Outcomes of High-Risk Breast MRI Screening in Women Without Prior History of Breast Cancer: Effectiveness Data from a Tertiary Care Center.

OBJECTIVE: To evaluate the diagnostic performance outcomes of a breast MRI screening program in high-risk women without prior history of breast cancer. METHODS: Retrospective cohort study of 1 405 consecutive screening breast MRI examinations in 681 asymptomatic women with high risk of breast cancer without prior history of breast cancer from January 1, 2015, to December 31, 2019. Outcomes (sensitivity, specificity, positive predictive value, negative predictive value, false-negative rate [FNR], cancer detection rate [CDR]) and characteristics of cancers were determined based on histopathology or 12-month follow-up. MRI examinations performed, BI-RADS assessments, pathology outcomes, and CDRs were analyzed overall and by age decade. Results in incidence screening round (MRI in last 18 months) and nonincidence round were compared. RESULTS: Breast MRI achieved CDR 20/1000, sensitivity 93.3% (28/30), and specificity 83.4% (1 147/1375). Twenty-eight (28/1 405, CDR 20/1000) screen-detected cancers were identified: 18 (64.3%, 18/28) invasive and 10 (35.7%, 10/28) ductal carcinoma in situ. Overall, 92.9% (26/28) of all cancers were stage 0 or 1 and 89.3% (25/28) were node negative. All 14 incidence screening round malignancies were stage 0 or 1 with N0 disease. Median size for invasive carcinoma was 8.0 mm and for ductal carcinoma in situ was 9.0 mm. There were two false-negative exams for an FNR 0.1% (2/1 405). CONCLUSION: High-risk screening breast MRI was effective at detecting early breast cancer and associated with favorable outcomes.

Digital Breast Tomosynthesis Slab Thickness: Impact on Reader Performance and Interpretation Time.

Background Digital breast tomosynthesis (DBT) helps reduce recall rates and improve cancer detection compared with two-dimensional (2D) mammography but has a longer interpretation time. Purpose To evaluate the effect of DBT slab thickness and overlap on reader performance and interpretation time in the absence of 1-mm slices. Materials and Methods In this retrospective HIPAA-compliant multireader study of DBT examinations performed between August 2013 and July 2017, four fellowship-trained breast imaging radiologists blinded to final histologic findings interpreted DBT examinations by using a standard protocol (10-mm slabs with 5-mm overlap, 1-mm slices, synthetic 2D mammogram) and an experimental protocol (6-mm slabs with 3-mm overlap, synthetic 2D mammogram) with a crossover design. Among the 122 DBT examinations, 74 mammographic findings had final histologic findings, including 31 masses (26 malignant), 20 groups of calcifications (12 malignant), 18 architectural distortions (15 malignant), and five asymmetries (two malignant). Durations of reader interpretations were recorded. Comparisons were made by using receiver operating characteristic curves for diagnostic performance and paired t tests for continuous variables. Results Among 122 women, mean age was 58.6 years ± 10.1 (standard deviation). For detection of malignancy, areas under the receiver operating characteristic curves were similar between protocols (range, 0.83-0.94 vs 0.84-0.92; P ≥ .63). Mean DBT interpretation time was shorter with the experimental protocol for three of four readers (reader 1, 5.6 minutes ± 1.7 vs 4.7 minutes ± 1.4 [P < .001]; reader 2, 2.8 minutes ± 1.1 vs 2.3 minutes ± 1.0 [P = .001]; reader 3, 3.6 minutes ± 1.4 vs 3.3 minutes ± 1.3 [P = .17]; reader 4, 4.3 minutes ± 1.0 vs 3.8 minutes ± 1.1 [P ≤ .001]), with 72% reduction in both mean number of images and mean file size (P < .001 for both). Conclusion A digital breast tomosynthesis reconstruction protocol that uses 6-mm slabs with 3-mm overlap, without 1-mm slices, had similar diagnostic performance compared with the standard protocol and led to a reduced interpretation time for three of four readers. © RSNA, 2020 See also the editorial by Chang in this issue.

Prospective Imaging Trial Assessing Gadoteridol Retention in the Deep Brain Nuclei of Women Undergoing Breast MRI.

RATIONALE AND OBJECTIVES: To assess for indirect evidence of gadoteridol retention in the deep brain nuclei of women undergoing serial screening breast MRI. METHODS: This HIPAA-compliant prospective observational noninferiority imaging trial was approved by the IRB. From December 2016 to March 2018, 12 consented subjects previously exposed to 0-1 doses of gadoteridol (group 1) and 7 consented subjects previously exposed to ≥4 doses of gadoteridol (group 2) prospectively underwent research-specific unenhanced brain MRI including T1w spin echo imaging and T1 mapping. Inclusion criteria were: (1) planned breast MRI with gadoteridol, (2) no gadolinium exposure other than gadoteridol, (3) able to undergo MRI, (4) no neurological illness, (5) no metastatic disease, (6) no chemotherapy. Regions of interest were manually drawn in the globus pallidus, thalamus, dentate nucleus, and pons. Globus pallidus/thalamus and dentate nucleus/pons signal intensities and T1-time ratios were calculated using established methods and correlated with cumulative gadoteridol dose (mL). RESULTS: All subjects were female (mean age: 50 ± 12 years) and previously had received an average of 0.5 ± 0.5 (group 1) and 5.9 ± 2.1 (group 2) doses of gadoteridol (cumulative dose: 8 ± 8 and 82 ± 31 mL, respectively), with the last dose an average of 492 ± 299 days prior to scanning. There was no significant correlation between cumulative gadoteridol dose (mL) and deep brain nuclei signal intensity at T1w spin echo imaging (p = 0.365-0.512) or T1 mapping (p = 0.197-0.965). CONCLUSION: We observed no indirect evidence of gadolinium retention in the deep brain nuclei of women undergoing screening breast MRI with gadoteridol.

Use of Screening Mammography to Detect Occult Malignancy in Autologous Breast Reconstructions: A 15-year Experience.

Purpose To examine how often screening mammography depicts clinically occult malignancy in breast reconstruction with autologous myocutaneous flaps (AMFs). Materials and Methods Between January 1, 2000, and July 15, 2015, the authors retrospectively identified 515 women who had undergone mammography of 618 AMFs and who had at least 1 year of clinical follow-up. Of the 618 AMFs, 485 (78.5%) were performed after mastectomy for cancer and 133 (21.5%) were performed after prophylactic mastectomy. Medical records were used to determine the frequency, histopathologic characteristics, presentation, time to recurrence, and detection modality of malignancy. Cancer detection rate (CDR), sensitivity, specificity, positive predictive value, and false-positive biopsy rate were calculated. Results An average of 6.7 screening mammograms (range, 1-16) were obtained over 15.5 years. The frequency of local-regional recurrence (LRR) was 3.9% (20 of 515 women; 95% confidence interval [CI]: 2.2%, 5.6%); all LRRs were invasive, and none were detected in the breast mound after prophylactic mastectomy. Of the 20 women with LRR, 13 (65%) were screened annually before the diagnosis. Seven of those 13 women (54%) had clinically occult LRR, and mammography depicted five. Five of the six clinically evident recurrences (83%) were interval cancers. The median time between reconstruction and first recurrence was 4.4 years (range, 0.8-16.2 years). The CDR per AMF was 1.5 per 1000 screening mammograms (five of 3358; 95% CI: 0.18, 2.8) after mastectomy for cancer and 0 of 1000 examinations (0 of 805 mammograms; 95% CI: 0, 5) after prophylactic mastectomy. Sensitivity, specificity, positive predictive value, and false-positive biopsy rate were 42% (five of 12), 99.4% (4125 of 4151), 16% (five of 31), and 0.6% (26 of 4151), respectively. Conclusion The CDR of screening mammography (1.5 per 1000 screening mammograms) of the AMF after mastectomy for cancer is comparable to that for one native breast of an age-matched woman. Screening mammography adds little value after prophylactic mastectomy. © RSNA, 2018.

Pleomorphic Lobular Carcinoma In Situ: Imaging Features, Upgrade Rate, and Clinical Outcomes.

OBJECTIVE: Pleomorphic lobular carcinoma in situ (PLCIS) is an aggressive subtype of lobular carcinoma in situ treated similarly to ductal carcinoma in situ. The purpose of this study was to determine the imaging findings, upgrade rate of PLCIS at core needle biopsy (CNB), and the treatment and outcomes of these patients. MATERIALS AND METHODS: This retrospective single-institution study included women with PLCIS at CNB or excisional biopsy without concomitant DCIS or invasive carcinoma between January 1, 1999, and July 20, 2016. Imaging findings, detection mode, treatment, and outcomes were reviewed. Retrospective review of the images was performed. Upgrade rate to ductal carcinoma in situ or invasive carcinoma at lumpectomy was calculated. RESULTS: Twenty-one patients had a finding of PLCIS at CNB (n = 16) or excisional biopsy (n = 5). Four of 15 (27%; 95% CI, 4-49%) cases of PLCIS at CNB were upgraded to DCIS (two cases) or invasive lobular cancer (two cases) at lumpectomy (one patient declined excision). No unique mammographic features were predictive of need to upgrade or extent of disease. Among the patients with pure PLCIS (not upgraded), 13 of 16 (81%) presented with fine pleomorphic calcifications on screening mammograms, 1 of 16 (6%) with distortion and calcifications, 1 of 16 (6%) with a mass, and 1 of 16 (6%) with nonmass enhancement at MRI. The median imaging size was 11 mm (mean, 14 mm; range, 3-47 mm). Twelve of 16 (75%) patients were treated with lumpectomy and 4 of 16 (25%) with mastectomy. Eight of 16 (50%) patients received adjuvant hormonal therapy, and 2 of 16 (17%) received radiation. There were no local recurrences. CONCLUSION: PLCIS most commonly presented as fine pleomorphic calcifications on mammograms and had a high upgrade rate after CNB. CNB diagnosis of PLCIS requires surgical excision.

Improving Breast MR Wait Times: A Model for Transitioning Newly Implemented Diagnostic Imaging Procedures into Routine Clinical Operation.

PURPOSE: The purpose of this quality improvement (QI) initiative was to increase patient access to breast MR while maintaining diagnostic image quality. METHODS: Institutional review board approval was waived for this HIPAA-compliant QI initiative, which was conducted from December 2014 through March 2016. Breast MR wait times, scheduling grids, and staffing models were reviewed to identify root causes of elevated wait times. Breast MR wait times were tracked on a biweekly basis as root causes were identified and action plans were implemented. Patient recall rates for repeat MR imaging were tracked. A retrospective analysis of image quality was performed in a randomly selected sample (20 per month; total: 320 examinations). Wait time and image quality data were analyzed with statistical process control charts and logistic regression. RESULTS: In all, 798 breast MR examinations were performed during the study period. Monthly volume increased from 23 in December 2014 to 50 in March 2016 (range: 23-64). Wait time for a routine breast MRI fell from 101 days before implementation to 5 days at study completion. The technical recall rate was 0.5% (4 of 798); no recall was performed for a technologist-related error or scan quality concern. The proportion of examinations with minor (31% [99 of 320]) or major (3% [9 of 320]) image quality impairments did not significantly change during the study period (P = .69-.70). CONCLUSION: A specialized MR examination was transitioned into routine clinical operation while maintaining image quality. This model may be useful for transitioning other specialized diagnostic imaging examinations into routine clinical practice.

Harms of Restrictive Risk-Based Mammographic Breast Cancer Screening.

OBJECTIVE: The objective of this study was to determine if restrictive risk-based mammographic screening could miss breast cancers that population-based screening could detect. MATERIALS AND METHODS: Through a retrospective search of records at a single institution, we identified 552 screen-detected breast cancers in 533 patients. All in situ and invasive breast cancers detected at screening between January 1, 2011, and December 31, 2014, were included. Medical records were reviewed for history, pathology, cancer size, nodal status, breast density, and mammographic findings. Mammograms were interpreted by one of 14 breast imaging radiologists with 3-30 years of experience, all of whom were certified according to the Mammography Quality Standards Act. Patient ages ranged from 36 to 88 years (mean, 61 years). The breast cancer risks evaluated were family history of breast cancer and dense breast tissue. Positive family history was defined as a first-degree relative with breast cancer. Dense breast parenchyma was either heterogeneously or extremely dense. RESULTS: Group 1 consisted of the 76.7% (409/533) of patients who had no personal history of breast cancer. Of these patients, 75.6% (309/409) had no family history of breast cancer, and 56% (229/409) had nondense breasts. Group 2 consisted of the 16.7% (89/533) of patients who were 40-49 years old. Of these patients, 79.8% (71/89) had no family history of breast cancer, and 30.3% (27/89) had nondense breasts. Ductal carcinoma in situ made up 34.6% (191/552) of the cancers; 65.4% (361/552) were invasive. The median size of the invasive cancers was 11 mm. Of the screen-detected breast cancers, 63.8% (352/552) were minimal cancers. CONCLUSION: Many screen-detected breast cancers occurred in women without dense tissue or a family history of breast cancer. Exclusive use of restrictive risk-based screening could result in delayed cancer detection for many women.

Characterization of Breast Masses in Digital Breast Tomosynthesis and Digital Mammograms: An Observer Performance Study.

RATIONALE AND OBJECTIVES: This study aimed to compare Breast Imaging Reporting and Data System (BI-RADS) assessment of lesions in two-view digital mammogram (DM) to two-view wide-angle digital breast tomosynthesis (DBT) without DM. MATERIALS AND METHODS: With Institutional Review Board approval and written informed consent, two-view DBTs were acquired from 134 subjects and the corresponding DMs were collected retrospectively. The study included 125 subjects with 61 malignant (size: 3.9-36.9 mm, median: 13.4 mm) and 81 benign lesions (size: 4.8-43.8 mm, median: 12.0 mm), and 9 normal subjects. The cases in the two modalities were read independently by six experienced Mammography Quality Standards Act radiologists in a fully crossed counterbalanced manner. The readers were blinded to the prevalence of malignant, benign, or normal cases and were asked to assess the lesions based on the BI-RADS lexicon. The ratings were analyzed by the receiver operating characteristic methodology. RESULTS: Lesion conspicuity was significantly higher (P << .0001) and fewer lesion margins were considered obscured in DBT. The mean area under the receiver operating characteristic curve for the six readers increased significantly (P = .0001) from 0.783 (range: 0.723-0.886) for DM to 0.911 (range: 0.884-0.936) for DBT. Of the 366 ratings for malignant lesions, 343 on DBT and 278 on DM were rated as BI-RADS 4a and above. Of the 486 ratings for benign lesions, 220 on DBT and 206 on DM were rated as BI-RADS 4a and above. On average, 17.8% (65 of 366) more malignant lesions and 2.9% (14 of 486) more benign lesions would be recommended for biopsy using DBT. The inter-radiologist variability was reduced significantly. CONCLUSION: With DBT alone, the BI-RADS assessment of breast lesions and inter-radiologist reliability were significantly improved compared to DM.

Does Direct Radiologist-Patient Verbal Communication Affect Follow-Up Compliance of Probably Benign Assessments?

PURPOSE: The aim of this study was to determine whether direct verbal communication of results by a radiologist affected follow-up compliance rates for probably benign breast imaging findings. METHODS: This study was institutional review board approved and HIPAA compliant. A retrospective search identified all patients from January 1, 2010 to December 31, 2010 who had breast findings newly assessed as probably benign (BI-RADS category 3). Patients were categorized by whether the radiologist or the technologist verbally communicated the result and follow-up recommendation. Patient adherence to 6-, 12-, and 24-month follow-up imaging recommendations was recorded. RESULTS: Compliance data were available for 770 of 819 patients in the study. Overall compliance was 83.0% (639 of 770) for 6-month examinations, 68.1% (524 of 770) for 6- and 12-month examinations, and 57.4% (442 of 770) for 6-, 12-, and 24-month examinations. For patients who initially underwent diagnostic mammography alone, there was no significant difference in compliance between those who had and those who did not have radiologist-patient communication (6 months, 81.9% vs 80.8% [P = .83]; 6 and 12 months, 70.8% vs 67.3% [P = .58]; 6, 12, and 24 months, 54.2% vs 58.4% [P = .53]). For patients who initially underwent diagnostic mammography alone versus ultrasound with or without diagnostic mammography, there was no significant difference in compliance (6 months, 81.1% vs 84.3% [P = .24]; 6 and 12 months, 68.1% vs 68.0% [P = .96]; 6, 12, and 24 months, 57.4% vs 57.4% [P = .00]). CONCLUSIONS: High initial compliance was achieved by radiologist or technologist verbal communication of findings and recommendations. Direct communication by the radiologist did not increase compliance compared with communication by a technologist.

Surgical biopsy is still necessary for BI-RADS 4 calcifications found on digital mammography that are technically too faint for stereotactic core biopsy.

The purpose of this study was to evaluate the outcome of faint BI-RADS 4 calcifications detected with digital mammography that were not amenable to stereotactic core biopsy due to suboptimal visualization. Following Institutional Review Board approval, a HIPAA compliant retrospective search identified 665 wire-localized surgical excisions of calcifications in 606 patients between 2007 and 2010. We included all patients that had surgical excision for initial diagnostic biopsy due to poor calcification visualization, whose current imaging was entirely digital and performed at our institution and who did not have a diagnosis of breast cancer within the prior 2 years. The final study population consisted of 20 wire-localized surgical biopsies in 19 patients performed instead of stereotactic core biopsy due to poor visibility of faint calcifications. Of the 20 biopsies, 4 (20% confidence intervals 2, 38%) were malignant, 5 (25%) showed atypia and 11 (55%) were benign. Of the malignant cases, two were invasive ductal carcinoma (2 and 1.5 mm), one was intermediate grade DCIS and one was low-grade DCIS. Malignant calcifications ranged from 3 to 12 mm. The breast density was scattered in 6/19 (32%), heterogeneously dense in 11/19 (58%) and extremely dense in 2/19 (10%). Digital mammography-detected faint calcifications that were not amenable to stereotactic biopsy due to suboptimal visualization had a risk of malignancy of 20%. While infrequent, these calcifications should continue to be considered suspicious and surgical biopsy recommended.

Long-term clinical outcomes in women with breast pain in the absence of additional clinical findings: mammography remains indicated.

The purpose of the study was to determine the long-term clinical outcomes of women with breast pain in the absence of additional symptoms or signs (isolated breast pain), and the utility of mammography in their work-up. IRB approved, HIPAA compliant study retrospectively reviewed 1,386 patients referred for breast imaging with ICD-9 code for breast pain between 1/1/2006 and 12/31/2007. Of these, 617 consecutive women (mean age, 49 years) with isolated breast pain, mammogram, and follow-up (mean, 51 months) constituted the study group. Clinical data, mammographic and sonographic BI-RADS assessments, and geographic relationship between the site of cancer and pain were evaluated. The frequency of malignancies and of specific benign outcomes, both at and subsequent to the time of presentation, was determined. Breast cancer and specific benign outcomes were diagnosed in the painful breast of 11/617 (1.8 %) and 63/617 (10.2 %) women, respectively. Majority of the cancers (9/11, 81.8 %) were diagnosed subsequent (5-52 months) to initial imaging evaluation, whereas the majority of benign outcomes (52/63, 82.5 %) were diagnosed at initial presentation. Diagnostic mammography at initial presentation had a negative predictive value of 99.8 % (95 % CI 99.1 %, 100 %), specificity of 98.5 % (95 % CI 97.2 %, 99.3 %), and sensitivity of 66.7 % (95 % CI 11.6 %, 94.5 %). Three cancers were subsequently diagnosed in the contralateral (non-painful) breast. Eleven of 14 (78.6 %) cancers were in the symptomatic breast, of which 9 (81.8 %) geographically corresponded to the same area of focal pain. Thus, infrequently, breast cancer may clinically present as or be preceded by isolated breast pain and diagnostic mammography is useful for assessment.

Digital breast tomosynthesis: observer performance of clustered microcalcification detection on breast phantom images acquired with an experimental system using variable scan angles, angular increments, and number of projection views.

PURPOSE: To investigate the dependence of microcalcification cluster detectability on tomographic scan angle, angular increment, and number of projection views acquired at digital breast tomosynthesis ( DBT digital breast tomosynthesis ). MATERIALS AND METHODS: A prototype DBT digital breast tomosynthesis system operated in step-and-shoot mode was used to image breast phantoms. Four 5-cm-thick phantoms embedded with 81 simulated microcalcification clusters of three speck sizes (subtle, medium, and obvious) were imaged by using a rhodium target and rhodium filter with 29 kV, 50 mAs, and seven acquisition protocols. Fixed angular increments were used in four protocols (denoted as scan angle, angular increment, and number of projection views, respectively: 16°, 1°, and 17; 24°, 3°, and nine; 30°, 3°, and 11; and 60°, 3°, and 21), and variable increments were used in three (40°, variable, and 13; 40°, variable, and 15; and 60°, variable, and 21). The reconstructed DBT digital breast tomosynthesis images were interpreted by six radiologists who located the microcalcification clusters and rated their conspicuity. RESULTS: The mean sensitivity for detection of subtle clusters ranged from 80% (22.5 of 28) to 96% (26.8 of 28) for the seven DBT digital breast tomosynthesis protocols; the highest sensitivity was achieved with the 16°, 1°, and 17 protocol (96%), but the difference was significant only for the 60°, 3°, and 21 protocol (80%, P < .002) and did not reach significance for the other five protocols (P = .01-.15). The mean sensitivity for detection of medium and obvious clusters ranged from 97% (28.2 of 29) to 100% (24 of 24), but the differences fell short of significance (P = .08 to >.99). The conspicuity of subtle and medium clusters with the 16°, 1°, and 17 protocol was rated higher than those with other protocols; the differences were significant for subtle clusters with the 24°, 3°, and nine protocol and for medium clusters with 24°, 3°, and nine; 30°, 3°, and 11; 60°, 3° and 21; and 60°, variable, and 21 protocols (P < .002). CONCLUSION: With imaging that did not include x-ray source motion or patient motion during acquisition of the projection views, narrow-angle DBT digital breast tomosynthesis provided higher sensitivity and conspicuity than wide-angle DBT digital breast tomosynthesis for subtle microcalcification clusters.

Imaging of breast cancer-related changes after nonsurgical therapy.

OBJECTIVE: The purpose of this article is to review both expected and unexpected thoracic CT manifestations of nonsurgical breast cancer treatment with multimodality imaging correlation. Specific topics include the spectrum of posttherapy changes attributed to chemotherapy and radiation therapy and the spread of breast cancer. CONCLUSION: Thoracic CT is an important tool commonly used for breast cancer staging and surveillance and for diagnostic indications such as shortness of breath and chest pain. Imaging findings can be related to progression of disease or to associated conditions, such as pulmonary embolism. The hallmarks of breast cancer spread in the thorax include pulmonary nodules, enlarged lymph nodes, pleural effusions, thickening or nodularity, and sclerotic or lytic skeletal lesions. Less common findings including pulmonary lymphangitic tumor spread and pericardial metastasis. The findings also may represent the sequelae of surgery, radiation therapy, or chemotherapy for breast cancer. Knowledge of various treatment methods and their expected and unexpected CT findings is important for recognizing treatment-related abnormalities to avoid confusion with breast cancer spread and thereby minimize the risk that unnecessary further diagnostic imaging will be performed.

Imaging of breast cancer-related changes after surgical therapy.

OBJECTIVE: The purpose of this article is to discuss the surgical treatment of breast cancer and its resultant thoracic CT and multimodality imaging manifestations. CONCLUSION: Many breast cancer patients undergo cross-sectional imaging at some point during or after treatment. Thoracic CT is an important modality performed for staging and surveillance. Thoracic CT examinations often show findings related to patients' surgical or adjuvant treatment. The postsurgical changes visible on thoracic CT may include those related to lumpectomy, mastectomy, breast reconstruction, and axillary surgery. Postsurgical complications may also be seen, including fluid collections, infection, fat necrosis, and lymphedema. Recognition and appropriate interpretation of the posttherapeutic spectrum of findings are important to avoid unnecessary diagnostic imaging and minimize patient anxiety.

Breast mass characterization using 3-dimensional automated ultrasound as an adjunct to digital breast tomosynthesis: a pilot study.

OBJECTIVES: The purpose of this study was to retrospectively evaluate the effect of 3-dimensional automated ultrasound (3D-AUS) as an adjunct to digital breast tomosynthesis (DBT) on radiologists' performance and confidence in discriminating malignant and benign breast masses. METHODS: Two-view DBT (craniocaudal and mediolateral oblique or lateral) and single-view 3D-AUS images were acquired from 51 patients with subsequently biopsy-proven masses (13 malignant and 38 benign). Six experienced radiologists rated, on a 13-point scale, the likelihood of malignancy of an identified mass, first by reading the DBT images alone, followed immediately by reading the DBT images with automatically coregistered 3D-AUS images. The diagnostic performance of each method was measured using receiver operating characteristic (ROC) curve analysis and changes in sensitivity and specificity with the McNemar test. After each reading, radiologists took a survey to rate their confidence level in using DBT alone versus combined DBT/3D-AUS as potential screening modalities. RESULTS: The 6 radiologists had an average area under the ROC curve of 0.92 for both modalities (range, 0.89-0.97 for DBT and 0.90-0.94 for DBT/3D-AUS). With a Breast Imaging Reporting and Data System rating of 4 as the threshold for biopsy recommendation, the average sensitivity of the radiologists increased from 96% to 100% (P > .08) with 3D-AUS, whereas the specificity decreased from 33% to 25% (P > .28). Survey responses indicated increased confidence in potentially using DBT for screening when 3D-AUS was added (P < .05 for each reader). CONCLUSIONS: In this initial reader study, no significant difference in ROC performance was found with the addition of 3D-AUS to DBT. However, a trend to improved discrimination of malignancy was observed when adding 3D-AUS. Radiologists' confidence also improved with DBT/3DAUS compared to DBT alone.

Update on emerging technologies in breast imaging.

Despite mammography's proven efficacy, there continues to be interest in newer technologies in breast cancer detection and expanded use of established technologies, especially in women with dense breast tissue and those at high risk. This article reflects on the development in the last ten years of some of these modalities and their current use.

Digital breast tomosynthesis is comparable to mammographic spot views for mass characterization.

PURPOSE: To determine if digital breast tomosynthesis (DBT) performs comparably to mammographic spot views (MSVs) in characterizing breast masses as benign or malignant. MATERIALS AND METHODS: This IRB-approved, HIPAA-compliant reader study obtained informed consent from all subjects. Four blinded Mammography Quality Standards Act-certified academic radiologists individually evaluated DBT images and MSVs of 67 masses (30 malignant, 37 benign) in 67 women (age range, 34-88 years). Images were viewed in random order at separate counterbalanced sessions and were rated for visibility (10-point scale), likelihood of malignancy (12-point scale), and Breast Imaging Reporting and Data System (BI-RADS) classification. Differences in mass visibility were analyzed by using the Wilcoxon matched-pairs signed-ranks test. Reader performance was measured by calculating the area under the receiver operating characteristic curve (A(z)) and partial area index above a sensitivity threshold of 0.90 (A(z)(0.90)) by using likelihood of malignancy ratings. Masses categorized as BI-RADS 4 or 5 were compared with histopathologic analysis to determine true-positive results for each modality. RESULTS: Mean mass visibility ratings were slightly better with DBT (range, 3.2-4.4) than with MSV (range, 3.8-4.8) for all four readers, with one reader's improvement achieving statistical significance (P = .001). The A(z) ranged 0.89-0.93 for DBT and 0.88-0.93 for MSV (P ≥ .23). The A(z)((0.90)) ranged 0.36-0.52 for DBT and 0.25-0.40 for MSV (P ≥ .20). The readers characterized seven additional malignant masses as BI-RADS 4 or 5 with DBT than with MSV, at a cost of five false-positive biopsy recommendations, with a mean of 1.8 true-positive (range, 0-3) and 1.3 false-positive (range, -1 to 4) assessments per reader. CONCLUSION: In this small study, mass characterization in terms of visibility ratings, reader performance, and BI-RADS assessment with DBT was similar to that with MSVs. Preliminary findings suggest that MSV might not be necessary for mass characterization when performing DBT.

Factors that impact the duration of MRI-guided core needle biopsy.

OBJECTIVE: The purpose of our study was to determine which patient-related, target lesion-related, or procedure-related variables impact the duration of MRI-guided core needle breast biopsy. MATERIALS AND METHODS: Between July 11, 2006, and September 26, 2007, data were collected for 75 single-target MRI-guided 9-gauge vacuum-assisted core needle biopsy procedures using a grid-guidance technique and performed at a single institution. The following variables were studied: MRI suite occupation time, number of operators, patient age and breast size, target morphology and location, approach to target, equipment used, number of image acquisitions and times the patient was moved in and out of the closed magnet, and occurrence of complications. Statistical analysis was performed using the Student's t test, analysis of variance, and Pearson's correlation, with p values < 0.05 considered significant. RESULTS: The mean duration was 57.9 minutes (SD, 17.2 minutes; range, 30-109 minutes). None of the patient- or target-related variables significantly impacted the duration, although lesions located in the anterior third of the breast showed a trend to prolong the procedure (p = 0.059). The time to complete a procedure was reduced when the operating radiologist was assisted by a breast imaging fellow-in-training (p = 0.01). Increasing numbers of image acquisitions and times the patient was moved in and out of the magnet significantly lengthened the procedure duration (p = 0.0001 for both). No major complications occurred. Biopsies yielded 16% (12/75) malignant and 84% (63/75) benign diagnoses. CONCLUSION: Variables that minimized procedure duration were number of image acquisitions, number of patient insertions or removals from the magnet, and assistance of a breast imaging fellow-in-training. No patient-related or target-related variables impacted procedure time.

Estimating the effects of informal radiology resident teaching on radiologist productivity: what is the cost of teaching?

RATIONALE AND OBJECTIVES: One mission of an academic radiology department is to teach. The greatest teaching effort is directed at radiology residents. As clinical work demands increase, informal, non-revenue-generating, teaching may suffer. We sought to determine the economic consequences of teaching. MATERIALS AND METHODS: With the use of a picture archiving and communications system, 6 radiology faculty members independently interpreted and dictated digitally acquired bone and chest radiographs for 1 hour alone and again 10-12 weeks later with a first-year resident. During the second session, the quality of teaching was graded by independent observers. The number of cases, relative value units (RVUs), and reimbursement for each session were calculated. RESULTS: The difference in number of cases dictated working alone (mean, 44.7) and with a first-year resident (mean, 23.5) was significant (P = 0.007). The difference between RVUs generated by faculty alone (mean, 9.0) and with a resident (mean, 4.5) also was significant (P = 0.006), and the difference in dollars billed when working alone (mean, $1558.45) and with a resident (mean, $777.65) was significant (P = 0.007). As teaching quality increased, the number of cases interpreted, dollars billed, and RVUs trended lower. CONCLUSION: Informal resident teaching significantly reduces clinical throughput, reducing examination volume, RVUs, and dollars billed by approximately half.