Detecting accurate tumor size across imaging modalities in breast cancer.

BACKGROUND: Of the most common imaging modalities for breast cancer diagnosis - mammogram (MAM), ultrasound (US), magnetic resonance imaging (MRI) - it has not been well established which of these most accurately corresponds to the histological tumor size. OBJECTIVE: To determine which imaging modality (MAM, US, MRI) is most accurate for determining the histological tumor size of breast lesions. METHODS: A retrospective study of 76 breast cancers found in 73 female patients who received MAM, US, and/or MRI was performed. 239 charts were reviewed and 73 patients met inclusion criteria. Analysis was performed using signed rank tests comparing the reported tumor size on the imaging modality to the tumor size on pathology report. RESULTS: Mammography and ultrasonography underestimated tumor size by 3.5 mm and 4 mm (p-values < 0.002), respectively. MRI tends to overestimate tumor size by 3 mm (p-value = 0.0570). Mammogram was equivalent to pathological size within 1 mm 24% of the time and within 2 mm 35% of the time. CONCLUSIONS: No one single modality is the most accurate for detecting tumor size. When interpreting the size reported on breast imaging modalities, the amount of underestimation and overestimation in tumor size should be considered for both clinical staging and surgical decision-making.

Kinetic patterns of benign and malignant breast lesions on contrast enhanced digital mammogram.

PURPOSE: To evaluate the kinetic patterns of benign and malignant breast lesions using contrast-enhanced digital mammogram (CEDM). METHODS: Women with suspicious breast lesions on mammography or ultrasound were enrolled. Single-view mediolateral oblique (MLO) CEDM of an affected breast was acquired at 2, 3, 4, 7, and 10 min after injection of contrast agent. Three readers visually and semi-quantitatively analyzed the enhancement of suspicious lesions. The kinetic pattern of each lesion was classified as persistent, plateau, or washout over two time intervals, 2-4 min and 2-10 min, by comparing the signal intensity at the first time interval with that at the second. RESULTS: There were 73 malignant and 75 benign lesions in 148 patients (mean age: 52 years). Benign and malignant breast lesions showed the highest signal intensity at 3 min and 2 min, respectively. Average areas under receiver operating characteristic (ROC) curve for diagnostic accuracy based on lesion enhancement at different time points were 0.73 at 2 min, 0.72 at 3 min, 0.69 at 4 min, 0.67 at 7 min, and 0.64 at 10 min. Diagnostic performance was significantly better at 2, 3, and 4 min than at 7 and 10 min (all p < 0.05). A washout kinetic pattern was significantly associated with malignant lesions at 2-4 min and 2-10 min frames according to two of the three readers' interpretations (all p ≤ 0.001). CONCLUSION: Applications of optimal time intervals and kinetic patterns show promise in differentiation of benign and malignant breast lesions on CEDM.

A comparative study of perioperative techniques to attain negative margins and spare healthy breast tissue in breast conserving surgery.

BACKGROUND AND AIM: Traditionally lumpectomy as a part of breast-conserving surgery (BCS) is performed by palpation-guided method leading to positive margins and large excision volumes. There is no evidence suggesting that wide margin excisions decrease intra-breast tumour recurrence. Various perioperative techniques are used for margin assessment. We aimed to compare three commonly used techniques, i.e., ultrasound-guided surgery, palpation-guided surgery and cavity shaving for attaining negative margins and estimating the extent of healthy breast tissue resection. METHOD: A prospective comparative study was performed on 90 patients who underwent breast conservation surgery for early breast cancer between August 2018 and June 2019. Tumour excision with a minimum of 1 cm margin was done either using ultrasound, palpation or cavity shaving. Histopathological evaluation was done to assess the margin status and excess amount of resected normal breast tissue. Calculated resection ratio (CRR) defining the excess amount of the resected breast tissue was achieved by dividing the total resection volume (TRV) by optimal resection volume (ORV). The time taken for excision was also recorded. RESULTS: Histopathology of all 90 patients (30 in each group) revealed a negative resection margin in 93.3% of 30 patients in palpation-guided surgery group and 100% in both ultrasound-guided surgery and cavity shaving groups. Two patients (6.7%) from the cavity shaving group had positive margins on initial lumpectomy but shave margins were negative. TRV was significantly less in the ultrasound-guided surgery group compared to the palpation-guided surgery group and cavity shaving group (76.9 cm3, 94.7 cm3 and 126.3 cm3 respectively; p < 0.0051). CRR was 1.2 in ultrasound group compared to 1.9 in palpation group and 2.1 in cavity shave group which was also statistically significant (p < 0.0001).Excision time was significantly less (p < 0.001) in palpation-guided surgery group (13.8 min) compared to cavity shaving group (15.1 min) and ultrasound-guided group (19.4 min). CONCLUSION: Ultrasound-guided surgery is more accurate in attaining negative margins with the removal of least amount of healthy breast tissue compared to palpation-guided surgery and cavity shaving.

A phased approach to implementing the Breast Imaging Reporting and Data System (BI-RADS) in low-income and middle-income countries.

BACKGROUND: Successful breast cancer detection programs rely on standardized reporting and interpreting systems, such as the Breast Imaging Reporting and Data System (BI-RADS), to improve system performance. In low-income and middle-income countries, evolving diagnostic programs have insufficient resources to either fully implement BI-RADS or to periodically evaluate the program's performance, which is a necessary component of BI-RADS. This leads to inconsistent breast ultrasound interpretation and a failure to improve performance. METHODS: The authors applied the Breast Health Global Initiative's phased implementation strategy to implement diagnostic ultrasound and BI-RADS within the context of a limited-resource setting. RESULTS: The authors recommended starting with triage ultrasound to distinguish suspicious masses from normal breast tissue and benign masses such as cysts because the majority of health workers performing ultrasounds at this level have minimal breast imaging experience. Transitioning to full diagnostic ultrasound with condensed or full BI-RADS should occur after performance and quality metrics have been met. CONCLUSIONS: Transitioning through these phases across facilities likely will occur at different times, particularly in rural versus urban settings.

Predictive value of comb-push ultrasound shear elastography for the differentiation of reactive and metastatic axillary lymph nodes: A preliminary investigation.

OBJECTIVES: To evaluate the predictive performance of comb-push ultrasound shear elastography for the differentiation of reactive and metastatic axillary lymph nodes. METHODS: From June 2014 through September 2018, 114 female volunteers (mean age 58.1±13.3 years; range 28-88 years) with enlarged axillary lymph nodes identified by palpation or clinical imaging were prospectively enrolled in the study. Mean, standard deviation and maximum shear wave elastography parameters from 117 lymph nodes were obtained and compared to fine needle aspiration biopsy results. Mann-Whitney U test and ROC curve analysis were performed. RESULTS: The axillary lymph nodes were classified as reactive or metastatic based on the fine needle aspiration outcomes. A statistically significant difference between reactive and metastatic axillary lymph nodes was observed based on comb-push ultrasound shear elastography (CUSE) results (p<0.0001) from mean and maximum elasticity values. Mean elasticity showed the best separation with a ROC analysis resulting in 90.5% sensitivity, 94.4% specificity, 0.97 area under the curve, 95% positive predictive value, and 89.5% negative predictive value with a 30.2-kPa threshold. CONCLUSIONS: CUSE provided a quantifiable parameter that can be used for the assessment of enlarged axillary lymph nodes to differentiate between reactive and metastatic processes.

Breast Cancer Screening and Diagnosis: A Synopsis of the European Breast Guidelines.

Description: The European Commission Initiative for Breast Cancer Screening and Diagnosis guidelines (European Breast Guidelines) are coordinated by the European Commission's Joint Research Centre. The target audience for the guidelines includes women, health professionals, and policymakers. Methods: An international guideline panel of 28 multidisciplinary members, including patients, developed questions and corresponding recommendations that were informed by systematic reviews of the evidence conducted between March 2016 and December 2018. GRADE (Grading of Recommendations Assessment, Development and Evaluation) Evidence to Decision frameworks were used to structure the process and minimize the influence of competing interests by enhancing transparency. Questions and recommendations, expressed as strong or conditional, focused on outcomes that matter to women and provided a rating of the certainty of evidence. Recommendations: This synopsis of the European Breast Guidelines provides recommendations regarding organized screening programs for women aged 40 to 75 years who are at average risk. The recommendations address digital mammography screening and the addition of hand-held ultrasonography, automated breast ultrasonography, or magnetic resonance imaging compared with mammography alone. The recommendations also discuss the frequency of screening and inform decision making for women at average risk who are recalled for suspicious lesions or who have high breast density.

Sonoelastography of retroareolar carcinomas.

PURPOSE: To review the sonographic and elastographic features of retroareolar carcinomas. MATERIALS: Institutional review board approval was obtained. Among 967 sonographically guided biopsies (2013-2014) (14-gauge cores), 53 yielded the diagnosis of retroareolar carcinoma (located less than 2cm from the nipple on mammograms). Out of these 53 lesions, 30 were assessed additionally with strain elastography prior to the biopsy in addition to conventional sonographic analysis. Imaging features were analyzed in consensus by two radiologists. Elasticity score was evaluated by the score defined by Itoh (Tsukuba score). Descriptive analysis was performed. RESULTS: A total of 30 lesions were included (30 patients; mean age, 66.03 (±12.88)). The mean size of the lesions at diagnosis was 23.97mm (±13.64). Sonographically, most of lesions appeared as hypoechoic masses (96.5%, 28/29) displaying an irregular shape (75.9%, 22/29), non parallel orientation (58.6%, 17/29), non circumscribed margins (86.2%, 25/29), posterior attenuation (93.3%, 28/29). Among the 30 lesions, 3.3% (1/30) of lesions appeared as an attenuation and distortion without discrete mass. Most of the lesions were categorized as BI-RADS category 5 (76.7%, 23/30). Approximately half of lesions (53.3%, 16/30) appeared as firm and larger than 2D mode with strain elastography according to the Tsukuba score. CONCLUSION: Retroareolar carcinoma displayed malignant features at US and elastographic examination. In our study population, the addition of elastography to breast US in this location did not improve diagnostic accuracy.

Breast imaging for aesthetic surgery: British Society of Breast Radiology (BSBR), Association of Breast Surgery Great Britain & Ireland (ABS), British Association of Plastic Reconstructive and Aesthetic Surgeons (BAPRAS).

This is an overview of the guidelines for breast imaging before and after aesthetic (cosmetic) breast surgery, which includes but is not limited to implants, lipomodelling and mammoplasty procedures. The guidelines are based on a review of the literature and consensus of breast imaging and aesthetic breast surgery specialists. 1. Pre-aesthetic surgery 2. Post-aesthetic surgery If breast imaging or breast assessment is required, it should be performed in a designated breast facility with access to specialist breast imaging and a complete breast multidisciplinary team in accordance with national guidelines and recommendations.

Ultrasound shear wave elastography of breast lesions: correlation of anisotropy with clinical and histopathological findings.

BACKGROUND: Ultrasound shear-wave elastography (SWE) may increase specificity of breast lesion assessment with ultrasound, but elasticity measurements may change with transducer orientation, defined as anisotropy. In this study, we aimed to observe the anisotropy of SWE of breast lesions, and its correlation with clinical and histopathological findings. METHODS: This retrospective study was approved by institutional review board. From June 2014 to June 2015, a total of 276 women (mean age, 48.75 ± 12.12 years) with 276 breast lesions (174 malignant, 102 benign) were enrolled for conventional ultrasound and SWE before surgical excision. Elasticity modulus in the longest diameter and orthogonal diameter were recorded, including maximum elasticity (Emax), mean elasticity (Emean), standard deviation (Esd) and ratio between mean elasticity of lesion and normal fatty tissue (Eratio). Anisotropy coefficients including anisotropic difference (AD) and anisotropy factors (AF) were calculated, and correlations with malignancy, tumor size, palpability, movability, lesion location and histopathology were analyzed. RESULTS: The average Emax, Emean, Esd and Eratio of the longest diameter were significantly higher than orthogonal diameter (P < 0.05). AUCs of ADs and AFs were inferior to quantitative parameters (P < 0.001), with AUCs of AFs superior to ADs (P < 0.001). ADs showed no significant correlation with malignancy, palpability, movability, distance from nipple and skin, and histopathological patterns. ADmean was significantly higher in inner half than outer half of the breast (P = 0.034). Higher AFs were significantly correlated with larger lesion size (P = 0.042), palpability (P < 0.05), shorter distance from nipple and skin (P < 0.05) and higher suspicion for malignancy (P < 0.001). AFs were significantly higher in IDC than DCIS (P < 0.05), higher in Grade II/III than Grade I IDC (P < 0.001), and correlated with ER/PR(+) (P < 0.05). CONCLUSIONS: AF of SWE was an indicator for malignancy and more aggressive breast cancer.

Auto strain ratio system for the quality control of breast strain elastography.

PURPOSE: To determine the reproducibility, accuracy, and quantitative values of the auto strain ratio system (ASRS)-a newly developed strain elastography-based program. MATERIALS AND METHODS: First, the accuracy of ASRS was verified using a breast phantom. A prospective clinical study was then performed in patients. Two hundred and one women (mean age 52.4 years ± SD 14.5) with 232 breast lesions (177 benign and 55 malignant) were enrolled in this study. We assessed the correlation between ASRS and manual strain ratio (MSR), calculating the diagnostic performance to determine the cut-off. The area under the receiver operating characteristic curve (AUC) was calculated. RESULTS: ASRS was strongly correlated with the subtle differences in phantom stiffness (R = 0.87). In the clinical study, there was a significant correlation between MSR and ASRS with R = 0.79 (P < 0.001). ASRS (cut-off = 3.9) had a sensitivity of 81.8%, specificity of 88.7%, accuracy of 87.1%, positive predictive value of 69.2%, and negative predictive value of 94%. The AUC of ASRS was 0.89. CONCLUSION: The findings from this study have demonstrated that it is possible to quantify strain elastography and control its accuracy. ASRS is expected to contribute to the standardization of breast elastography.

Role of BI-RADS Ultrasound Subcategories 4A to 4C in Predicting Breast Cancer.

BACKGROUND: The Breast Imaging Reporting and Data System (BI-RADS) ultrasound (US) categorization revised in 2013 by the American College of Radiology resulted in unquestionable standardization of reports and confirmed category 3 and 5 as benign and malignant lesions, respectively. In contrast, suspected images (category 4) have subcategorization criteria, although theses have been detailed difficult to apply. The aim of the present study was to determine the role of the US 4A to 4C BI-RADS subcategories in predicting malignancy. PATIENTS AND METHODS: We performed a cross-sectional study of diagnostic tests to estimate the performance of the US BI-RADS categorization to clearly differentiate benign from malignant lesions. A total of 975 US examinations performed at the Hospital Femina, Grupo Hospitalar Conceição teaching hospitals from January 2012 through March 2015 were included in the present study. The US BI-RADS lexicon was used to classify the examination findings. Suspicious lesions underwent core needle biopsy, and the US and histology reports were compared to determine the performance using receiver operating characteristic curves. RESULTS: Overall, the BI-RADS US categorization showed good discriminating accuracy with a receiver operating characteristic curve of 91% (95% confidence interval [CI], 88%-93%). However, BI-RADS subcategory 4b had a positive predictive value of 25% (95% CI, 20%-31%) and subcategory 4A had a positive predictive value of only 6% (95% CI, 3.5%-9.8%). CONCLUSION: Our results have shown that US BI-RADS subcategories 4A and 4B are clearly unfit for use in screening tests, because they cannot rule out the need for biopsy. Therefore, management will not be improved by subcategorizing category 4, because all suspicious lesions will still require definite biopsy.

Verification of recall criteria for masses detected on ultrasound breast cancer screening.

PURPOSE: Mammography is the only modality for breast cancer screening demonstrated to reduce the mortality rate. However, ultrasonographic screening is already being widely performed as opportunistic screening in Japan. The recall criteria for masses are very important as quality controls. The purpose of this study was to verify these criteria at multiple institutions. METHODS: Screening was performed by five institutions in various regions in Japan. The total number of cases screened at all five institutions was 10,519. RESULTS: The findings that could be concluded to be benign were a cystic pattern and three features of a solid pattern. The cystic pattern was noted in 6512 cases, typical fibroadenoma in 1483 cases, and typical complicated cyst in 70 cases. Only three of these 8065 cases were cancers, so the negative predictive value was 99.9%. The solid pattern with obvious malignant features, i.e., masses with an echogenic halo and/or interruption of the interface and masses with multiple echogenic foci, were noted in 33 cases. Twenty of the 33 cases were malignancy, resulting in a positive predictive value of 66.7%. CONCLUSION: Although some parts of the criteria should be considered further for verification and revision, the current recall criteria are mostly valid.

Segmentation of breast ultrasound images based on active contours using neutrosophic theory.

PURPOSE: Ultrasound imaging is an effective approach for diagnosing breast cancer, but it is highly operator-dependent. Recent advances in computer-aided diagnosis have suggested that it can assist physicians in diagnosis. Definition of the region of interest before computer analysis is still needed. Since manual outlining of the tumor contour is tedious and time-consuming for a physician, developing an automatic segmentation method is important for clinical application. METHODS: The present paper represents a novel method to segment breast ultrasound images. It utilizes a combination of region-based active contour and neutrosophic theory to overcome the natural properties of ultrasound images including speckle noise and tissue-related textures. First, due to inherent speckle noise and low contrast of these images, we have utilized a non-local means filter and fuzzy logic method for denoising and image enhancement, respectively. This paper presents an improved weighted region-scalable active contour to segment breast ultrasound images using a new feature derived from neutrosophic theory. RESULTS: This method has been applied to 36 breast ultrasound images. It generates true-positive and false-positive results, and similarity of 95%, 6%, and 90%, respectively. CONCLUSION: The purposed method indicates clear advantages over other conventional methods of active contour segmentation, i.e., region-scalable fitting energy and weighted region-scalable fitting energy.

Inter-rater reliability and double reading analysis of an automated three-dimensional breast ultrasound system: comparison of two independent examiners.

PURPOSE: Breast ultrasound could be a valuable tool complementary to mammography in breast cancer screening. Automated 3D breast ultrasound (ABUS) addresses challenges of hand-held ultrasound and could allow double reading analysis of ultrasound images. This trial assesses the inter-rater reliability and double reading analysis of an ABUS system. METHODS: To assess the reproducibility and diagnostic validity of the ABUS system, SomoV™, a blinded double reading analysis, was performed in 1019 patients (2038 breasts) by two examiners (examiner A/B) and compared to single reading results, as well as to the reference standard regarding its diagnostic validity. Cohen's kappa coefficients were calculated to measure the inter-rater reliability and agreement of the different diagnostic modalities. Patient comfort and time consumption for image acquisition and reading were analyzed descriptively as secondary objectives. RESULTS: Analysis of inter-rater reliability yielded agreement in 81.6% (κ = 0.37; p < 0.0001) showing fair agreement. Single reading analysis of SomoV™ exams (examiner A/examiner B) compared to reference standard showed good specificity (examiner A: 88.3%/examiner B: 84.5%), fair inter-rater agreement (examiner A: κ = 0.31/examiner B: κ = 0.31), and adequate sensitivity (examiner A: 53.1%/examiner B: 64.2%). Double reading analysis yielded good sensitivity and specificity (73.7 and 77.7%). Mammography (n = 1911) alone detected 160 of 176 carcinomas (sensitivity 90.1%). Adding SomoV™ to mammography would have detected 12 additional carcinomas, resulting in a higher sensitivity of 97.7%. CONCLUSION: SomoV™ is a promising technique with good sensitivity, high patient comfort, and fair inter-examiner reliability. It allows double reading analysis that, in combination with mammography, could increase detection rates in breast cancer screening.

Sparse Representation Based Multi-Instance Learning for Breast Ultrasound Image Classification.

We propose a novel method based on sparse representation for breast ultrasound image classification under the framework of multi-instance learning (MIL). After image enhancement and segmentation, concentric circle is used to extract the global and local features for improving the accuracy in diagnosis and prediction. The classification problem of ultrasound image is converted to sparse representation based MIL problem. Each instance of a bag is represented as a sparse linear combination of all basis vectors in the dictionary, and then the bag is represented by one feature vector which is obtained via sparse representations of all instances within the bag. The sparse and MIL problem is further converted to a conventional learning problem that is solved by relevance vector machine (RVM). Results of single classifiers are combined to be used for classification. Experimental results on the breast cancer datasets demonstrate the superiority of the proposed method in terms of classification accuracy as compared with state-of-the-art MIL methods.

Breast Ultrasound Technology and Performance Evaluation of Ultrasound Equipment: B-Mode.

Ultrasound (US) has become increasingly important in imaging and image-guided interventional procedures. In order to ensure that the imaging equipment performs to the highest level achievable and thus provides reliable clinical results, a number of quality control (QC) methods have been developed. Such QC is increasingly required by accrediting agencies and professional organizations; however, these requirements typically do not include detailed procedures for how the tests should be performed. In this paper, a detailed overview of QC methods for general and breast US imaging using computer-based objective methods is described. The application of QC is then discussed within the context of a common clinical application (US-guided needle biopsy) as well as for research applications, where QC may not be mandated, and thus is rarely discussed. The implementation of these methods will help in finding early stage equipment faults and in optimizing image quality, which could lead to better detection and classification of suspicious findings in clinical applications, as well as improving the robustness of research studies.

Elastography Complements Ultrasound as Principle Modality in Breast Lesion Assessment.

BACKGROUND: The study aimed to improve breast cancer diagnosis with new ultrasound (US) modalities. We examined whether real-time elastography (RTE) complements the diagnostic performance of US. METHODS: The Ethical Committee approved the study. Patients provided written informed consent and received a whole breast workup. Breast lesions were evaluated by US and RTE. Lesions were assessed by BI-RADS, Tsukuba score (TS) and strain ratio (SR). RESULTS: The study included 164 breast lesions of which 101 were benign and 63 malignant. Women with benign lesions were predominantly premenopausal with sonographic dense breast tissue. Women with breast cancer were mostly postmenopausal, with a low sonographic density. Benign lesions had a mean TS of 2.05, which was significantly lower than the mean TS of 3.25 for malignant lesions. The SR for benign lesions (SR 1.83) was significantly smaller than for breast cancer (SR 4.83). Sensitivity and specificity was 95 and 81% for BI-RADS, 39 and 94% for TS, and 57 and 83% for SR, with a cutoff at 2.5. The combination of BI-RADS, TS and SR yielded a sensitivity of 95% and a specificity of 85%. CONCLUSION: Besides morphologic features revealed by US, elastic properties of breast lesions obtained by RTE can be exploited for diagnostic breast imaging.

Diagnosis of sub-centimetre breast lesions: combining BI-RADS-US with strain elastography and contrast-enhanced ultrasound-a preliminary study in China.

OBJECTIVES: To compare the diagnostic efficacies of B-mode ultrasound (US), strain elastography (SE), contrast-enhanced ultrasound (CEUS) and the combination of these modalities for breast lesions <1 cm in size. METHODS: Between January 2013 and October 2015, 203 inpatients with 209 sub-centimetre breast lesions categorised as BI-RADS-US (Breast Imaging Reporting and Data System for Ultrasound) 3-5 were included. US, SE and CEUS were performed to evaluate each lesion. The diagnostic performances of different ultrasonic modalities were compared. The diagnostic efficacies of BI-RADS-US and our re-rating systems were also compared. The pathology findings were used as the reference standard. RESULTS: The specificities of US, SE and CEUS for tumour differentiation were 17.4 %, 56.2 % and 86.0 %, respectively (P < 0.05); and the sensitivities were 100 %, 93.2 % and 93.2 % for US, SE and CEUS, respectively (P < 0.05). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was 0.867 for original BI-RADS-US, 0.882 for BI-RADS-US combined with only SE, 0.953 for BI-RADS-US combined with only CEUS and 0.924 for BI-RADS-US combined with both SE and CEUS. The best combination was BI-RADS-US combined with only CEUS. CONCLUSIONS: Evaluating sub-centimetre breast lesions with SE and CEUS could increase the diagnostic specificity while retaining high sensitivity compared with B-mode ultrasound. KEY POINTS: • Evaluating breast lesions with SE and CEUS could increase the diagnostic specificity • SE and CEUS offer alternatives to biopsy and possibly allow shorter-interval follow-ups • BI-RADS-US combined with CEUS exhibited the best diagnostic performance.

ACR Appropriateness Criteria Breast Cancer Screening.

Mammography is the recommended method for breast cancer screening of women in the general population. However, mammography alone does not perform as well as mammography plus supplemental screening in high-risk women. Therefore, supplemental screening with MRI or ultrasound is recommended in selected high-risk populations. Screening breast MRI is recommended in women at high risk for breast cancer on the basis of family history or genetic predisposition. Ultrasound is an option for those high-risk women who cannot undergo MRI. Recent literature also supports the use of breast MRI in some women of intermediate risk, and ultrasound may be an option for intermediate-risk women with dense breasts. There is insufficient evidence to support the use of other imaging modalities, such as thermography, breast-specific gamma imaging, positron emission mammography, and optical imaging, for breast cancer screening. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review includes an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.