Can Radiologists Predict the Presence of Ductal Carcinoma In Situ and Invasive Breast Cancer?

OBJECTIVE: We hypothesize that radiologists' estimated percentage likelihood assessments for the presence of ductal carcinoma in situ (DCIS) and invasive cancer may predict histologic outcomes. MATERIALS AND METHODS: Two hundred fifty cases categorized as BI-RADS category 4 or 5 at four University of California Medical Centers were retrospectively reviewed by 10 academic radiologists with a range of 1-39 years in practice. Readers assigned BI-RADS category (1, 2, 3, 4a, 4b, 4c, or 5), estimated percentage likelihood of DCIS or invasive cancer (0-100%), and confidence rating (1 = low, 5 = high) after reviewing screening and diagnostic mammograms and ultrasound images. ROC curves were generated. RESULTS: Sixty-two percent (156/250) of lesions were benign and 38% (94/250) were malignant. There were 26 (10%) DCIS, 20 (8%) invasive cancers, and 48 (19%) cases of DCIS and invasive cancer. AUC values were 0.830-0.907 for invasive cancer and 0.731-0.837 for DCIS alone. Sensitivity of 82% (56/68), specificity of 84% (153/182), positive predictive value (PPV) of 66% (56/85), negative predictive value (NPV) of 93% (153/165), and accuracy of 84% ([56 + 153]/250) were calculated using an estimated percentage likelihood of 20% or higher as the prediction threshold for invasive cancer for the radiologist with the highest AUC (0.907; 95% CI, 0.864-0.951). Every 20% increase in the estimated percentage likelihood of invasive cancer increased the odds of invasive cancer by approximately two times (odds ratio, 2.4). For DCIS, using a threshold of 40% or higher, sensitivity of 81% (21/26), specificity of 79% (178/224), PPV of 31% (21/67), NPV of 97% (178/183), and accuracy of 80% ([21 + 178]/250) were calculated. Similarly, these values were calculated at thresholds of 2% or higher (BI-RADS category 4) and 95% or higher (BI-RADS category 5) to predict the presence of malignancy. CONCLUSION: Using likelihood estimates, radiologists may predict the presence of invasive cancer with fairly high accuracy. Radiologist-assigned estimated percentage likelihood can predict the presence of DCIS, albeit with lower accuracy than that for invasive cancer.

Upgrade rates of high-risk breast lesions diagnosed on core needle biopsy: a single-institution experience and literature review.

Optimal management of high-risk breast lesions detected by mammogram yielding atypical ductal hyperplasia, flat epithelial atypia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar without atypia on core needle biopsy is controversial. This is a single-institution retrospective review of 5750 core needle biopsy cases seen over 14.5 years, including 249 (4.3%), 72 (1.3%), 50 (0.9%), 37 (0.6%), and 54 (0.9%) cases of atypical ductal hyperplasia, flat epithelial atypia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar without atypia, respectively. Patient age, radiologic characteristics, needle gauge, and excision diagnoses were recorded. Of 462 high-risk cases analyzed, 333 (72%) underwent excision. Upgrade rate to ductal carcinoma in situ, pleomorphic carcinoma in situ, or invasive mammary carcinoma was 18% for atypical ductal hyperplasia, 11% for flat epithelial atypia, 9% for atypical lobular hyperplasia, 28% for lobular carcinoma in situ, and 16% for radial scar. Carcinoma diagnosed on excision was more likely to be in situ than invasive, and if invasive, more likely to be low grade than high grade. Overall, cases that were benign (vs high risk or carcinoma) on excision were less likely to have residual calcifications after biopsy (17% vs 27%, P=0.013), and more likely to have a smaller mass size (<1 cm) (82% vs 50%, P=0.001). On subgroup analysis, atypical ductal hyperplasia cases that were benign (vs high risk or carcinoma) on excision were more likely to have smaller mass size (<1 cm) (P=0.025). Lobular neoplasia diagnosed incidentally (vs targeted) on core needle biopsy was less likely to upgrade on excision (5% vs 39%, P=0.002). A comprehensive literature review was performed, identifying 116 studies reporting high-risk lesion upgrade rates, and our upgrade rates were similar to those of more recent larger studies. Careful radiological-pathological correlation is needed to identify high-risk lesion subgroups that may not need excision.

Impact of Breast Density Legislation on Breast Cancer Risk Assessment and Supplemental Screening: A Survey of 110 Radiology Facilities.

Breast density notification laws, passed in 19 states as of October 2014, mandate that patients be informed of their breast density. The purpose of this study is to assess the impact of this legislation on radiology practices, including performance of breast cancer risk assessment and supplemental screening studies. A 20-question anonymous web-based survey was emailed to radiologists in the Society of Breast Imaging between August 2013 and March 2014. Statistical analysis was performed using Fisher's exact test. Around 121 radiologists from 110 facilities in 34 USA states and 1 Canadian site responded. About 50% (55/110) of facilities had breast density legislation, 36% of facilities (39/109) performed breast cancer risk assessment (one facility did not respond). Risk assessment was performed as a new task in response to density legislation in 40% (6/15) of facilities in states with notification laws. However, there was no significant difference in performing risk assessment between facilities in states with a law and those without (p < 0.831). In anticipation of breast density legislation, 33% (16/48), 6% (3/48), and 6% (3/48) of facilities in states with laws implemented handheld whole breast ultrasound (WBUS), automated WBUS, and tomosynthesis, respectively. The ratio of facilities offering handheld WBUS was significantly higher in states with a law than in states without (p < 0.001). In response to breast density legislation, more than 33% of facilities are offering supplemental screening with WBUS and tomosynthesis, and many are performing formal risk assessment for determining patient management.

Patients' Perceptions of Radiation Exposure Associated With Mammography.

OBJECTIVE: Radiation associated with breast imaging is a sensitive issue, particularly for women who undergo mammography as a screening measure to detect breast cancer. Misinformation and misunderstanding regarding the risks associated with ionizing radiation have created heightened public concern and fear, which may result in avoidance of diagnostic procedures. The objectives of this study were to ascertain patients' knowledge and opinion of ionizing radiation as a whole and specifically in mammography, as well as to determine common misunderstandings and points of view that may affect women's decisions about whether to have a mammogram. MATERIALS AND METHODS: Over a 9-month period, a total of 1725 patients presenting for a mammogram completed a 25-point questionnaire focused on the following: general knowledge of radiation dose in common imaging modalities, the amount of radiation associated with a mammogram relative to five radiation benchmarks, and patients' opinions of the involvement of radiation in their health care. RESULTS: Although 65% of the women receiving a mammogram responded that they had been informed of the risks and benefits of the examination, 60% overestimated the radiation in a mammogram. CONCLUSION: Efforts should be made to accurately inform women of the risks and benefits of mammography, specifically highlighting the low dose of mammographic ionizing radiation and providing objective facts to ensure that they are making an informed decision regarding screening.

Criteria for identifying radiologists with acceptable screening mammography interpretive performance on basis of multiple performance measures.

OBJECTIVE: Using a combination of performance measures, we updated previously proposed criteria for identifying physicians whose performance interpreting screening mammography may indicate suboptimal interpretation skills. MATERIALS AND METHODS: In this study, six expert breast imagers used a method based on the Angoff approach to update criteria for acceptable mammography performance on the basis of two sets of combined performance measures: set 1, sensitivity and specificity for facilities with complete capture of false-negative cancers; and set 2, cancer detection rate (CDR), recall rate, and positive predictive value of a recall (PPV1) for facilities that cannot capture false-negative cancers but have reliable cancer follow-up information for positive mammography results. Decisions were informed by normative data from the Breast Cancer Surveillance Consortium (BCSC). RESULTS: Updated combined ranges for acceptable sensitivity and specificity of screening mammography are sensitivity≥80% and specificity≥85% or sensitivity 75-79% and specificity 88-97%. Updated ranges for CDR, recall rate, and PPV1 are: CDR≥6 per 1000, recall rate 3-20%, and any PPV1; CDR 4-6 per 1000, recall rate 3-15%, and PPV1≥3%; or CDR 2.5-4.0 per 1000, recall rate 5-12%, and PPV1 3-8%. Using the original criteria, 51% of BCSC radiologists had acceptable sensitivity and specificity; 40% had acceptable CDR, recall rate, and PPV1. Using the combined criteria, 69% had acceptable sensitivity and specificity and 62% had acceptable CDR, recall rate, and PPV1. CONCLUSION: The combined criteria improve previous criteria by considering the interrelationships of multiple performance measures and broaden the acceptable performance ranges compared with previous criteria based on individual measures.

Educational interventions to improve screening mammography interpretation: a randomized controlled trial.

OBJECTIVE: The objective of our study was to conduct a randomized controlled trial of educational interventions that were created to improve performance of screening mammography interpretation. MATERIALS AND METHODS: We randomly assigned physicians who interpret mammography to one of three groups: self-paced DVD, live expert-led educational seminar, or control. The DVD and seminar interventions used mammography cases of varying difficulty and provided associated teaching points. Interpretive performance was compared using a pretest-posttest design. Sensitivity, specificity, and positive predictive value (PPV) were calculated relative to two outcomes: cancer status and consensus of three experts about recall. The performance measures for each group were compared using logistic regression adjusting for pretest performance. RESULTS: One hundred two radiologists completed all aspects of the trial. After adjustment for preintervention performance, the odds of improved sensitivity for correctly identifying a lesion relative to expert recall were 1.34 times higher for DVD participants than for control subjects (95% CI, 1.00-1.81; p = 0.050). The odds of an improved PPV for correctly identifying a lesion relative to both expert recall (odds ratio [OR] = 1.94; 95% CI, 1.24-3.05; p = 0.004) and cancer status (OR = 1.81; 95% CI, 1.01-3.23; p = 0.045) were significantly improved for DVD participants compared with control subjects, with no significant change in specificity. For the seminar group, specificity was significantly lower than the control group (OR relative to expert recall = 0.80; 95% CI, 0.64-1.00; p = 0.048; OR relative to cancer status = 0.79; 95% CI, 0.65-0.95; p = 0.015). CONCLUSION: In this randomized controlled trial, the DVD educational intervention resulted in a significant improvement in screening mammography interpretive performance on a test set, which could translate into improved interpretative performance in clinical practice.

Diagnostic mammography: identifying minimally acceptable interpretive performance criteria.

PURPOSE: To develop criteria to identify thresholds for the minimally acceptable performance of physicians interpreting diagnostic mammography studies. MATERIALS AND METHODS: In an institutional review board-approved HIPAA-compliant study, an Angoff approach was used to set criteria for identifying minimally acceptable interpretive performance for both workup after abnormal screening examinations and workup of a breast lump. Normative data from the Breast Cancer Surveillance Consortium (BCSC) was used to help the expert radiologist identify the impact of cut points. Simulations, also using data from the BCSC, were used to estimate the expected clinical impact from the recommended performance thresholds. RESULTS: Final cut points for workup of abnormal screening examinations were as follows: sensitivity, less than 80%; specificity, less than 80% or greater than 95%; abnormal interpretation rate, less than 8% or greater than 25%; positive predictive value (PPV) of biopsy recommendation (PPV2), less than 15% or greater than 40%; PPV of biopsy performed (PPV3), less than 20% or greater than 45%; and cancer diagnosis rate, less than 20 per 1000 interpretations. Final cut points for workup of a breast lump were as follows: sensitivity, less than 85%; specificity, less than 83% or greater than 95%; abnormal interpretation rate, less than 10% or greater than 25%; PPV2, less than 25% or greater than 50%; PPV3, less than 30% or greater than 55%; and cancer diagnosis rate, less than 40 per 1000 interpretations. If underperforming physicians moved into the acceptable range after remedial training, the expected result would be (a) diagnosis of an additional 86 cancers per 100,000 women undergoing workup after screening examinations, with a reduction in the number of false-positive examinations by 1067 per 100,000 women undergoing this workup, and (b) diagnosis of an additional 335 cancers per 100,000 women undergoing workup of a breast lump, with a reduction in the number of false-positive examinations by 634 per 100,000 women undergoing this workup. CONCLUSION: Interpreting physicians who fall outside one or more of the identified cut points should be reviewed in the context of an overall assessment of all their performance measures and their specific practice setting to determine if remedial training is indicated.

The California breast density information group: a collaborative response to the issues of breast density, breast cancer risk, and breast density notification legislation.

In anticipation of breast density notification legislation in the state of California, which would require notification of women with heterogeneously and extremely dense breast tissue, a working group of breast imagers and breast cancer risk specialists was formed to provide a common response framework. The California Breast Density Information Group identified key elements and implications of the law, researching scientific evidence needed to develop a robust response. In particular, issues of risk associated with dense breast tissue, masking of cancers by dense tissue on mammograms, and the efficacy, benefits, and harms of supplementary screening tests were studied and consensus reached. National guidelines and peer-reviewed published literature were used to recommend that women with dense breast tissue at screening mammography follow supplemental screening guidelines based on breast cancer risk assessment. The goal of developing educational materials for referring clinicians and patients was reached with the construction of an easily accessible Web site that contains information about breast density, breast cancer risk assessment, and supplementary imaging. This multi-institutional, multidisciplinary approach may be useful for organizations to frame responses as similar legislation is passed across the United States. Online supplemental material is available for this article.

Cost minimization analysis of ultrasound-guided diagnostic evaluation of probably benign breast lesions.

The objective of this study was to compare direct health care costs for two competing diagnostic strategies for probably benign breast lesions detected by ultrasound in young women. We developed a decision analytic model and performed a cost minimization analysis comparing ultrasound-guided vacuum-assisted core biopsy and conservative short-term diagnostic ultrasound follow-up. Relative probabilities for diagnostic outcomes were derived from pooled analysis of the medical literature. Direct health care costs were estimated using United States national average figures from calendar year 2010. Deterministic sensitivity analyses were conducted, as well as a first-order Monte Carlo simulation to confirm cost differences between the two strategies. The conservative short-term imaging follow-up strategy ($639.55 average cost per patient) was the most economical strategy compared to immediate vacuum-assisted core biopsy ($879.55 average cost per patient). Sensitivity analyses demonstrated that the preferred strategy is most dependent on the probabilities of detecting change in appearance on follow-up ultrasound, having a benign finding on immediate core biopsy, and finding cancer on a biopsy triggered by an interval change in ultrasound appearance. The model was also sensitive to the costs of vacuum-assisted core biopsy and diagnostic ultrasound. Conservative imaging follow-up of BIRADS 3 breast masses by ultrasound is cost saving compared to immediate vacuum-assisted core biopsy, with a potential of saving more than one-third of overall costs associated with the diagnostic work-up of such lesions. Watchful waiting with short-term interval follow-up ultrasounds will spare women from unnecessary procedures and spare the United States health care system from unnecessary direct health care costs.

Patients' willingness to participate in a breast cancer biobank at screening mammogram.

To characterize patients' willingness to donate a biospecimen for future research as part of a breast cancer-related biobank involving a general screening population. We performed a prospective cross-sectional study of 4,217 women aged 21-89 years presenting to our facilities for screening mammogram between December 2010 and October 2011. This HIPAA-compliant study was approved by our institutional review board. We collected data on patients' interest in and actual donation of a biospecimen, motivators and barriers to donating, demographic information, and personal breast cancer risk factors. A multivariate logistic regression analysis was performed to identify patient-level characteristics associated with an increased likelihood to donate. Mean patient age was 57.8 years (SD 11.1 years). While 66.0 % (2,785/4,217) of patients were willing to donate blood or saliva during their visit, only 56.4 % (2,378/4,217) actually donated. Women with a college education (OR = 1.27, p = 0.003), older age (OR = 1.02, p < 0.001), previous breast biopsy (OR = 1.23, p = 0.012), family history of breast cancer (OR = 1.23, p = 0.004), or a comorbidity (OR = 1.22, p = 0.014) were more likely to donate. Asian-American women were significantly less likely to donate (OR = 0.74, p = 0.005). The major reason for donating was to help all future patients (42.3 %) and the major reason for declining donation was privacy concerns (22.3 %). A large proportion of women participating in a breast cancer screening registry are willing to donate blood or saliva to a biobank. Among minority participants, Asian-American women are less likely to donate and further qualitative research is required to identify novel active recruitment strategies to insure their involvement.

Ordering of CT by emergency department provider type: analysis of a nationally representative sample.

OBJECTIVE: Given the growing concern about CT overutilization, we provide a descriptive trend analysis of CT studies ordered in U.S. emergency departments by nonphysician health care providers and examine whether there is a significant difference in ordering patterns between nonphysicians and physicians. MATERIALS AND METHODS: We used a nationally representative data sample for 2001-2008 to describe trends in CT studies ordered in U.S. emergency departments by nonphysician health care providers. We performed a multivariate logistic regression with hospital fixed effects on the most recently available data to determine whether there is a difference in ordering patterns between the two provider groups. RESULTS: From 2001 to 2008, the number of emergency department visits associated with CT studies managed solely by nonphysician health care providers increased from 100,626 to 620,296. Over this same period, the proportion of emergency department visits associated with CT managed solely by nonphysician providers grew from 1.5% to 3.6%. Controlling for hospital-level and patient-level variables, patient visits managed solely by nonphysician providers had 0.38 times the odds of CT utilization compared with patient visits managed by physicians. CONCLUSION: Although both the total number and the proportion of emergency department visits managed independently by nonphysician providers and associated with CT have grown rapidly in the past decade, nonphysician health care providers are less likely to order CT compared with physicians. The types of ordering providers and their differing practices should become part of the discourse regarding appropriate CT utilization.

Use of BI-RADS 3-probably benign category in the American College of Radiology Imaging Network Digital Mammographic Imaging Screening Trial.

PURPOSE: To determine (a) how often the Breast Imaging Reporting and Data System (BI-RADS) category 3 was used in the American College of Radiology Imaging Network (ACRIN) Digital Mammographic Imaging Screening Trial (DMIST), either at the time of screening mammography or after work-up, (b) how often subjects actually returned for the recommended follow-up examination, and (c) the rate and stages of any malignancies subsequently found in subjects for whom short-term interval follow-up was recommended. MATERIALS AND METHODS: This study was approved by the Institutional Review Board at all institutions where subjects were enrolled. All subjects participating in DMIST gave informed consent and the study was HIPAA-compliant. A total of 47,599 DMIST-eligible and evaluable subjects, all of whom consented to undergo both digital and screen-film mammography, were included in this analysis. Cases referred for short-term interval follow-up based on digital, screen-film, or both imaging examinations were determined. Compliance with the recommendations and the final outcome (malignancy diagnosis at biopsy or no malignancy confirmed through follow-up) of each evaluable case were determined. RESULTS: A total of 1114 of the 47,599 (2.34%) subjects had tumors assigned a BI-RADS 3 category and were recommended to undergo short-interval follow-up. In this study, 791 of 1114 (71%) of the subjects were compliant with the recommendation and returned for short-interval follow-up. Of the women who did not return for short-interval follow-up, 70% (226 of 323) did return for their next annual mammography. Among all subjects whose tumors were assigned a BI-RADS 3 category either at screening mammography or after additional work-up, nine of 1114 (0.81%) were found to have cancer. Of the nine biopsy-proved cancers, six were invasive cancers and three were ductal carcinoma in situ stage Tis-T1c. The invasive cancers were all less than 2 cm in size. CONCLUSION: In DMIST, radiologists used the BI-RADS 3 classification infrequently (2.3% of patients). Tumors assigned a BI-RADS 3 category had a low rate of malignancy. The relatively high rate of noncompliance with short-interval follow-up recommendations (323 of 1114, or 29%) supports prior recommendations that radiologists thoroughly evaluate lesions before placing them in this category.

Influence of annual interpretive volume on screening mammography performance in the United States.

PURPOSE: To examine whether U.S. radiologists' interpretive volume affects their screening mammography performance. MATERIALS AND METHODS: Annual interpretive volume measures (total, screening, diagnostic, and screening focus [ratio of screening to diagnostic mammograms]) were collected for 120 radiologists in the Breast Cancer Surveillance Consortium (BCSC) who interpreted 783 965 screening mammograms from 2002 to 2006. Volume measures in 1 year were examined by using multivariate logistic regression relative to screening sensitivity, false-positive rates, and cancer detection rate the next year. BCSC registries and the Statistical Coordinating Center received institutional review board approval for active or passive consenting processes and a Federal Certificate of Confidentiality and other protections for participating women, physicians, and facilities. All procedures were compliant with the terms of the Health Insurance Portability and Accountability Act. RESULTS: Mean sensitivity was 85.2% (95% confidence interval [CI]: 83.7%, 86.6%) and was significantly lower for radiologists with a greater screening focus (P = .023) but did not significantly differ by total (P = .47), screening (P = .33), or diagnostic (P = .23) volume. The mean false-positive rate was 9.1% (95% CI: 8.1%, 10.1%), with rates significantly higher for radiologists who had the lowest total (P = .008) and screening (P = .015) volumes. Radiologists with low diagnostic volume (P = .004 and P = .008) and a greater screening focus (P = .003 and P = .002) had significantly lower false-positive and cancer detection rates, respectively. Median invasive tumor size and proportion of cancers detected at early stages did not vary by volume. CONCLUSION: Increasing minimum interpretive volume requirements in the United States while adding a minimal requirement for diagnostic interpretation could reduce the number of false-positive work-ups without hindering cancer detection. These results provide detailed associations between mammography volumes and performance for policymakers to consider along with workforce, practice organization, and access issues and radiologist experience when reevaluating requirements.

Breast imaging training and attitudes: update survey of senior radiology residents.

OBJECTIVE: The purpose of this study was to investigate the training and attitudes of senior residents regarding breast imaging. MATERIALS AND METHODS: In 2008 a follow-up survey was completed by a chief or senior resident at 201 radiology training programs in North America. Questions included organization of breast imaging rotation, resident responsibilities, clinical practice protocols at the institution, resident impressions regarding breast imaging, and resident interest in performing breast imaging after residency. Results were compared with those of a survey completed in 2000. RESULTS: Of 201 training programs, 200 (99.5%) had dedicated breast imaging rotations; 190 (95%), 12 weeks or longer; and 39 (19%), 16 weeks or longer. Residents regularly performed real-time ultrasound imaging in 138 programs (69%), needle localization in 159 (79%), ultrasound-guided biopsy in 154 (77%), and stereotactically guided biopsy in 145 programs (72%). One hundred sixty-two residents (81%) reported that interpreting mammograms was more stressful than interpretation of other imaging studies; 143 (71%) believed that only breast imaging subspecialists should interpret mammograms; and 104 (52%) would not consider pursuing a breast imaging fellowship. As in 2000, the most common reasons cited for not considering a fellowship were lack of interest in the field, fear of lawsuits, and the stressful nature of the job. CONCLUSION: Residency programs have devoted more time to breast imaging and made improvements in their curricula, but current residents report decreased opportunities to perform some studies and procedures. Although most residents would not consider a fellowship and did not want to interpret mammograms in future practice, the percentage of residents who would not consider breast imaging as a subspecialty has decreased since 2000. An accurate picture of current breast imaging curricula and variations among residency programs is necessary to identify and correct systemic problems and to improve the training of future breast imagers.

Mammographic signs of systemic disease.

Although mammography is primarily used for the detection of breast cancer, it can occasionally reveal breast abnormalities related to extramammary disease. Cardiovascular diseases such as congestive heart failure and central venous obstruction may manifest as venous engorgement and breast edema at mammography. Pathologic arterial calcifications seen at mammography can indicate an underlying risk factor for accelerated atherosclerosis such as chronic renal failure. Connective tissue diseases including rheumatoid arthritis, systemic lupus erythematosus, dermatomyositis-polymyositis, and systemic scleroderma typically manifest with bilateral axillary lymphadenopathy, and stromal calcifications are also seen in the latter three disease processes. Some diseases such as neurofibromatosis type 1 and filariasis may manifest with pathognomonic findings at mammography, whereas other systemic diseases such as Wegener granulomatosis, sarcoidosis, and amyloidosis can manifest as nonspecific breast masses that are indistinguishable from breast cancer and usually require tissue biopsy for confirmation. Knowledge of the imaging characteristics of various systemic diseases affecting the breast will aid the radiologist in differentiating systemic disease from suspect breast lesions, thereby helping ensure appropriate follow-up. Furthermore, recognition of systemic diseases such as Cowden syndrome that are associated with an increased risk of breast cancer will allow the radiologist to recommend appropriate surveillance.

Identifying minimally acceptable interpretive performance criteria for screening mammography.

PURPOSE: To develop criteria to identify thresholds for minimally acceptable physician performance in interpreting screening mammography studies and to profile the impact that implementing these criteria may have on the practice of radiology in the United States. MATERIALS AND METHODS: In an institutional review board-approved, HIPAA-compliant study, an Angoff approach was used in two phases to set criteria for identifying minimally acceptable interpretive performance at screening mammography as measured by sensitivity, specificity, recall rate, positive predictive value (PPV) of recall (PPV(1)) and of biopsy recommendation (PPV(2)), and cancer detection rate. Performance measures were considered separately. In phase I, a group of 10 expert radiologists considered a hypothetical pool of 100 interpreting physicians and conveyed their cut points of minimally acceptable performance. The experts were informed that a physician's performance falling outside the cut points would result in a recommendation to consider additional training. During each round of scoring, all expert radiologists' cut points were summarized into a mean, median, mode, and range; these were presented back to the group. In phase II, normative data on performance were shown to illustrate the potential impact cut points would have on radiology practice. Rescoring was done until consensus among experts was achieved. Simulation methods were used to estimate the potential impact of performance that improved to acceptable levels if effective additional training was provided. RESULTS: Final cut points to identify low performance were as follows: sensitivity less than 75%, specificity less than 88% or greater than 95%, recall rate less than 5% or greater than 12%, PPV(1) less than 3% or greater than 8%, PPV(2) less than 20% or greater than 40%, and cancer detection rate less than 2.5 per 1000 interpretations. The selected cut points for performance measures would likely result in 18%-28% of interpreting physicians being considered for additional training on the basis of sensitivity and cancer detection rate, while the cut points for specificity, recall, and PPV(1) and PPV(2) would likely affect 34%-49% of practicing interpreters. If underperforming physicians moved into the acceptable range, detection of an additional 14 cancers per 100000 women screened and a reduction in the number of false-positive examinations by 880 per 100000 women screened would be expected. CONCLUSION: This study identified minimally acceptable performance levels for interpreters of screening mammography studies. Interpreting physicians whose performance falls outside the identified cut points should be reviewed in the context of their specific practice settings and be considered for additional training.

Combined DCE-MRI and single-voxel 2D MRS for differentiation between benign and malignant breast lesions.

Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and proton (1H) magnetic resonance spectroscopy (MRS) provide structural and biochemical information, including vascular volume, vascular permeability and tissue metabolism. In this study, we performed analysis of the enhancement characteristic from DCE-MRI and the biochemical information provided by two-dimensional (2D) Localized Correlated Spectroscopy (L-COSY) MRS to determine the sensitivity and specificity of using DCE-MRI alone compared to the combination with 2D MRS. The metabolite ratios from the 2D MRS spectra were analyzed using multivariate statistical analyses to determine a method capable of automatic separation of the patient cohort into malignant and benign lesions. A total of 24 lesions were studied with 21 diagnosed accurately using the enhancement characteristics alone resulting in sensitivity and specificity of 100% and 73%, respectively. Analysis of the 2D MRS data demonstrated a significant difference (p < 0.05) in 12 of 18 metabolite ratios analyzed for malignant compared to benign lesions. Previous research focused on utilizing the choline signal to noise ratio (SNR) as a marker for malignancy has been verified using 2D MRS in this study. Using Fisher's linear discriminant test using water (WAT)/olefinic fat diagonal (UFD), choline (CHO)/fat (FAT), CHO/UFD, and FAT/methyl fat (FMETD) as predictors the sensitivity and specificity increased to 92% and 100%, respectively. Using the Classification and Regression Tree (CART) statistical analysis the resulting sensitivity and specificity were 100% and 91%, respectively, with the most accurate predictor for differentiating malignant and benign determined to be FAT/FMETD. The cases within the study that presented a indeterminate diagnosis using DCE-MRI alone were able to be accurately diagnosed when the metabolic information from 2D MRS was incorporated. The results suggest improved breast cancer detection through the combination of morphological and enhancement information from DCE-MRI and metabolic information from 2D MRS.

The positive predictive value of BI-RADS microcalcification descriptors and final assessment categories.

OBJECTIVE: The purpose of this article is to retrospectively assess the likelihood of malignancy of microcalcifications according to the BI-RADS descriptors in a digital mammography environment. MATERIALS AND METHODS: The study included 146 women with calcifications who underwent imaging-guided biopsy between April 2005 and July 2006. Digital mammograms procured before biopsy were analyzed independently by two breast imaging subspecialists blinded to biopsy results. Lesions described discordantly were settled by consensus. One of the radiologists provided a BI-RADS final assessment score. RESULTS: The overall positive predictive value of biopsies was 28.8%. The individual morphologic descriptors predicted the risk of malignancy as follows: fine linear/branching, 16 (70%) of 23 cases; fine pleomorphic, 14 (28%) of 50 cases; coarse heterogeneous, two (20%) of 10 cases; amorphous, 10 (20%) of 51 cases; and typically benign, zero (0%) of 12 cases. Fisher-Freeman-Halton exact testing showed statistical significance among morphology descriptors (p < 0.001) and distribution descriptors (p < 0.001). The positive predictive value for malignancy according to BI-RADS assessment categories were as follows: category 2, 0%; category 3, 0%; category 4A, 13%; category 4B, 36%; category 4C, 79%; and category 5, 100%. CONCLUSION: BI-RADS morphology and distribution descriptors can aid in assessing the risk of malignancy of microcalcifications detected on full-field digital mammography. The positive predictive value increased in successive BI-RADS categories (4A, 4B, and 4C), verifying that subdivision provides an improved assessment of suspicious microcalcifications in terms of likelihood of malignancy.

Invasive lobular carcinoma of the breast: spectrum of mammographic, US, and MR imaging findings.

The reported prevalence of invasive lobular carcinoma (ILC) is variable, with more recent studies indicating that ILC accounts for 10%-15% of all invasive breast carcinomas. However, the radiologic diagnosis and management of ILC can be uniquely challenging. Current imaging modalities are not very specific for differentiating ILC from other invasive breast cancers, and ILC has a tendency to have appearances at mammography that are atypical for invasive ductal carcinomas, resulting in higher false-negative rates. The clinical detection of ILC can also be difficult, since ILC frequently fails to form a palpable lesion. This tendency of ILC to have atypical imaging and clinical appearances is related to its histopathologic features and its failure to elicit a desmoplastic response. Despite these diagnostic challenges, however, imaging remains crucial in the detection and management of ILC. Mammography, ultrasonography (US), and magnetic resonance (MR) imaging all play important roles, with each modality having its own advantages and limitations. The use of US and MR imaging as adjuncts to mammography increases sensitivity in the detection of ILC and provides useful information for further management and presurgical planning. Familiarity with the spectrum of imaging appearances of ILC is essential.