Persistent inter-observer variability of breast density assessment using BI-RADS® 5th edition guidelines.

OBJECTIVES: Due to most states' legislation, mammographic density categorization has potentially far-reaching implications, but remains subjective based on BIRADS® guidelines. We aimed to determine 1) effect of BI-RADS® 5th edition (5th-ed) vs 4th-edition (4th-ed) guidelines on reader agreement regarding density assessment; 2) 5th-ed vs 4th-ed density distribution, and visual vs quantitative assessment agreement; 3) agreement between experienced vs less experienced readers. METHODS: In a retrospective review, six breast imaging radiologists (BIR) (23-30 years' experience) visually assessed density of 200 screening mammograms performed September 2012-January 2013 using 5th-ed guidelines. Results were compared to 2016 data of the same readers evaluating the same mammograms using 4th-ed guidelines after a training module. 5th-ed density categorization by seven junior BIR (1-5 years' experience) was compared to eight experienced BIR. Nelson et al.'s kappas (κm, κw), Fleiss' κF, and Cohen's κ were calculated. Quantitative density using Volpara was compared with reader assessments. RESULTS: Inter-reader weighted agreement using 5th-ed is moderately strong, 0.73 (κw, s.e. = 0.01), similar to 4th-ed, 0.71 (κw, s.e. = 0.03). Intra-reader Cohen's κ is 0.23-0.34, similar to 4th-ed. Binary not-dense vs dense categorization, using 5th-ed results in higher dense categorization vs 4th-ed (p < 0.001). 5th-ed density distribution results in higher numbers in categories B/C vs 4th-ed (p < 0.001). Distribution for 5th-ed does not differ based on reader experience (p = 0.09). Reader vs quantitative weighted agreement is similar (5th-ed, Cohen's κ = 0.76-0.85; 4th-ed, Cohen's κ = 0.68-0.83). CONCLUSION: There is persistent subjectivity of visually assessed mammographic density using 5th-ed guidelines; experience does not correlate with better inter-reader agreement.

Can Digital Breast Tomosynthesis Replace Full-Field Digital Mammography? A Multireader, Multicase Study of Wide-Angle Tomosynthesis.

OBJECTIVE. The purpose of this study was to test the hypothesis whether two-view wide-angle digital breast tomosynthesis (DBT) can replace full-field digital mammography (FFDM) for breast cancer detection. SUBJECTS AND METHODS. In a multireader multicase study, bilateral two-view FFDM and bilateral two-view wide-angle DBT images were independently viewed for breast cancer detection in two reading sessions separated by more than 1 month. From a pool of 764 patients undergoing screening and diagnostic mammography, 330 patient-cases were selected. The endpoints were the mean ROC AUC for the reader per breast (breast level), ROC AUC per patient (subject level), noncancer recall rates, sensitivity, and specificity. RESULTS. Twenty-nine of 31 readers performed better with DBT than FFDM regardless of breast density. There was a statistically significant improvement in readers' mean diagnostic accuracy with DBT. The subject-level AUC increased from 0.765 (standard error [SE], 0.027) for FFDM to 0.835 (SE, 0.027) for DBT (p = 0.002). Breast-level AUC increased from 0.818 (SE, 0.019) for FFDM to 0.861 (SE, 0.019) for DBT (p = 0.011). The noncancer recall rate per patient was reduced by 19% with DBT (p < 0.001). Masses and architectural distortions were detected more with DBT (p < 0.001); calcifications trended lower (p = 0.136). Accuracy for detection of invasive cancers was significantly greater with DBT (p < 0.001). CONCLUSION. Reader performance in breast cancer detection is significantly higher with wide-angle two-view DBT independent of FFDM, verifying the robustness of DBT as a sole view. However, results of perception studies in the vision sciences support the inclusion of an overview image.

Optimizing Success and Avoiding Mishaps in the Most Difficult Image-guided Breast Biopsies.

Breast cancer is an increasing challenge in developed and limited resource areas of the world. Early detection of breast cancer offers the best chance for optimal care and best outcomes. A critical step in early detection is to obtain efficient and accurate tissue diagnoses. Although image-guided core needle breast biopsies are usually straightforward for experienced breast imagers, there are some not uncommon scenarios that present particular challenges. In this review article we will discuss these difficult situations and offer our tried and true methods to ensure safe and successful biopsies, while using stereotactic, ultrasound, and MRI guidance.

Comparing search patterns in digital breast tomosynthesis and full-field digital mammography: an eye tracking study.

As a promising imaging modality, digital breast tomosynthesis (DBT) leads to better diagnostic performance than traditional full-field digital mammograms (FFDM) alone. DBT allows different planes of the breast to be visualized, reducing occlusion from overlapping tissue. Although DBT is gaining popularity, best practices for search strategies in this medium are unclear. Eye tracking allowed us to describe search patterns adopted by radiologists searching DBT and FFDM images. Eleven radiologists examined eight DBT and FFDM cases. Observers marked suspicious masses with mouse clicks. Eye position was recorded at 1000 Hz and was coregistered with slice/depth plane as the radiologist scrolled through the DBT images, allowing a 3-D representation of eye position. Hit rate for masses was higher for tomography cases than 2-D cases and DBT led to lower false positive rates. However, search duration was much longer for DBT cases than FFDM. DBT was associated with longer fixations but similar saccadic amplitude compared with FFDM. When comparing radiologists' eye movements to a previous study, which tracked eye movements as radiologists read chest CT, we found DBT viewers did not align with previously identified "driller" or "scanner" strategies, although their search strategy most closely aligns with a type of vigorous drilling strategy.

Stereotactic core needle breast biopsy marker migration: An analysis of factors contributing to immediate marker migration.

OBJECTIVES: To evaluate breast biopsy marker migration in stereotactic core needle biopsy procedures and identify contributing factors. METHODS: This retrospective study analyzed 268 stereotactic biopsy markers placed in 263 consecutive patients undergoing stereotactic biopsies using 9G vacuum-assisted devices from August 2010-July 2013. Mammograms were reviewed and factors contributing to marker migration were evaluated. Basic descriptive statistics were calculated and comparisons were performed based on radiographically-confirmed marker migration. RESULTS: Of the 268 placed stereotactic biopsy markers, 35 (13.1%) migrated ≥1 cm from their biopsy cavity. Range: 1-6 cm; mean (± SD): 2.35 ± 1.22 cm. Of the 35 migrated biopsy markers, 9 (25.7%) migrated ≥3.5 cm. Patient age, biopsy pathology, number of cores, and left versus right breast were not associated with migration status (P> 0.10). Global fatty breast density (P= 0.025) and biopsy in the inner region of breast (P = 0.031) were associated with marker migration. Superior biopsy approach (P= 0.025), locally heterogeneous breast density, and t-shaped biopsy markers (P= 0.035) were significant for no marker migration. CONCLUSIONS: Multiple factors were found to influence marker migration. An overall migration rate of 13% supports endeavors of research groups actively developing new biopsy marker designs for improved resistance to migration. KEY POINTS: • Breast biopsy marker migration is documented in 13% of 268 procedures. • Marker migration is affected by physical, biological, and pathological factors. • Breast density, marker shape, needle approach etc. affect migration. • Study demonstrates marker migration prevalence; marker design improvements are needed.

Positioning in breast MR imaging to optimize image quality.

Improper positioning of the breasts in a dedicated breast coil causes inhomogeneous fat saturation as well as other artifacts that decrease the sensitivity of breast magnetic resonance imaging. Improper positioning can create artifacts that can obscure a malignancy or cause it to be missed. Goals of proper positioning include imaging the maximum area of breast tissue, minimizing skin folds, and achieving homogeneous fat suppression and nondeformed breast parenchyma. Review of prior images gives the technologist an impression of what the positioning and imaging challenges may be in each patient before the patient enters the imaging unit. Checking the triplane localizer images and repositioning as necessary before any diagnostic or interventional imaging is key. Using a fat saturation pad, changing the arm position, or "rolling" the patient may be considered in difficult cases. Padding to support the patient in an oblique position, using angled sponges to increase breast compression thickness, and raising the grid to access posterior lesions may be helpful in targeting difficult-to-access lesions for biopsy. Using the presented positioning techniques and suggestions, in addition to strict attention to detail before imaging, will improve image quality, decrease imaging time and suboptimal images, and limit the need for repeat imaging studies.

Number of mammography cases read per year is a strong predictor of sensitivity.

Early detection of breast cancers affects the 5-year recurrence rates and treatment options for diagnosed patients, and consequently, many countries have instituted nationwide screening programs. This study compared the performance of expert radiologists from Australia and the United States in detection of breast cancer. Forty-one radiologists, 21 from Australia and 20 from the United States, reviewed 30 mammographic cases containing two-view mammograms. Twenty cases had abnormal findings and 10 cases had normal findings. Radiologists were asked to locate malignancies and assign a level of confidence. A jackknife free-response receiver operating characteristic, figure of merit (JAFROC, FOM), inferred receiver operating characteristic, area under curve (ROC, AUC), specificity, sensitivity, and location sensitivity were calculated using Ziltron software and JAFROC v4.1. A Mann-Whitney U test was used to compare the performance of Australian and U.S. radiologists. The results showed that when experience and the number of mammograms read per year were taken into account, the Australian radiologists sampled showed significantly higher sensitivity and location sensitivity ([Formula: see text]). JAFROC (FOM) and inferred ROC (AUC) analysis showed no difference between the overall performance of the two countries. ROC (AUC) and location sensitivity were higher for the Australian radiologists who read the most cases per year.

What radiologists need to know about diagnosis and treatment of inflammatory breast cancer: a multidisciplinary approach.

Inflammatory breast cancer (IBC) is a rare breast cancer with a highly virulent course and low 5-year survival rate. Trimodality treatment that includes preoperative chemotherapy, mastectomy, and radiation therapy is the therapeutic mainstay and has been shown to improve prognosis. Proper diagnosis and staging of IBC is critical to treatment planning and requires a multidisciplinary approach that includes imaging. Patients with IBC typically present with rapid onset of breast erythema, edema, and peau d'orange. Both tissue diagnosis of malignancy and clinical findings of inflammatory disease are required to confirm diagnosis of IBC. Imaging is used to identify a biopsy target; direct biopsy; stage IBC; differentiate curable from incurable (stage IV) disease; and help plan chemotherapy, surgical management, and radiation therapy. Comparison of baseline and posttreatment images helps confirm and quantitate disease response. When imaging is used early in the course of therapy to noninvasively predict treatment response, optimal tailored strategies for management of IBC can be implemented. Imaging is vital to diagnosis and treatment planning for patients with IBC, and radiologists are an integral part of the multidisciplinary patient care team.

Variations in physician recommendations for surgery after diagnosis of a high-risk lesion on breast core needle biopsy.

OBJECTIVE: This article focuses on four high-risk lesions: lobular neoplasia, benign papilloma, radial scar, and flat epithelial atypia. Controversies exist in the management after core biopsy of each of these lesions--whether to perform immediate surgical excision so as not to miss an associated malignancy or imaging follow-up because concomitant malignancy is low. This review is staged in two parts per lesion. The first is from data gathered during the last two American Roentgen Ray Society annual meetings from the audience response system querying practice management styles per diagnostic lesion. The second part is a brief review of selected articles recommending either follow-up or surgery. The strengths and weaknesses of each article are discussed. CONCLUSION: Our opinion is that neither recommendation, surgical excision or follow-up, is well substantiated in the literature and that our ignorance is not serving the needs of women worldwide. The time is now for a prospective trial.

Basal subtype of invasive breast cancer is associated with a higher risk of true recurrence after conventional breast-conserving therapy.

PURPOSE: To determine whether breast cancer subtype is associated with patterns of ipsilateral breast tumor recurrence (IBTR), either true recurrence (TR) or elsewhere local recurrence (ELR), among women with pT1-T2 invasive breast cancer (IBC) who receive breast-conserving therapy (BCT). METHODS AND MATERIALS: From Jan 1998 to Dec 2003, 1,223 women with pT1-T2N0-3 IBC were treated with BCT (lumpectomy plus whole-breast radiation). Ninety percent of patients received adjuvant systemic therapy, but none received trastuzumab. Biologic cancer subtypes were approximated by determining estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), and human epidermal growth factor receptor-2-positive (HER-2+) expression, classified as luminal A (ER+ or PR+ and HER-2 negative [HER-2-]), luminal B (ER+ or PR+ and HER-2+), HER-2 (ER- and PR- and HER-2+), and basal (ER- and PR- and HER-2- ) subtypes. Imaging, pathology, and operative reports were reviewed by two physicians independently, including an attending breast radiologist. Readers were blinded to subtype and outcome. TR was defined as IBTR within the same quadrant and within 3 cm of the primary tumor. All others were defined as ELR. RESULTS: At a median follow-up of 70 months, 24 patients developed IBTR (5-year cumulative incidence of 1.6%), including 15 TR and 9 ELR patients. At 5 years, basal (4.4%) and HER-2 (9%) subtypes had a significantly higher incidence of TR than luminal B (1.2%) and luminal A (0.2%) subtypes (p < 0.0001). On multivariate analysis, basal subtype (hazard ratio [HR], 4.8, p = 0.01), younger age at diagnosis (HR, 0.97; p = 0.05), and increasing tumor size (HR, 2.1; p = 0.04) were independent predictors of TR. Only younger age (HR, 0.95; p = 0.01) significantly predicted for ELR. CONCLUSIONS: Basal and HER-2 subtypes are significantly associated with higher rates of TR among women with pT1-T2 IBC after BCT. Younger age predicts for both TR and ELR. Strategies to reduce TR in basal breast cancers, such as increased boost doses, concomitant radiation and chemotherapy, or targeted therapy agents, should be explored.

Controversies on the management of high-risk lesions at core biopsy from a radiology/pathology perspective.

Readers may feel less than satisfied when they discover that there is no consensus on the appropriate recommendations for follow-up of risk lesions following percutaneous core biopsy. The significance of this article is in the details of the methodologies and results, and much less in the numbers. The overall goal is to emphasize the flaws in current studies.

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.

Comparison of conventional, compounding, computer enhancement, and compounding with computer enhancement in ultrasound imaging of the breast.

OBJECTIVE: Real-time spatial compounding and computer enhancement (CE) in ultrasound have become commercially available for better visualization of breast masses. This study evaluated image quality and diagnostic information using these techniques as compared with conventional ultrasound in breast imaging. MATERIALS AND METHODS: One hundred consecutive lesions in 81 patients with clinically detectable breast lesions were imaged using conventional, compounding, CE, and compounding with CE. The images were blinded to technique and patient information and were then randomized. Three blinded reviewers analyzed the images and rated them for margin definition, near-field detail, definition of lesion, shadowing, and posterior enhancement on a scale of 1 (worse) to 5 (best) independently. The blinded reviewers then ranked the 4 images of the same lesion from best to worse. RESULTS: The lesions included benign (81) and malignant (19) lesions. All reviewers selected compounding with CE 100% of the time as the best image, when the images of the same lesion were presented in a set. Compounding alone was selected second, CE was selected as third, and conventional imaging was selected as having the worst image quality in all cases. Individual image quality was compounding with CE, 4.86; compounding, 4.10; CE, 3.80; and conventional, 3.09; on the 5-point scale. CONCLUSION: Compounding with CE significantly improves the image quality over conventional breast ultrasound. Compounding and CE enhance image quality when used individually, but the combination of the 2 techniques is superior.

Analysis of the mammographic and sonographic features of pseudoangiomatous stromal hyperplasia.

OBJECTIVE: The purpose of this study was to describe the imaging findings in 149 patients with pseudoangiomatous stromal hyperplasia (PASH) who had undergone at least 4 years of clinical follow-up for detection of subsequent malignancy. CONCLUSION: PASH is a common entity that presents with benign imaging features without evidence of subsequent malignant potential. At our institution, in the absence of suspicious features a diagnosis of PASH at core biopsy is considered sufficient, and surgical excision has been obviated.

Detecting nonpalpable recurrent breast cancer: the role of routine mammographic screening of transverse rectus abdominis myocutaneous flap reconstructions.

PURPOSE: To perform a retrospective cohort study to determine the rates of recall and cancer detection and then to develop a decision analytic model to evaluate the effectiveness of routine screening of transverse rectus abdominis myocutaneous (TRAM) flap reconstructions. MATERIALS AND METHODS: This study was approved by the institutional review board, and the methods comply with HIPAA regulations. A retrospective search of the institutional mammographic results database was done to identify bilateral screening mammographic examinations obtained from January 1, 1999, through July 15, 2005. The search included the term TRAM; the recall and cancer detetion rates were then detected. Subsequently, a decision analytic model was constructed to evaluate a hypothetical cohort of women with TRAM flap reconstructions. RESULTS: Of 554 mammograms (265 TRAM flap reconstructions), 546 (98.6%) had negative results (Breast Imaging Reporting and Data System category 1 or 2). Eight (1.4%) had positive test results (Breast Imaging Reporting and Data System category 0, 3, 4, or 5). All suspicious lesions underwent biopsy and had benign pathologic results. No interval breast cancers were identified. The detection rate for nonpalpable recurrent breast cancer was 0% (exact 95% confidence interval: 0.0%, 1.4%). According to decision analysis, screening would help detect an estimated 12 additional recurrent cancers per 1000 women screened, providing an additional 1.6 days of life expectancy for the screened cohort. Under base-case conditions, screening of TRAM flap reconstructions is less effective than screening asymptomatic women in their 40s. Sensitivity analysis revealed that a benefit equivalent to that of screening asymptomatic women in their 40s was achievable under conditions related to estimates of screening effectiveness and cancer detection rate. CONCLUSION: Routine screening mammography of TRAM flap reconstructions has a very low detection rate for nonpalpable recurrent breast cancer. Decision analysis indicates that screening such women is less effective than screening asymptomatic women in their 40s for primary breast cancer.

Blinded comparison of computer-aided detection with human second reading in screening mammography.

OBJECTIVE: The purpose of this study was to compare a human second reader with computer-aided detection (CAD) for the reduction of false-negative cases by a primary radiologist. We retrospectively reviewed our clinical practice. MATERIALS AND METHODS: We found that 6,381 consecutive screening mammograms were interpreted by a primary reader. This radiologist then reinterpreted the studies using CAD ("CAD reader"). A second human reader who was blinded to the CAD results but knowledgeable of the primary reader's findings reviewed the studies, looking for abnormalities not seen by the first reader. RESULTS: Two cancers were called back by the second human reader that were not called back by the CAD reader; however, the CAD system had marked the findings, but they were dismissed by the primary reader. Because of the small numbers, the difference between the CAD and second human reader was not statistically significant. The CAD and human second readers increased the recall rates 6.4% and 7.2% (p = 0.70), respectively, and the biopsy rates 10% and 14.7%. The positive predictive value was 0% (0/3) for the CAD reader and was 40% (2/5) for the human second reader. The relative increases in the cancer detection rate compared with the primary reader's detection rate were 0% for the CAD reader and 15.4% (2/13) for the human second reader (p = 0.50). CONCLUSION: A human second reader or the use of a CAD system can increase the cancer detection rate, but we found no statistical difference between the two because of the small sample size. A possible benefit from a human second reader is that CAD systems can only point to possible abnormalities, whereas a human must determine the significance of the finding. Having two humans review a study may increase detection rates due to interpreter--hence, perceptual--variability and not just increased detection.

Model-based region-of-interest selection in dynamic breast MRI.

Magnetic resonance imaging (MRI) is emerging as a powerful tool for the diagnosis of breast abnormalities. Dynamic analysis of the temporal pattern of contrast uptake has been applied in differential diagnosis of benign and malignant lesions to improve specificity. Selecting a region of interest (ROI) is an almost universal step in the process of examining the contrast uptake characteristics of a breast lesion. We propose an ROI selection method that combines model-based clustering of the pixels with Bayesian morphology, a new statistical image segmentation method. We then investigate tools for subsequent analysis of signal intensity time course data in the selected region. Results on a database of 19 patients indicate that the method provides informative segmentations and good detection rates.