Hye Mi Gweon

Added Value of Shear-Wave Elastography for Evaluation of Breast Masses Detected with Screening US Imaging

PURPOSE To evaluate the additional value of shear-wave elastography (SWE) to B-mode ultrasonography (US) and to determine an appropriate guideline for the combined assessment of screening US-detected breast masses. MATERIALS AND METHODS This study was conducted with institutional review board approval, and written informed consent was obtained. From March 2010 to February 2012, B-mode US and SWE were performed in 159 US-detected breast masses before biopsy. For each lesion, Breast Imaging Reporting and Data System (BI-RADS) category on B-mode US images and the maximum stiffness color and elasticity values on SWE images were assessed. A guideline for adding SWE data to B-mode US was developed with the retrospective cohort to improve diagnostic performance in sensitivity and specificity and was validated in a distinct prospective cohort of 207 women prior to biopsy. RESULTS Twenty-one of 159 masses in the development cohort and 12 of 207 breast masses in the validation cohort were malignant. In the development cohort, when BI-RADS category 4a masses showing a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images were downgraded to category 3, specificity increased from 9.4% (13 of 138) to 59.4% (82 of 138) and 57.2% (79 of 138) (P < .001), respectively, without loss in sensitivity (100% [21 of 21]). In the validation cohort, specificity increased from 17.4% (34 of 195) to 62.1% (121 of 195) and 53.3% (104 of 195) (P < .001) respectively, without loss in sensitivity (91.7% [11 of 12]). CONCLUSION The addition of SWE to B-mode US improved diagnostic performance with increased specificity for screening US-detected breast masses. BI-RADS category 4a masses detected at US screening that showed a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images can be safely followed up instead of performing biopsy.

Three-dimensional shear-wave elastography for differentiating benign and malignant breast lesions: comparison with two-dimensional shear-wave elastography

AbstractObjectivesTo evaluate the interobserver agreement and the diagnostic performance of 3D shear-wave elastography (SWE) for breast lesions in comparison with 2D SWE.MethodsA total of 163 breast lesions (malignant 48, benign 115) in 146 women who underwent B-mode ultrasound and SWE before biopsy were included. Two radiologists reviewed six data sets (B-mode, SWE, and a combination of both for 2D and 3D ultrasound). B-mode and SWE features were recorded. BI-RADS category was assigned for B-mode and combined sets. Interobserver variability was assessed using the κ statistic. Diagnostic performance of each data set was evaluated using the area under the ROC curve (AUC).ResultsSWE showed substantial to almost perfect agreement, with Ehomo in 2D SWE being higher than in 3D SWE. The AUC of 2D SWE was higher than 3D SWE for all SWE features, significantly so for Ecol (0.933 vs. 0.867, P = 0.002) and Emax (0.961 vs. 0.874, P = 0.006). After adding SWE to B-mode ultrasound, the AUC in 2D ultrasound increased significantly (0.968 vs. 0.912, P = 0.008), but 3D ultrasound showed no significant difference (0.966 vs. 0.935; P = 0.07).ConclusionFor 3D SWE, interobserver agreement was good, but the diagnostic performance was inferior to 2D SWE even after adding to B-mode ultrasound.Key Points• Shear-wave elastography (SWE) provides further diagnostic information during breast ultrasound. • 3D SWE diagnostic performance is inferior to 2D SWE. • In 3D SWE, interobserver agreement was good. • 2D B-mode ultrasound showed significant diagnostic improvement when combined with 2D SWE. • 3D B-mode ultrasound performance was not significantly improved when combined with 3D SWE.

Breast MR Imaging Screening in Women with a History of Breast Conservation Therapy

PURPOSE To retrospectively investigate the outcomes of single-screening breast magnetic resonance (MR) imaging in women who had a history of breast conservation therapy (BCT) for breast cancers and who had previous negative mammography and ultrasonographic (US) findings. MATERIALS AND METHODS This study was institutional review board-approved and informed consent was waived. Between January 2008 and March 2012, 607 consecutive women (median age, 48 years; age range, 20-72 years) who underwent BCT for breast cancer, had negative mammography and US findings, and underwent subsequent screening breast MR imaging were studied. Of the study population, 91.8% (557 of 607) patients underwent preoperative MR examinations. Cancer detection rate, characteristics of detected cancers, positive predictive value (PPV), sensitivity, and specificity were assessed. Multivariate logistic regression analysis was performed to identify independent clinical-pathologic factors associated with women with cancers detected by using MR imaging. RESULTS Eleven cancers (eight invasive, three ductal carcinoma in situ; median invasive size, 0.8 cm; range, 0.4-1.4 cm; all node negative) were additionally detected with MR imaging in 607 women (18.1 cancers per 1000 women). PPV for recall, PPV for biopsy, sensitivity, and specificity were 9.4% (11 of 117 examinations), 43.5% (10 of 23 examinations), 91.7% (11 of 12 examinations), and 82.2% (489 of 595 examinations), respectively. At multivariate analysis, the independent factors associated with women with MR-detected cancers were age younger than 50 years at initial diagnosis (P < .001) and more than a 24-month interval between initial surgery and screening MR imaging (P = .011). CONCLUSION Single-screening MR imaging depicted 18.1 additional cancers per 1000 women with a history of BCT. Multivariate analysis revealed age younger than 50 years at initial younger than 50 years.

Comparison of strain and shear wave elastography for the differentiation of benign from malignant breast lesions, combined with B-mode ultrasonography: qualitative and quantitative assessments.

Our aim was to compare the diagnostic performance of strain elastography (SE) and shear-wave elastography (SWE), combined with B-mode ultrasonography (US), in breast cancer. For 79 breast lesions that underwent SE and SWE, two radiologists reviewed five data sets (B-mode US, SWE, SE and two combined sets). Qualitative and quantitative elastographic data and Breast Imaging Reporting and Data System (BI-RADS) categories were recorded. The area under the receiver operating characteristic curve (AUC) was evaluated. No significant difference in the AUC between the two elastography methods was noted. After subjective assessment by reviewers, the AUC for the combined sets was improved (SWE, 0.987; SE, 0.982; B-mode US, 0.970; p < 0.05). When SE and SWE were added, 38% and 56% of benign BI-RADS category 4a lesions with a low suspicion of cancer were downgraded without false-negative results, respectively. SE and SWE performed similarly. Therefore, addition of SE or SWE improved the diagnostic performance of B-mode US, potentially reducing unnecessary biopsies.

Clinical application of qualitative assessment for breast masses in shear-wave elastography

PURPOSE To evaluate the interobserver agreement and the diagnostic performance of various qualitative features in shear-wave elastography (SWE) for breast masses. MATERIALS AND METHODS A total of 153 breast lesions in 152 women who underwent B-mode ultrasound and SWE before biopsy were included. Qualitative analysis in SWE was performed using two different classifications: E values (Ecol; 6-point color score, Ehomo; homogeneity score and Esha; shape score) and a four-color pattern classification. Two radiologists reviewed five data sets: B-mode ultrasound, SWE, and combination of both for E values and four-color pattern. The BI-RADS categories were assessed B-mode and combined sets. Interobserver agreement was assessed using weighted κ statistics. Areas under the receiver operating characteristic curve (AUC), sensitivity, and specificity were analyzed. RESULTS Interobserver agreement was substantial for Ecol (κ=0.79), Ehomo (κ=0.77) and four-color pattern (κ=0.64), and moderate for Esha (κ=0.56). Better-performing qualitative features were Ecol and four-color pattern (AUCs, 0.932 and 0.925) compared with Ehomo and Esha (AUCs, 0.857 and 0.864; P<0.05). The diagnostic performance of B-mode ultrasound (AUC, 0.950) was not significantly different from combined sets with E value and with four color pattern (AUCs, 0.962 and 0.954). When all qualitative values were negative, leading to downgrade the BI-RADS category, the specificity increased significantly from 16.5% to 56.1% (E value) and 57.0% (four-color pattern) (P<0.001) without improvement in sensitivity. CONCLUSION The qualitative SWE features were highly reproducible and showed good diagnostic performance in suspicious breast masses. Adding qualitative SWE to B-mode ultrasound increased specificity in decision making for biopsy recommendation.

Role of diffusion-weighted MRI: predicting axillary lymph node metastases in breast cancer

Background Ultrasound (US) is probably the standard imaging procedure in most centers, and US-guided fine needle aspiration can be added if suspicious lymph nodes are found. However, US-guided fine needle aspiration is an invasive method to diagnose a metastasis and has showed relatively low sensitivity. In general, diffusion-weighted (DW) magnetic resonance imaging (MRI) has become an emerging technique for discriminating benign from malignant breast lesions in a short imaging acquisition time. Purpose To evaluate the potential for using DW MRI with an apparent diffusion coefficient (ADC) value to predict axillary lymph node metastases in patients with invasive breast cancer. Material and Methods This study enrolled 110 axillary lymph nodes from 110 consecutive women who were diagnosed with invasive breast cancer for preoperative breast MRI and US. The largest enhancing ipsilateral axillary lymph nodes were included in this study, and benign and metastatic axillary lymph nodes were compared according to the pathologic reports. The cut-off ADC value to differentiate between benign and metastatic axillary lymph nodes was evaluated with receiver-operating characteristic curve analysis. Diagnostic performance of ultrasound and DW MRI was calculated for enhancing lymph node in dynamic contrast-enhanced MRI. Results Nodal metastases were documented in 68 (62%) axillary lymph nodes. The mean size of metastatic axillary lymph nodes was larger than that of benign axillary lymph nodes (15.5 mm vs. 10.9 mm, P < 0.001). The mean ADC value (0.69 × 10−3 mm2/s) of the metastases was significantly lower than that of the benign axillary lymph nodes (1.04 × 10−3 mm2/s) (P < 0.001). The ADC value cut-off between metastatic and benign axillary lymph nodes was 0.90 × 10−3 mm2/s. Using ADC cut-off, sensitivity, specificity, and accuracy of DW MRI were 100%, 83.3%, and 93.6%, respectively. The sensitivity, specificity, and accuracy of US showed 94.1%, 54.8%, and 79.1%, respectively. Conclusion DW MRI of axillary lymph nodes can provide reliable information for the differentiation of benign from metastatic axillary lymph nodes in invasive breast cancer patients.

Automated Volumetric Breast Density Measurements in the Era of the BI-RADS Fifth Edition: A Comparison With Visual Assessment

OBJECTIVE The purpose of this study is to evaluate automated volumetric measurements in comparison with visual assessment of mammographic breast density by use of the fifth edition of BI-RADS. MATERIALS AND METHODS A total of 1185 full-field digital mammography examinations with standard views were retrospectively analyzed. All images were visually assessed by two blinded radiologists according to breast density category in the fifth edition of the BI-RADS lexicon. Automated volumetric breast density assessment was performed using two different software programs, Quantra and Volpara. A weighted kappa value was calculated to assess the degree of agreement among the visual and volumetric assessments of the density category. The volumes of fibroglandular tissue or total breast and the percentage breast density provided by the two software programs were compared. RESULTS Compared with a visual assessment, the agreement of density category ranged from moderate to substantial in Quantra (κ = 0.54-0.61) and fair to moderate in Volpara (κ = 0.32-0.43). The distribution of density category was statistically significantly different among visual and volumetric measurements (p < 0.0001). Quantra assigned category A and B (43.5%) more frequently than did the radiologists (25.6%) or Volpara (16.0%). Volpara assigned category D (42.1%) more frequently than did the radiologists (19.5%) or Quantra (15.4%). Between the two software programs, the means of all volumetric data were statistically significantly different (p < 0.0001), but were well correlated (γ = 0.79-0.99; p < 0.0001). CONCLUSION More mammographic examinations were classified as nondense breast tissue using the Quantra software and as dense breast tissue using the Volpara software, as compared with visual assessments according to the BI-RADS fifth edition.

Diagnostic performance of qualitative shear-wave elastography according to different color map opacities for breast masses.

PURPOSE To compare the diagnostic performance of qualitative shear-wave elastography (SWE) according to three different color map opacities for breast masses MATERIALS AND METHODS 101 patients aged 21-77 years with 113 breast masses underwent B-mode US and SWE under three different color map opacities (50%, 19% and 100%) before biopsy or surgery. Following SWE features were reviewed: visual pattern classification (pattern 1-4), color homogeneity (Ehomo) and six-point color score of maximum elasticity (Ecol). Combined with B-mode US and SWE, the likelihood of malignancy (LOM) was also scored. The area under the curve (AUC) was obtained by ROC curve analysis to assess the diagnostic performance under each color opacity. RESULTS A visual color pattern, Ehomo, Ecol and LOM scoring were significantly different between benign and malignant lesions under all color opacities (P<0.001). For 50% opacity, AUCs of visual color pattern, Ecol, Ehomo and LOM scoring were 0.902, 0.951, 0.835 and 0.975. But, for each SWE feature, there was no significant difference in the AUC among three different color opacities. For all color opacities, visual color pattern and Ecol showed significantly higher AUC than Ehomo. In addition, a combined set of B-mode US and SWE showed significantly higher AUC than SWE alone for color patterns, Ehomo, but no significant difference was found in Ecol. CONCLUSION Qualitative SWE was useful to differentiate benign from malignant breast lesion under all color opacities. The difference in color map opacity did not significantly influence diagnostic performance of SWE.

Evaluation of Left Atrial Volumes Using Multidetector Computed Tomography: Comparison with Echocardiography

Objective To prospectively assess the relationship between the two different measurement methods for the evaluation of left atrial (LA) volume using cardiac multidetector computed tomography (MDCT) and to compare the results between cardiac MDCT and echocardiography. Materials and Methods Thirty-five patients (20 men, 15 women; mean age, 60 years) underwent cardiac MDCT angiography for coronary artery disease. The LA volumes were measured using two different methods: the two dimensional (2D) length-based (LB) method measured along the three-orthogonal planes of the LA and the 3D volumetric threshold-based (VTB) method measured according to the threshold 3D segmentation of the LA. The results obtained by cardiac MDCT were compared with those obtained by echocardiography. Results The LA end-systolic and end-diastolic volumes (LAESV and LAEDV) measured by the 2D-LB method correlated well with those measured by the 3D-VTB method using cardiac MDCT (r = 0.763, r = 0.786, p = 0.001). However, there was a significant difference in the LAESVs between the two measurement methods using cardiac MDCT (p < 0.05). The LAESV measured by cardiac MDCT correlated well with measurements by echocardiography (r = 0.864, p = 0.001), however with a significant difference (p < 0.01) in their volumes. The cardiac MDCT overestimated the LAESV by 22% compared to measurements by echocardiography. Conclusion A significant correlation was found between the two different measurement methods for evaluating LA volumes by cardiac MDCT. Further, cardiac MDCT correlates well with echocardiography in evaluating the LA volume. However, there are significant differences in the LAESV between the two measurement methods using cardiac MDCT and between cardiac MDCT and echocardiography.

Shear-wave elastography in breast ultrasonography: the state of the art

Shear-wave elastography (SWE) is a recently developed ultrasound technique that can visualize and measure tissue elasticity. In breast ultrasonography, SWE has been shown to be useful for differentiating benign breast lesions from malignant breast lesions, and it has been suggested that SWE enhances the diagnostic performance of ultrasonography, potentially improving the specificity of conventional ultrasonography using the Breast Imaging Reporting and Data System criteria. More recently, not only has SWE been proven useful for the diagnosis of breast cancer, but has also been shown to provide valuable information that can be used as a preoperative predictor of the prognosis or response to chemotherapy.