Added value of the EUSOBI diffusion levels in breast MRI.

OBJECTIVES: To investigate whether using the diffusion levels (DLs) proposed by the European Society of Breast Imaging (EUSOBI) improves the diagnostic accuracy of breast MRI. MATERIALS AND METHODS: This retrospective study included 145 women who, between September 2019 and June 2020, underwent breast 1.5-T MRI with DWI. Reader 1 and reader 2 (R1-R2) independently assessed breast lesions using the BI-RADS on dynamic contrast-enhanced imaging and T2-weighted imaging. DWI was subsequently disclosed, allowing readers able to measure lesions ADC and subjectively express the overall risk of malignancy on a 1-5 Likert scale. ADCs were interpreted as a range of values corresponding to the EUSOBI DLs. The analysis evaluated the inter-reader agreement in measuring ADC and DLs, the per-DL malignancy rate, and accuracy for malignancy using ROC analysis against histological examination or a 3-year follow-up. RESULTS: Lesions were malignant and showed non-mass enhancement in 67.7% and 76.1% of cases, respectively. ADC was measurable in 63.2%/66.7% of lesions (R1/R2), with a minimal discrepancy on Bland-Altman analysis and 0.948 (95%CI 0.925-0.965)/0.989 (95%CI 0.988-0.991) intraclass correlation coefficient in measuring ADC/DLs. The malignancy rate (R1/R2) increased from 0.5/0.5% ("very high" DL) to 96.0/96.8% ("very low" DL), as expected. Likert categorization showed larger areas under the curve than the BI-RADS for both R1 (0.91 versus 0.87; p = 0.0208) and R2 (0.91 versus 0.89; p = 0.1171), with improved specificity (81.5% versus 78.5% for R1 and 84.4% versus 81.2% for R2). CONCLUSION: Though ADC was not measurable in about one-third of lesions, DLs were categorized with excellent inter-reader agreement, improving the specificity for malignancy. CLINICAL RELEVANCE STATEMENT: DLs proposed by the EUSOBI are a reproducible tool to interpret the ADC of breast lesions and, in turn, to improve the specificity of breast MRI and reduce unnecessary breast biopsies. KEY POINTS: • The European Society of Breast Imaging proposed diffusion levels for the interpretation of the apparent diffusion coefficient in diffusion-weighted imaging of the breast. • Adding diffusion levels to the interpretation of magnetic resonance imaging improved the diagnostic accuracy for breast cancer, especially in terms of specificity. • Diffusion levels can favor a more widespread and standardized use of diffusion-weighted imaging of the breast.

Pathological outcome of sonographically occult architectural distortions (AD) visible only on digital breast tomosynthesis, and comparison with AD visible also on 2D mammography.

PURPOSE: To evaluate the rates of malignant and of high-risk lesions among sonographically occult architectural distortions (AD) visible only on digital breast tomosynthesis (DBT) and compare them with AD visible on 2D mammography (2D) and DBT. METHOD: The records of 1104 DBT-vacuum assisted biopsies (DBT-VAB) were retrospectively reviewed and 218 cases of AD were identified. Complete radiologic examinations and pathologic results were available for 113 sonographically occult AD (1 clinically-detected, 112 clinically-occult). 2D and DBT images were reviewed and AD were divided into a "DBT-detected" group (visible on only DBT) and a "2D-detected" group (visible both in 2D and DBT). The rates of malignant and of high-risk lesions in the "DBT-detected" AD group were calculated and compared to those of the "2D-detected" AD group. RESULTS: Thirty-five (31%) of 113 AD were assessed as "DBT-detected", while 78 (69%) as "2D-detected". DBT-VAB results were benign lesions in 63 (56%) AD, high-risk lesions in 32 (28%) AD and malignant lesions in 18 (16%) AD. Four (12.5%) high-risk lesions were upgraded to malignancy at surgery. Based on final pathology, the malignancy rate was significantly higher in the "DBT-detected" group than the "2D-detected" group (34% [12/35 cases] vs 13% [10/78]; p < 0.05). The high-risk lesion rates were 32% (11/35 cases) in the "DBT-detected" group and 22% (17/78 cases) in the "2D-detected" group (p > 0.05). CONCLUSIONS: AD visible on only DBT proved to be malignant in about one third of cases, which exceeded the malignancy rate of AD visible on also 2D. A similar proportion of DBT-only AD was represented by high-risk lesions.

Multireader comparison of contrast-enhanced mammography versus the combination of digital mammography and digital breast tomosynthesis in the preoperative assessment of breast cancer.

PURPOSE: To compare preoperative contrast-enhanced spectral mammography (CEM) versus digital mammography plus digital breast tomosynthesis (DM + DBT) in detecting breast cancer (BC) and assessing its size. MATERIAL AND METHODS: We retrospectively included 78 patients with histological diagnosis of BC who underwent preoperative DM, DBT, and CEM over one year. Four readers, blinded to pathology and clinical information, independently evaluated DM + DBT versus CEM to detect BC and measure its size. Readers' experience ranged 3-10 years. We calculated the per-lesion cancer detection rate (CDR) and the complement of positive predictive value (1-PPV) of both methods, stratifying analysis on the total of lesions, index lesions, and additional lesions. The agreement in assessing cancer size versus pathology was assessed with Bland-Altman analysis. RESULTS: 100 invasive BCs (78 index lesions and 22 additional lesions) were analyzed. Compared to DM + DBT, CEM showed higher overall CDR in less experienced readers (range 0.85-0.90 vs. 0.95-0.96), and higher CDR for additional lesions, regardless of the reader (range 0.54-0.68 vs. 0.77-0.86). CEM increased the detection of additional disease in dense breasts in all readers and non-dense breasts in less experienced readers only. The 1-PPV of CEM (range 0.10-0.18) was comparable to that of DM + DBT (range 0.09-0.19). At Bland-Altman analysis, DM + DBT and CEM showed comparable mean differences and limits of agreement in respect of pathologic cancer size. CONCLUSION: Preoperative CEM improved the detection of additional cancer lesions compared to DM + DBT, particularly in dense breasts. CEM and DM + DBT achieved comparable performance in cancer size assessment.

Diagnostic Performance of Digital Breast Tomosynthesis, Unenhanced MRI, and Their Combination in the Preoperative Assessment of Breast Cancer: A Multi-reader Study.

RATIONALE AND OBJECTIVES: To compare the diagnostic performance of digital breast tomosynthesis (DBT) and unenhanced magnetic resonance imaging (UMRI) in the preoperative assessment of breast cancer. MATERIALS AND METHODS: We retrospectively included 59 patients with 74 pathology-proven cancers who underwent DBT and preoperative 1.5 T magnetic resonance imaging between January 2016 and February 2017. Four residents with 2-3 years of experience, blinded to pathology, independently reviewed DBT and UMRI (diffusion-weighted and unenhanced T1-weighted sequences), using the breast imaging reporting and data system (BI-RADS) and a 0-5 Likert score, respectively. We calculated per-lesion sensitivity and positive predictive value of DBT, UMRI, and combined DBT+UMRI, as well as the agreement between DBT and UMRI vs. pathology in assessing cancer size (Bland-Altman analysis). Logistic regression was performed to assess clinical features predictive of missing cancer. RESULTS: Of 74 lesions, 84% were invasive ductal carcinoma, 27% of which with an in situ component; 31% of cancers were ≤10 mm large. Sensitivity of UMRI (74-85%) was equal or higher than that of DBT (68-82%), with similar positive predictive value (93-97% vs. 98-100%, respectively). DBT+UMRI increased the sensitivity up to 88%. UMRI showed closer limits of agreement with pathological size than DBT. Missing cancer was independently predicted by size ≤10 mm on DBT, UMRI, and DBT+UMRI (odds ratio 18.7, 5.1, and 13.3, respectively), and by increased breast density on DBT alone (odds ratio 3.50). CONCLUSION: UMRI was equal or better than DBT in the preoperative assessment of breast cancer. Combined imaging achieved up to 88% per-lesion sensitivity, suggesting potential use in clinical practice.

Lesions of uncertain malignant potential of the breast (B3) on vacuum-assisted biopsy for microcalcifications: Predictors of malignancy.

PURPOSE: To investigate clinical, radiologic and pathologic features of B3 lesions diagnosed on VABB targeting microcalcifications, for identifying predictors of malignancy. METHOD: This retrospective multi-centre study included consecutive VABBs performed over a 10-year period on suspicious microcalcifications not associated with other radiological signs diagnosed as B3 on histology from VABB, with outcomes ascertained by surgical excision. Clinical, demographic, radiological and histological (B3 subcategory) data were collected. For statistical analysis (univariate and binary logistic regression), the primary outcome variable was the upgrade rate to malignancy after surgery. Predictors of upgrade to malignancy were identified from clinical, demographic, radiological and pathological variables (including B3 subcategory). RESULTS: Amongst 447 VABBs, there were 57(12.7 %) upgrades to malignancy at surgical histology (36 DCIS and 21 invasive cancer). At univariate analysis, variables significantly associated with increased risk of upgrade to malignancy were age>55 years (p = 0.01), lesion size>10 mm (p < 0.0001), BI-RADS 4b-c and 5 (p = 0.0001), and fine pleomorphic morphology (p = 0.002) of microcalcifications. Binary logistic regression confirmed as significant independent risk factors age, lesion size and BI-RADS category (p = 0.02, 0.02 and 0.0006 respectively). Amongst subcategories of B3 lesions, lobular neoplasia was significantly(p = 0.04) associated with upgrade, confirmed as an independent risk factor [p = 0.03, OR = 2.3(1.1-4.7)]. Flat epithelial atypia was significantly(p = 0.004) associated with reduced odds of upgrade, but binary logistic regression showed only borderline association [p = 0.052, OR = 0.4(0.2-1.01)]. CONCLUSIONS: Across B3 lesions diagnosed on histology from VABB of suspicious microcalcifications, older age, size>10 mm, BI-RADS category≥ 4b on imaging, and lobular neoplasia were risk factors for upgrade to malignancy. This information can be used to discuss patients' tailored management options.

Comparison between an abbreviated and full MRI protocol for detecting additional disease when doing breast cancer staging.

BACKGROUND: Previous studies have shown that abbreviated magnetic resonance imaging (aMRI) compares well to full-protocol MRI (fpMRI) in breast cancer (BC) screening, with the potential advantage of a less costly and complex examination. To our knowledge, the role for aMRI in staging BC has been poorly investigated, especially in assessing additional disease (ie, additional lesions compared to the index one prompting the examination). PURPOSE: To compare aMRI and fpMRI in detecting additional disease in BC staging. STUDY TYPE: Retrospective monocentric cohort study. POPULATION: In all, 87 patients with 89 biopsy-proven index lesions referred to staging fpMRI between January-June 2016. FIELD STRENGTH/SEQUENCE: A 1.5T magnet using short tau inversion recovery (STIR) T2 -weighted imaging, echoplanar diffusion-weighted imaging, and 3D fast long angle shot (FLASH) T1 -weighted imaging. ASSESSMENT: During independent sessions, four readers with 1.5-20 years of experience in breast imaging, blinded to the pathological examination and previous imaging, assessed multifocal, multicentric, and contralateral additional lesions on fpMRI and aMRI (including precontrast T1 -weighted 3D FLASH sequence, first postcontrast subtracted T1 -weighted 3D FLASH sequence, and a transverse maximum intensity projection reconstruction). STATISTICAL TESTS: We calculated the per-lesion cancer detection rate (CDR), positive predictive value (PPV), and false discovery rate (FDR) for additional disease, assessing the significance of intrareader differences in CDR with the McNemar test. RESULTS: Pathological analysis found 36 additional lesions (multifocal, multicentric, and contralateral in 20, 15, and 1 cases, respectively). Readers' CDR was comparably high using aMRI (range 88.9-94.4%) or fpMRI (range 91.7-94.4%) (P > 0.05). PPV and FDR of aMRI (ranges 76.2-84.6% and 15.4-23.8%, respectively), and fpMRI (ranges 76.7-82.9% and 17.2-23.3%, respectively) were comparable on an intrareader basis. Using aMRI, two out of four readers induced two false-negative cases (one case each) with presumably limited impact on surgical planning (multifocal cancers <1 cm in size). DATA CONCLUSION: aMRI was comparable to fpMRI in staging additional BC. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:e222-e230.

Do clinical and radiologic features help predict malignancy of B3 breast lesions without epithelial atypia (B3a)?

OBJECTIVES: To evaluate excision histology outcome of B3a lesions diagnosed at imaging-guided core biopsy and assess whether clinical and radiologic features may predict upgrade to malignancy. METHODS: A total of 153 B3a lesions (74 papillomas, 51 radial scars and 28 fibro-epithelial lesions) that underwent surgical excision were assessed. PPV for malignancy in all B3a lesions and specific for each sub-category was evaluated. Multivariate analysis was conducted to identify association between clinical (age, family or personal history of breast cancer, symptoms), diagnostic findings (imaging modality, lesion size, final BI-RADS category) and final excision outcome. RESULTS: Eleven (7%) of 153 B3a lesions were upgraded to malignancy. All carcinomas diagnosed on excision were non-high grade DCIS. Following features were significantly associated with malignancy: lesions identified only on mammography (3/21; 14%), both mammography and ultrasound (7/44; 16%), lesion size > 10 mm (10/74; 13.5%) and BI-RADS category 4-5 (8/29; 27.6%). The absence of residual microcalcification after biopsy was associated with decreased risk for malignancy (15/16[93.7%]; p = 0.0297). Lesion size > 10 mm (OR = 9.3832; 95%; p = 0.0398) and BI-RADS category 4-5 (OR = 12.6004; 95%; p = 0.0006) were found to be independent predictors of upgrade to malignancy. CONCLUSIONS: B3a lesions are associated with low risk of malignancy at excision. Lesion size > 10 mm and BI-RADS 4-5 category may represent useful predictors of upgrade to malignancy.

Automated breast ultrasound: basic principles and emerging clinical applications.

Automated breast ultrasound (ABUS) is a recently introduced ultrasonography technique, developed with the purpose to standardize breast ultrasonography and overcome some limitations of handheld ultrasound (HHUS), such as operator dependence and the considerable amount of medical time necessary to perform and interpret HHUS. This new ultrasonography technique separates the moment of image acquisition (that may be performed also by a technician) from that of its interpretation, increasing reproducibility, reducing operator-dependence and physician time. Moreover, multiplanar reconstructions, especially the coronal view, introduce new diagnostic information. ABUS, with those advantages, has the potential to be used as an adjunctive tool to screening mammography, especially in the dense breast, where mammography has a relatively low sensitivity. Women's awareness of risks related to breast density is a hot topic, especially in the USA where legislative breast density notification laws increase the demand for supplemental ultrasound screening. Therefore, ABUS might have the potential to respond to this need. The purpose of this article is to present a summary of current state-of-the-art of ABUS technology and applications, with an emphasis on breast cancer screening. This article discusses also how to overcome some ABUS limitations, in order to be familiar with the new technique.

Automated breast volume scanner (ABVS) in assessing breast cancer size: A comparison with conventional ultrasound and magnetic resonance imaging.

OBJECTIVES: To compare automated breast volume scanner (ABVS), ultrasound (US) and MRI in measuring breast cancer size, and evaluate the agreement between ABVS and US in assessing lesion location and sonographic features. METHODS: We retrospectively included 98 women with 100 index cancers who had undergone US and ABVS followed by 1.5T MRI. Images were interpreted by a pool of readers reporting lesion size, location and breast imaging reporting and data system (BI-RADS) features. Bland-Altman analysis (with logarithmic data transformation), intraclass correlation coefficient (ICC) and Cohen's kappa statistic were used for statistical analysis. RESULTS: MRI showed the best absolute agreement with histology in measuring cancer size (ICC 0.93), with LOA comparable to those of ABVS (0.63-1.99 vs. 0.52-1.73, respectively). Though ABVS and US had highly concordant measurements (ICC 0.95), ABVS showed better agreement with histology (LOA 0.52-1.73 vs. 0.45-1.86, respectively), corresponding to a higher ICC (0.85 vs. 0.75, respectively). Except for posterior features (k=0.39), the agreement between US and ABVS in attributing site and BI-RADS features ranged from substantial to almost perfect (k=0.68-0.85). CONCLUSIONS: ABVS performs better than US and approaches MRI in predicting breast cancer size. ABVS performs comparably to US in sonographic assessment of lesions. KEY POINTS: • ABVS approaches MRI in predicting breast cancer size. • ABVS is equivalent to US in localising and characterising breast cancer. • ABVS is more accurate than US in assessing breast cancer size. • ABVS has the potential to replace US in breast cancer staging.

Results of Short-Term Follow-Up in BI-RADS 3 and 4a Breast Lesions with a Histological Diagnosis of Fibroadenoma at Percutaneous Needle Biopsy.

OBJECTIVE: To evaluate the usefulness of short-term (6 months) follow-up in patients with Breast Imaging Report and Data System (BI-RADS) 3 and 4a lesions, after a diagnosis of fibroadenoma at an image-guided biopsy. PATIENTS AND METHODS: The data of 318 women with 349 biopsy-proven fibroadenomas, a 6-month follow-up, and a follow-up of ≥ 24 months were retrospectively reviewed. Information on clinical history, lesion characteristics on ultrasound (US), mammography, and magnetic resonance imaging (MRI), BI-RADS classification, and follow-up was collected. The false-negative (FN) rate and the negative predictive value (NPV) for the biopsy were calculated. RESULTS: 43 patients (13.5%) presented with a palpable nodule; 18 (5.7%) had a history of breast cancer. There were 334 lesions visible on US (95.7%), 57 on US and mammography (16.3%), and 15 on mammography only (4.3%); 37 lesions were first detected on MRI. All lesions were stable at 6 months. After an at least 1-year follow-up, 4 lesions changed their features and were excised. Histology showed 1 invasive lobular cancer, 1 ductal carcinoma in situ, 1 phyllodes tumor, and 1 papilloma. The FN rate of the needle biopsy was 1.1% and the NPV was 98.9%. CONCLUSION: For lesions initially described as BI-RADS 3 and 4a with a histological diagnosis of fibroadenoma after biopsy, short-term follow-up can be avoided.

Comparison between automated breast volume scanner (ABVS) versus hand-held ultrasound as a second look procedure after magnetic resonance imaging.

OBJECTIVES: To evaluate the agreement between automated breast volume scanner (ABVS) and conventional ultrasound (US) as a second-look (SL) tool for assessing additional findings found on MRI. METHODS: Over a 7-month period, we prospectively assigned to SL-US and SL-ABVS all patients undergoing 1.5 T breast MRI in whom additional findings were found. Five experienced breast radiologists independently interpreted SL-US and SL-ABVS in blinded sessions to evaluate the detection rate of MRI findings and assign them to BI-RADS categories. We calculated the agreement between the two methods in assessing MRI findings as significant (BI-RADS 3-5) versus not significant (BI-RADS 1-2), as well as their cancer detection rate. RESULTS: In a population of 131 patients, SL-ABVS and SL-US showed a comparable detection rate of MRI findings (69.3 vs. 71.5%) (p > 0.05; McNemar test), with an almost perfect agreement in assessing them as significant or not (k = 0.94). This translated into a comparably high cancer detection rate (83.8% for SL-ABVS vs. 87.0% for SL-US). Only 1/31 cancers was missed by SL-ABVS. CONCLUSIONS: SL-ABVS and SL-US are nearly equivalent in assessing the significance of MRI findings, leading to a comparable cancer detection rate. SL-ABVS has the potential to replace SL-US in the SL scenario. KEY POINTS: • SL-ABVS shows almost perfect agreement with SL-US in assessing MRI findings. • SL-ABVS shows a comparably high cancer detection rate with respect to SL-US. • SL-ABVS has the potential to replace SL-US in evaluating additional MRI findings.

Agreement between MRI and pathologic breast tumor size after neoadjuvant chemotherapy, and comparison with alternative tests: individual patient data meta-analysis.

BACKGROUND: Magnetic resonance imaging (MRI) may guide breast cancer surgery by measuring residual tumor size post-neoadjuvant chemotherapy (NAC). Accurate measurement may avoid overly radical surgery or reduce the need for repeat surgery. This individual patient data (IPD) meta-analysis examines MRI's agreement with pathology in measuring the longest tumor diameter and compares MRI with alternative tests. METHODS: A systematic review of MEDLINE, EMBASE, PREMEDLINE, Database of Abstracts of Reviews of Effects, Heath Technology Assessment, and Cochrane databases identified eligible studies. Primary study authors supplied IPD in a template format constructed a priori. Mean differences (MDs) between tests and pathology (i.e. systematic bias) were calculated and pooled by the inverse variance method; limits of agreement (LOA) were estimated. Test measurements of 0.0 cm in the presence of pathologic residual tumor, and measurements >0.0 cm despite pathologic complete response (pCR) were described for MRI and alternative tests. RESULTS: Eight studies contributed IPD (N = 300). The pooled MD for MRI was 0.0 cm (LOA: +/-3.8 cm). Ultrasound underestimated pathologic size (MD: -0.3 cm) relative to MRI (MD: 0.1 cm), with comparable LOA. MDs were similar for MRI (0.1 cm) and mammography (0.0 cm), with wider LOA for mammography. Clinical examination underestimated size (MD: -0.8 cm) relative to MRI (MD: 0.0 cm), with wider LOA. Tumors "missed" by MRI typically measured 2.0 cm or less at pathology; tumors >2.0 cm were more commonly "missed" by clinical examination (9.3 %). MRI measurements >5.0 cm occurred in 5.3 % of patients with pCR, but were more frequent for mammography (46.2 %). CONCLUSIONS: There was no systematic bias in MRI tumor measurement, but LOA are large enough to be clinically important. MRI's performance was generally superior to ultrasound, mammography, and clinical examination, and it may be considered the most appropriate test in this setting. Test combinations should be explored in future studies.

Comparison between different imaging techniques in the evaluation of malignant breast lesions: can 3D ultrasound be useful?

PURPOSE: This study was done to assess the feasibility of three-dimensional ultrasonography (3D-US) for volume calculation of solid breast lesions. MATERIALS AND METHODS: The volumes of 36 malignant lesions were measured using conventional 2D-US, 3D-US and magnetic resonance imaging (MRI) and compared with that obtained with histology (standard of reference). With 2D Ultrasouns, volume was estimated by measuring three diameters and calculating volume with the mathematical formula for spheres. With 3D-US, stored images were retrieved and boundaries of masses were manually outlined; volume calculation was performed with VOCAL software. For MRI, volume measurements were obtained with special software for 3D reconstructions, after each lesion had been manually outlined. Histology measured the three main diameters and the volume was estimated using the mathematical formula for spheres. Interclass correlation coefficient (ICC) and Bland-Altman plots were used to assess agreement between the volumes measured. RESULTS: ICC indicated that a good level of concordance was identified between 3D-US and histology (0.79). According to the Bland-Altman analysis, limits of agreement of mean differences of the volumes measured with the three imaging modalities were comparable with histology: -2 ÷ 1.5 cm(3) for 3D-US; -2.3 ÷ 1.3 cm(3) for 2D-US and -2.2 ÷ 1.6 cm(3) for MRI. CONCLUSIONS: 3D-US is a reliable method for the volumetric assessment of breast lesions. 3D-US is able to provide valuable information for the preoperative evaluation of lesions.

Role of magnetic resonance imaging in probably benign (BI-RADS category 3) microcalcifications of the breast.

PURPOSE: This study was undertaken to evaluate whether magnetic resonance (MR) imaging is able to rule out malignancy in the case of BI-RADS 3 microcalcifications, providing a sufficient negative predictive value (NPV) for early work-up, and to reduce unnecessary stereotactically guided vacuum-assisted biopsy (SVAB) procedures. MATERIALS AND METHODS: We prospectively enrolled consecutive women with BI-RADS 3 microcalcifications, who subsequently underwent MR imaging and SVAB. The MR studies were reviewed according to the MR-BI-RADS classification system; lesions assessed as MR-BI-RADS 1 and 2 were considered negative for malignancy, categories MR-BI-RADS 3, 4 and 5 indicated malignant lesions. The presence of additional findings was recorded. Histologic analysis and follow-up were the reference standard. MR sensitivity, specificity, positive predictive value (PPV) and NPV were calculated. RESULTS: The final population consisted of 71 lesions. Histologic analysis showed malignancy in six cases (malignancy rate 8%). At MR analysis, 60 (85%) lesions were considered negative for malignancy and 11 (15%) malignant. Additional MR imaging findings were identified in 19 (27%) patients, all corresponding to nonmalignant lesions. MR sensitivity was 33%, specificity 86%, PPV 18% and NPV 93%. CONCLUSIONS: Because of its relatively low NPV, MR imaging is not able to safely exclude malignancy in the case of BI-RADS 3 microcalcifications. The relatively high malignancy rate found in this study might support SVAB in the case of BI-RADS 3 microcalcifications.

High-risk breast lesions at imaging-guided needle biopsy: usefulness of MRI for treatment decision.

OBJECTIVE: The purpose of this study is to evaluate the role of MRI for characterization of high-risk breast lesions diagnosed at imaging-guided needle biopsy. MATERIALS AND METHODS: In this retrospective analysis of 220 patients, 227 high-risk lesions (94 papillomas, 64 radial sclerosing lesions, 46 lobular neoplasias, and 23 atypical ductal hyperplasias) found at 11-gauge vacuum-assisted or 14-gauge needle biopsy were studied with dynamic MRI (time resolution, 84 or 88 seconds; gadopentetate dimeglumine or gadobenate dimeglumine, 0.1 mmol/kg). When lesions showed contrast enhancement on subtracted images, they were considered suspicious for malignancy. The reference standard was histopathologic examination after surgical excision in 190 of 227 (84%) lesions and negative follow-up (≥ 24 months) in 37 of 227 (16%) lesions. Predictive values and likelihood ratios were calculated. RESULTS: Of 227 lesions, 155 (68%) were contrast enhancing and 72 (32%) were not. Of 155 contrast-enhancing lesions, 28 (18%) were upgraded to malignancy after surgical excision (nine papillomas, one radial sclerosing lesion, 11 lobular neoplasias, and seven atypical ductal hyperplasias); there were 11 invasive carcinomas and 17 ductal carcinomas in situ, four of the latter being G3. Of 72 non-contrast-enhancing lesions, two (3%) were upgraded to malignancy after surgical excision (one radial sclerosing lesion and one lobular neoplasia), both of which were G1 ductal carcinoma in situ. Cancer probability was significantly higher for contrast-enhancing (18%) than for non-contrast-enhancing (3%) lesions (p = 0.001) and for nonmasslike (43%) than for masslike (14%) lesions (p = 0.005). The positive predictive value was 18% (28/155; 95% CI, 13-24%), the negative predictive value was 97% (70/72; 95% CI, 94-99%), the positive likelihood ratio was 1.448 (95% CI, 1.172-1.788), and the negative likelihood ratio was 0.188 (95% CI, 0.152-0.232). CONCLUSION: The absence of enhancement at dynamic MRI allowed reliable exclusion of invasive cancers among high-risk lesions diagnosed at needle biopsy.

Magnetic resonance imaging of radial sclerosing lesions (radial scars) of the breast.

PURPOSE: To identify magnetic resonance (MR) imaging (MRI) features of radial sclerosing lesions (RSLs) of the breast. METHODS AND MATERIALS: The radiologic and pathologic records for 4629 consecutive patients undergoing MR examinations of the breast were retrospectively reviewed. Patients who received a pathologic diagnosis of RSL without atypia or carcinoma at surgical excision were identified. The MR images were evaluated according to the BI-RADS-MRI lexicon by two experienced breast radiologists. The frequency of morphologic and kinetic patterns and of BI-RADS-MRI assessment categories was calculated. RESULTS: Twenty-nine patients with 29 surgically excised RSL were identified. Nine (31%) RSL were MR-occult; the remaining 20 (69%) RSL presented as masses (10/20, 50%), architectural distortions (5/20, 25%), non-mass lesions (4/20, 20%), and focus (1/20, 5%). Kinetic analysis was performed in 18 RSL: enhancement features were benign in 9 (50%) cases, suspicious in 7 (39%) cases and indeterminate in 2 (11%) cases. Twelve (41%) MR examinations were assessed as suspicious (BI-RADS-MRI 4 and 5), and 17 (59%) as negative (BI-RADS-MRI 1) or benign (BI-RADS-MRI 2 and 3). CONCLUSION: RSLs are often visualized on MR imaging. Just as in mammography and sonography, RSL can have variable morphologic and kinetic features, and not infrequently they can mimic invasive carcinoma of the breast.

Nonsurgical management of high-risk lesions diagnosed at core needle biopsy: can malignancy be ruled out safely with breast MRI?

OBJECTIVE: The purpose of this study was to investigate whether breast MRI can be used to rule out malignancy in patients with high-risk lesions diagnosed at imaging-guided core needle biopsy. SUBJECTS AND METHODS: The subjects were women consecutively registered between October 2004 and April 2010 who had high-risk lesions diagnosed at mammographically or sonographically guided core needle biopsy and subsequently underwent MRI and surgical excision. MR images were reviewed by two experienced breast radiologists. Lesions assessed as BI-RADS category 1-3 were considered negative for malignancy, and BI-RADS 4 and 5 lesions were considered malignant. Histologic findings at surgical excision were the reference standard. The sensitivity, specificity, and positive and negative predictive values of MRI in the detection of associated malignancy were calculated for the entire set of lesions and for each histologic subtype. RESULTS: The final sample consisted of 169 high-risk lesions in 166 patients. At MRI analysis, 116 (68.6%) lesions were considered negative for malignancy, and the other 53 (31.4%) malignant. At surgical excision, 22 malignant lesions were found. The overall sensitivity, specificity, and positive and negative predictive values of MRI were 72.7% (16/22), 74.8% (110/147), 30.2% (16/53), and 94.8% (110/116). The negative predictive values for papilloma, radial scar, lobular neoplasia, and atypical ductal hyperplasia were 97.4% (38/39), 97.6% (41/42), 88.0% (22/25), and 90.0% (9/10). CONCLUSION: Patients with high-risk lesions associated with the lowest likelihood of malignancy (papilloma and radial scar) and without suspicious MRI findings can safely undergo follow-up instead of surgery. Because of the low negative predictive value, however, MRI is not helpful in cases of lobular neoplasia and atypical ductal hyperplasia, and all these lesions should be excised.