Non-mass Enhancement Research Articles

Non-mass enhancement on breast MRI: Clues to a more confident diagnosis

BackgroundNon-mass enhancement (NME) seen on dynamic contrast enhanced breast MRI (DCE-MRI) may be caused by benign, high risk or malignant lesions. Making a clear distinction between these lesions is challenging due to the significant overlap in their imaging appearance. Our study aims to assess the various patterns of distribution, internal enhancement patterns (IEPs) and kinetics of NME using the BI-RADS lexicon fifth edition with histopathologic correlation to aid in making a more confident recommendation regarding clinical management.ResultsSixty-six female patients with NME on DCE-MRI were included. Thirty-four lesions (51.5%) were histopathologically proven to be benign and 32 (48.5%) were malignant. Segmental distribution was the most common pattern and was found in 22 cases (33.3%), 14 of them were malignant with p-value < 0.05. Linear distribution was reported in 14 cases, (21.2%), five of which were malignant, with p-value > 0.05. Thirteen cases (19.7%) had focal distribution, only two of them were malignant with p-value < 0.05. Twelve cases (18.2%) were of regional distribution, seven of which were malignant. Multiregional and diffuse distribution were the least common and were found in 3% and 4.5% of cases respectively. As for the enhancement pattern, 30 cases (45.5%) had heterogeneous enhancement. Nineteen of which were malignant with a p-value < 0.05. Clumped enhancement was found in 24 cases (36.4%); 12 cases were found to be malignant. Nine cases (13.6%) were of homogeneous enhancement, all of them were benign and three cases (4.5%) were of clustered ring enhancement with p-value > 0.05. Restricted diffusion value was detected in 75% of malignant cases with p-value < 0.05. In terms of kinetic curve, the most frequent curve was found to be type II plateau curve (26 cases, 39.4%), 15 cases were of benign pathology and the other 11 cases were proven to be malignant. Followed by type III washout curve which was detected in 25 cases (37.9%), 20 cases were malignant and five cases were benign. And type I persistent curve was found in 15 cases (22.7%); 14 cases were histopathologically proven to be benign, and only one case was of malignant pathology, with a total p-value < 0.05.ConclusionsOur study found that the most common distribution pattern was segmental distribution, being statistically significant with p-value < 0.05, being more common among malignant lesions. As for the enhancement pattern, heterogeneous enhancement was the most common pattern, mainly detected in malignant lesions, with p-value < 0.05. The most common type of kinetic curve was type II curve.

Abstract PO4-19-10: Selective Avoidance of Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy In HER-2 Positive/Triple Negative Breast Cancer Patients With Excellent Radiologic Response to the Breast and Axilla

Abstract Background Neoadjuvant chemotherapy (NACT) for breast cancer (BC) is downstaging inoperable tumors into operable tumors and de-escalating breast/axillary surgery. According to advanced NACT, dual human epidermal growth factor-2 (HER2) blockage in HER2-positive BC, carboplatin, and immunotherapy in triple-negative breast cancer (TNBC) revealed pathologic complete response (ypCR) rates of up to 68% and 80%, the indications for NACT have expanded to early BC and the expected ypCR rate has increased. Therefore, it may be reasonable to consider omitting surgery in cases with excellent responses to NACT. Although sentinel lymph node biopsy (SLNB) is minimally invasive, some patients still experience complications such as lymphedema, pain, sensory loss, and axillary web syndrome. Several recent retrospective studies and pilot prospective studies have reported axillary pathologic complete response (ApCR) is highly correlated with breast pathologic complete response (BpCR). In cN0 with HER2+ BC and TNBC, the ApCR rate in BpCR after NACT was reported up to 100%, and in cN1 with HER2+ BC and TNBC, the ApCR rate in BpCR after NACT was reported about 85%. There are many studies predicting BpCR using radiologic imaging such as breast mammography (MMG), ultrasonography (USG), and magnetic resonance imaging (MRI). However, the combination of tri-modality (MMG, USG, MRI) could not confirm BpCR. The current study is screened in cT1-3N0-1M0, HER2+ or TNBC, and planned breast-conserving surgery (BCS) patients after NACT with excellent response at the combination of tri-modality imaging (breast MMG, breast USG, breast MRI) and with expected BpCR at physical examination. Methods Trial design The ASLAN trial is a prospective, multicenter, single-arm, clinical study. The five tertiary care hospitals in South Korea are participating which are members of the Korean Breast Cancer Study Group (KBCSG). Eligibility Inclusion criteria: women aged 20-69; cT1-3N0-1M0; HER2+ or TNBC (defined by ER-negative (&amp;lt; 10% positive cells in IHC) and PR-negative (&amp;lt; 10% positive cells in IHC)); expected complete remission at physical examination and radiological expected Tumor size ≤ 2cm or non-mass enhancement ≤ 4cm at breast MRI after standard NACT; planned breast-conserving surgery (BCS) with whole-breast irradiation; ECOG performance status 0-1. Exclusion criteria: SLNB before NACT; previous axillary surgery; bilateral BC; pregnancy. Intervention In eligible patients, BCS was performed. After BCS, patients who showed BpCR are enrolled with the omission of SLNB. Patients with no BpCR proceed with routine axillary surgery. Sample size calculation The assumption for an acceptable 5-year RFS ≥84% is based on previous study findings. The calculated total case number for per-protocol analysis is N=178. By Jun 2023, 153 patients had been enrolled and the target accrual of 178 patients is expected to be complete by Dec 2023. Study outcomes Primary endpoint: 5-year recurrence-free survival. Secondary endpoint: local recurrence-free survival, breast cancer-specific survival, overall survival, ipsilateral axillary recurrence interval, distant metastasis-free survival, contralateral breast-free survival, re-operation rate according to breast biopsy after NACT, adverse event, and quality of life. Accrual Plans The first patient was enrolled on Sep 2021. Among 223 patients who were screened, 153 patients have been enrolled in Jun 2023. We plan to complete the target accrual by Dec 2023. Conclusion The primary aim of the ASLAN trial is to demonstrate the oncologic safety of omitting axillary surgery for the excellent response after NACT in HER2+ or TNBC, early breast cancer patients undergoing BCS and adjuvant RT ASLAN trial, altogether with the EUBREAST-01 and ASCIS trials, will answer the very important question that may alter the axillary surgery in highly selected patients after NACT Citation Format: Jai Min Ryu, Wonshik Han, Han-Byoel Lee, Sung Gwe Ahn, Hee Jeong Kim, Hyung Seok Park, Ji Soo Choi, Hyunjun Lee, Hae Young Kim, Jeong Eon Lee. Selective Avoidance of Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy In HER-2 Positive/Triple Negative Breast Cancer Patients With Excellent Radiologic Response to the Breast and Axilla [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-19-10.

Abstract PO2-07-08: The efficacy of an MRI/US fusion technique for MRI-detected lesions previously undetected by conventional B-mode second-look US

Abstract Introduction Breast magnetic resonance imaging (MRI) is performed for preoperative screening of breast cancer and surveillance of BRCA gene carriers, and some lesions, called MRI-detected lesions, can only be detected by MRI. When MRI-detected lesions are found, second-look ultrasound (US) is recommended as the first choice for confirmation. However, the detection of MRI-detected lesions by conventional B-mode (cB-mode) second-look US varies from institution to institution, and it is often difficult to ensure objectivity and reproducibility. We use an MRI/US fusion technique called real-time virtual sonography (RVS) for the detection of MRI-detected lesions. RVS uses a magnetic position tracking system to display real-time US images on the same monitor as MRI images. Few reports on second-look US using RVS have examined its detection rate of MRI-detected lesions and the histopathological results of these lesions. In this study, we retrospectively reviewed MRI-detected lesions identified by second-look US using RVS but not by cB-mode second-look US from January 2018 to December 2022, with the goal of evaluating these lesions’ pathological characteristics. Materials and methods Consecutive patients who had one or more MRI-detected lesions not detected by cB-mode second-look US were enrolled in this study between January 2018 and December 2021. Second-look US using RVS was conducted after an additional supine MRI with a body surface coil was performed. Results A total of 36 patients with 38 lesions were included in this study. The mean age was 54 years old (range: 31–76). We were able to detect 31 (82%) of the 39 MRI-detected lesions by second-look US using RVS. These lesions were characterized as follows: mass, 14; non-mass-enhancement (NME), 13; and focal, 4. US-guided biopsy or excisional biopsy was performed on all lesions, and 11 (35%) of 31 lesions were malignant. We were able to detect 14 (74%) of the 19 mass lesions, and 3 were malignant (invasive ductal carcinoma (IDC) [luminal A type] in all 3 cases). We detected 13 (93%) of the 14 NME lesions, and 7 were malignant: 6 were ductal carcinoma in situ (DCIS) (high grade, 3; intermediate grade, 2; and low grade, 1), and 1 was IDC (luminal A type). Finally, we were able to detect 4 (80%) of the 5 focal lesions, 1 of which was malignant (DCIS [low grade]). Of 22 patients aged 55 years or younger, 3 had malignant lesions (IDC [luminal A type] in 2, DCIS [high grade] in 1). Of 15 patients aged 56 years or older, 8 had malignant lesions (DCIS in 7 [high grade, 2; intermediate grade, 2; low grade, 1] and IDC [luminal A type] in 1). Conclusions In this study, second-look US using RVS identified 82% of MRI-detected lesions that were not identified with cB-mode second-look US. Of these MRI-detected lesions, 35% were malignant. These results suggest that second-look US using RVS is useful for identifying MRI-detected lesions that are not detected by cB-mode second-look US. Citation Format: Masayuki Saito, Hirona Banno, Yukie Ito, Mirai Ido, Manami Goto, Takahito Ando, Yukako Mouri, Junko Kousaka, Kmihito Fujii, Tsuneo Imai, Shogo Nakano. The efficacy of an MRI/US fusion technique for MRI-detected lesions previously undetected by conventional B-mode second-look US [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-07-08.

Assessing MRI Sensitivity and Specificity for Detecting Occult Nipple-Areolar Complex Malignancy in Nipple-Sparing Mastectomy Candidates: A Systematic Review and Meta-Analysis

Background: Approximately 8% of breast cancers originate within the central ducts near the nipple-areolar complex(NAC), which revealed higher rates of occult involvement than previously thought. Precise preoperative imaging to assess NAC and subjacent tumor involvement has become critical to identify candidates for nipple-sparing mastectomy(NSM) while ensuring oncological safety. The aim of our study is to determine whether MRI could be used for the detection of subtle neoplastic infiltration. Method: Electronic databases including PubMed, Scopus, Web of Science, and EMBASE were systematically searched to identify all relevant studies on diagnostic performance of Magnetic Resonance Imaging(MRI) in malignant extension to the nipple published before 2024. The keywords include MRI, NAC, breast cancer, NSM. True Positive(TP), True Negative(TN), False Positive(FP), False Negative(FN) were extracted for analysis. Finally, 5 articles were selected for our meta-analysis. STATA version 15 was used to analysis data. Result: Our meta-analysis showed a pooled sensitivity of 89%(95% CI: 81%-94%)with low heterogeneity(I2 = 17.51%), and a pooled specificity of 89% (95% CI: 71%-96%), with significant heterogeneity(I2 = 95.87%). The pooled positive diagnostic likelihood ratio(pDLR) was 7.81(95% CI: 2.82-21.61, I2 = 92.66%), and the negative diagnostic likelihood ratio(nDLR) was 0.12(95% CI: 0.07-0.22, I2 = 11.94%). Conclusion: Diagnostic MRI characteristics such as NAC enhancement, non-mass enhancement(NME) type, mass size (greater than 20 mm), and tumor-to-nipple distance(TND) were assocaited with the presence of NAC involement. Because of high diagnostic accuracy, MRI imaging can be used as a helpful tool for NAC diagnosis.

Prognostic Molecular Biomarkers in Breast Cancer Lesions with Non-Mass Enhancement on MR.

Clustered ring enhancement (CRE) is a new lexicon for non-mass enhancement (NME) of breast MR in the 5th BIRADS, indicating a high suspicion of malignancy. We wonder if the presence of CRE correlates with expression of prognostic molecular biomarkers of breast cancer. A total of 58 breast lesions, which MRI reported with NME, were collected between July 2013 and December 2018. The patterns of enhancement including CRE were reviewed and the pathological results with expression of molecular biomarkers were collected. The association between MRI NME, pathological, and IHC stain findings were investigated under univariate analysis. A total of 58 breast lesions were pathologically proven to have breast cancer, comprising 31 lesions with CRE and 27 lesions without CRE on breast MRI. The expression of the estrogen receptor (ER) (p = 0.017) and the progesterone receptor (PR) (p = 0.017) was significantly lower in lesions with CRE as compared with those without CRE. The expression of Ki-67 (≥25%) was significantly higher in lesions with CRE (p = 0.046). The lesions with CRE had a lower expression ratio of ER (50.71 ± 45.39% vs. 74.26 ± 33.59%, p = 0.028). Our study indicated that lesions with CRE may possess different features from those without CRE in molecular expression, bearing a more aggressive behavior.

Can the abbreviated MRI protocol replace the standard full protocol in the detection and characterization of breast non-mass enhancement?

BackgroundBreast MRI full diagnostic protocol (FDP) showed great value in detecting and characterizing non-mass enhancement (NME); however, it is costly and time-consuming. MRI abbreviated protocol (AP) showed comparable accuracy to FDP in various indications but has not been specifically tested in NME. Our study purpose is to assess the accuracy of the AP in the detection and characterization of breast NME in comparison with the FDP and to perform time analysis of the AP.MethodsPatients who demonstrated NME in dynamic contrast-enhanced MRI were included to be assessed using AP and FDP. Image analysis was performed blindly and independently. Firstly, reconstructed images from the pre- and first post-contrast T1WI (first maximum intensity projection and subtraction) were made available as AP. Later, the time/signal intensity curve and remaining images of the FDP were added to the assessment. Both protocols were compared regarding acquisition time, interpretation time, BI-RADS scores and accuracy in the detection and characterization of NME in correlation to histopathology and/or follow-up. Validity statistics, Cohen-Kappa and ROC curve were used.ResultsFifty-nine NME lesions were identified. AP acquisition and interpretation times were significantly shorter than those of the FDP (3.3 vs. 35 min) and (45 “25–75 s” vs. 108 “80–150 s”) (P < 0.001), respectively. There was almost perfect agreement between the two protocols in the BIRADS grading of NME (k = 0.950, P < 0.001). In ROC curve analysis, the FDP was insignificantly more accurate than the AP (84.8% vs. 81.4%, P = 0.144).ConclusionsBreast MRI–AP is comparable to the FDP in the detection and characterization of breast NME with advantageous time saving.

Investigation of imaging features in contrast-enhanced magnetic resonance imaging of benign and malignant breast lesions

PurposeThis 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 MethodsIn 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.ResultsDifferences 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.ConclusionThis 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.

Evaluation of Features in Probably Benign and Malignant Nonmass Enhancement in Breast MRI.

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a highly sensitive breast imaging modality in detecting breast carcinoma. Nonmass enhancement (NME) is uniquely seen on MRI of the breast. The correlation between NME features and pathologic results has not been extensively explored. Our goal was to evaluate the characteristics of probably benign and suspicious NME lesions in MRI and determine which features are more associated with malignancy. We performed a retrospective research after approval by the hospital ethics committee on women who underwent breast MRI from March 2017 to March 2020 and identified 63 lesions of all 400 NME that were categorized as probably benign or suspicious according to the BI-RADS classification (version 2013). MRI features of NME findings including the location, size, distribution and enhancement pattern, kinetic curve, diffusion restriction, and also pathology result or 6-12-month follow-up MRI were evaluated and analyzed in each group (probably benign or suspicious NME). Vacuum-guided biopsies (VAB) were performed under mammographic or sonographic guidance and confirmed with MRI by visualization of the inserted clips. Segmental distribution and clustered ring internal enhancement were significantly associated with malignancy (p value<0.05), while linear distribution or homogeneous enhancement patterns were associated with benignity (p value <0.05). Additionally, the plateau and washout types in the dynamic curve were only seen in malignant lesions (p value <0.05). The presence of DWI restriction in NME lesions was also found to be a statistically important factor. Understanding the imaging findings of malignant NME is helpful to determine when biopsy is indicated. The correlation between NME features and pathologic results is critical in making appropriate management.

The Oncological and Surgical Outcomes of Immediate Oncoplastic Breast Reconstruction With Contralateral Breast Adjustment.

Oncoplastic surgery is an expanding approach for managing breast conservation because it offers improved cosmetic outcomes while maintaining oncological safety. This study aimed to assess the oncological and surgical outcomes of patients who underwent oncoplastic procedures at a single institution. The study population includes all consecutive breast cancer patients who underwent lumpectomy followed by immediate oncoplastic breast reconstruction with contralateral breast adjustment between 2010 and 2021. Following IRB approval, patient demographics, tumor characteristics, surgical details, complications, and follow-up were evaluated for this group. Quality of life (QOL) and patient-reported outcome measures were assessed through questionnaires. Following multidisciplinary tumor board discussion, 77 patients (82 breasts) underwent oncoplastic surgery. Of these, 92.2% underwent breast MRI prior to surgery with mean mass enhancement of 2.35 cm (range, 0-8.5 cm) and non-mass enhancement of 5.77 cm (range, 0-14 cm), and 44% presented with multifocal disease. The final positive surgical margin rate was 2.4%, and all conserved breasts received adjuvant radiation therapy. The 5-year local recurrence rate for invasive tumors was 4.1%. QOL scores were generally high, with most patients reporting good to excellent cosmetic outcomes and high personal satisfaction with breast appearance and softness. Physicians reported breast symmetry in 89.5%. The findings suggest that oncoplastic surgery with contralateral breast adjustment is safe, effective, and an excellent option for breast cancer patients wishing for breast conservation even for large or multifocal masses, with favorable oncologic and cosmetic outcomes. The QOL analysis indicates high patient satisfaction. These results support the use of oncoplastic surgery in the management of breast cancer.

Radiologic-Pathologic Correlation of Nonmass Enhancement Contiguous with Malignant Index Breast Cancer Masses at Preoperative Breast MRI.

Purpose To determine the pathologic features of nonmass enhancement (NME) directly adjacent to biopsy-proven malignant masses (index masses) at preoperative MRI and determine imaging characteristics that are associated with a malignant pathologic condition. Materials and Methods This retrospective study involved the review of breast MRI and mammography examinations performed for evaluating disease extent in patients newly diagnosed with breast cancer from July 1, 2016, to September 30, 2019. Inclusion criteria were limited to patients with an index mass and the presence of NME extending directly from the mass margins. Wilcoxon rank sum test, Fisher exact test, and χ2 test were used to analyze cancer, patient, and imaging characteristics associated with the NME diagnosis. Results Fifty-eight patients (mean age, 58 years ± 12 [SD]; all women) were included. Malignant pathologic findings for mass-associated NME occurred in 64% (37 of 58) of patients, 43% (16 of 37) with ductal carcinoma in situ and 57% (21 of 37) with invasive carcinoma. NME was more likely to be malignant when associated with an index cancer that had a low Ki-67 index (<20%) (P = .04). The presence of calcifications at mammography correlating with mass-associated NME was not significantly associated with malignant pathologic conditions (P = .19). The span of suspicious enhancement measured at MRI overestimated the true span of disease at histologic evaluation (P < .001), while there was no evidence of a difference between span of calcifications at mammography and true span of disease at histologic evaluation (P = .27). Conclusion Mass-associated NME at preoperative MRI was malignant in most patients with newly diagnosed breast cancer. The span of suspicious enhancement measured at MRI overestimated the true span of disease found at histologic evaluation. Keywords: Breast, Mammography © RSNA, 2024 See also the commentary by Newell in this issue.

Accuracy of cone-beam breast computed tomography for assessing breast cancer tumor size-comparison with breast magnetic resonance imaging.

Accurate preoperative assessment of tumor size is important in developing a surgical plan for breast cancer. The purpose of this study was to evaluate the accuracy of cone-beam breast computed tomography (CBBCT) and magnetic resonance imaging (MRI) in the assessment of tumor size and to analyze the factors influencing the discordance. In this retrospective study, patients with breast cancer who underwent preoperative contrast-enhanced CBBCT (CE-CBBCT) and dynamic contrast-enhanced MRI (DCE-MRI) and received a complete pathologic diagnosis from August 2020 to December 2021 were included, using the pathological result as the gold standard. Two radiologists assessed the CBBCT and MRI features and measured the tumor size with a 2-week washout period. Intraclass correlation coefficient (ICC) and Bland-Altman analyses were used to assess inter-observer reproducibility and agreement based on CBBCT, MRI and pathology. Univariate analyses of differences in clinical, pathological and CBBCT/MRI features between the concordant and discordant groups was performed using the t-test, Mann-Whitney U-test, Chi-squared test and Fisher's exact test. Multivariate analyses were used to identify factors associated with discordance of CBBCT/MRI with pathology. A total of 115 female breast cancer patients (115 lesions) were included. All patients had a single malignant tumor of the unilateral breast. The reproducibility and the agreement ranged from moderate to excellent (ICC =0.607-0.983). Receiver operating characteristic (ROC) analyses showed that the cut-off values of CBBCT-pathology and MRI-pathology discordance were 2.25 and 2.65 cm, respectively. CBBCT/MRI-pathology concordance was significantly associated with the extent of pathology, lesion type, presence of calcification, human epidermal growth factor receptor 2 (HER2) status and fatty infiltration (P<0.05). In lesions containing calcification, the difference of CBBCT-pathology was significantly smaller than MRI-pathology (P=0.021). Non-mass enhancement (NME) was the main predictor of CBBCT- or MRI-pathology discordance [odds ratio (OR) =3.293-6.469, P<0.05], and HER2 positivity was a predictor of CBBCT-pathology discordance (OR =3.514, P=0.019). CBBCT and MRI have comparable accuracy in measurement of tumor size, and CBBCT is advantageous in assessing the size of calcified lesions. NME and HER2 positivity are significant predictors of CBBCT-pathology discordance. This suggests that CBBCT might serve as an alternative imaging technique to assess tumor size when patients do not tolerate MRI.

It's Complicated: Managing Nonmass Enhancement Found at Breast MRI in Patients with Newly Diagnosed Cancer.

It's Complicated: Managing Nonmass Enhancement Found at Breast MRI in Patients with Newly Diagnosed Cancer.

Contrast-Enhanced Mammography-Guided Biopsy: Preliminary Results of a Single-Center Retrospective Experience.

Background: CEM-guided breast biopsy is an advanced diagnostic procedure that takes advantage of the ability of CEM to enhance suspicious breast lesions. The aim pf this paper is to describe a single-center retrospective experience on CEM-guided breast biopsy in terms of procedural features and histological outcomes. Methods: 69 patients underwent the procedure. Patient age, breast density, presentation, dimensions, and lesion target enhancement were recorded. All the biopsy procedures were performed using a 7- or 10-gauge (G) vacuum-assisted biopsy needle. The procedural approach (horizontal or vertical) and the decubitus of the patient (lateral or in a sitting position) were noted. Results: A total of 69 patients underwent a CEM-guided biopsy. Suspicious lesions presented as mass enhancement in 35% of cases and non-mass enhancement in 65% of cases. The median size of the target lesions was 20 mm. The median procedural time for each biopsy was 10 ± 4 min. The patients were placed in a lateral decubitus position in 52% of cases and seated in 48% of cases. The most common approach was horizontal (57%). The mean AGD was 14.8 mGy. At histology, cancer detection rate was 28% (20/71). Conclusions: CEM-guided biopsy was feasible, with high procedure success rates and high tolerance by the patients.

Imaging Changes and Outcomes of Patients Undergoing Active Monitoring for Ductal Carcinoma In Situ: Seven-Year Follow-up Study

Rationale and ObjectiveTo determine the imaging changes and their associated positive predictive value (PPV) for invasive breast cancer in women undergoing active monitoring for DCIS. Materials and MethodsIn this seven-year follow-up retrospective IRB-exempted cohort study, we reviewed patients diagnosed with DCIS who elected active monitoring between 2003 to 2022 at a single academic institution. Imaging characteristics, histopathology at initial diagnosis, and subsequent follow-up were recorded. Low-risk DCIS was defined as low or intermediate grade and hormone receptor (HR) positive (estrogen and/or progesterone receptor positive) disease diagnosed in women at least 40 years of age. Progression was defined as subsequent ipsilateral invasive breast cancer diagnosis. ResultsThere were 39 patients with a median age of 58.4 years (IQR: 51.1 – 69.6 years) and a median follow-up of 4.3 years (range: 0.6-16.4 years). Nearly two thirds of patients (64%, 25/39) had stable imaging (range: 0.6-16.4 years) and remained progression-free during active monitoring. Among the remaining 14 patients (36%) there were 24 imaging findings which prompted 22 subsequent core needle biopsies (range: 1-3 biopsies per patient) and two surgical biopsies. The positive predictive value (PPV) of invasive cancer was 29% (7/24) overall and 38% (3/8) for masses, 33% (3/9) for calcifications, 17% (1/6) for non-mass enhancement, and 0% (0/1) for architectural distortion. ConclusionsOf the radiographic changes prompting an additional biopsy, development of a new mass (38%) and new calcifications (33%) had the highest PPV for invasive progression. Close imaging follow-up should be a critical component for patients undergoing monitoring for DCIS.

Staging of breast cancer in the breast and regional lymph nodes using contrast-enhanced photon-counting detector CT: accuracy and potential impact on patient management.

To describe the feasibility and evaluate the performance of multiphasic photon-counting detector (PCD) CT for detecting breast cancer and nodal metastases with correlative dynamic breast MRI and digital mammography as the reference standard. Adult females with biopsy-proven breast cancer undergoing staging breast MRI were prospectively recruited to undergo a multiphasic PCD-CT using a 3-phase protocol: a non-contrast ultra-high-resolution (UHR) scan and 2 intravenous contrast-enhanced scans with 50 and 180 s delay. Three breast radiologists compared CT characteristics of the index malignancy, regional lymphadenopathy, and extramammary findings to MRI. Thirteen patients underwent both an MRI and PCD-CT (mean age: 53 years, range: 36-75 years). Eleven of thirteen cases demonstrated suspicious mass or non-mass enhancement on PCD-CT when compared to MRI. All cases with metastatic lymphadenopathy (3/3 cases) demonstrated early avid enhancement similar to the index malignancy. All cases with multifocal or multicentric disease on MRI were also identified on PCD-CT (3/3 cases), including a 4 mm suspicious satellite lesion. Four of five patients with residual suspicious post-biopsy calcifications on mammograms were detected on the UHR PCD-CT scan. Owing to increased field-of-view at PCD-CT, a 5 mm thoracic vertebral metastasis was identified at PCD-CT and not with the breast MRI. A 3-phase PCD-CT scan protocol shows initial promising results in characterizing breast cancer and regional lymphadenopathy similar to MRI and detects microcalcifications in 80% of cases. UHR and spectral capabilities of PCD-CT may allow for comprehensive characterization of breast cancer and may represent an alternative to breast MRI in select cases.

Correlation between dynamic contrast-enhanced MRI characteristics and apparent diffusion coefficient with Ki-67-positive expression in non-mass enhancement of breast cancer

As a remarkably specific characteristic of breast cancer observed on magnetic resonance imaging (MRI), the association between the NME type breast cancer and prognosis, including Ki-67, necessitates comprehensive exploration. To investigate the correlation between dynamic contrast-enhanced MRI (DCE-MRI) characteristics and apparent diffusion coefficient (ADC) values with Ki-67-positive expression in NME type breast cancer. A total of 63 NME type breast cancer patients were retrospectively reviewed. Malignancies were confirmed by surgical pathology. All patients underwent DCE and diffusion-weighted imaging (DWI) before surgery. DCE-MRI characteristics, including tumor distribution, internal enhancement pattern, axillary adenopathy, and time-intensity curve types were observed. ADC values and lesion sizes were also measured. The correlation between these features and Ki-67 expression were assessed using Chi-square test, Fisher’s exact test, and Spearman rank analysis. The receiver operating characteristic curve and area under the curve (AUC) was used to evaluate the diagnostic performance of Ki-67-positive expression. Regional distribution, TIC type, and ipsilateral axillary lymph node enlargement were correlated with Ki-67-positive expression (χ2 = 0.397, 0.357, and 0.357, respectively; P < 0.01). ADC value and lesion size were positively correlated with Ki-67-positive expression (rs = 0.295, 0.392; P < 0.05). The optimal threshold values for lesion size and ADC value to assess Ki-67 expression were determined to be 5.05 (AUC = 0.759) cm and 0.403 × 10–3 s/mm2 (AUC = 0.695), respectively. The best diagnosis performance was the ADC combined with lesion size (AUC = 0.791). The ADC value, lesion size, regional distribution, and TIC type in NME type breast cancer were correlated with Ki-67-positive expression. These features will aid diagnosis and treatment of NME type breast cancer.

Magnetic Resonance Imaging Features Associated with a High and Low Expression of Tumor-Infiltrating Lymphocytes: A Stratified Analysis According to Molecular Subtypes.

A total of 457 patients, including 241 HR+/HER2- patients, 134 HER2+ patients, and 82 TN patients, were studied. The percentage of TILs in the stroma adjacent to the tumor cells was assessed using a 10% cutoff. The low TIL percentages were 82% in the HR+ patients, 63% in the HER2+ patients, and 56% in the TN patients (p < 0.001). MRI features such as morphology as mass or non-mass enhancement (NME), shape, margin, internal enhancement, presence of peritumoral edema, and the DCE kinetic pattern were assessed. Tumor sizes were smaller in the HR+/HER2- group (p < 0.001); HER2+ was more likely to present as NME (p = 0.031); homogeneous enhancement was mostly seen in HR+ (p < 0.001); and the peritumoral edema was present in 45% HR+, 71% HER2+, and 80% TN (p < 0.001). In each subtype, the MR features between the high- vs. low-TIL groups were compared. In HR+/HER2-, peritumoral edema was more likely to be present in those with high TILs (70%) than in those with low TILs (40%, p < 0.001). In TN, those with high TILs were more likely to present a regular shape (33%) than those with low TILs (13%, p = 0.029) and more likely to present the circumscribed margin (19%) than those with low TILs (2%, p = 0.009).

Subcategorization of suspicious non-mass-like enhancement lesions(BI-RADS-MRI Category4)

BackgroundThis study aims to providing a reliable method that has good compliance and is easy to master to improve the accuracy of NMLE diagnosis.MethodsThis study retrospectively analyzed 122 cases of breast non-mass-like enhancement (NMLE) lesions confirmed by postoperative histology. MRI features and clinical features of benign and malignant non-mass enhancement breast lesions were compared by using independent sample t test, χ2test and Fisher exact test. P < 0.05 was considered statistically significant. Statistically significant parameters were then included in logistic regression analysis to build a multiparameter differential diagnosis modelto subdivide the BI-RADS Category 4.ResultsThe distribution (odds ratio (OR) = 8.70), internal enhancement pattern (OR = 6.29), ADC value (OR = 5.56), and vascular sign (OR = 2.84) of the lesions were closely related to the benignity and malignancy of the lesions. These signs were used to build the MRI multiparameter model for differentiating benign and malignant non-mass enhancement breast lesions. ROC analysis revealed that its optimal diagnostic cut-off value was 5. The diagnostic specificity and sensitivity were 87.01% and 82.22%, respectively. Lesions with 1–6 points were considered BI-RADS category 4 lesions, and the positive predictive values of subtypes 4a, 4b, and 4c lesions were15.79%, 31.25%, and 77.78%, respectively.ConclusionsComprehensively analyzing the features of MRI of non-mass enhancement breast lesions and building the multiparameter differential diagnosis model could improve the differential diagnostic performance of benign and malignant lesions.

Added value of the EUSOBI diffusion levels in breast MRI

ObjectivesTo 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 methodsThis 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.ResultsLesions 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).ConclusionThough 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 statementDLs 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.

Role of Magnetic Resonance Mammography in the Evaluation of Indeterminate Breast Lesions.

Background: Malignancy of the breast is one of the most common cancers among females worldwide. Magnetic resonance mammography (MRM) is a valuable complement to conventional methods for the early diagnosis of disease, thereby providing patients with a better prognosis. The number of unnecessary biopsies and repeated excisions in cases of indeterminate breast lesions detected on conventional imaging is high. Aims: The purpose of this study was to evaluate the role of MRM in the evaluation of indeterminate breast lesions [Breast Imaging Reporting and Data System (BIRADS) 3/4] found in conventional mammography and ultrasonography (USG), taking the histopathological examination (HPE) as the gold standard. Materials and methods: A total of 38 patients with conventional radiological imaging diagnosis of indeterminate breast lesions (BIRADS 3/4) were included in this study and evaluated using contrast-enhanced MRM according to the MR-BIRADS lexicon (5th edition). Morphological characteristics of lesions were evaluated to determine the probability of malignancy. Histopathology was kept as the gold standard for comparing all the statistical parameters. Results: There were a total of 40 lesions, 35 masses, and five nonmass enhancement (NME) available for evaluation out of the 38 patients. The sensitivity of margins to detect malignancy approached 100%; however, it had a slightly lower specificity of 66.67%. Magnetic resonance imaging (MRI) showed good diagnostic performance with sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 85, 90, 89.47, 85.71, and 87.50%, respectively. Conclusion: The MRI has been shown to be useful as a problem-solving tool in breast cancer screening, clarifying indeterminate findings and avoiding unnecessary short follow-ups and percutaneous biopsies. How to cite this article: Mishra E, Kaur N, Kaur R, et al. Role of Magnetic Resonance Mammography in the Evaluation of Indeterminate Breast Lesions. J Assoc Physicians India 2023;71(11):76-84.