteristics of Probably Benign Lesions Seen at Breast MRI.

OBJECTIVE: The purposes of this study were to evaluate the frequency, follow-up compliance, and cancer rate of MRI BI-RADS category 3 lesions and to determine the cancer rate for individual BI-RADS descriptors. MATERIALS AND METHODS: A retrospective review was conducted of breast MRI examinations with an assessment of probably benign (BI-RADS category 3) from among 4279 consecutive breast MRI examinations performed from January 2005 through December 2009. The review revealed 282 (6.6%) examinations with 332 lesions defined as BI-RADS 3. Pathologic results, 2 years of follow-up imaging findings, or both were reviewed. The frequency of BI-RADS 3 assessments, follow-up imaging compliance, and cancer yield were calculated. Three fellowship-trained breast imagers reevaluated all lesions and recorded descriptors from the MRI lexicon of the fifth edition of the BI-RADS atlas. The distribution and likelihood of malignancy for each descriptor were calculated. RESULTS: The follow-up compliance rate was 84.3% (280/332), and the malignancy rate was 4.3% (12/280). There were 50 (17.9%) individual foci, 61 (21.8%) multiple foci, 74 (26.4%) masses, and 95 (33.9%) nonmass enhancement lesions. Masses were most commonly oval (59.5% [44/74]), circumscribed (75.7% [56/74]), and homogeneously enhancing (43.2% [32/74]). Nonmass enhancement was most commonly focal (57.9% [55/95]) with heterogeneous enhancement (53.7% [51/95]) Most of the lesions had persistent kinetics (74.3% [208/280]). The background parenchymal enhancement was most commonly mild (51.1% [143/280]). CONCLUSION: MRI BI-RADS category 3 is not frequently used, and the levels of patient compliance with follow-up imaging are acceptable. The cancer yield for probably benign lesions is greater for MRI-detected than for mammographically detected lesions, especially for specific BI-RADS descriptors.

Interobserver Variability Between Breast Imagers Using the Fifth Edition of the BI-RADS MRI Lexicon.

OBJECTIVE: The purpose of this study was to assess the interobserver variability of users of the MRI lexicon in the fifth edition of the BI-RADS atlas. MATERIALS AND METHODS: Three breast imaging specialists reviewed 280 routine clinical breast MRI findings reported as BI-RADS category 3. Lesions reported as BI-RADS 3 were chosen because variability in the use of BI-RADS descriptors may influence which lesions are classified as probably benign. Each blinded reader reviewed every study and recorded breast features (background parenchymal enhancement) and lesion features (lesion morphology, mass shape, mass margin, mass internal enhancement, nonmass enhancement distribution, nonmass enhancement internal enhancement, enhancement kinetics) according to the fifth edition of the BI-RADS lexicon and provided a final BI-RADS assessment. Interobserver variability was calculated for each breast and lesion feature and for the final BI-RADS assessment. RESULTS: Interobserver variability for background parenchymal enhancement was fair (ĸ = 0.28). There was moderate agreement on lesion morphology (ĸ = 0.53). For masses, there was substantial agreement on shape (ĸ = 0.72), margin (ĸ = 0.78), and internal enhancement (ĸ = 0.69). For nonmass enhancement, there was substantial agreement on distribution (ĸ = 0.69) and internal enhancement (ĸ = 0.62). There was slight agreement on lesion kinetics (ĸ = 0.19) and final BI-RADS assessment (ĸ = 0.11). CONCLUSION: There is moderate to substantial agreement on most MRI BI-RADS lesion morphology descriptors, particularly mass and nonmass enhancement features, which are important predictors of malignancy. Considerable disagreement remains, however, among experienced readers whether to follow particular findings.

Screening the Implant-Augmented Breast with Digital Breast Tomosynthesis: Is Tomosynthesis Necessary for Non-implant-Displaced Views?

OBJECTIVE: To determine cancer visualization utility and radiation dose for non-implant-displaced (ID) views using standard protocol with digital breast tomosynthesis (DBT) vs alternative protocol with 2D only when screening women with implant augmentation. METHODS: This retrospective cohort study identified women with implants who underwent screening DBT examinations that had abnormal findings from July 28, 2014, to December 31, 2021. Three fellowship-trained breast radiologists independently reviewed examinations retrospectively to determine if the initially identified abnormalities could be visualized on standard protocol (DBT with synthesized 2D (S2D) for ID and non-ID views) and alternate protocol (DBT with S2D for ID and only the S2D images for non-ID views). Estimated exam average glandular dose (AGD) and associations between cancer visualization with patient and implant characteristics for both protocols were evaluated. RESULTS: The study included 195 patients (mean age 55 years ± 10) with 223 abnormal findings. Subsequent biopsy was performed for 86 abnormalities: 59 (69%) benign, 8 (9%) high risk, and 19 (22%) malignant. There was no significant difference in malignancy visualization rate between standard (19/223, 8.5%) and alternate (18/223, 8.1%) protocols (P = .92), but inclusion of the DBT for non-ID views found one additional malignancy. Total examination AGD using standard protocol (21.9 mGy ± 5.0) was significantly higher than it would be for estimated alternate protocol (12.6 mGy ± 5.0, P <.001). This remained true when stratified by breast thickness: 6.0-7.9 cm, 8.0-9.9 cm, >10.0 cm (all P <.001). CONCLUSION: The inclusion of DBT for non-ID views did not significantly increase the cancer visualization rate but did significantly increase overall examination AGD.

Feasibility of Prospective Assignment of Initial Method of Detection of Breast Cancer: A Multicenter Pilot Study.

OBJECTIVE: To determine the feasibility of standardized, prospective assignment of initial method of detection (MOD) of breast cancer by radiologists in diverse practice settings. METHODS: This multicenter, retrospective study analyzed the rate of assignment of MOD in four geographically varied health systems. A universal protocol for basic MOD assignment was agreed upon by the authors before start of the pilot study. Radiologists at each site were instructed how to assign MOD. Charts were then reviewed to determine the frequency and accuracy of MOD assignment for all cases subsequently diagnosed with breast cancer. When available, data regarding frequency of tumor registry abstraction were also reviewed for frequency and accuracy. RESULTS: A total of 2,328 patients with a new diagnosis of breast cancer were evaluated across the sites over the study period. Of these patients, initial MOD was prospectively assigned by the radiologist in 94% of cases. Of the cases in which MOD was assigned, retrospective review confirmed accurate assignment in 96% of cases. CONCLUSIONS: Prospective, standardized assignment of initial MOD of breast cancer is feasible across different practice sites and can be accurately captured in tumor registries. Standard collection of MOD would provide critical data about the impact of screening mammography in the United States.

Myeloid Sarcoma of the Breast: A Diagnostic Dilemma With Pathologic Correlation.

Myeloid sarcoma (MS) is a rare extramedullary solid tumor arising most often in patients with current or subsequent acute myeloid leukemia (AML). Patients of all ages may present with involvement of the skin, lymph nodes, intestinal tract, bone, and/or central nervous system. Isolated involvement of the breast is rare, and only a small number of cases have been described in the literature. Breast MS may present as a palpable mass on clinical evaluation. In this broad literature review from 2010 to 2022, the most common findings on mammography are either solitary or multiple masses, followed by architectural distortion and, less commonly, no discrete findings. Sonography may demonstrate hypoechoic or mixed echogenicity mass(es) with circumscribed or indistinct, not discrete margins. Myeloid sarcoma may present as an enhancing mass or nonmass enhancement on breast MRI and is typically moderately radiotracer avid on 18F-fluorodeoxyglucose-PET. At histopathology, MS is characterized by myeloid blasts in varying stages of granulocytic or neutrophilic maturation; diagnosis typically requires immunophenotyping. There is no consensus for treatment of MS, although systemic chemotherapy for AML is often used as MS is considered the tissue equivalent of AML. This article will discuss and illustrate imaging and pathology findings when the breast is involved by MS.

Using the BI-RADS lexicon in a restrictive form of double reading as a strategy for minimizing screening mammography recall rates.

OBJECTIVE: The purpose of this article is to determine the potential reduction in screening recall rates by strictly following standardized BI-RADS lexicon for lesions seen on screening mammography. MATERIALS AND METHODS: Of 3084 consecutive mammograms performed at our screening facilities, 345 women with 437 lesions were recalled for additional imaging and constituted our study population. Three radiologists retrospectively classified lesions using the standard BI-RADS lexicon and assigned each to one of four groups: group A, the finding met criteria for recall by the BI-RADS lexicon; group B, the finding did not meet strict BI-RADS criteria for recall but was sufficiently indeterminate to warrant recall by the majority of the study panel; group C, the finding was classifiable by the BI-RADS lexicon but was not recalled because it was benign or stable; and group D, the questioned finding was not considered an abnormality by our study panel. Recall rates and the cancer detection rate were determined. The adjusted recall rate was calculated for lesions considered appropriate for recall (group A), and the reduction in the recall rate was determined. RESULTS: Nineteen malignancies were detected in our recalled population, for a cancer detection rate of 0.65%. All 19 malignancies were lesions considered appropriate for recall (group A). If only group A lesions had been recalled, the recall rate would have decreased from 11.4% to 6.2%, representing a 46% reduction in recalls without affecting the cancer detection rate. CONCLUSION: Using the BI-RADS lexicon as a decision-making aid may help adjust thresholds for recalling indeterminate or suspicious lesions and reduce recall rates from screening mammography.

Comparative performance of multiview stereoscopic and mammographic display modalities for breast lesion detection.

PURPOSE: Mammography is known to be one of the most difficult radiographic exams to interpret. Mammography has important limitations, including the superposition of normal tissue that can obscure a mass, chance alignment of normal tissue to mimic a true lesion and the inability to derive volumetric information. It has been shown that stereomammography can overcome these deficiencies by showing that layers of normal tissue lay at different depths. If standard stereomammography (i.e., a single stereoscopic pair consisting of two projection images) can significantly improve lesion detection, how will multiview stereoscopy (MVS), where many projection images are used, compare to mammography? The aim of this study was to assess the relative performance of MVS compared to mammography for breast mass detection. METHODS: The MVS image sets consisted of the 25 raw projection images acquired over an arc of approximately 45 degrees using a Siemens prototype breast tomosynthesis system. The mammograms were acquired using a commercial Siemens FFDM system. The raw data were taken from both of these systems for 27 cases and realistic simulated mass lesions were added to duplicates of the 27 images at the same local contrast. The images with lesions (27 mammography and 27 MVS) and the images without lesions (27 mammography and 27 MVS) were then postprocessed to provide comparable and representative image appearance across the two modalities. All 108 image sets were shown to five full-time breast imaging radiologists in random order on a state-of-the-art stereoscopic display. The observers were asked to give a confidence rating for each image (0 for lesion definitely not present, 100 for lesion definitely present). The ratings were then compiled and processed using ROC and variance analysis. RESULTS: The mean AUC for the five observers was 0.614 +/- 0.055 for mammography and 0.778 +/- 0.052 for multiview stereoscopy. The difference of 0.164 +/- 0.065 was statistically significant with a p-value of 0.0148. CONCLUSIONS: The differences in the AUCs and the p-value suggest that multiview stereoscopy has a statistically significant advantage over mammography in the detection of simulated breast masses. This highlights the dominance of anatomical noise compared to quantum noise for breast mass detection. It also shows that significant lesion detection can be achieved with MVS without any of the artifacts associated with tomosynthesis.

Predicting Upstaging of DCIS to Invasive Disease: Radiologists's Predictive Performance.

RATIONALE AND OBJECTIVES: The purpose of this study is to quantify breast radiologists' performance at predicting occult invasive disease when ductal carcinoma in situ (DCIS) presents as calcifications on mammography and to identify imaging and histopathological features that are associated with radiologists' performance. MATERIALS AND METHODS: Mammographically detected calcifications that were initially diagnosed as DCIS on core biopsy and underwent definitive surgical excision between 2010 and 2015 were identified. Thirty cases of suspicious calcifications upstaged to invasive ductal carcinoma and 120 cases of DCIS confirmed at the time of definitive surgery were randomly selected. Nuclear grade, estrogen and progesterone receptor status, patient age, calcification long axis length, and breast density were collected. Ten breast radiologists who were blinded to all clinical and pathology data independently reviewed all cases and estimated the likelihood that the DCIS would be upstaged to invasive disease at surgical excision. Subgroup analysis was performed based on nuclear grade, long axis length, breast density and after exclusion of microinvasive disease. RESULTS: Reader performance to predict upstaging ranged from an area under the receiver operating characteristic curve (AUC) of 0.541-0.684 with a mean AUC of 0.620 (95%CI: 0.489-0.751). Performances improved for lesions smaller than 2 cm (AUC: 0.676 vs 0.500; p = 0.002). The exclusion of microinvasive cases also improved performance (AUC: 0.651 vs 0.620; p = 0.005). There was no difference in performance based on breast density (p = 0.850) or nuclear grade (p = 0.270) CONCLUSION: Radiologists were able to predict invasive disease better than chance, particularly for smaller DCIS lesions (<2 cm) and after the exclusion of microinvasive disease.

Solitary, Well-Circumscribed, T2 Hyperintense Masses on MRI Have Very Low Malignancy Rates.

OBJECTIVE: The purpose of this study was to determine the malignancy rate of solitary MRI masses with benign BI-RADS descriptors. METHODS: A retrospective review was conducted of all breast MRI reports that described a mass with a final BI-RADS assessment of 3, 4, or 5, from February 1, 2005, through February 28, 2014 (n = 1510). Studies were excluded if the mass was not solitary, did not meet formal criteria for a mass, or had classically suspicious BI-RADS features (e.g., washout kinetics, and spiculated margin). The masses were reviewed by 2 fellowship-trained breast radiologists who reported consensus BI-RADS mass margin, shape, internal-enhancement, and kinetics descriptors. The T2 signal was reported as hyperintense if equal to or greater than the signal intensity of the axillary lymph nodes. Pathology results or 2 years of imaging follow-up were recorded. Comparisons were made between mass descriptors and clinical outcomes. RESULTS: There were 127 women with 127 masses available for analysis. There were 76 (60%) masses that underwent biopsy for an overall malignancy rate of 4% (5/127): 2 ductal carcinoma in situ (DCIS) and 3 invasive ductal carcinoma. The malignancy rate was 2% (1/59) for T2 hyperintense solitary masses. The malignancy rate was greater than 2% for all of the following BI-RADS descriptors: oval (3%, 3/88), round (5%, 2/39), circumscribed (4%, 5/127), homogeneous (4%, 3/74), and dark internal septations (4%, 2/44). CONCLUSION: T2 hyperintense solitary masses without associated suspicious features have a low malignancy rate, and they could be considered for a BI-RADS 3 final assessment.

MRI predictors of tumor-positive margins after breast-conserving surgery.

PURPOSE: The purpose of this study is to identify predictors of tumor-positive surgical margins after breast-conserving surgery on dynamic contrast-enhanced (DCE) MRI. MATERIALS AND METHODS: We conducted a retrospective study of consecutive women who underwent DCE MRI before breast-conserving surgery from 2005 to 2014. Patient demographics, indication for surgery, MRI findings, biopsy pathology results, and surgical outcomes were reviewed. The unpaired t-test and chi-square test were used to compare the positive and negative margins groups. RESULTS: 554 women (mean age, 56; range, 26-90) underwent DCE MRI before 575 breast-conserving surgeries for invasive carcinoma (n = 473) or ductal carcinoma in situ (DCIS) (n = 102). Positive margins requiring re-excision occurred in 19.7% (93/473) of surgeries for invasive carcinoma and 31.4% (32/102) of surgeries for DCIS. For invasive carcinoma surgeries, positive margins were more common when MRI demonstrated the finding of non-mass enhancement (NME) rather than the finding of enhancing mass (33.8% [22/65] versus 16.9% [61/360], p < 0.01). Tumor size on MRI was significantly larger in the positive margins group (2.5 cm versus 1.9 cm, p < 0.001). Positive margins were more common with invasive lobular rather than invasive ductal histology at core biopsy (38.3% [18/47] versus 16.0% [56/350], p < 0.001). For DCIS surgeries, there were no significant differences in positive margin rates related to MRI features. CONCLUSION: For invasive carcinoma surgeries, positive margins are associated with NME on MRI, larger tumor size on MRI, and lobular histology at core biopsy. These findings may be used to predict which patients are at risk for positive margins after breast-conserving surgery.