Screening Outcomes of Supplemental Automated Breast US in Asian Women with Dense and Nondense Breasts.

Background Automated breast (AB) US effectively depicts mammographically occult breast cancers in Western women. However, few studies have focused on the outcome of supplemental AB US in Asian women who have denser breasts than Western women. Purpose To evaluate the performance of supplemental AB US on mammography-based breast cancer screening in Asian women with dense breasts and those with nondense breasts. Materials and Methods A retrospective database search identified asymptomatic Korean women who underwent digital mammography (DM) and supplemental AB US screening for breast cancer between January 2018 and December 2019. We excluded women without sufficient follow-up, established final diagnosis, or histopathologic results. Performance measures of DM alone and AB US combined with DM (hereafter AB US plus DM) were compared. The primary outcome was cancer detection rate (CDR), and the secondary outcomes were sensitivity and specificity. Subgroup analyses were performed based on mammography density. Results From 2785 screening examinations in 2301 women (mean age, 52 years ± 9 [SD]), 28 cancers were diagnosed (26 screening-detected cancers, two interval cancers). When compared with DM alone, AB US plus DM resulted in a higher CDR of 9.3 per 1000 examinations (95% CI: 7.7, 10.3) versus 6.5 per 1000 examinations (95% CI: 5.2, 7.2; P < .001) and a higher sensitivity of 90.9% (95% CI: 77.3, 100.0) versus 63.6% (95% CI: 40.9, 81.8; P < .001) but a lower specificity of 86.8% (95% CI: 85.2, 88.2) versus 94.6% (95% CI: 93.6, 95.5; P < .001) in women with dense breasts. In women with nondense breasts, AB US plus DM resulted in a higher CDR of 9.5 per 1000 examinations (95% CI: 7.1, 10.6) versus 6.3 per 1000 examinations (95% CI: 3.5, 7.1; P < .001), whereas specificity was lower at 95.2% (95% CI: 93.4, 96.8) versus 97.1% (95% CI: 95.8, 98.4; P < .001). Conclusion In Asian women, the addition of automated breast US to digital mammography showed higher cancer detection rates but lower specificities in both dense and nondense breasts. © RSNA, 2023 Supplemental material is available for this article.

Effect of artificial intelligence-based computer-aided diagnosis on the screening outcomes of digital mammography: a matched cohort study.

OBJECTIVE: To investigate whether artificial intelligence-based computer-aided diagnosis (AI-CAD) can improve radiologists' performance when used to support radiologists' interpretation of digital mammography (DM) in breast cancer screening. METHODS: A retrospective database search identified 3158 asymptomatic Korean women who consecutively underwent screening DM between January and December 2019 without AI-CAD support, and screening DM between February and July 2020 with image interpretation aided by AI-CAD in a tertiary referral hospital using single reading. Propensity score matching was used to match the DM with AI-CAD group in a 1:1 ratio with the DM without AI-CAD group according to age, breast density, experience level of the interpreting radiologist, and screening round. Performance measures were compared with the McNemar test and generalized estimating equations. RESULTS: A total of 1579 women who underwent DM with AI-CAD were matched with 1579 women who underwent DM without AI-CAD. Radiologists showed higher specificity (96% [1500 of 1563] vs 91.6% [1430 of 1561]; p < 0.001) and lower abnormal interpretation rates (AIR) (4.9% [77 of 1579] vs 9.2% [145 of 1579]; p < 0.001) with AI-CAD than without. There was no significant difference in the cancer detection rate (CDR) (AI-CAD vs no AI-CAD, 8.9 vs 8.9 per 1000 examinations; p = 0.999), sensitivity (87.5% vs 77.8%; p = 0.999), and positive predictive value for biopsy (PPV3) (35.0% vs 35.0%; p = 0.999) according to AI-CAD support. CONCLUSIONS: AI-CAD increases the specificity for radiologists without decreasing sensitivity as a supportive tool in the single reading of DM for breast cancer screening. CLINICAL RELEVANCE STATEMENT: This study shows that AI-CAD could improve the specificity of radiologists' DM interpretation in the single reading system without decreasing sensitivity, suggesting that it can benefit patients by reducing false positive and recall rates. KEY POINTS: • In this retrospective-matched cohort study (DM without AI-CAD vs DM with AI-CAD), radiologists showed higher specificity and lower AIR when AI-CAD was used to support decision-making in DM screening. • CDR, sensitivity, and PPV for biopsy did not differ with and without AI-CAD support.

Prediction of pathologic complete response on MRI in patients with breast cancer receiving neoadjuvant chemotherapy according to molecular subtypes.

OBJECTIVES: This study aimed to investigate the predictability of breast MRI for pathologic complete response (pCR) by molecular subtype in patients with breast cancer receiving neoadjuvant chemotherapy (NAC) and investigate the MRI findings that can mimic residual malignancy. METHODS: A total of 506 patients with breast cancer who underwent MRI after NAC and underwent surgery between January and December 2018 were included. Two breast radiologists dichotomized the post-NAC MRI findings as radiologic complete response (rCR) and no-rCR. The diagnostic performance of MRI predicting pCR was evaluated. pCR was determined based on the final pathology reports. Tumors were divided according to hormone receptor (HR) and human epidermal growth factor receptor (HER) 2. Residual lesions on post-NAC MRI were divided into overt and subtle which classified as nodularity or delayed enhancement. Pearson's χ2 and Wilcoxon rank-sum tests were used for MRI findings causing false-negative pCR. RESULTS: The overall pCR rate was 30.04%. The overall accuracy for predicting pCR using MRI was 76.68%. The accuracy was significantly different by subtypes (p < 0.001), as follows in descending order: HR - /HER2 - (85.63%), HR + /HER2 - (82.84%), HR + /HER2 + (69.37%), and HR - /HER2 + (62.38%). MRI in the HR - /HER2 + type showed the highest false-negative rate (18.81%) for predicting pCR. The subtle residual enhancement observed only in the delayed phase was associated with false-negative findings (76.2%, p = 0.016). CONCLUSIONS: The diagnostic accuracy of MRI for predicting pCR differed by molecular subtypes. When the residual enhancement on MRI after NAC is subtle and seen only in the delayed phase, overinterpretation of residual tumors should be performed with caution. KEY POINTS: • In patients with breast cancer after completion of neoadjuvant chemotherapy, the diagnostic accuracy of MRI for predicting pathologic complete response (pCR) differed according to molecular subtype. • When residual enhancement on MRI is subtle and seen only in the delayed phase, this finding could be associated with false-negative pCR results.

Breast Cancer Screening with Abbreviated Breast MRI: 3-year Outcome Analysis.

Background Data are limited regarding the performance of abbreviated screening breast MRI during consecutive years and the characteristics of breast cancers missed and detected with it. Purpose To assess the longitudinal diagnostic performance of abbreviated screening MRI and to determine whether the screening outcomes of abbreviated MRI differed between yearly time periods for 3 consecutive years. Materials and Methods This retrospective study included 1975 consecutive women who underwent abbreviated screening MRI between September 2015 and August 2018. Breast Imaging Reporting and Data System (BI-RADS) categories 3-5 defined positive results, and BI-RADS categories 1-2 defined negative results. Cancer detection rate (CDR), sensitivity, specificity, positive predictive value (PPV), abnormal interpretation rate (AIR), and interval cancer rate were assessed annually. Yearly performance measures were compared with the Fisher exact test by using the permutation method. Clinical-pathologic and imaging characteristics of the missed and detected cancers were compared by using the Fisher exact test and the Wilcoxon rank sum test. Results A total of 1975 women (median age, 49 years; interquartile range, 44-56 years) underwent 3037 abbreviated MRI examinations over 3 years. CDR (year 1 to year 3, 6.9-10.7 per 1000 examinations), positive predictive value for recall (9.7% [six of 62] to 15.6% [12 of 77]), positive predictive value for biopsy (31.6% [six of 19] to 63.2% [12 of 19]), sensitivity (75.0% [six of eight] to 80.0% [12 of 15]), and specificity (93.5% [807 of 863] to 94.1% [1041 of 1106]) were highest in year 3, and AIR (7.1% [62 of 871] to 6.9% [77 of 1121]) was lowest in year 3. However, all outcome measures did not differ statistically between years 1, 2, and 3 (all P > .05). The interval cancer rate was 0.66 per 1000 examinations (two of 3037). Thirty-eight breast cancers were identified in 36 women; 29 were detected with abbreviated MRI, but nine were missed. Of these, seven were detected with other imaging modalities after negative results at the last screening MRI examination, and two were interval cancers. All missed cancers were node-negative early-stage invasive cancers and were smaller (median size, 0.8 cm vs 1.2 cm; P = .01) than detected cancers. Conclusion Screening outcome measures of abbreviated MRI were sustained without significant differences between 3 consecutive years. All cancers missed at abbreviated MRI were node-negative invasive cancers and tended to be smaller than detected cancers. © RSNA, 2021 See also the editorial by Lee in this issue. Online supplemental material is available for this article.

Non-mass lesions detected by breast US: stratification of cancer risk for clinical management.

OBJECTIVE: To develop a classification system using imaging features to interpret breast non-mass lesions (NMLs) detected on US and to stratify their cancer risk. METHODS: This retrospective study included 715 patients with 715 breast NMLs detected on breast US from 2012 to 2016. Each patient underwent mammography at the time of diagnosis. Radiologists assessed US and mammographic features and final BI-RADS categories. Multivariable logistic regression was used to find imaging features associated with malignancy in a development dataset (n = 460). A system to classify BI-RADS categories (3 to 5) was developed based on the odds ratios (ORs) of imaging features significantly associated with malignancy and validated in a distinct validation dataset (n = 255). RESULTS: Among 715 NMLs, 385 (53.8%) were benign and 330 (46.2%) were malignant. In the development dataset, the following B-mode US features were associated with malignancy (all p < 0.001): segmental distribution (OR = 3.03; 95% confidence interval [CI], 1.50-6.15), associated calcifications (OR = 4.26; 95% CI, 1.62-11.18), abnormal ductal change (OR = 4.91; 95% CI, 2.07-11.68), and posterior shadowing (OR = 20.20; 95% CI, 6.46-63.23). The following mammographic features were also associated with malignancy (all p < 0.001): calcifications (OR = 7.98; 95% CI, 3.06-20.81) and focal asymmetry (OR = 4.75; 95% CI, 1.90-11.88). In the validation dataset, our classification system using US and mammography showed a higher area under the curve (0.951-0.956) compared to when it was not applied (0.908-0911) to predict malignancy with BI-RADS categories (p < 0.05). CONCLUSION: Our classification system which incorporates US and mammographic features of breast NMLs can help interpret and manage all NMLs detected on breast US by stratifying cancer risk according to BI-RADS categories. KEY POINTS: • When diagnosing breast NMLs detected on US, suspicious US features are segmental distribution, associated abnormal ductal change, calcifications, and posterior shadowing within or around the NML on B-mode US, while a probably benign US feature is the presence of multiple small cysts. • Corresponding suspicious mammographic features of breast NMLs detected on US are associated calcifications and focal asymmetry. • Our classification system which incorporates US features with and without mammography can potentially be used to interpret and manage any NMLs detected on breast US in clinical practice.

Long-term Surveillance of Ductal Carcinoma in Situ Detected with Screening Mammography versus US: Factors Associated with Second Breast Cancer.

Background The relationship between method of breast cancer screening (mammography or US) and survival outcome in patients with screening-detected ductal carcinoma in situ (DCIS) has not been determined. Purpose To investigate whether different methods of breast cancer screening are associated with different survival outcomes in patients with screening-detected DCIS and to evaluate clinical-pathologic and imaging factors associated with second breast cancer. Materials and Methods We retrospectively identified women who underwent surgery to treat DCIS initially detected with screening mammography or US between July 2004 and December 2011 in a single institution. Overall survival (OS) and disease-free survival (DFS) were assessed. Factors associated with second breast cancer (invasive carcinoma or DCIS) were found with multivariable Cox proportional hazards regression analysis. Subgroups were analyzed according to screening method. Results A total of 814 women (median age, 47 years; age range, 25-81 years) were included; 627 underwent treatment for screening mammography-detected DCIS (mammography-detected group), and 187 underwent treatment for screening US-detected DCIS (US-detected group). During follow-up (median, 7 years; interquartile range, 5-8 years), 26 ipsilateral and 26 contralateral second breast cancers (6.4%, 52 of 814) were found, with 44 in the mammography-detected group and eight in the US-detected group. The overall 5-year OS and DFS rates were 100% and 95.3%, respectively. DFS rates did not differ according to screening method (P = .21, 5-year DFS rates were 94.9% in the mammography-detected group and 96.5% in the US-detected group). In the mammography-detected group, higher nuclear grade (intermediate grade: hazard ratio [HR], 5.7; 95% confidence interval [CI]: 1.3, 24.3; P = 0.02) (high grade: HR, 8.0; 95% CI: 1.9, 34.2; P = .01) and dense breast (HR, 3.5; 95% CI: 1.1, 11.4; P = 0.04) were associated with second breast cancer. In the US-detected group, human epidermal growth factor receptor 2 positivity was associated with second breast cancer (HR, 9.2; 95% CI: 2.2, 38.5; P = .002). Conclusion Disease-free survival of patients who underwent treatment for screening-detected ductal carcinoma in situ (DCIS) did not differ according to screening detection method. In patients with screening mammography-detected DCIS, higher nuclear grade and dense breast were associated with second breast cancer, and in patients with screening US-detected DCIS, human epidermal growth factor 2 positivity was associated with second breast cancer. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Fowler in this issue.

Comparison of synthetic and digital mammography with digital breast tomosynthesis or alone for the detection and classification of microcalcifications.

OBJECTIVE: To compare the performance of synthetic mammography (SM) and digital mammography (DM) with digital breast tomosynthesis (DBT) or alone for the evaluation of microcalcifications. METHODS: This retrospective study includes 198 mammography cases, all with DM, SM, and DBT images, from January to October 2013. Three radiologists interpreted images and recorded the presence of microcalcifications and their conspicuity scores and final BI-RADS categories (1, 2, 3, 4a, 4b, 4c, 5). Readers' area under the ROC curves (AUCs) were analyzed for SM plus DBT vs. DM plus DBT and SM alone vs. DM alone using the BI-RADS categories for the overall group and dense breast subgroup. RESULTS: Conspicuity scores of detected microcalcifications were neither significantly different between SM and DM with DBT nor alone (p>0.05). In predicting malignancy of detected microcalcifications, no significant difference was found between readers' AUCs for SM and DM with DBT or alone in the overall group or dense breast subgroup (p>0.05). CONCLUSIONS: Diagnostic performances of SM and DM for the evaluation of microcalcifications are not significantly different, whether performed with DBT or alone. KEY POINTS: • In DBT-imaging, SM and DM show comparable performances when evaluating microcalcifications. • For BI-RADS classification of microcalcifications, SM and DM show similar AUCs. • DBT with SM may be sufficient for diagnosing microcalcifications, without DM.

Preoperative Axillary US in Early-Stage Breast Cancer: Potential to Prevent Unnecessary Axillary Lymph Node Dissection.

Purpose To evaluate the value of preoperative axillary ultrasonography (US) for preventing unnecessary axillary lymph node dissection after sentinel lymph node (SLN) biopsy in a large series of patients with early-stage breast cancers treated with both breast-conserving surgery and SLN biopsy. Materials and Methods From March 2009 to February 2013, 1802 patients who underwent breast-conserving surgery for clinical T1-2/N0 cancers and SLN biopsy with or without axillary lymph node dissection were included. Preoperative axillary US results and clinical-pathologic variables were compared according to the status of non-SLN metastasis. Multivariate logistic regression analysis was performed to find factors associated with non-SLN metastasis. Results Of 1802 patients, 397 (22.0%) underwent axillary lymph node dissection due to positive SLN biopsy and 76 (4.2%) had non-SLN metastasis at final histopathologic examination. Patients with non-SLN metastasis were younger and showed positive axilla at US and clinical T2 stage more frequently (P < .05). At multivariate analysis, positive axilla at US (P = .001), clinical T2 stage (P = .005), and lymphovascular invasion (P < .001) were significantly associated with non-SLN metastasis. Among 1284 patients with negative axilla at US and clinical T1 stage cancer, 1254 (97.7%) did not have non-SLN metastasis and 30 (2.3%) had non-SLN metastasis. Conclusion Preoperative axillary US results and clinical T stage are associated with the status of non-SLN metastasis in patients with early breast cancer. The results of this study suggest that preoperative axillary US can help select patients at minimal risk of non-SLN metastasis, for whom axillary lymph node dissection can be omitted. © RSNA, 2018 Online supplemental material is available for this article.

Metastatic internal mammary lymph nodes or mimickers on parasternal ultrasonography: focusing on their distribution and depth.

Background Ultrasonography (US) is an important tool to evaluate the status of internal mammary lymph node (IMN). US features of metastatic IMNs could help determine when biopsy should be performed. Purpose To compare US features of metastatic IMNs to those of benign entities. Material and Methods In women with suspected IMN metastasis on US, their intercostal space (ICS) abnormalities were classified into metastatic IMN, benign IMN, and lymph node (LN) mimickers. US features, distribution, and depth of abnormalities in one ICS and involved ICS level were analyzed. Results Among 66 ICS abnormalities in 53 women, 46 were metastatic IMNs, ten were benign IMNs, and ten were LN mimickers. For metastatic IMNs, the second ICS was the most commonly involved ICS (n = 22), followed by the first (n = 13), the third (n = 8), and the fourth (n = 3). ICS level distribution of metastatic IMNs was not significantly ( P = 0.5407) different from that of non-metastatic lesions. Metastatic IMNs were predominantly seen in the posterior layer of ICS, significantly ( P < 0.0001) different from LN mimickers. Both metastatic IMNs and non-metastatic lesions were evenly distributed over the upper, middle, and lower part (in craniocaudal direction) of one ICS. Conclusion Metastatic IMNs are more likely to be found in the posterior layer of ICS. This can help distinguish them from LN mimickers. Any part (upper, middle, or lower) of one ICS in craniocaudal direction could be involved. The second ICS was the most commonly involved level.

Background parenchymal enhancement on breast MRI: association with recurrence-free survival in patients with newly diagnosed invasive breast cancer.

PURPOSE: To determine whether BPE in preoperative breast MRI influences patients' recurrence-free survival (RFS). METHODS: Between February 2010 and December 2011, 804 consecutive women with invasive breast cancer who had undergone preoperative breast MRI and curative cancer surgery were identified. BPE was visually graded by two reviewers. We determined the correlation between BPE grade and other clinicopathological variables, including age, adjuvant therapy, menopausal status, histologic grade, T stage, N stage, lymphovascular invasion, molecular subtype, surgical margin status, and mammographic density. A Cox proportional hazards model was used to analyze the effects of clinicopathological variables and radiological findings (BPE grade, mammographic density) on RFS. RESULTS: High BPE was associated with premenopausal status (Ps < 0.0001), higher mammographic density (Ps < 0.0001), progesterone receptor positivity (Ps = 0.039, 0.007, respectively), presence of lymphovascular invasion (Ps = 0.008, 0.001, respectively), and close surgical margin (Ps < 0.0001). Recurrences were observed in 75 patients after a mean follow-up period of 61.8 months (range 4-81 months). Non-minimal BPE grade (RFS hazard ratio = 3.086, P = 0.003 for reader 1; RFS hazard ratio = 2.221, P = 0.075 for reader 2) and T3 stage were associated with worse outcomes in postmenopausal women. In premenopausal women, non-minimal BPE grade by readers 1 and 2 did not affect the patients' outcomes. CONCLUSIONS: Increased BPE on preoperative breast MRI in postmenopausal women has potential as a predictor of poor RFS.

Breast Cancer Heterogeneity: MR Imaging Texture Analysis and Survival Outcomes.

Purpose To determine the relationship between tumor heterogeneity assessed by means of magnetic resonance (MR) imaging texture analysis and survival outcomes in patients with primary breast cancer. Materials and Methods Between January and August 2010, texture analysis of the entire primary breast tumor in 203 patients was performed with T2-weighted and contrast material-enhanced T1-weighted subtraction MR imaging for preoperative staging. Histogram-based uniformity and entropy were calculated. To dichotomize texture parameters for survival analysis, the 10-fold cross-validation method was used to determine cutoff points in the receiver operating characteristic curve analysis. The Cox proportional hazards model and Kaplan-Meier analysis were used to determine the association of texture parameters and morphologic or volumetric information obtained at MR imaging or clinical-pathologic variables with recurrence-free survival (RFS). Results There were 26 events, including 22 recurrences (10 local-regional and 12 distant) and four deaths, with a mean follow-up time of 56.2 months. In multivariate analysis, a higher N stage (RFS hazard ratio, 11.15 [N3 stage]; P = .002, Bonferroni-adjusted α = .0167), triple-negative subtype (RFS hazard ratio, 16.91; P < .001, Bonferroni-adjusted α = .0167), high risk of T1 entropy (less than the cutoff values [mean, 5.057; range, 5.022-5.167], RFS hazard ratio, 4.55; P = .018), and T2 entropy (equal to or higher than the cutoff values [mean, 6.013; range, 6.004-6.035], RFS hazard ratio = 9.84; P = .001) were associated with worse outcomes. Conclusion Patients with breast cancers that appeared more heterogeneous on T2-weighted images (higher entropy) and those that appeared less heterogeneous on contrast-enhanced T1-weighted subtraction images (lower entropy) exhibited poorer RFS. © RSNA, 2016 Online supplemental material is available for this article.

Breast Cancer Detected at Screening US: Survival Rates and Clinical-Pathologic and Imaging Factors Associated with Recurrence.

Purpose To determine the survival rates and clinical-pathologic and imaging factors associated with recurrence in women with breast cancer detected at screening ultrasonography (US). Materials and Methods This study was approved by the institutional review board, and the requirement to obtain informed consent was waived. A retrospective review of the databases of four institutions identified 501 women (median age, 47 years; range, 27-74 years) with breast cancer (425 invasive cancers and 76 ductal carcinoma in situ) detected at screening US between January 2004 and March 2011. Five-year overall survival (OS) and recurrence-free survival (RFS) rates were estimated, and the clinical-pathologic and imaging data were collected. Multivariate analysis was performed by using Cox proportional hazard regression to determine factors associated with recurrence. Results At a median follow-up of 7.0 years (range, 5.0-12.1 years), 15 (3.0%) recurrences were detected: five in ipsilateral breast and 10 in contralateral breast. The 5-year OS and RFS rates were 100% and 98.0% (95% confidence interval [CI]: 96.8%, 99.2%), respectively. In patients with invasive cancers, age younger than 40 years (hazard ratio: 3.632 [95% CI: 1.099, 11.998]; P = .032), the triple-negative subtype (hazard ratio: 7.498 [95% CI: 2.266, 24.816]; P = .001), and Breast Imaging Reporting and Data System (BI-RADS) category 4A lesions (hazard ratio: 5.113 [95% CI: 1.532, 17.195]; P = .008) were associated with recurrence. Conclusion Women with breast cancers detected at screening US have excellent outcomes, with a 5-year RFS rate of 98.0%. However, in patients with invasive breast cancer, age younger than 40 years, the triple-negative subtype, and BI-RADS category 4A lesions were associated with recurrence. © RSNA, 2017 Online supplemental material is available for this article.

Shear wave elastography in the diagnosis of breast non-mass lesions: factors associated with false negative and false positive results.

OBJECTIVE: To investigate factors related to false shear wave elastography (SWE) results for breast non-mass lesions (NMLs) detected by B-mode US. METHODS: This retrospective study enrolled 152 NMLs detected by B-mode US and later pathologically confirmed (79 malignant, 73 benign). All lesions underwent B-mode US and SWE. Quantitative (mean elasticity [E mean]) and qualitative (maximum stiffness colour) SWE parameters were assessed, and 'E mean > 85.1 kPa' or 'stiff colour (green to red)' determined malignancy. Final SWE results were matched to pathology results. Multivariate logistic regression analysis identified factors associated with false SWE results for diagnosis of breast NMLs. RESULTS: Associated calcifications (E mean: odds ratio [OR] = 7.60, P < 0.01; maximum stiffness colour: OR = 6.30, P = 0.02), in situ cancer compared to invasive cancer (maximum stiffness colour: OR = 5.29, P = 0.02), and lesion size (E mean: OR = 0.90, P < 0.01; maximum stiffness colour: OR = 0.91, P = 0.01) were significantly associated with false negative SWE results for malignant NMLs. Distance from the nipple (E mean: OR = 0.84, P = 0.03; maximum stiffness colour: OR = 0.93, P = 0.04) was significantly associated with false positive SWE results for benign NMLs. CONCLUSIONS: Presence of associated calcifications, absence of the invasive component, and smaller lesion size for malignant NMLs and shorter distance from the nipple for benign NMLs are factors significantly associated with false SWE results. KEY POINTS: • Calcification and size are associated with false negative SWE in malignant NMLs. • In situ cancer is associated with false negative SWE in malignant NMLs. • Distance from the nipple is associated with false positive SWE in benign NMLs. • These factors need consideration when performing SWE on breast NMLs.

An audit of the results of ultrasound-guided core needle biopsy of mammography versus ultrasound screen-detected breast lesions.

PURPOSE: To analyze the malignancy rate of ultrasound-guided core needle biopsy (US-CNB) for screen-detected breast lesions and to evaluate the results according to the mode of detection of the target lesions. METHODS: This is a retrospective review of 703 consecutive women who underwent US-CNB for screen-detected breast lesions at a single tertiary hospital. Breast Imaging Reporting and Data System (BI-RADS) categories and histopathological results of the target lesions were assessed. The cases were divided into two groups: the mammography-based detected lesions (M-group) and the US-based detected lesions (U-group). The biopsy performances of the two groups were compared using the χ2 test. RESULTS: The malignancy rate in the entire population was 22.0%: 0.8%, 12.3%, 65.2%, 89.3%, and 94.6% in BI-RADS categories 3, 4A, 4B, 4C, and 5, respectively. The malignancy rate was significantly higher in the M-group (54.1% [79/146]) than in the U-group (13.6% [76/557]) (p < 0.001). BI-RADS category 3 was the most common assessment overall that led to a US-CNB (362/703, 51.5%) and the rate of BI-RADS category 3 diagnoses that led to US-CNB was significantly higher in the U-group (p < 0.001). CONCLUSIONS: The malignancy rate associated with US-CNB for screen-detected breast lesions was 22.0%. The breast lesions detected by mammography have a higher malignancy rate than those detected by US. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:261-266, 2017.

Additional diagnostic value of shear-wave elastography and color Doppler US for evaluation of breast non-mass lesions detected at B-mode US.

OBJECTIVE: To evaluate the diagnostic value of shear-wave elastography (SWE) and colour Doppler ultrasound (US) for evaluation of breast non-mass lesions (NMLs) detected by B-mode US. METHODS: This retrospective study enrolled 116 NMLs (42 benign, 74 malignant). For each lesion, B-mode US, SWE and colour Doppler US were performed. Mean elasticity (E mean), maximum elasticity (E max) and vascularity were assessed by SWE and Doppler US. Diagnostic performances of B-mode US, SWE and Doppler US were calculated to differentiate benign and malignant NMLs. RESULTS: In benign NMLs, average E mean and E max were lower, and low vascularity (no flow or only one vessel flow) was more frequent (P < 0.001). When BI-RADS category 4a NMLs were downgraded to category 3 with 'E mean of 85.1 kPa or less' and/or 'low vascularity', specificities increased (69.0-90.5 %; P < 0.001), without significant loss in sensitivities (97.3-100 %). When these 4a NMLs were downgraded by the combination of SWE and Doppler US, all downgraded NMLs (59.3 %, 19/32) were confirmed as benign. CONCLUSIONS: Addition of SWE and colour Doppler US to B-mode US improved diagnostic performances in differentiating benign and malignant NMLs. This study suggests that the combination of SWE and colour Doppler may help patients with BI-RADS category 4a NMLs avoid unnecessary biopsies. KEY POINTS: • B-mode US features of malignant and benign NMLs may overlap. • SWE and colour Doppler provides useful information about breast NMLs. • SWE and colour Doppler may decrease unnecessary biopsies of breast NMLs.

Comparison between two-dimensional synthetic mammography reconstructed from digital breast tomosynthesis and full-field digital mammography for the detection of T1 breast cancer.

OBJECTIVE: To evaluate the interpretative performance of two-dimensional (2D) synthetic mammography (SM) reconstructed from digital breast tomosynthesis (DBT) in the detection of T1-stage invasive breast cancers, compared to 2D full-field digital mammography (FFDM). METHODS: This retrospective study enrolled 214 patients. For each patient, FFDM and DBT were performed between January and June 2013, and SM was reconstructed from DBT data. Three radiologists interpreted images and recorded visibility scores and morphologies of cancers. Diagnostic performances of SM and FFDM were compared. Percentages of detected cancers and visibility scores were compared for tumour size, and presence of calcifications for each observer. RESULTS: Observer sensitivity showed no difference for detection with SM and FFDM (P > 0.05). One observer showed a higher specificity (P = 0.02) and higher positive predictive value with SM (95 % CI 0.6-16.4), but the differences in the corresponding values between SM and FFDM for the other observers were not statistically significant. In subgroup analyses according to tumour size and presence of calcifications, percentages of detected cancers and visibility scores were not significantly different. CONCLUSIONS: Diagnostic performances of SM and FFDM are comparable for detecting T1-stage breast cancers. Therefore, our results indicate that SM may eliminate the need for additional FFDM during DBT-based imaging. KEY POINTS: • DBT plus FFDM increases radiation dose compared to FFDM alone. • Detecting T1-stage cancers with only SM is comparable to detection with FFDM. • Two-dimensional SM may replace dose-requiring FFDM in DBT-based imaging.

Shear-wave elastography in invasive ductal carcinoma: correlation between quantitative maximum elasticity value and detailed pathological findings.

BACKGROUND: Further information is needed regarding whether histopathological characteristics affect breast tumor elasticity. PURPOSE: To determine whether maximum elasticity values vary according to tumor-stroma ratio, dominant stroma type, or presence of fibrosis in invasive breast cancer. MATERIAL AND METHODS: This study included 71 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) who underwent breast shear-wave elastography (SWE). Maximum elasticity (Emax) values were retrospectively correlated with pathological findings that included tumor-stroma ratio, dominant stroma type (collagen, fibroblast, lymphocyte), and fibrosis. Multiple linear regression analysis was performed to determine variables independently associated with Emax. RESULTS: High histologic grade was significantly correlated with higher Emax (P = 0.042). Estrogen receptor and progesterone receptor expression negatively correlated with high elasticity values (P = 0.013 and P = 0.03, respectively). Breast cancers that exhibited higher cellularity demonstrated a greater level of stiffness that was not statistically significant (ρ = 0.153; P = 0.193). While dominant stroma type and fibrosis did not affect Emax (P = 0.197 and P = 0.598, respectively), lesion size was significantly associated with Emax (ρ = 0.474, P < 0.001). On multivariate analysis, only lesion size was significantly associated with Emax (P < 0.001). CONCLUSION: The composition of tumors did not affect their Emax.

Effect of menstrual cycle and menopausal status on apparent diffusion coefficient values and detectability of invasive ductal carcinoma on diffusion-weighted MRI.

The purpose of this study was to determine whether the apparent diffusion coefficient (ADC) and tumor detectability based on diffusion-weighted imaging (DWI) are affected by the menstrual cycle or menopausal status in breast cancer patients. Institutional review board approval was obtained, and the requirement for informed consent was waived. A total of 124 women with invasive ductal carcinoma not otherwise specified (IDC NOS) who underwent breast MRI with DWI were included in this study. Two radiologists retrospectively measured the ADCs of tumor and contralateral normal glandular tissue and scored the tumor detectability. The ADCs and detectability were compared to menstrual cycle and menopausal status, based on patient questionnaires. ADCs of tumors and contralateral tissue were significantly lower in postmenopausal women than in premenopausal women (P = 0.006 and P < 0.001, respectively). Tumor detectability did not differ significantly between the premenopausal and postmenopausal groups (P = 0.454). Normalized ADCs were not significantly lower in postmenopausal women compared to premenopausal women (P = 0.880). There was no statistically significant difference in the absolute, contralateral, and normalized ADCs (P = 0.091, 0.809, and 0.299, respectively), and the tumor detectability (P = 0.680) according to the menstrual cycle. Although ADCs of the IDC and normal glandular tissue in postmenopausal women were significantly lower than those in premenopausal women, the menstrual cycle did not affect tumor detectability and ADCs of IDC.

Ultrasonographic hyperechoic lesions of the breast: are they always benign?

BACKGROUND: Most of the breast lesions show hypoechogenicity relative to fat on ultrasonography. The frequency and malignancy rate of hyperechoic lesions are not investigated in a large series. PURPOSE: To evaluate the frequency and malignancy rate of hyperechoic lesions on breast sonography and to investigate sonographic characteristics that may predict malignancy in hyperechoic breast lesions. MATERIAL AND METHODS: Radiologic reports of 16,416 patients who underwent breast sonography between 2007 and 2008 were searched using "hyperechoic", "echogenic" or "heterogeneous echoic" to describe lesions. Sonographic findings were evaluated according to the Breast Imaging Reporting and Data System lexicon. Clinical records including follow-up and pathologic findings were also reviewed. We calculated the frequency of hyperechoic lesions and their malignancy rate. Differences in sonographic appearances between benign and malignant lesions were also investigated. RESULTS: Among the 16,416 patients, 103 (0.6%) hyperechoic lesions were identified (mean size, 1.79 cm). Of these 103 lesions, 27 (26.2%) were pathologically evaluated and five (4.9%, 4 invasive ductal carcinoma and 1 mucinous carcinoma) were confirmed as malignant. Among the 819 malignant lesions diagnosed using sonography-guided core needle biopsy, five (0.6%) were hyperechoic. In benign lesions, fat necrosis and fibroadenoma were common pathologic diagnoses. Malignant lesions were more likely to have irregular shape (P = 0.003), non-parallel orientation (P = 0.002), non-circumscribed margin (P = 0.007), and a hypoechoic area (P = 0.027) than benign lesions. All hyperechoic carcinomas were seen as suspicious masses on mammograms. CONCLUSION: Hyperechoic masses are very rare and mostly benign. As an adjunct to mammography, the imaging findings reported here could help to avoid misdiagnosis for malignant hyperechoic lesion.

Is Holm Zone III safe from fat necrosis in medial row perforator-based deep inferior epigastric perforator flaps?

BACKGROUND: This study investigated which zonal tissue would be more secure from the risk of fat necrosis between Holm zones II and III and examined the risk factors of fat necrosis in a clinical series of medial row perforator-based deep inferior epigastric artery perforator (DIEP) flaps. PATIENTS AND METHODS: A retrospective chart review was performed for patients undergoing unilateral breast reconstructions with medial row perforator DIEP flaps. Data regarding patients, operation-related characteristics, and complications including fat necrosis were collected. Fat necrosis was mainly diagnosed by ultrasound examination, and its location was also assessed. RESULTS: A total of 103 cases were analyzed. Fat necrosis was diagnosed in 13.6% of patients and developed more frequently in zone III (7.8%) than in zone II (4.9%). In risk factor analysis, the inset rate, the weight ratio of the inset flap to harvested flap, was significantly associated with the development of fat necrosis. The flaps with inset rates more than 79% showed 16 times higher risk of fat necrosis than those below 79% in multivariate analysis. The incidence of fat necrosis in zone III was significantly increased in the high inset rate group when compared with the low inset rate group, whereas the incidence in zone II did not change. CONCLUSIONS: In unilateral breast reconstruction using medial row perforator DIEP flaps, fat necrosis developed more frequently in zone III than in zone II, and this tendency was more prominent in high inset rate group. Not transferring excessive contralateral tissue including lateral zone III tissue might be helpful for reducing the risk of fat necrosis.