Colleen H. Neal

Ultrasonographic differentiation of malignant from benign breast lesions: a meta-analytic comparison of elasticity and BIRADS scoring

There has been controversy regarding the accuracy of breast ultrasound elastography (USE) compared to conventional B-mode Ultrasound (USB). The purpose of this study was to conduct a direct comparative effectiveness analysis of USB versus USE or their combination in differentiating breast lesions through systematically reviewing recent literature. An extensive literature search of PubMed and other medical and general purpose databases from inception through August 2011 was conducted. Published studies that reported a direct comparison of the diagnostic performance of USE, using elasticity score versus USB, using breast imaging reporting and data system (BIRADS) for characterization of focal breast lesions were included. Summary diagnostic performance measures were assessed for each of the tests and their combination using bivariate generalized linear mixed modeling. The two tests were combined as: (1) conjunctive, where the outcome of the combination of tests is positive only if both test results are positive; (2) disjunctive, where the outcome of a combination of tests is negative only if both tests are negative. Twenty nine studies provided relevant information on 5,511 breast masses (2,065 cancers, 3,446 benign lesions). Sensitivity of USB, USE, and their conjunctive and disjunctive combinations were 96% (95% credible interval (CrI), 93–98%), 79% (95% CrI, 74–83%), 73% (95% CrI, 67–78%), and 99% (95% CrI, 98–99%), respectively. Specificity of USB, USE, and their conjunctive and disjunctive combinations were 70% (95% CrI, 55–83%), 88% (95% CrI, 82–92%), 97% (95% CrI, 95–99%), and 56% (95% CrI, 43–69%), respectively. The application of USE as a single test is not superior to USB alone. However, in low risk patients it is recommended to perform an USE following a positive USB result to decrease the rate of unnecessary biopsies.

Sonography of Morel-Lavallée Lesions

Objective. The purpose of this series was to retrospectively characterize the sonographic appearance of posttraumatic Morel‐Lavallée lesions. Methods. After Institutional Review Board approval was obtained, a search of the radiology information system database with correlation to medical records identified 21 posttraumatic fluid collections of the hip and thigh in 15 patients. Sonographic images were retrospectively reviewed by 1 author to characterize the echogenicity, homogeneity, shape, margins, location, compressibility, and vascularity of the fluid collection. Results were correlated with the age of the fluid collection and aspiration results where possible. Results. All fluid collections (21/21) were located between the deep fat and fascia, with a shape that was fusiform in 12 (60%) of 20, flat in 5 (25%), and lobular in 3 (15%) (shape not determined in 1 case). Regarding echogenicity, 15 (71%) of the 21 collections were hypoechoic, and 6 (29%) were anechoic; 13 (62%) were heterogeneous, and 8 (38%) were homogeneous. The lobular fluid collections were all less than 2 weeks of age, and the flat fluid collections were all greater than 6 months of age. All homogeneous fluid collections were greater than 8 months of age. There was no relationship between the age of a fluid collection and its echogenicity. Conclusions. Morel‐Lavallée lesions had a variable appearance, being more homogeneous and flat or fusiform in shape with a well‐defined margin as the lesions aged. All Morel‐Lavallée lesions were hypoechoic or anechoic, compressible, and located between the deep fat and overlying fascia.

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.

Multi-site clinical evaluation of DW-MRI as a treatment response metric for breast cancer patients undergoing neoadjuvant chemotherapy

Purpose To evaluate diffusion weighted MRI (DW-MR) as a response metric for assessment of neoadjuvant chemotherapy (NAC) in patients with primary breast cancer using prospective multi-center trials which provided MR scans along with clinical outcome information. Materials and Methods A total of 39 patients with locally advanced breast cancer accrued from three different prospective clinical trials underwent DW-MR examination prior to and at 3–7 days (Hull University), 8–11 days (University of Michigan) and 35 days (NeoCOMICE) post-treatment initiation. Thirteen patients, 12 of which participated in treatment response study, from UM underwent short interval (<1hr) MRI examinations, referred to as “test-retest” for examination of repeatability. To further evaluate stability in ADC measurements, a thermally controlled diffusion phantom was used to assess repeatability of diffusion measurements. MRI sequences included contrast-enhanced T1-weighted, when appropriate, and DW images acquired at b-values of 0 and 800 s/mm2. Histogram analysis and a voxel-based analytical technique, the Parametric Response Map (PRM), were used to derive diffusion response metrics for assessment of treatment response prediction. Results Mean tumor apparent diffusion coefficient (ADC) values generated from patient test-retest examinations were found to be very reproducible (|ΔADC|<0.1x10-3mm2/s). This data was used to calculate the 95% CI from the linear fit of tumor voxel ADC pairs of co-registered examinations (±0.45x10-3mm2/s) for PRM analysis of treatment response. Receiver operating characteristic analysis identified the PRM metric to be predictive of outcome at the 8–11 (AUC = 0.964, p = 0.01) and 35 day (AUC = 0.770, p = 0.05) time points (p<.05) while whole-tumor ADC changes where significant at the later 35 day time interval (AUC = 0.825, p = 0.02). Conclusion This study demonstrates the feasibility of performing a prospective analysis of DW-MRI as a predictive biomarker of NAC in breast cancer patients. In addition, we provide experimental evidence supporting the use of sensitive analytical tools, such as PRM, for evaluating ADC measurements.

Digital breast tomosynthesis: studies of the effects of acquisition geometry on contrast-to-noise ratio and observer preference of low-contrast objects in breast phantom images

The effect of acquisition geometry in digital breast tomosynthesis was evaluated with studies of contrast-to-noise ratios (CNRs) and observer preference. Contrast-detail (CD) test objects in 5 cm thick phantoms with breast-like backgrounds were imaged. Twelve different angular acquisitions (average glandular dose for each ~1.1 mGy) were performed ranging from narrow angle 16° with 17 projection views (16d17p) to wide angle 64d17p. Focal slices of SART-reconstructed images of the CD arrays were selected for CNR computations and the reader preference study. For the latter, pairs of images obtained with different acquisition geometries were randomized and scored by 7 trained readers. The total scores for all images and readings for each acquisition geometry were compared as were the CNRs. In general, readers preferred images acquired with wide angle as opposed to narrow angle geometries. The mean percent preferred was highly correlated with tomosynthesis angle (R = 0.91). The highest scoring geometries were 60d21p (95%), 64d17p (80%), and 48d17p (72%); the lowest scoring were 16d17p (4%), 24d9p (17%) and 24d13p (33%). The measured CNRs for the various acquisitions showed much overlap but were overall highest for wide-angle acquisitions. Finally, the mean reader scores were well correlated with the mean CNRs (R = 0.83).

Does digital mammography increase detection of high-risk breast lesions presenting as calcifications?

OBJECTIVE The objective of our study was to evaluate whether the transition from film-screen mammography (FSM) to digital mammography (DM) was associated with increased detection of high-risk breast lesions. MATERIALS AND METHODS A retrospective search identified 142 cases of atypia or lobular neoplasia (LN) diagnosed in women with mammographic calcifications between January 2004 and August 2010. We excluded lesions upgraded to cancer at excisional biopsy, lesions in women with ipsilateral cancer within 2 years of mammography, and lesions that presented as a mass only. The cases included in the cohort were 82 (57.7%) cases of atypical ductal hyperplasia; 17 (12%) atypical lobular hyperplasia; 25 (17.6%) lobular carcinoma in situ (LCIS); 12 (8.5%) atypia and LCIS; and six (4.2%) other atypia. The institution transitioned from predominantly performing FSM in 2004 to performing only DM by 2010. Pathology was interpreted by breast pathologists. The annual detection rate was calculated by dividing the number of high-risk lesions by mammography volume. RESULTS Of the 142 cases of atypia or LN, 52 (36.6%) were detected using FSM and 90 (63.4%) were detected using DM. The detection rate was higher with DM (1.24/1000 mammographic studies) than FSM (0.37/1000 mammographic studies). The detection rate by year ranged between 0.21 and 0.64 per 1000 mammographic studies for FSM and between 0.32 and 1.49 per 1000 mammographic studies for DM. The median size of the calcifications was 8 mm on DM and 7 mm on FSM. The most common appearance was clustered amorphous or indistinct calcifications on both FSM and DM. CONCLUSION The transition from FSM to DM was associated with a threefold increase in the detection rate of high-risk lesions. Improved detection may allow enhanced screening, risk reduction treatment, and possibly breast cancer prevention. However, increased detection of high-risk lesions may also result in oversurveillance and treatment.

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.

Is the Upgrade Rate of Atypical Ductal Hyperplasia Diagnosed by Core Needle Biopsy of Calcifications Different for Digital and Film-Screen Mammography?

OBJECTIVE The purpose of this study was to establish the upgrade rate of atypical ductal hyperplasia (ADH) diagnosed by stereotactic vacuum-assisted core needle biopsy for calcifications detected by digital mammography as compared with film-screen mammography. MATERIALS AND METHODS A retrospective record search identified 101 cases of ADH. Criteria included women with calcifications biopsied using stereotactic vacuum-assisted core needle biopsy at our institution between January 2001 and December 2011. The center transitioned from film-screen mammography in 2001 to all digital mammography by 2010. Stereotactic vacuum-assisted core needle biopsies were performed using 11-gauge (59/101 [58%]) or 8-gauge (42/101 [42%]) needles. All pathology was interpreted by breast pathologists using standard criteria. RESULTS Of 101 cases of ADH, 57 (56.4%) were detected using digital and 44 (43.6%) were detected using film-screen mammography. Seven of 57 (12.3%) cases of ADH detected by digital mammography were upgraded to ductal carcinoma in situ (DCIS) (n = 6) or invasive cancer (n = 1). Six of 44 (13.6%) cases of ADH detected by film-screen mammography were upgraded to DCIS (n = 5) or invasive cancer (n = 1) (p = 0.84). There was a trend toward low-grade DCIS in cases detected by digital mammography (3/7 [42.9%]) as compared with film-screen mammography (1/6 [16.7%]) (p = 0.68). A nonsignificant overall higher percentage of upgrades occurred when calcifications were not completely removed (10/52 [19.2%]) as compared with completely removed (3/47 [6.4%]). There was no difference in upgrade rate of stereotactic vacuum-assisted core needle biopsy performed using 11-gauge (7/59 [11.9%]) versus 8-gauge (6/42 [14.3%]) needles. CONCLUSION The upgrade rate of ADH diagnosed by stereotactic vacuum-assisted core needle biopsy was not significantly different between digital and film-screen mammography. The current recommendation for excision of ADH diagnosed by stereotactic vacuum-assisted core needle biopsy should be applied to ADH detected by digital mammography.

Simulation in Radiology Education: Thinking Outside the Phantom.

OBJECTIVE The purpose of this article is to discuss the use of simulation in radiology education. CONCLUSION Simulation is an engaging way to educate radiology trainees. It allows trainees to improve their procedural and clinical skills in a calm, supportive environment that optimizes patient safety. Familiarity with the principles of simulation education may help radiologists evaluate their training curricula to identify skills that could be augmented with simulation training.

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.