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Purpose: Breast density assessment is an essential component of risk-stratified and supplemental breast cancer screenings for the future generation. International collaborative research and cooperation are required to determine global trends and differences in mammographic breast density. Due to the cost and energy associated with the use of film or digital mammograms, international breast density assessment studies tend to be challenging. A novel breast density assessment method using portable document format (PDF) is currently explored and the justification is needed. This study aimed to investigate the inter-method agreement between two viewing platforms - mammograms on PDF and mammograms on a workstation - for a subjective breast density assessment., Methods: Three radiologists assessed 100 cases with 200 normal bilateral mediolateral oblique view images twice at 1-month interval using mammograms on PDF and mammograms on a workstation. Further, to assess intra-reader agreement, one reader performed two readings of the PDF set at 1-month interval. The reading order of the images was changed each time. Weighted kappa coefficient (κw) was used to assess inter-method and intra-observer agreements., Results: The average inter-method agreement was substantial (κw = 0.74, range = 0.73-0.76) on a four-grade scale (fatty, scattered, heterogeneously dense, or extremely dense) and almost perfect (κw = 0.81, range = 0.78-0.84) on a two-grade scale (non-dense or dense). The intra-observer agreement was almost perfect on a four-grade scale (κw = 0.85) and two-grade scale (κw = 0.90)., Conclusion: The PDF and mammography workstation readings for breast density assessment had almost perfect inter-method agreements. Moreover, the intra-observer agreement of PDF reading was almost perfect.

Purpose: Three-dimensional contrast-enhanced magnetic resonance imaging (3D-Ce-MRI) is a most powerful tool for evaluation of neoadjuvant chemotherapy (NAC). However, the use of contrast agent is invasive, expensive, and time consuming, Thus, contrast agent-free imaging is preferable. We aimed to investigate the tumor volume change after NAC using maximum intensity projection diffusion-weighted image (MIP-DWI) and 3D-Ce-MRI., Method: We finally enrolled 55 breast cancer patients who underwent NAC in 2018. All MRI analyses were performed using SYNAPSE VINCENT® medical imaging system (Fujifilm Medical, Tokyo, Japan). We evaluated the tumor volumes before, during, and after NAC. Tumor volume before NAC on 3D-Ce-MRI was termed Pre-CE and those during and after NAC were termed Post-CE. The observer raised the lower end of the window width until the tumor was clearly visible and then manually deleted the non-tumor tissues. A month thereafter, the same observer who was blinded to the 3D-Ce-MRI results randomly evaluated the tumor volumes (Pre-DWI and Post-DWI) using MIP-DWI with the same method. Tumor volume change between ΔCE (Pre-CE - Post-CE/Pre-CE) and ΔDWI (Pre-DWI - Post-DWI/Pre-DWI) and the processing time for both methods (Time-DWI and Time-CE) were compared., Results: We enrolled 55 patients. Spearman's rho between ΔDWI and ΔCE for pure mass lesions, and non-mass enhancement (NME) was 0.89 (p < 0.01), 0.63(p < 0.01) respectively. Time-DWI was significantly shorter than Time-CE (41.3 ± 21.2 and 199.5 ± 98.3 respectively, p < 0.01)., Conclusions: Non-contrast-enhanced Breast MRI enables appropriate and faster evaluation of tumor volume change after NAC than 3D-Ce-MRI especially for mass lesions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Purpose: This study aimed to enhance the diagnostic accuracy of contrast-enhanced breast magnetic resonance imaging (MRI) using gadobutrol for differentiating benign breast lesions from malignant ones. Moreover, this study sought to address the limitations of current imaging techniques and criteria based on the Breast Imaging Reporting and Data System (BI-RADS)., Materials and Methods: In a multicenter retrospective study conducted in Japan, 200 women were included, comprising 100 with benign lesions and 100 with malignant lesions, all classified under BI-RADS categories 3 and 4. The MRI protocol included 3D fast gradient echo T1- weighted images with fat suppression, with gadobutrol as the contrast agent. The analysis involved evaluating patient and lesion characteristics, including age, size, location, fibroglandular tissue, background parenchymal enhancement (BPE), signal intensity, and the findings of mass and non-mass enhancement. In this study, univariate and multivariate logistic regression analyses were performed, along with decision tree analysis, to identify significant predictors for the classification of lesions., Results: Differences in lesion characteristics were identified, which may influence malignancy risk. The multivariate logistic regression model revealed age, lesion location, shape, and signal intensity as significant predictors of malignancy. Decision tree analysis identified additional diagnostic factors, including lesion margin and BPE level. The decision tree models demonstrated high diagnostic accuracy, with the logistic regression model showing an area under the curve of 0.925 for masses and 0.829 for non-mass enhancements., Conclusion: This study underscores the importance of integrating patient age, lesion location, and BPE level into the BI-RADS criteria to improve the differentiation between benign and malignant breast lesions. This approach could minimize unnecessary biopsies and enhance clinical decision-making in breast cancer diagnostics, highlighting the effectiveness of gadobutrol in breast MRI evaluations., (© 2024. The Author(s).)

Background: Visual assessment of mammographic breast composition remains the most common worldwide, although subjective variability limits its reproducibility. This study aimed to investigate the inter- and intra-observer variability in qualitative visual assessment of mammographic breast composition through a multi-institutional observer performance study for the first time in Japan., Methods: This study enrolled 10 Japanese physicians from five different institutions. They used the new Japanese breast-composition classification system 4th edition to subjectively evaluate the breast composition in 200 pairs of right and left normal mediolateral oblique mammograms (number determined using precise sample size calculations) twice, with a 1-month interval (median patient age: 59 years [range 40-69 years]). The primary endpoint of this study was the inter-observer variability using kappa (κ) value., Results: Inter-observer variability for the four and two classes of breast-composition assessment revealed moderate agreement (Fleiss' κ: first and second reading = 0.553 and 0.587, respectively) and substantial agreement (Fleiss' κ: first and second reading = 0.689 and 0.70, respectively). Intra-observer variability for the four and two classes of breast-composition assessment demonstrated substantial agreement (Cohen's κ, median = 0.758) and almost perfect agreement (Cohen's κ, median = 0.813). Assessments of consensus between the 10 physicians and the automated software Volpara® revealed slight agreement (Cohen's κ; first and second reading: 0.104 and 0.075, respectively)., Conclusions: Qualitative visual assessment of mammographic breast composition using the new Japanese classification revealed excellent intra-observer reproducibility. However, persistent inter-observer variability, presenting a challenge in establishing it as the gold standard in Japan., (© 2024. The Author(s), under exclusive licence to The Japanese Breast Cancer Society.)

Breast cancer mortality has not been reduced in Japan despite more than 20 years of population-based screening mammography. Screening mammography might not be suitable for Japanese women who often have dense breasts, thus decreasing mammography sensitivity because of masking. The J-START study showed that breast ultrasonography increases the sensitivity and the detection rate for early invasive cancers and lowers the rate of interval cancers for Japanese women in their 40 s. Breast awareness and breast cancer survival are directly correlated; however, breast awareness is not widely known in Japan. Next-generation breast cancer screening in Japan should consist of breast awareness campaigns for improving breast cancer literacy and supplemental breast ultrasonography to address the problem of false-negative mammograms attributable to dense breasts., (© 2023. The Author(s).)

The definition of a non-mass lesion on breast ultrasound (US) is designed for everyday practice to provide unambiguous clinical management and to assist physicians and sonographers as they interpret breast US images. The field of breast imaging research requires consistent and standardized terminology for non-mass lesions identified on breast US, especially when differentiating benign from malignant lesions. Physicians and sonographers should be aware of the benefits and limitations of the terminology and use them precisely. I am hopeful that the next edition of the Breast Imaging Reporting and Data System (BI-RADS) lexicon will include standardized terminology for describing non-mass lesions detected on breast US., (© 2023. The Author(s).)

Purpose: To compare the reader performance of artificial intelligence computer-aided detection synthesized mammograms (AI CAD SM) with that of digital mammograms (DM) when used alone or in combination with digital breast tomosynthesis (DBT) images., Materials and Methods: This retrospective multireader (n = 4) study compared the reader performances in 388 cases (84 cancer, 83 benign, and 221 normal or benign cases). The overall accuracy of the breast-based assessment was determined by four radiologists using two sequential reading modes: DM followed by DM + DBT; and AI CAD SM followed by AI CAD SM + DBT. Each breast was rated by each reader using five-category ratings, where 3 or higher was considered positive. The area under the receiver-operating characteristic curve (AUC) and reading time were evaluated., Results: The mean AUC values for DM, AI CAD SM, DM + DBT, and AI CAD SM + DBT were 0.863, 0.895, 0.886, and 0.902, respectively. The mean AUC of AI CAD SM was significantly higher (P < 0.0001) than that of DM. The mean AUC of AI CAD SM + DBT was higher than that of DM + DBT (P = 0.094). A significant reduction in the reading time was observed after using AI CAD SM + DBT when compared with that after using DM + DBT (P < 0.001)., Conclusion: AI CAD SM + DBT might prove more effective than DM + DBT in a screening setting because of its lower radiation dose, noninferiority, and shorter reading time compared to DM + DBT., (© 2022. The Author(s).)

Background: Current breast cancer screening programs worldwide offer only mammography for asymptomatic women, without clinical breast examination (CBE). The sensitivity and specificity of true asymptomatic screening mammography are important, especially in Japan., Methods: This study used data from the Japan Strategic Anti-cancer Randomized Trial (J-START) results, and then calculated the sensitivity and specificity of screening mammography without CBE among Japanese women aged 40-49 years., Results: The sensitivity and specificity of modern film mammography, performed biennially, among Japanese women aged 40-49 years were 71.7% and 92.6%, respectively. The sensitivity of mammography alone was 47.4%. From the secondary analysis, the sensitivity of mammography alone was 44.1% for women with dense breasts and 34.8% for women with non-dense breasts., Conclusion: The sensitivity of mammography alone of 47.4% is too low. The low sensitivity of screening mammography for true asymptomatic Japanese women aged 40-49 years places this population at an elevated risk, which can justify performing adjunctive ultrasonography., (© 2022. The Author(s), under exclusive licence to The Japanese Breast Cancer Society.)

Background: To examine the accuracy of MRI and Doppler ultrasound (US) for detecting residual tumor after neoadjuvant chemotherapy (NAC) for breast cancer and evaluate whether adjunctive Doppler US improves the MRI accuracy., Methods: We reviewed 276 invasive breast cancer cases treated with NAC. Tumors were classified into four subtypes based on estrogen receptor and HER2 status. Response to NAC was evaluated using contrast-enhanced MRI and Doppler US. Residual Doppler flow was assumed to indicate a residual tumor. MRI and Doppler findings were compared with the histopathological findings of resected specimens. Pathological complete response (pCR) was defined as neither in situ nor invasive cancer left., Results: Of the 276 tumors, imaging complete responses were observed using MRI and Doppler US in 62 (22%) and 111 (40%), respectively, whereas pCR was achieved in 44 (16%). MRI and Doppler US predicted residual tumor with 88% and 69% sensitivity, 80% and 91% specificity, 87% and 73% accuracy, 96% and 98% PPV, and 56% and 36% NPV, respectively. The accuracies of MRI and Doppler US were significantly higher for HER2-negative than HER2-positive tumors (p < 0.001 and p = 0.043, respectively). Seven (26%) of 27 false-negative cases identified by MRI were correctly diagnosed as positives with adjunctive Doppler US., Conclusions: Although MRI accurately detected residual tumor with 87% accuracy, this was still not sufficient to meet clinical demands and differed with tumor subtype. Adjunctive Doppler US in cases that appear to show a complete response on MRI might reduce chances of false negatives and increase the NPV of MRI for predicting residual tumor., (© 2021. The Japanese Breast Cancer Society.)

Mammography is the only screening method with evidence in support of reduced breast cancer mortality, but yields poor accuracy outcomes in women with dense breast tissue. The Japan Strategic Anti-cancer Randomized Trial (J-START) was conducted as part of the measures implemented to deal with women with dense breast tissue. Although the sensitivity was increased, the specificity was significantly lower in the intervention group because further examination was required in all positive cases classified by either mammography or ultrasound in the J-START. To address the issue, an overall assessment system of combined mammography and adjunctive ultrasound for breast cancer screening has been developed in Japan. The basic concept is based on a comprehensive assessment that includes a mammography assessment followed by an adjunctive assessment for ultrasound similar to the clinical setting. Currently, mammography alone is recommended for population-based breast cancer screening in Japan, but additional ultrasonography is extensively available for women, especially for women with dense breasts with shared decision-making for personalized breast cancer screening. The overall assessment system is recommended for use in Japan when breast cancer screening is conducted using both mammography and ultrasonography. In this article, we summarize the advantages of the overall assessment and the simultaneous mammography/ultrasound method, the basic approach used in Japan to assign the overall assessment category for breast cancer screening, and we outline the future directions of adjunctive screening ultrasound.

Purpose: Given that a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) is an important prognostic factor, evaluating pretreatment imaging findings is important. Outcomes for triple negative breast cancer (TNBC) vary with the histological classification, indicating that this classification is clinically significant. In this study, we focus on the most common histological subtype of TNBC, invasive carcinoma of no special type (NST), to evaluate whether intramammary edema (intra-E) and intratumoral necrosis (intra-N) on T2-weighted magnetic resonance imaging (T2WI) is a useful predictor of pCR., Method: We retrospectively included patients with biopsy-diagnosed TNBC-NST who received NAC between January 2014 and December 2017. Intra-E and intra-N were evaluated on T2WI before NAC. We grouped intra-E into no edema, peritumoral edema, prepectoral edema, and subcutaneous edema, and we defined intra-N as water-like signal intensity without enhancement on T2WI. We also evaluated tumor size, Ki-67 expression, and histological/nuclear grade, as well as their correlation with intra-E and intra-N., Results: Fifty-seven patients with TNBC-NST were enrolled. There was no correlation with the rate of pCR and the presence of either intra-E or intra-N before NAC. Only intra-E and tumor size showed a positive correlation., Conclusions: In patients with TNBC-NST, intra-E and intra-N did not correlate with pCR, but intra-E did positively correlate with tumor size. NST may exhibit a greater response to NAC, regardless of whether intra-E or intra-N is present or not on the pretreatment MRI., Key Points: • Pathological complete response in TNBC-NST had no correlation with intramammary edema or intratumoral necrosis. • NAC may be justified in TNBC-NST even in the presence of edema or necrosis. • The extension of edema correlated with tumor size of TNBC-NST.

This article updates readers as to what is new in the Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer Screening and Diagnosis, 2018 Edition. Breast cancer screening issues are covered, including matters of breast density and possible supplemental modalities, along with appropriate pre-operative/follow-up diagnostic breast imaging tests. Up-to-date clinical practice guidelines for breast cancer screening and diagnosis should help to provide patients and clinicians with not only evidence-based breast imaging options, but also accurate and balanced information about the benefits and harms of intervention, which ultimately enables shared decision making about imaging test plans.

The Breast Cancer Clinical Practice Guidelines, 2018 edition, written in Japanese and organized by the Japanese Breast Cancer Society, were published in Japanese in May 2018. The process of making these guidelines, as well as the content, was largely changed and compared with previous editions. The concept of these guidelines is to act as a support tool for shared decision making between doctor and patient. The procedure of creating the guidelines referred to Minds Handbook for Clinical Practice Guideline Development 2014. This guideline, written in Japanese, consists of two booklets: (1) the epidemiology and diagnosis booklet covering screening, radiological, and pathological diagnosis and (2) the treatment booklet covering surgical therapy, radiation therapy, and systemic therapy. This review article consists of five parts, including the history of the Breast Cancer Clinical Practice Guidelines, the concept, process, content, and recommendation grade. I believe this brief summary concerning the Breast Cancer Clinical Practice Guidelines 2018 edition in English will be helpful for both Japanese and foreign investigators.

Magnetic resonance imaging (MRI) is a highly sensitive imaging modality that frequently reveals additional breast lesions that are occult on mammography and ultrasonography (US) and are thus difficult to diagnose. It is important to investigate these MRI-detected suspicious lesions, which are associated with a fairly high rate of malignancy. In this review, we have discussed MRI/US fusion technology, a magnetic position tracking system that synchronizes real-time US and MRI to improve lesion detection and enables comparisons of MRI and US findings of the detected lesions. This combination increases the precision of second-look US. We hope that our review underscores the importance of understanding the US findings and histopathology of MRI-detected breast lesions, as this will enable radiologists to perform appropriate assessments.

Background: Breast cancer growth is generally expected to differ between tumor subtypes. We aimed to evaluate tumor doubling time (DT) using ultrasonography and verify whether each tumor subtype has a unique DT., Methods: This retrospective study included 265 patients with invasive breast cancer who received serial ultrasonography between diagnosis and surgery. Tumor diameters were measured in three directions and DTs were calculated according to an exponential growth model using the volume change during serial ultrasonography. We investigated the relationships between DT, tumor subtype, and histopathological factors., Results: Volumes did not change in 95 (36%) of 265 tumors and increased in 170 (64%) tumors during serial ultrasonography (mean interval, 56.9 days). The mean volume increases of all tumors and volume-increased tumors were 22.1% and 34.5%, respectively. Triple-negative tumors had greater volume increases (40% vs. 20%, p = 0.001) and shorter DT (124 vs. 185 days, p = 0.027) than estrogen receptor (ER)+/human epidermal growth factor receptor 2 (HER2)- tumors. Volume-increased tumors had higher Ki-67 indices than those of volume-stable tumors in ER+/HER2- (p = 0.002) and ER+/HER2+ tumors (p = 0.011) and higher histological grades in all tumors except triple-negative tumors (p < 0.001). Triple-negative tumors with DTs < 90 days (short-DT) showed higher Ki-67 indices than those with DTs > 90 days (long-DT) (p = 0.008). In ER+/HER2- tumors, histological grades were higher for short-DT than for long-DT tumors (p = 0.022)., Conclusion: Differences in tumor DT depending on breast cancer subtype, Ki-67 index, and histological grade were confirmed using serial ultrasonography even during preoperative short interval.

We investigated the radiologic-pathologic correlation of a strong hypointense rim on T2-weighted images (T2-hypo-rim) surrounding breast mass lesions and evaluated its clinical significance. We retrospectively reviewed 3503 consecutive breast magnetic resonance imaging (MRI) examinations. The T2-hypo-rim was defined as a border of strong hypointensity compared with the fat signal on fat-suppressed T2-weighted images. Detected lesions with T2-hypo-rim were classified as a solid or cystic mass with MRI and correlated with histopathologic findings. Sixty-two masses (2%; 34 solid, 28 cystic) with T2-hypo-rim were detected [44 breast cancers, 18 benign lesions, including 15 (24%) papillary tumors]. Patients with cancer were significantly older than those with benign lesions (P = .002). Breast cancers were significantly larger than benign masses (P = .023). In 49 of 62 lesions (24 solid and 16 cystic cancers; three solid and six cystic benign masses), the rims were accurately correlated with the histopathologic findings. All malignant and benign cystic masses exhibited hemosiderin deposits in the cyst walls. However, 22 of 24 solid cancers and no solid benign masses exhibited hemosiderin at the tumor periphery (92% and 0%, respectively, P < .001). In addition, a thick fibrous capsule was present in nine (38%) of 24 solid cancers and none of the solid benign lesions. Strong T2-hypo-rims mostly correlated with hemosiderin deposits and/or sometimes fibrous capsules. Although the rims could not distinguish malignant from benign cystic lesions, they indicated malignancy in solid mass lesions on MRI. Additionally, the rims often indicated papillary tumors., (© 2018 Wiley Periodicals, Inc.)

Rationale and Objectives: We aimed to compare the contrast enhancement between tumor and mammary-gland tissue to distinguish lesions in the super-early phase, during which minimal contrast media uptake is observed in mammary-gland tissue., Materials and Methods: Dynamic magnetic resonance imaging, including the super-early phase with bolus tracking (BT) method (to determine the optimal imaging start time), was performed by using identical parameters to obtain transverse fat-suppressed T1-weighted images of both breasts. The percent enhancement (PE) and the contrast ratio (CR) indicators for tumor and mammary-gland tissue were assessed in each dynamic phase., Results: The PE values of the tumor were 62.4% and 151.6%, and those of the mammary gland were 0.3% and 20.7% in the super-early and early phases, respectively. Therefore, virtually no background parenchymal enhancement was observed in the super-early phase. The variation in the PE values during the super-early phase was significantly smaller when the values were determined with the BT method (P < .05). The CR was highest in the early phase, and the CR in the super-early phase was lower than in the other phases. Early-phase PE and CR were significantly higher in invasive cancer cases than in noninvasive cancer cases (P < .01). A significant difference in the imaging start time was observed for the anatomic side factor by the BT method., Conclusion: Background parenchymal enhancement almost never appeared in the super-early phase, but the CR was lower in the super-early phase than in the early phase. The BT method allowed for an optimal imaging start time for the super-early phase and yielded images with less deviation of contrast enhancement., (Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Objective: To compare the visibility of circumscribed masses on digital breast tomosynthesis (DBT) images and 2D mammograms and determine the usefulness of DBT for differentiation between benign and malignant circumscribed masses., Methods: Seventy-one (19 malignant and 52 benign) mammographic well-circumscribed masses were included. Visibility of the masses and halo signs on DBT images were retrospectively compared with 2D mammograms. The effects of mammographic breast density on mass visibility were also evaluated., Results: For DBT, 83% were superior and 17% were equivalent in visibility of the masses to that of 2D, and superiority of DBT was significantly enhanced in the high breast density group compared with the low breast density group (91% vs 68%, respectively, p = 0.016). Three lesions were only detected on DBT. There was no significant difference in the superiority of DBT for lesion visibility between malignant and benign masses. The halo sign was detected in 58% lesions on DBT and in 4% on 2D (p < 0.001)., Conclusion: Circumscribed masses were better visualized on DBT than on 2D mammograms, particularly in high-density breasts. The halo sign often appeared on DBT and gave a clearer mass margin. However, circumscribed masses on DBT are not assured of being benign., Key Points: • Circumscribed masses were better visualized on breast tomosynthesis than on 2D mammography. • Tomosynthesis visualized circumscribed masses better than 2D for all breast density categories. • Halo signs often appeared on tomosynthesis and contributed to detect circumscribed margins. • Circumscribed masses on tomosynthesis images are not assured of being benign lesions.

Purpose: This article discusses possible supplemental breast cancer screening modalities for younger women with dense breasts from a perspective of population-based breast cancer screening program in Japan., Conclusion: Supplemental breast cancer screening modalities have been proposed to increase the sensitivity and detection rates of early stage breast cancer in women with dense breasts; however, there are no global guidelines that recommend the use of supplemental breast cancer screening modalities in such women. Also, no criterion standard exists for breast density assessment. Based on the current situation of breast imaging in Japan, the possible supplemental breast cancer screening modalities are ultrasonography, digital breast tomosynthesis, and breast magnetic resonance imaging. An appropriate population-based breast cancer screening program based on the balance between cost and benefit should be a high priority. Further research based on evidence-based medicine is encouraged. It is very important that the ethnicity, workforce, workflow, and resources for breast cancer screening in each country should be considered when considering supplemental breast cancer screening modalities for women with dense breasts.

Objectives: The purpose of our study was to assess whether there is a potential additional value of real-time virtual sonography (RVS) to second-look ultrasound (US) examination and biopsy for breast lesions identified on MRI alone., Methods: A retrospective review of the records of 70 consecutive patients (78 lesions) with breast abnormalities identified on MRI alone was performed. All suspicious enhancing lesions were subsequently evaluated with second-look US. Lesions not observed on second-look US underwent RVS. Pathological findings were confirmed by subsequent percutaneous biopsy or excision., Results: Of the 78 MRI-detected lesions, second-look US correlation was made in 50 (64 %), including 22 malignant and 28 benign lesions. The remaining 28 lesions (36 %) were scheduled to undergo RVS. Four lesions were not visible on the second breast MRI. The remaining 24 lesions were RVS correlated and underwent RVS-guided biopsy; these included seven malignant and 17 benign lesions. Overall, 74 of 74 (100 %) true MRI-detected lesions were confirmed by histological results without using MRI-guided breast biopsy. The cancer rate was 29 %., Conclusions: RVS can increase the sonographic detection and biopsy rate of lesions identified on breast MRI alone., Key Points: • All 74 MRI-detected lesions were confirmed without using MRI-guided biopsy. • Four lesions were not visible on second breast MRI. • RVS can increase sonographic detection of lesions identified on breast MRI alone. • RVS-guided breast biopsy can be an alternative to MRI-guided biopsy.

Metastasis from breast carcinoma is an uncommon occurrence in skeletal muscle, compared to local invasion into muscle from direct tumor spread. A 49-year-old woman was referred to our hospital with an 8.5-cm mass in the right breast. Core needle biopsy revealed metaplastic carcinoma with squamous metaplasia. The mass was rapidly growing and metaplastic, so mastectomy with dissection of axillary lymph nodes was performed. Pathological examination showed metaplastic carcinoma, histological grade 3, triple negative, and a MIB-1 labeling index of 80%. Six months postoperatively, during adjuvant chemotherapy treatment, she reported numbness and pain in the right lateral thigh and a mass in the right lower abdomen. Computed tomography revealed multiple lined masses in the abdominal wall and iliac muscle. Core needle biopsy showed metastatic breast carcinoma. Radio- and chemotherapy were administered, but the mass in the muscle became enlarged. To control her pain, a combined treatment with morphine, fentanyl, ketamine, antiepilepsy drug, and NSAIDs was administered. Liver metastasis appeared 9 months (15 months postoperatively) after recognition of muscle metastasis, and the patient died 16 months postoperatively. Skeletal muscle metastasis is uncommon, and therapeutic intervention is mainly palliative. The most common symptom of skeletal muscle metastasis is pain; thus, pain control is a pivotal goal of treatment.

Edema, defined as high signal intensity on T2-weighted images, is a useful breast MRI finding, which compensates for the moderate specificity of breast MRI. Although diffuse breast edema can be caused by benign and malignant etiologies, focal edema is commonly associated with malignancy except for previous procedures including biopsy and surgery. For more accurate comprehension of the appropriate usage of breast edema, focal breast edema should be divided into three different types: peritumoral edema, prepectoral edema, and subcutaneous edema. It is useful to review and clarify these types of focal breast edema based on pathological findings as this may help predict the likelihood of malignancy in breast MRI lesions.

Background: The specificity of breast MRI is only moderate. The unsatisfactory specificity of breast MRI has prompted evaluation of high signal intensity (SI) on T2-weighted imaging (T2WI). The purpose of the study was to investigate the prevalence of prepectoral edema determined using high SI on T2WI with fat-suppression 3 T MRI and to correlate its presence with prognostic factors of breast cancer., Methods: The retrospective study comprised 589 consecutive histopathologically confirmed lesions, 460 malignant and 129 benign, identified by 3 T MRI. Presence of prepectoral edema was evaluated on T2WI with fat suppression, and its diagnostic value for malignancies and correlation with clinicopathological findings in histopathologically confirmed breast cancer were assessed., Results: Prepectoral edema was present in 54 of the 460 breast cancers (9 % of the total 589) and none of the 129 benign lesions. Its sensitivity and specificity were 12 and 100 %, respectively. The positive predictive value was 100 %. Young age (p = 0.01), large tumor size (p < 0.0001), high histological grade (p < 0.0001), invasive ductal carcinoma (p < 0.0001), high lymphovascular invasion degree (p < 0.0001), high axillary lymph node positivity (p < 0.0001), high inflammatory breast cancer rate (p < 0.0001), high neoadjuvant chemotherapy rate (p < 0.0001), and chemoresistant breast cancers (p < 0.0001) were significantly associated with prepectoral edema. There was no association of the morphological lesion type on MRI and dynamic enhancement imaging pattern with the presence of prepectoral edema., Conclusion: Prepectoral edema has low prevalence but is specific for breast cancer and correlated with prognostic factors.

Breast ultrasonography (US) is an indispensable tool for diagnosis of palpable and non-palpable breast masses and can facilitate good patient care for breast cancer. However, it is of limited value in cases of isoechoic lesions surrounded by fat, heterogeneous echoic lesions surrounded by a heterogeneous background, deep lesions in huge breasts, subareolar lesions, and lesions caused by poor and underdeveloped operator skills. Some breast tumors such as ductal carcinoma in situ and invasive lobular carcinoma are easily missed on US because of the nature of the lesions. Recent studies have emphasized the use of tools complementary to B-mode US, including real-time elastography and Doppler imaging, in the evaluation of breast lesions missed on US. Radiologists can take a number of steps that will enhance the accuracy of US image interpretation and decrease the rate of false-negative findings. These steps include reviewing clinicopathological data, using mammography and MRI to help assess breast lesions missed on US, strictly adhering to positioning and technical requirements, being alert to subtle features of missed breast lesions, and judging a lesion by its most malignant feature.

Digital breast tomosynthesis (DBT) is a new modality that aids in breast cancer detection. It is a pseudo-three-dimensional digital mammography imaging system that produces a series of 1-mm-slice images with multiple very low-dose X-ray projections to reveal the inner architecture of the breast after eliminating interference from overlapping breast tissue. This review article provides an overview of the current and potential use of DBT. The illustrations and discussion are based on our experience with the Selenia Dimensions (Hologic, USA) DBT system approved by the US Food and Drug Administration.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare subtype of cutaneous lymphoma, which is characterized by infiltration of neoplastic cytotoxic T cells into the subcutaneous tissue. We here report the case of a 66-year-old woman with SPTCL of the breast, which is a very uncommon location. Multiple suspicious irregular small masses in the subcutaneous fat were detected by mammography, and sonograms revealed hyperechoic masses. Elastography was useful to improve depiction and delineation of SPTCL in the hyperechoic subcutaneous fat, and dynamic contrast-enhanced MRI examinations showed multiple irregular rim enhanced masses with persistent enhancement. FDG-PET CT images showed hypermetabolism in areas corresponding to other imaging techniques. MRI can be useful for diagnosis of fat necrosis, which is a primary radiologic feature of SPTCL. However, fat necrosis has multitude of appearances by various imaging techniques, which typically indicate a benign disease, but may indicate a malignancy. Therefore, an ultrasonographically guided core needle biopsy is useful for a diagnosis of SPTCL of the breast. The presence of multiple subcutaneous nodules throughout the body on CT imaging may be an important finding that suggests a diagnosis of SPTCL.

This article reviews various non-mass-like ultrasonography (US) findings of the breast and the sonographic-pathologic correlation with Doppler techniques, elastography, and MRI. High-resolution US allows for identification of small, clinically occult non-mass-like US findings. Ductal carcinoma in situ and invasive lobular carcinoma usually manifest as a non-mass-like lesion on US. It is useful to classify non-mass-like lesions on US in a similar manner to the classification of non-mass-like enhancement on MRI.

Inflammatory breast carcinoma (IBC) is rare; however, it is the most aggressive variant of breast cancer with a very poor outcome. Locally advanced breast cancer and acute mastitis have a presentation similar to that of IBC. Therefore, the diagnosis of IBC remains a challenge in breast imaging. MRI can play a crucial role in the differential diagnosis by providing criteria indicative of IBC. Several MRI findings, especially T2-weighted images, are promising for more reliable and accurate interpretation of IBC.

Purpose: The purpose of this study was to assess the correlation between mammographic density, age, and background enhancement on breast MRI without adjusting for the phase in patients' menstrual cycle., Material and Methods: The background enhancement of bilateral breast MRI and the breast density of mammography in 146 consecutive women without adjusting for the phase in patients' menstrual cycle were reviewed. The breast density was classified into four categories according to the American College of Radiology the Breast Imaging Reporting and Data System lexicon. The background enhancement was classified into four categories: minimal, mild, moderate, and marked. The correlations of mammographic breast density as well as age with background enhancement on breast MRI were examined., Results: There was a significant correlation between mammographic breast density and background enhancement (p = 0.011). All nine cases with almost completely fat mammographic breast density showed minimal (78%) or mild (12%) background enhancement on breast MRI. There was a significant inverse correlation between age and background enhancement (p < 0.0001). Younger patients with dense breasts were more likely to demonstrate moderate/marked background enhancement., Conclusion: When no adjusting for the phase in patients' menstrual cycle, a significant correlation was observed between background enhancement and mammographic density. A significant inverse correlation was also observed between age and background enhancement., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

This article describes a systematic approach to choosing needles and probes for ultrasonographically guided (US-guided) percutaneous breast biopsy under various circumstances. The accuracy of US-guided percutaneous breast biopsy depends upon both the method chosen and lesion characteristics. Target accuracy and proper procedures are essential for predicting the yield regardless of the method chosen. Considering accuracy and cost, vacuum-assisted biopsy (VAB) should be offered only to appropriately selected patients. In particular, VAB should be the first choice for US-guided percutaneous breast biopsy of non-mass-like lesions.

Background: Just as mammographic breast density influences mammographic sensitivity, the degree of background enhancement in breast magnetic resonance imaging (MRI) may influence the sensitivity of breast MRI. The purpose of this study is to assess the influence of background enhancement on the accuracy of breast cancer extent assessment using MRI and to assess the correlation between the accuracy of breast cancer extent assessment and the kinetic analysis of background enhancement in dynamic contrast-enhanced MRI., Methods: Seventy bilateral breast MRI examinations were evaluated to assess the extent of a known primary tumor. Background enhancement was classified into four categories by visual assessment: minimal, mild, moderate, and marked, in the early dynamic phase and in the late dynamic phase. The correlation of the results with histological findings was examined., Results: Background enhancement grade showed a significant tendency to increase during dynamic contrast-enhanced MRI. When classifying background enhancement at early dynamic phase, the accuracy of tumor extent assessment by MRI with moderate/marked background enhancement was 60%, which was lower than the 78% accuracy with minimal/mild background enhancement, but not significantly so (p = 0.153). When classifying background enhancement at late dynamic phase, the accuracy with moderate/marked background enhancement was 61%, which was significantly lower than the 83% accuracy with minimal/mild background enhancement (p = 0.034). There was no tumor-size-related bias between the groups (p = 0.089)., Conclusion: The degree of background enhancement on breast MRI affects the accuracy of breast cancer extent assessment, especially at late dynamic phase.

Objective: The purpose of this article is to determine the effectiveness of MRI for visualizing spiculated breast cancer lesions that were previously identified using mammography and to compare the diagnostic quality of 3- and 1.5-T dynamic MRI by assessing the visualization of spiculation in such lesions., Materials and Methods: One hundred twenty MRI studies of breast cancers clearly identified as spiculated masses using mammography (71 MRI studies at 3 T that included both bilateral axial and unilateral sagittal images and 49 MRI studies at 1.5 T that included bilateral axial images only) were independently reviewed by three radiologists. The three different radiologists scored the visualization of the spiculation with respect to 3-T sagittal, 3-T axial, or 1.5-T axial images., Results: The diagnostic quality of sagittal 3-T dynamic MRI studies, as determined by assessing the visualization of spiculation, was significantly better than that of axial 3-T (p = 0.009) and 1.5-T (p = 0.004) studies. For small (< 1 cm) lesions, the diagnostic quality of sagittal 3-T studies determined by assessing the visualization of spiculation was significantly better than that of axial 1.5-T studies (p = 0.029)., Conclusion: Unilateral sagittal in-plane and through-plane high-spatial-resolution 3-T images can offer particularly higher spatial resolution for improved assessment of spiculation than do axial in-plane high-spatial-resolution images obtained at 1.5 and 3 T.

Objective: The purpose of this study was to analyze the features of nonmasslike enhancement detected on 3-T MRI and to determine which of these features are significant predictors of malignancy., Materials and Methods: Retrospective review was performed of 124 consecutive patients with nonmasslike enhancement detected on 3-T MRI after biopsy or surgery. We described nonmasslike enhancement using the descriptors in the BI-RADS MRI lexicon. In addition to the BI-RADS descriptors, whether clustered ring enhancement was present and whether surrounding high signal intensity (SI) was present on T2-weighted imaging were assessed., Results: Cancer was identified in 85 lesions (69%). Of these lesions, ductal carcinoma in situ (DCIS) was found in 41 (48%) and invasive cancer in 44 (52%). The features found to be significant predictors of malignancy were segmental (p = 0.001), focal (p = 0.006), dendritic (p = 0.017), and clustered ring enhancement (p = 0.026) and surrounding high SI on T2-weighted imaging (p < 0.0001). The features found to be significant predictors of invasive cancer were dendritic enhancement (p < 0.0001) and surrounding high SI on T2-weighted imaging (p < 0.0001). There were no significant predictive features for DCIS. Homogeneous enhancement was found to be a significant predictor of benignancy (p = 0.001). Kinetic patterns were not significant predictors of malignancy. Nonmasslike enhancement of 1 cm or larger was more often malignant than lesions smaller than 1 cm (p < 0.0001). In multivariate analysis, a lesion size of 1 cm or larger was found to be the only significant predictor of malignancy for nonmasslike enhancement., Conclusion: Segmental, focal, dendritic, and clustered ring enhancement; surrounding high SI on T2-weighted imaging; and a lesion size of 1 cm or larger can act as predictors of malignancy for nonmasslike enhancement detected on 3-T MRI, but kinetic characteristics cannot.

Purpose: To retrospectively evaluate the accuracy of clip placement on the basis of measurements obtained on pre- and post-vacuum-assisted 11-gauge stereotactic biopsy mammograms and to analyze the factors that can predict which patients will experience a significant movement of the clip., Materials and Methods: The pre- and post-vacuum-assisted 11-guage stereotactic biopsy mammographic findings in 204 cases undergoing clip placement were reviewed. The clip-to-lesion distance was measured. The correlations between the clinical-mammographic findings and the likelihood of clip movement were evaluated., Results: Target mammographic lesion types of the 204 cases were characterized as calcification in all but one case, which was a distortion lesion. The clip-to-lesion distance was within 5 mm on both the craniocaudal and mediolateral oblique projections in 119 (58%) cases, within 6-10 mm in 28 (14%), within 11-19 mm in 25 (12%), and was > 20 mm in 32 (16%). The variability of the clip-to-lesion distance was greatest in the plane orthogonal to the compression plane used for stereotactic biopsy. Breast thickness was the only factor that was predictive of a significant movement of the clip, and thin breasts tended to exhibit greater clip movement., Conclusion: Breast thickness may be a useful factor for predicting the degree of clip movement after 11-gauge vacuum-assisted stereotactic biopsy.

Rim enhancement is defined as enhancement that is more pronounced at the periphery of a mass. It can have varying appearances, ranging from a thin pattern to one that is thicker. This internal enhancement characteristic is an established characteristic of malignant lesions. Additionally, the use of combined descriptors, especially internal enhancement characteristics and the associated margin, can provide a more powerful predictive value than that of individual descriptors. The margin assessment of rim-enhancing masses is important and can vary in appearance from smooth to spiculated. Moreover, rim enhancement may be dynamic in that it changes appearance during the dynamic phases of contrast- enhanced breast magnetic resonance imaging (ce-MRI), and this feature can lead to confusion in the correct application of this lexicon. Rim-enhancing masses on ce-MRI are typically of two morphological types (i.e., a thin rim-enhancing mass with a smooth margin and a thick rim-enhancing mass with a spiculated margin). It is helpful to review and clarify the lexicon of rim enhancement using combined descriptors based on the pathological findings as doing so can help predict the likelihood of malignancy of ce-MRI lesions.

Objective: The purpose of this study was to assess the influence of background enhancement on the detection and staging of breast cancer using MRI as an adjunct to mammography or ultrasound., Methods: One hundred forty-six bilateral breast MRI examinations were evaluated to assess the extent of a known primary tumour and to problem solve after mammography or ultrasound without adjusting for the phase in the patients' menstrual cycle. The background enhancement was classified into four categories by visual evaluation: minimal, mild, moderate and marked., Results: In total, 131 histologically confirmed abnormal cases (104 malignant and 27 benign) and 15 normal cases were included in the analysis. There was no tumour size-related bias between the groups (p = 0.522). For the primary index tumour, the sensitivities of MRI with minimal/mild and moderate/marked background enhancement were 100% and 76% (p = 0.001), respectively. Thus, the degree of background enhancement did not affect the specificity. For evaluating tumour extent (n = 104), the accuracy of MRI with moderate/marked background enhancement (52%) was significantly lower than that with minimal/mild background enhancement (84%; p = 0.002)., Conclusion: The degree of background enhancement affected the detection and staging of breast cancer using MRI.

Background: Patients who achieve pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) have favorable disease-free survival rates. A few studies have suggested that lymphovascular invasion degree may play an important role in predicting pCR. This study aims to confirm the role of lymphatic invasion degree in predicting pCR in breast cancer patients after NAC., Methods: We retrospectively analyzed 120 patients treated with NAC and surgery. The following pathological features were evaluated on surgical specimens after NAC: histological grade, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), lymphovascular invasion degree, intratumoral necrosis positivity, and axillary lymph node positivity., Results: pCR and marked response were achieved in 12% (14/120) and 35% (42/120), respectively, of 120 breast cancers in 120 women. Breast cancers with pCR or marked response were classified as chemosensitive. The remaining 64 breast cancers (53%) were classified as chemoresistant. Severe lymphovascular invasion (P = .003), large tumor size (P = .029), ER positivity (P = .001), and PR positivity (P = .006) were significantly associated with chemoresistant breast cancer. Invasive ductal carcinoma (P = .028) and HER-2 positivity (P < .0001) were significantly associated with chemosensitive breast cancer. On multivariate analysis, HER-2 positivity (P < .0001), invasive ductal carcinoma (P = .047), and marked/moderate lymphovascular invasion (P = .023) were the three factors that remained statistically significant in the model to predict histological therapeutic effect., Conclusion: Lymphovascular invasion degree is one of the important factors to predict NAC efficacy for breast cancer.

Little is known about the MR imaging features of triple-negative breast cancer (TNBC), but TNBC has a worse prognosis because it has no effective therapeutic targets, such as estrogen receptor for endocrine therapy and human epidermal growth factor receptor 2 (HER2) for anti-HER2 therapy. MR findings of a unifocal lesion, mass lesion type, smooth mass margin, rim heterogeneous enhancement, persistent enhancement pattern, and very high signal intensity on T2-weighted images are typical features of breast MR imaging associated with TNBC. Although TNBC can mimic a benign morphology, the early MR imaging recognition of TNBC could assist in both the pretreatment planning and the prognosis, as well as adding to our understanding of the biological behavior of TNBC.

Magnetic resonance imaging (MRI) and computed tomography (CT) can be used for pretreatment evaluation of intraductal tumor extension of breast cancer. Images of intraductal tumor extension obtained by MRI and multidetector CT (MDCT) are shown to illustrate the similarities and differences in the imaging features of these two techniques. MRI is an excellent tool and MDCT is a fair one for evaluating intraductal tumor extension of breast cancer.

Objective: To retrospectively evaluate the magnetic resonance (MR) imaging findings of breast cancer before neoadjuvant chemotherapy (NAC) and to compare findings of chemosensitive breast cancer with those of chemoresistant breast cancer., Methods: The MR imaging findings before NAC in 120 women undergoing NAC were reviewed. The MR imaging findings were compared with the pathological findings and responses., Results: A complete response (pCR) and marked response were achieved in 12 and 35% of 120 breast cancers in 120 women respectively. Breast cancers with a pCR or marked response were classified as chemosensitive breast cancer. The remaining 64 breast cancers (53%) were classified as chemoresistant breast cancer. Large tumour size, a lesion without mass effect, and very high intratumoural signal intensity on T2-weighted MR images were significantly associated with chemoresistant breast cancer. Lesions with mass effect and washout enhancement pattern were significantly associated with chemosensitive breast cancer. Areas with very high intratumoural signal intensity on T2-weighted images corresponded pathologically to areas of intratumoural necrosis., Conclusion: Several MR imaging features of breast cancer before NAC can help predict the efficacy of NAC.

We describe the current status of mammographic screening and investigate how digital mammography is used in screening in Japan. Despite the widespread use of digital mammographic equipment, the mammographic screening rate for invited women is very low. In the majority of cases, digital hard copy images are read for screening. Soft-copy reading of digital mammography is not widely used, because of the difficulty of handling large amounts of CR data, the cost of workstations with 5 M LCD monitors, and the loading of full-field digital mammography on the mobile unit. Digital mammography has a number of advantages and has increasingly replaced conventional film-screen mammography, becoming the gold standard in combination with soft-copy reading in screening settings.

Digital mammography has been proposed as an alternative to screen-film mammography. Digital mammography has many technical advantages over film mammography, including image-enhancement capability, faster image acquisition, and better storage and transmission for archiving. However, its full potential can only be achieved through soft-copy reading. Soft-copy reading in digital mammography is still a relatively new technique, and has several issues which must still be resolved. It is necessary to optimize display formats and software as soon as possible to standardize soft-copy reading in digital mammography.

Background: A disadvantage of the image-guided core needle biopsy is that needle tract seeding may occur and affect the local recurrence and overall survival rates of patients after breast-conserving surgery, although the chance is small. The purpose of this study was to compare the potential risk of needle tract seeding of breast cancer from ultrasonographically guided needle biopsies that were performed with a directional vacuum-assisted device and an automated core needle gun., Methods: The study compared the biopsies of 148 breast cancers performed using ultrasonographically guided core needle biopsy with the biopsies of 105 breast cancers performed using the vacuum suction probe. The potential risk of needle tract seeding of the breast cancer was defined by the cytological results derived from the needle wash material. The atypical/indeterminate, suspicious/probably malignant, and malignant categories were considered to represent positive cases., Results: There were significantly fewer positive cytological findings derived from the needle wash material with the directional vacuum-assisted device (33%) than with the automated core needle gun (69%) (P < 0.0001)., Conclusion: The use of the directional vacuum-assisted device significantly decreases the potential risk of needle tract seeding of breast cancer after an ultrasonographically guided needle biopsy.

The purpose of our study was to review the magnetic resonance (MR) imaging findings and pathological diagnoses of benign and malignant solid circumscribed breast masses. This article reviews the MR imaging findings of solid circumscribed breast masses. A strategy for the diagnosis of solid circumscribed breast masses with MR imaging is herein presented that incorporates the signal intensity characteristics on T(1)- and T(2)-weighted images with the kinetic curve assessment reflected by the temporal and spatial uptake of contrast medium.