Marie A. Ganott

Digital Breast Tomosynthesis: Observer Performance Study

OBJECTIVE The purpose of this study was to compare in a retrospective observer study the diagnostic performance of full-field digital mammography (FFDM) with that of digital breast tomosynthesis. MATERIALS AND METHODS Eight experienced radiologists interpreted images from 125 selected examinations, 35 with verified findings of cancer and 90 with no finding of cancer. The four display conditions included FFDM alone, 11 low-dose projections, reconstructed digital breast tomosynthesis images, and a combined display mode of FFDM and digital breast tomosynthesis images. Observers rated examinations using the screening BI-RADS rating scale and the free-response receiver operating characteristic paradigm. Observer performance levels were measured as the proportion of examinations prompting recall of patients for further diagnostic evaluation. The results were presented in terms of true-positive fraction and false-positive fraction. Performance levels were compared among the acquisitions and reading modes. Time to view and interpret an examination also was evaluated. RESULTS Use of the combination of digital breast tomosynthesis and FFDM was associated with 30% reduction in recall rate for cancer-free examinations that would have led to recall if FFDM had been used alone (p < 0.0001 for the participating radiologists, p = 0.047 in the context of a generalized population of radiologists). Use of digital breast tomosynthesis alone also tended to reduce recall rates, an average of 10%, although the observed decrease was not statistically significant (p = 0.09 for the participating radiologists). There was no convincing evidence that use of digital breast tomosynthesis alone or in combination with FFDM results in a substantial improvement in sensitivity. CONCLUSION Use of digital breast tomosynthesis for breast imaging may result in a substantial decrease in recall rate.

Detection and Classification of Calcifications on Digital Breast Tomosynthesis and 2D Digital Mammography: A Comparison

OBJECTIVE The purpose of this article is to compare the ability of digital breast tomosynthesis and full field digital mammography (FFDM) to detect and characterize calcifications. MATERIALS AND METHODS One hundred paired examinations were performed utilizing FFDM and digital breast tomosynthesis. Twenty biopsy-proven cancers, 40 biopsy-proven benign calcifications, and 40 randomly selected negative screening studies were retrospectively reviewed by five radiologists in a crossed multireader multimodal observer performance study. Data collected included the presence of calcifications and forced BI-RADS scores. Receiver operator curve analysis using BI-RADS was performed. RESULTS Overall calcification detection sensitivity was higher for FFDM (84% [95% CI, 79-88%]) than for digital breast tomosynthesis (75% [95% CI, 70-80%]). [corrected] In the cancer cohort, 75 (76%) of 99 interpretations identified calcification in both modes. Of those, a BI-RADS score less than or equal to 2 was rendered in three (4%) and nine (12%) cases with FFDM and digital breast tomosynthesis, respectively. In the benign cohort, 123 (62%) of 200 interpretations identified calcifications in both modes. Of those, a BI-RADS score greater than or equal to 3 was assigned in 105 (85%) and 93 (76%) cases with FFDM and digital breast tomosynthesis, respectively. There was no significant difference in the nonparametric computed area under the receiver operating characteristic curves (AUC) using the BI-RADS scores (FFDM, AUC = 0.76 and SD = 0.03; digital breast tomosynthesis, AUC = 0.72 and SD = 0.04 [p = 0.1277]). CONCLUSION In this small data set, FFDM appears to be slightly more sensitive than digital breast tomosynthesis for the detection of calcification. However, diagnostic performance as measured by area under the curve using BI-RADS was not significantly different. With improvements in processing algorithms and display, digital breast tomosynthesis could potentially be improved for this purpose.

Digital Breast Tomosynthesis: A Pilot Observer Study

OBJECTIVE The objective of our study was to assess ergonomic and diagnostic performance-related issues associated with the interpretation of digital breast tomosynthesis-generated examinations. MATERIALS AND METHODS Thirty selected cases were read under three different display conditions by nine experienced radiologists in a fully crossed, mode-balanced observer performance study. The reading modes included full-field digital mammography (FFDM) alone, the 11 low-dose projections acquired for the reconstruction of tomosynthesis images, and the reconstructed digital breast tomosynthesis examination. Observers rated cases under the free-response receiver operating characteristic, as well as a screening paradigm, and provided subjective assessments of the relative diagnostic value of the two digital breast tomosynthesis-based image sets as compared with FFDM. The time to review and diagnose each case was also evaluated. RESULTS Observer performance measures were not statistically significant (p > 0.05) primarily because of the small sample size in this pilot study, suggesting that showing significant improvements in diagnosis, if any, will require a larger study. Several radiologists did perceive the digital breast tomosynthesis image set and the projection series to be better than FFDM (p < 0.05) for diagnosing this specific case set. The time to review, interpret, and rate the examinations was significantly different for the techniques in question (p < 0.05). CONCLUSION Tomosynthesis-based breast imaging may have great potential, but much work is needed before its optimal role in the clinical environment is known.

Breast cancer measurements with magnetic resonance imaging, ultrasonography, and mammography.

SummaryBackground: Accurate measurement of the size of breast cancers becomes more important as breast cancer therapy advances. This study reports the accuracy of magnetic resonance imaging (MRI), ultrasonography and mammography for measuring the largest breast cancer diameter in comparison to the pathology measurement.Materials and methods: Fourteen breast cancers were examined in 13 women with MRI, ultrasonography and mammography. The age range was 31–73 (mean 56). Six of the cancers were in premenopausal women. The MRI was performed with the intravenous injection of gadolinium based contrast agent and a three dimensional fast spoiled gradient echo sequence with fat suppression. The largest cancer diameter was measured with each imaging technique and compared to the largest cancer diameter measured at pathology.Results: At pathological examination cancers ranged from 0.6 to 6 cm (mean 2.2) in largest diameter. MRI measurements had the highest correlation coefficient (r = 0.98) and the smallest standard error (0.34). Ultrasonography measurements had a correlation coeffient of r = 0.45 and a standard error of 0.78. Mammography measurements had a correlation coefficient of r = 0.46 and a standard error of 1.04.Conclusions: MRI was more accurate than ultrasonography and mammography in measuring the largest cancer diameters in this group of women. This was particularly evident for several larger cancers, and a postchemotherapy cancer.

Digital Breast Tomosynthesis versus Supplemental Diagnostic Mammographic Views for Evaluation of Noncalcified Breast Lesions

PURPOSE To compare the diagnostic performance of breast tomosynthesis versus supplemental mammography views in classification of masses, distortions, and asymmetries. MATERIALS AND METHODS Eight radiologists who specialized in breast imaging retrospectively reviewed 217 consecutively accrued lesions by using protocols that were HIPAA compliant and institutional review board approved in 182 patients aged 31-60 years (mean, 50 years) who underwent diagnostic mammography and tomosynthesis. The lesions in the cohort included 33% (72 of 217) cancers and 67% (145 of 217) benign lesions. Eighty-four percent (182 of 217) of the lesions were masses, 11% (25 of 217) were asymmetries, and 5% (10 of 217) were distortions that were initially detected at clinical examination in 8% (17 of 217), at mammography in 80% (173 of 217), at ultrasonography (US) in 11% (25 of 217), or at magnetic resonance imaging in 1% (2 of 217). Histopathologic examination established truth in 191 lesions, US revealed a cyst in 12 lesions, and 14 lesions had a normal follow-up. Each lesion was interpreted once with tomosynthesis and once with supplemental mammographic views; both modes included the mediolateral oblique and craniocaudal views in a fully crossed and balanced design by using a five-category Breast Imaging Reporting and Data System (BI-RADS) assessment and a probability-of-malignancy score. Differences between modes were analyzed with a generalized linear mixed model for BI-RADS-based sensitivity and specificity and with modified Obuchowski-Rockette approach for probability-of-malignancy-based area under the receiver operating characteristic (ROC) curve. RESULTS Average probability-of-malignancy-based area under the ROC curve was 0.87 for tomosynthesis versus 0.83 for supplemental views (P < .001). With tomosynthesis, the false-positive rate decreased from 85% (989 of 1160) to 74% (864 of 1160) (P < .01) for cases that were rated BI-RADS category 3 or higher and from 57% (663 of 1160) to 48% (559 of 1160) for cases rated BI-RADS category 4 or 5 (P < .01), without a meaningful change in sensitivity. With tomosynthesis, more cancers were classified as BI-RADS category 5 (39% [226 of 576] vs 33% [188 of 576]; P = .017) without a decrease in specificity. CONCLUSION Tomosynthesis significantly improved diagnostic accuracy for noncalcified lesions compared with supplemental mammographic views.

Digital Breast Tomosynthesis in the Diagnostic Environment: A Subjective Side-by-Side Review

OBJECTIVE The purpose of our study was to subjectively compare additional mammographic views to digital breast tomosynthesis (DBT) in the characterizing of known masses, architectural distortions, or asymmetries. MATERIALS AND METHODS Four experienced radiologists serially reviewed the imaging studies of 25 women with known masses, including full-field digital mammography (FFDM), additional views, and DBT. After review of the examinations, radiologists rated their relative preference in terms of classifying the finding in question when aided by the additional views versus aided by DBT, their combined diagnostic BI-RADS rating of the finding when both examinations were available, and whether or not they felt comfortable eliminating ultrasound in the specific cases being evaluated as a result of the DBT. RESULTS FFDM and DBT (combined) were perceived to be better for diagnosis in 50% (50/100) of the ratings (25 cases x four readers = 100 ratings) compared with FFDM and additional diagnostic views. Over all readers, 92% of the ratings for verified cancer cases and 50% of the ratings for high-risk cases were rated as BI-RADS 4 or 5. In 12% (12/100) of the ratings, radiologists indicated that the availability of DBT would have eliminated the need for ultrasound as a part of the diagnostic process. CONCLUSION DBT may be an alternative to obtaining additional mammographic views in most but not all cases of patients with a lesion that is not solely calcifications. In a fraction of cases, the use of DBT may eliminate the need for ultrasound.

Recall and detection rates in screening mammography: A review of clinical experience: Implications for practice guidelines

The authors investigated the correlation between recall and detection rates in a group of 10 radiologists who had read a high volume of screening mammograms in an academic institution.

Radioactive Seed Localization Versus Wire Localization for Lumpectomies: A Comparison of Outcomes

OBJECTIVE The purpose of this study was to compare outcomes of radioactive seed localization (RSL) versus wire localization using surgical margin size, reexcision and reoperation rates, specimen size, radiology resource utilization, and cosmesis as measures. MATERIALS AND METHODS Patients who underwent RSL before segmental mastectomy from April 1, 2011, to March 1, 2012, for biopsy-proven cancer were selected. Each was matched using tumor size, type, and surgeon to a wire localization control case, resulting in 232 cases. Width of the closest surgical margin, reexcision rate, and reoperation rate were compared as were the ratios of tumor volume to initial surgical specimen volume and tumor volume to all surgically excised volume (including reexcisions and reoperations). Cosmetic outcome was analyzed by comparison of Harvard scores and specimen volume with breast volume. Radiology resource utilization was compared before and after RSL implementation. RESULTS No significant differences between methods were found in closest surgical margin (RSL mean, 0.45 cm; wire localization mean, 0.45 cm; p=0.972), reexcision rate (RSL mean, 21.1%; wire localization mean, 26.3%; p=0.360), reoperation rate (RSL, 11.4%; wire localization, 12.7%; p=0.841), ratio of the tumor volume to initial surgical specimen volume (RSL mean, 0.027; wire localization mean, 0.028; p=0.886), ratio of the tumor volume to total volume resected (RSL mean, 0.024; wire localization mean, 0.024; p=0.997), or in clinical or computed cosmesis scores (clinical p=0.5; calculated p=0.060). There was a 34% increase in scheduled biopsy slot utilization, 50% savings in time spent scheduling, and a 4.1-day average decrease in biopsy wait time after RSL institution. CONCLUSION RSL is an acceptable alternative to wire localization and offers significant improvements in workflow.

Rationale of excisional biopsy after the diagnosis of benign radial scar on core biopsy: a single institutional outcome analysis.

Background:Radial scar (RS) is characterized by a fibroelastic core with entrapped ducts and lobules. Association with carcinoma is not uncommon. There is some dilemma as to the need for excisional biopsy or follow-up after RS diagnosis on core biopsy. Aim:To determine the necessity of excisional biopsy after the diagnosis of benign RS by core biopsy. Study Design:A total of 67 RS specimens associated with benign findings on core biopsy obtained between 2003 and 2008 were reviewed. They were grouped by their accompanying histopathologic features found upon subsequent surgical excision: benign, high-risk lesion (HRL), or carcinoma. Demographic features, radiologic findings, and needle gauge were compared within subgroups. Results:After surgical excision, 15 (22.4%) patients in the benign group were upgraded to a HRL, 4 (5.9%) patients were upgraded to carcinoma, and 48 (71.6%) remained benign. We found that malignancy is associated with RS more frequently if the patient is older and postmenopausal. Other variables such as symptoms at presentation, presence and type of abnormality on mammography (Breast Imaging Reporting and Data System score), breast density, size of biopsy needle used, and number of core samples retrieved did not help to predict the presence of carcinoma. Conclusions:The HRL and cancer upgrade rate of RS, requiring further intervention such as surgery or chemoprevention, is 28% in this study. However, we found that age and menopausal status may be taken into consideration when making the decision to follow up or excise the RS diagnosed on core biopsy. There is insufficient data to support the predictive value of any variables. Therefore, RS associated with benign findings on core biopsy should be excised.

Risk of Malignancy When Microscopic Radial Scars and Microscopic Papillomas Are Found at Percutaneous Biopsy

OBJECTIVE The objective of our study was to assess the incidence of associated malignancy when microscopic radial scars and microscopic intraductal papillomas are encountered at percutaneous biopsy for lesions that otherwise reveal benign histopathology. MATERIALS AND METHODS A search of the pathology database for the period from December 14, 2006, through December 21, 2009, identified patients with a microscopic radial scar, a microscopic intraductal papilloma, or both at percutaneous biopsy. Patients whose percutaneous biopsy was performed for a lesion that revealed carcinoma or a high-risk pathology result were excluded to avoid confounding bias, as were patients who had only imaging follow-up. Only patients who underwent surgery solely for the study lesion were included. The lesion type that prompted core biopsy, biopsy guidance and device, sample number, and surgical outcomes were recorded. The incidences of benign, high-risk, and malignant pathology findings from surgery were calculated. RESULTS The search revealed 35 patients (18 microscopic radial scars, 17 microscopic papillomas) who underwent surgery solely for the study lesion. Stereotactic guidance was used for 15 (43%); ultrasound, for 12 (34%); and MRI, for eight (23%). At surgery, 12 patients (34%) had high-risk histopathology results and 23 (66%) had benign results. No study lesions were upgraded to malignancy. CONCLUSION Our study found no evidence of associated malignancy at surgical excision when microscopic radial scars and microscopic intraductal papillomas were encountered at percutaneous biopsy in patients who otherwise had benign histopathology results; thus, routine imaging follow-up may be performed.