MR-guided vacuum-assisted breast biopsy of MRI-only lesions: a single center experience

Diagnostic performance of MRI-guided vacuum-assisted breast biopsy (VABB): an essential but still underused technique

BACKGROUND

Magnetic resonance imaging (MRI)-guided vacuum-assisted breast biopsy (VABB) is an increasingly requested procedure, but it implies training and experience both in its execution and in determining radiological-pathological concordance and is therefore performed in dedicated breast centers. The purpose of this study is to evaluate the diagnostic performance of MRI-guided vacuum-assisted biopsy and to determine the upgrade rate after surgery or follow-up.

METHODS

We retrospectively evaluated all consecutive patients with suspicious MRI findings without corresponding mammographic and ultrasonographic findings who underwent MRI-guided vacuum-assisted breast biopsy (VABB) at our Institution from November 2020 to March 2023. We determined the sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and accuracy of the procedure; we also assessed upgrade rate to malignancies using surgery or at least 1-year negative follow-up as reference standard. Fisher's exact test was used to evaluate the correlation between enhancement size and type (mass/non-mass) and histological outcomes.

RESULTS

A total of 121 patients with 122 suspicious breast lesions have been included. 29.5% (n = 36) of these lesions were classified as malignant (B5), 23% (n = 28) were lesions with uncertain malignant potential (B3 lesions), and 47.5% (n =58) were benign (B2). Among B5 lesions, 47.22% (n =17) were ductal carcinomas in situ (DCIS) and 52.77% (n = 19) were invasive carcinomas. Among patients with already diagnosed breast cancer (n = 36), MRI-guided VABB identified additional foci of disease in 36.1% (n = 13) of the cases, specifically 10 foci on the same breast and 3 in the contralateral breast. Accuracy of MRI-guided VABB was 96.7%, SE was 90%, SP was 100%, PPV was 100%, and NPV was 95.3%. 4 benign lesions (B2 and B3) were upgraded to B5 lesions after surgery or follow-up; the upgrade rate to malignancies was 3.28%. Fisher's exact test showed a significant association between enhancement size and histological outcomes (OR = 2.38, p = 0.046), while enhancement type was not significantly correlated (OR = 0.88, p = 0.841). No major complications have been reported.

CONCLUSIONS

MRI-guided VABB has proven to be a mini-invasive, safe, and accurate procedure for the diagnostic work-up of suspected breast lesions, which can help in the management of patients aiding in the correct surgical decisional process.

Can structured integration of BI-RADS criteria by a clinical decision rule reduce the number of unnecessary biopsies in BI-RADS 4 lesions? A systematic review and meta-analysis

AIM

This systematic review and meta-analysis investigate the added value of structured integration of Breast Imaging Reporting and Data System (BI-RADS) criteria using the Kaiser score (KS) to avoid unnecessary biopsies in BI-RADS 4 lesions.

MATERIAL AND METHODS

A systematic review and meta-analysis were conducted using predefined criteria. Eligible articles, published in English until May 2024, dealt with KS in the context of BI-RADS 4 MRI. Two reviewers extracted study characteristics, including true positives (TP), false positives (FP), true negatives (TN), and false negatives (FN). Sensitivity, specificity, negative likelihood ratio, and positive likelihood ratio were calculated using bivariate random effects. Fagan nomograms identified the maximum pre-test probability at which post-test probabilities of a negative MRI aligned with the 2% malignancy rate benchmark for downgrading BI-RADS 4 to BI-RADS 3. I² statistics and meta-regression explored sources of heterogeneity. p-values < 0.05 were considered significant.

RESULTS

Seven studies with 1877 lesions (833 malignant, 1044 benign) were included. The average breast cancer prevalence was 47.3%. Pooled sensitivity was 94.3% (95%-CI 88.9%-97.1%), and pooled specificity was 68.1% (95%-CI 56.6%-77.7%) using a random effects model. Overall, 52/833 cases were FNs (6.2%). Fagan nomograms showed that KS could rule out breast cancer in BI-RADS 4 lesions at a pre-test probability of 20.3% for all lesions, 25.4% for masses, and 15.2% for non-mass lesions.

CONCLUSIONS

In MRI-assessed BI-RADS 4 lesions, applying structured BI-RADS criteria with the KS reduces unnecessary biopsies by 70% with a 6.2% FN rate. Breast cancer can be ruled out up to pre-test probabilities of 20.3%.

KEY POINTS

Question What, if any, value is added by structured integration of BI-RADS criteria using the Kaiser Score (KS) to avoid unnecessary biopsies in BI-RADS 4 lesions? Findings The structured integration of BI-RADS criteria using the Kaiser Score (KS) reduces unnecessary biopsies in BI-RADS 4 lesions by 70%. Clinical relevance The structured approach offered by the Kaiser Score (KS) avoids unnecessary recalls, potentially reducing patient anxiety, lessening the burden on medical personnel, and the need for further imaging and biopsies due to more objective and thus efficient clinical decision-making in evaluating BI-RADS 4 lesions.

Clinical Outcomes of Benign Concordant MRI-Guided Breast Biopsies

INTRODUCTION

MRI-guided biopsy is the standard of care for breast imaging findings seen only by MRI. Although a non-zero false-negative rate of MRI-guided breast biopsy has been reported by multiple studies, there are varied practice patterns for imaging follow-up after a benign concordant MRI guided biopsy. This study assessed the outcomes of benign concordant MRI-guided biopsies at a single institution.

PATIENTS AND METHODS

This IRB-approved, retrospective study included patients with MRI-guided biopsies of breast lesions from November 1, 2014, to August 31, 2020. Only image-concordant breast lesions with benign histopathology and those follow up with MRI imaging or excision were included in the study.

RESULTS

Out of 275 lesions in 216 patients that met the inclusion criteria, 274 lesions were followed with MRI (range, 5-79 months; average, 25.5 months) and showed benign or stable features upon follow-up. One out of 275 lesions (0.4%), a 6 mm focal nonmass enhancement, was ultimately found to represent malignancy after initial MRI-guided biopsy yielded fibrocystic changes. The lesion was stable at a 6-month follow-up MRI but increased in size at 18 months. Repeat biopsy by ultrasound guidance yielded invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS).

CONCLUSION

Breast MRI-guided biopsy has a low false-negative rate. Our single malignancy from a total of 275 lesions gives a false negative rate of 0.4%. This data also supports a longer follow-up interval than the commonly performed 6-month follow-up, in order to assess for interval change.

Evaluation of the intramammary distribution of breast lesions detected by MRI but not conventional second-look B-mode ultrasound using an MRI/ultrasound fusion technique

The objective of this study was to evaluate the intramammary distribution of MRI-detected mass and focus lesions that were difficult to identify with conventional B-mode ultrasound (US) alone. Consecutive patients with lesions detected with MRI but not second-look conventional B-mode US were enrolled between May 2015 and June 2023. Following an additional supine MRI examination, we performed third-look US using real-time virtual sonography (RVS), an MRI/US image fusion technique. We divided the distribution of MRI-detected mammary gland lesions as follows: center of the mammary gland versus other (superficial fascia, deep fascia, and atrophic mammary gland). We were able to detect 27 (84%) of 32 MRI-detected lesions using third-look US with RVS. Of these 27 lesions, 5 (19%) were in the center of the mammary gland and 22 (81%) were located in other areas. We were able to biopsy all 27 lesions; 8 (30%) were malignant and 19 (70%) were benign. Histopathologically, three malignant lesions were invasive ductal carcinoma (IDC; luminal A), one was IDC (luminal B), and four were ductal carcinoma in situ (low-grade). Malignant lesions were found in all areas. During this study period, 132 MRI-detected lesions were identified and 43 (33%) were located in the center of the mammary gland and 87 (64%) were in other areas. Also, we were able to detect 105 of 137 MRI-detected lesions by second-look conventional-B mode US and 38 (36%) were located in the center of the mammary gland and 67 (64%) were in other areas. In this study, 81% of the lesions identified using third-look US with RVS and 64% lesions detected by second-look conventional-B mode US were located outside the center of the mammary gland. We consider that adequate attention should be paid to the whole mammary gland when we perform third-look US using MRI/US fusion technique.

MRI-visualized T2 hyperintense breast lesions: identifying clinical and imaging factors linked to malignant biopsy outcomes

PURPOSE

To determine the malignancy rate for MRI-guided breast biopsies performed for T2 hyperintense breast lesions and to assess additional clinical and MRI characteristics that can predict benign and malignant outcomes.

METHODS

A retrospective chart review of consecutive MRI-guided breast biopsies performed in two tertiary hospitals was conducted over two years. Biopsies performed for T2 hyperintense lesions were selected, and further lesion imaging characteristics and patient risk factors were collected. Univariate and multivariate modeling regression were used to determine additional imaging and patient factors associated with malignant outcomes for biopsies of T2 hyperintense lesions.

RESULTS

Out of 369 MRI-guided breast biopsies, 100 (27%) were performed for T2 hyperintense lesions. Two biopsy-proven benign lesions were excluded as the patient was lost on follow-up. With a study cohort of 98 lesions, the final pathology results were benign for 80 (80%) of these lesions, while 18 (18%) were malignant. Using multivariate logistic modeling, patient age > 50 (OR 5.99 (1.49, 24.08 95% CI), p < 0.05) and lesion size > 3 cm (OR 5.54 (1.54-18.7), p < 0.01) were found to be important predictors of malignant outcomes for MRI biopsies performed for T2 hyperintense lesions.

CONCLUSION

Our study observed a high malignancy rate, challenging the assumption that T2 hyperintensity can be considered a benign imaging characteristic for otherwise suspicious MRI-detected lesions. Decision-making regarding tissue sampling should be made based on a thorough evaluation of more reliable additional demographic and imaging factors, including patient age and lesion size.

MRI only detected lesions: Can contrast enhanced mammography guided biopsy be an alternative method: Initial clinical findings

OBJECTIVE

This study aims to analyze our initial findings regarding CEM-guided stereotactic vacuum-assisted biopsy for MRI-only detected lesions and compare biopsy times by MRI-guided biopsy.

MATERIALS AND METHODS

In this retrospective analysis, CEM-guided biopsies of MRI-only detected breast lesions from December 2021 to June 2023were included. Patient demographics, breast density, lesion size, background parenchymal enhancement on CEM, lesion positioning, procedure duration, and number of scout views were documented. Initially, seven patients had CEM imaging before biopsy; for later cases, CEM scout views were used for simultaneous lesion depiction and targeting.

RESULTS

Two cases were excluded from the initial 28 patients with 29 lesions resulting in a total of 27 lesions in 26 women (mean age:44.96 years). Lesion sizes ranged from 4.5 to 41 mm, with two as masses and the remaining as non-mass enhancements. Histopathological results identified nine malignancies (33.3 %, 9/27), including invasive cancers (55.6 %, 5/9) and DCIS (44.4 %, 4/9). The biopsy PPV rate was 33.3 %. Benign lesions comprised 66.7 %, with 22.2 % high-risk lesions. The biopsy success rate was 93.1 % (27/29), and minor complications occurred in seven cases (25.9 %, 7/27), mainly small hematomas and one vasovagal reaction (3.7 %, 1/27). Median number of scout views required was 2, with no significant differences between cases with or without prior CEM (P = 0.8). Median duration time for biopsy was 14 min, significantly shorter than MRI-guided bx at the same institution (P < 0.001) by 24 min with predominantly upright positioning of the patient (88.9 %) and horizontal approach of the needle (92.6 %).

CONCLUSION

This study showed that CEM-guided biopsy is a feasible and safe alternative method and a faster solution for MRI-only detected enhancing lesions and can be accurately performed without the need for prior CEM imaging.

Contrast-enhanced breast imaging: Current status and future challenges

BACKGROUND

Contrast-enhanced breast MRI and recently also contrast-enhanced mammography (CEM) are available for breast imaging. The aim of the current overview is to explore existing evidence and ongoing challenges of contrast-enhanced breast imaging.

METHODS

This narrative provides an introduction to the contrast-enhanced breast imaging modalities breast MRI and CEM. Underlying principle, techniques and BI-RADS reporting of both techniques are described and compared, and the following indications and ongoing challenges are discussed: problem-solving, high-risk screening, supplemental screening in women with extremely dense breast tissue, breast implants, neoadjuvant systemic therapy (NST) response monitoring, MRI-guided and CEM- guided biopsy.

RESULTS

Technique and reporting for breast MRI are standardised, for the newer CEM standardisation is in progress. Similarly, compared to other modalities, breast MRI is well established as superior for problem-solving, screening women at high risk, screening women with extremely dense breast tissue or with implants; and for monitoring response to NST. Furthermore, MRI-guided biopsy is a reliable technique with low long-term false negative rates. For CEM, data is as yet either absent or limited, but existing results in these settings are promising.

CONCLUSION

Contrast-enhanced breast imaging achieves highest diagnostic performance and should be considered essential. Of the two contrast-enhanced modalities, evidence of breast MRI superiority is ample, and preliminary results on CEM are promising, yet CEM warrants further study.

Added value of clinical decision rules for the management of enhancing breast MRI lesions: A systematic comparison of the Kaiser score and the Göttingen score

PURPOSE

We investigated the added value of two internationally used clinical decision rules in the management of enhancing lesions on breast MRI.

METHODS

This retrospective, institutional review board approved study included consecutive patients from two different populations. Patients received breast MRI according to the recommendations of the European Society of Breast Imaging (EUSOBI). Initially, all examinations were assessed by expert readers without using clinical decision rules. All lesions rated as category 4 or 5 according to the Breast Imaging Reporting and Data System were histologically confirmed. These lesions were re-evaluated by an expert reader blinded to the histology. He assigned each lesion a Göttingen score (GS) and a Kaiser score (KS) on different occasions. To provide an estimate on inter-reader agreement, a second fellowship-trained reader assessed a subset of these lesions. Subgroup analyses based on lesion type (mass vs. non-mass), size (>1 cm vs. ≤ 1 cm), menopausal status, and significant background parenchymal enhancement were conducted. The areas under the ROC curves (AUCs) for the GS and KS were compared, and the potential to avoid unnecessary biopsies was determined according to previously established cutoffs (KS > 4, GS > 3) RESULTS: 527 lesions in 506 patients were included (mean age: 51.8 years, inter-quartile-range: 43.0-61.0 years). 131/527 lesions were malignant (24.9 %; 95 %-confidence-interval: 21.3-28.8). In all subgroups, the AUCs of the KS (median = 0.91) were higher than those of the GS (median = 0.83). Except for "premenopausal patients" (p = 0.057), these differences were statistically significant (p ≤ 0.01). Kappa agreement was higher for the KS (0.922) than for the GS (0.358).

CONCLUSION

Both the KS and the GS provided added value for the management of enhancing lesions on breast MRI. The KS was superior to the GS in terms of avoiding unnecessary biopsies and showed superior inter-reader agreement; therefore, it may be regarded as the clinical decision rule of choice.

Reducing False Negatives in Biopsy of Suspicious MRI Findings

Breast MRI is a highly sensitive imaging modality that often detects findings that are occult on mammography and US. Given the overlap in appearance of benign and malignant lesions, an accurate method of tissue sampling for MRI-detected findings is essential. Although MRI-directed US and correlation with mammography can be helpful for some lesions, a correlate is not always found. MRI-guided biopsy is a safe and effective method of tissue sampling for findings seen only on MRI. The unique limitations of this technique, however, contribute to false negatives, which can result in delays in diagnosis and adverse patient outcomes; this is of particular importance as most MRI examinations are performed in the high-risk or preoperative setting. Here, we review strategies to minimize false negatives in biopsy of suspicious MRI findings, including appropriate selection of biopsy modality, use of meticulous MRI-guided biopsy technique, management after target nonvisualization, assessment of adequate lesion sampling, and determination of radiology-pathology concordance. A proposed management algorithm for MRI-guided biopsy results will also be discussed.

Performance Benchmark Metrics and Clinicopathologic Outcomes of MRI-Guided Breast Biopsies: A Systematic Review and Meta-Analysis

Objective

To determine key performance metrics of magnetic resonance imaging (MRI)-guided breast biopsies (MRGB) to help identify reference benchmarks.

Materials and Methods

We identified studies reporting MRGB results up to 04.01.2021 in the Embase database, Ovid Medline (R) Process, Other Non-Indexed Citations, Ovid Medline (R) and completed a PRISMA checklist and sources of bias (QUADAS-2). The inclusion criteria were English language, available histopathological outcomes, or at least one imaging follow-up after biopsy. A random intercept logistic regression model was used to pool rates. Between-study heterogeneity was quantified by the I2 statistic.

Results

A total of 11,215 lesions in 50 articles were analyzed. The technical success rate was 99.10% [95% confidence interval (CI): 97.89-99.62%]. The MRI indications were staging in 1,496 (28.05%, 95% CI: 26.85-29.28%), screening in 1,427 (26.76%, 95% CI: 25.57-27.97%), surveillance in 1,027 (19.26%, 95% CI: 18.21-20.34%), diagnostic in 1,038 (19.46%, 95% CI: 18.41-20.55%), unknown primary in 74 (1.39%, 95% CI: 1.09-1.74%), and other in 271 (5.08%, 95% CI: 4.51-5.71%). Histopathology was benign in 65.06% (95% CI: 59.15-70.54%), malignant in 29.64% (95% CI: 23.58-36.52%) and high risk in 16.69% (95% CI: 9.96-26.64%). Detection of malignancy was significantly lower in those patients who underwent MRI for screening purposes (odds ratio 0.47, 95% CI: 0.25-0.87; p = 0.02), while mass lesions were more likely to yield malignancy compared to non-mass and foci [27.39% vs 11.36% (non-mass),18.03% (foci); p<0.001]. Surgical upgrade to invasive cancer occurred in 12.24% of ductal carcinoma in situ (95% CI: 7.76-18.77%) and malignancy in 15.14% of high-risk lesions (95% CI: 10.69-21.17%). MRI follow-up was performed in 1,651 (20.92%) patients after benign results [median=25 months (range: 0.4-117)]. Radiology-pathology discordance (2.48%, 95% CI: 1.62-3.77%), false negative after a benign-concordant biopsy (0.75%, 95% CI: 0.34-1.62%) and biopsy complications (2.36%, 95% CI: 2.03-2.72%) were rare.

Conclusion

MRGB is a highly accurate minimally-invasive diagnostic technique with low false-negative and complication rates. MRI indication and lesion type should be considered when evaluating the performance of institutional MRGB programs.

A Comparative Study of Multiple Deep Learning Models Based on Multi-Input Resolution for Breast Ultrasound Images

Purpose

The purpose of this study was to explore the performance of different parameter combinations of deep learning (DL) models (Xception, DenseNet121, MobileNet, ResNet50 and EfficientNetB0) and input image resolutions (REZs) (224 × 224, 320 × 320 and 488 × 488 pixels) for breast cancer diagnosis.

Methods

This multicenter study retrospectively studied gray-scale ultrasound breast images enrolled from two Chinese hospitals. The data are divided into training, validation, internal testing and external testing set. Three-hundreds images were randomly selected for the physician-AI comparison. The Wilcoxon test was used to compare the diagnose error of physicians and models under P=0.05 and 0.10 significance level. The specificity, sensitivity, accuracy, area under the curve (AUC) were used as primary evaluation metrics.

Results

A total of 13,684 images of 3447 female patients are finally included. In external test the 224 and 320 REZ achieve the best performance in MobileNet and EfficientNetB0 respectively (AUC: 0.893 and 0.907). Meanwhile, 448 REZ achieve the best performance in Xception, DenseNet121 and ResNet50 (AUC: 0.900, 0.883 and 0.871 respectively). In physician-AI test set, the 320 REZ for EfficientNetB0 (AUC: 0.896, P < 0.1) is better than senior physicians. Besides, the 224 REZ for MobileNet (AUC: 0.878, P < 0.1), 448 REZ for Xception (AUC: 0.895, P < 0.1) are better than junior physicians. While the 448 REZ for DenseNet121 (AUC: 0.880, P < 0.05) and ResNet50 (AUC: 0.838, P < 0.05) are only better than entry physicians.

Conclusion

Based on the gray-scale ultrasound breast images, we obtained the best DL combination which was better than the physicians.

Role of breast MRI in predicting histologic upgrade risks in high-risk breast lesions: A review

PURPOSE

This article reviews the frequency, upgrade rate and valuable imaging characteristics for predicting the histologic upgrade risks of high-risk lesions on MRI, so as to provide a reference for the management of the lesions.

METHODS

A comprehensive search for relevant publications from January 2011 to January 2021 was conducted in the PubMed database. The frequency, upgrade rate and valuable imaging characteristics for predicting the upgrade risks of high-risk lesions on MRI included in the articles were reviewed, and the management of high-risk lesions was provided with a reference according to the review results.

RESULTS AND CONCLUSIONS

In terms of management options, Atypical ductal hyperplasia (ADH) and Lobular neoplasia (LN) (the top two high-risk lesions with the highest upgrade rate and frequency) were treated with surgical resection. However, the final treatment decision for other high-risk lesions should be made by a multidisciplinary committee. In terms of the value of breast MRI in predicting the upgrade risks of high-risk lesions, the lesions that were confirmed to upgrade after surgery showed some enhancement characteristics, especially for ADH and LN. At the same time, Dynamic contrast-enhanced MRI (DCE-MRI) has a high negative predictive value (NPV) in predicting the upgrade risks of the high-risk lesions, hence misdiagnosis and overtreatment can be reduced. Diffusion-weighted imaging (DWI) and relative apparent diffusion coefficient (rADC) can be used to predict the upgrade risks of the lesions, and the ADC of upgraded lesions is lower than that of non-upgraded lesions. However, these conclusions should be confirmed by further studies.

An A.I. classifier derived from 4D radiomics of dynamic contrast-enhanced breast MRI data: potential to avoid unnecessary breast biopsies

Objectives

Due to its high sensitivity, DCE MRI of the breast (bMRI) is increasingly used for both screening and assessment purposes. The high number of detected lesions poses a significant logistic challenge in clinical practice. The aim was to evaluate a temporally and spatially resolved (4D) radiomics approach to distinguish benign from malignant enhancing breast lesions and thereby avoid unnecessary biopsies.

Methods

This retrospective study included consecutive patients with MRI-suspicious findings (BI-RADS 4/5). Two blinded readers analyzed DCE images using a commercially available software, automatically extracting BI-RADS curve types and pharmacokinetic enhancement features. After principal component analysis (PCA), a neural network–derived A.I. classifier to discriminate benign from malignant lesions was constructed and tested using a random split simple approach. The rate of avoidable biopsies was evaluated at exploratory cutoffs (C₁, 100%, and C₂, ≥ 95% sensitivity).

Results

Four hundred seventy (295 malignant) lesions in 329 female patients (mean age 55.1 years, range 18–85 years) were examined. Eighty-six DCE features were extracted based on automated volumetric lesion analysis. Five independent component features were extracted using PCA. The A.I. classifier achieved a significant (p < .001) accuracy to distinguish benign from malignant lesion within the test sample (AUC: 83.5%; 95% CI: 76.8–89.0%). Applying identified cutoffs on testing data not included in training dataset showed the potential to lower the number of unnecessary biopsies of benign lesions by 14.5% (C₁) and 36.2% (C₂).

Conclusion

The investigated automated 4D radiomics approach resulted in an accurate A.I. classifier able to distinguish between benign and malignant lesions. Its application could have avoided unnecessary biopsies.

Key Points

• Principal component analysis of the extracted volumetric and temporally resolved (4D) DCE markers favored pharmacokinetic modeling derived features.

• An A.I. classifier based on 86 extracted DCE features achieved a good to excellent diagnostic performance as measured by the area under the ROC curve with 80.6% (training dataset) and 83.5% (testing dataset).

• Testing the resulting A.I. classifier showed the potential to lower the number of unnecessary biopsies of benign breast lesions by up to 36.2%, p < .001 at the cost of up to 4.5% (n = 4) false negative low-risk cancers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07787-z.

Long-term MRI-guided vacuum-assisted breast biopsy results of 600 single-center procedures

OBJECTIVES

The objective of this study is to report on the performance of the MRI-guided VABB in our center and to look at the long-term outcome of biopsies with benign histology over a period of 19 years.

METHODS

In a single-center retrospective review study, data of 600 VABB procedures performed between September 1999 and March 2017 were evaluated. We collected patient demographics, histopathological diagnosis at MRI-VABB, and basic lesion characteristics (size, location). Data from the Belgian Cancer Registry was cross-referenced with our database to find out which patients with benign MRI-VABB results developed a malignant lesion over time.

RESULTS

These 600 VABB procedures were performed in 558 women with a mean patient age of 51.8 years (range 18-82 years). Our technical success rate was 99.3%. We found 27.67% B5 lesions, 9.82% B3 lesions, and 0.17% B4 lesions. Of 362 benign MRI-guided VABBs, follow-up data was available for a mean follow-up period of 7.6 years (0.8-18.3). Only one (0.3%) biopsy was a false negative lesion after MRI-guided VABB during follow-up. Short-term FU-MRI provided no increase in detection rate.

CONCLUSION

The accuracy of MRI-guided VABB is high with a very low false negative rate of 0.3% on long-term follow-up. The value of short-term FU-MRI for every case after MRI-guided VABB may be questioned.

KEY POINTS

• MRI-guided vacuum-assisted breast biopsies yield a large portion of clinically relevant lesions (9.82% B3, 0.17% B4, and 27.67% B5 lesions). • The false negative biopsy rate of MRI-guided VABB in this study with a mean follow-up time of 7.6 years was only 0.3%. • Performing a short-term follow-up MRI after a benign MRI-guided VABB concordant to the MRI appearance may be questioned.

Vacuum-Assisted Breast Biopsy System: No Innovation Without Evaluation

Background Vacuum-assisted breast biopsy (VABB) has recently been gaining more popularity as a modality to reach the final diagnosis, especially in indeterminate breast lesions, resulting in a decreased number of surgical interventions and unnecessary follow-ups. Objective While our primary aim was to look into the outcomes of the VABB technique, our secondary aim was to assess the impact of the method on changes in patients' management. Patients and methods This study was a retrospective database analysis of vacuum-assisted biopsies (VABs) carried out at our breast unit during the period between January 2011 and January 2018. All our cases were image-guided; the caliber of vacuum-assisted needles used was 8 gauge (G) and 11 G. Patient demographics, lesion characteristics, and outcomes were retrieved from patients' notes and the hospital database. Results A total of 122 female patients were included in the analysis, out of whom 41.8% (51 patients) were screen-detected, and 58.1% (71 patients) were symptomatic presentations. The mean lesion size on imaging was 14.8 mm (SD: 12.6); 50% (61 patients) had stereotactic vacuum-assisted breast biopsy (SVAB), and 50% (61 patients) had ultrasound-guided vacuum-assisted breast biopsy (US-VAB). Post-procedure histology was upgraded in 19.6% (24 patients), downgraded in 18.8% (23 patients), and remained unchanged in 61.4% (75 patients). Conclusion VABB is a safe and efficient procedure for the diagnosis and management of indeterminate and suspicious breast lesions. It provides an adequate amount of tissue, which can help in upgrading or downgrading histopathologically diagnosed patients, thereby decreasing the need for surgery.

MRI features of pseudoangiomatous stromal hyperplasia with histopathological correlation

Pseudoangiomatous stromal hyperplasia (PASH), a rare, noncancerous lesion, is often an incidental finding on magnetic resonance imaging (MRI)-guided biopsy analysis of other breast lesions. We sought to describe the characteristics of PASH on MRI and identify the extent to which these characteristics are correlated with the amount of PASH in the pathology specimens. We identified 69 patients who underwent MRI-guided biopsies yielding a final pathological diagnosis of PASH between 2008 and 2015. We analyzed pre-biopsy MRI scans to document the appearance of the lesions of interest. All biopsy samples were classified as having ≤50% PASH or ≥51% PASH present on the pathological specimen. On MRI, 9 lesions (13%) appeared as foci, 19 (28%) appeared as masses with either washout or persistent kinetics, and 41 (59%) appeared as regions of nonmass enhancement. Of this latter group, 33 lesions (80%) showed persistent kinetic features. Masses, foci, and regions of nonmass enhancement did not significantly correlate with the percentage of PASH present in the biopsy specimens (P ≥ .05). Our findings suggest that PASH has a wide-ranging appearance on MRI but most commonly appears as a region of nonmass enhancement with persistent kinetic features. Our finding that most specimens had ≤50% PASH supports the notion that PASH is usually an incidental finding. We did not identify a definitive imaging characteristic that reliably identifies PASH.

MRI-guided breast biopsy based on diffusion-weighted imaging: a feasibility study

Objectives

This study evaluated the feasibility of DWI for lesion targeting in MRI-guided breast biopsies. Furthermore, it assessed device positioning on DWI during biopsy procedures.

Methods

A total of 87 biopsy procedures (5/87 bilateral) consecutively performed between March 2019 and June 2020 were retrospectively reviewed: in these procedures, a preliminary DWI sequence (b = 1300 s/mm²) was acquired to assess lesion detectability. We included 64/87 procedures on lesions detectable at DWI; DWI sequences were added to the standard protocol to localize lesion and biopsy device and to assess the site marker correct positioning.

Results

Mass lesions ranged from 5 to 48 mm, with a mean size of 10.7 mm and a median size of 8 mm. Non-mass lesions ranged from 7 to 90 mm, with a mean size of 33.9 mm and a median size of 31 mm. Positioning of the coaxial system was confirmed on both T1-weighted and DWI sequences. At DWI, the biopsy needle was detectable in 62/64 (96.9%) cases; it was not visible in 2/64 (3.1%) cases. The site marker was always identified using T1-weighted imaging; a final DWI sequence was acquired in 44/64 cases (68.8%). In 42/44 cases (95.5%), the marker was recognizable at DWI.

Conclusions

DWI can be used as a cost-effective, highly reliable technique for targeting both mass and non-mass lesions, with a minimum size of 5 mm, detectable at pre-procedural DWI. DWI is also a feasible technique to localize the biopsy device and to confirm the deployment of the site marker.

Key Points

• MRI-guided breast biopsy is performed in referral centers by an expert dedicated staff, based on prior MR imaging; contrast agent administration is usually needed for lesion targeting.

• DWI represents a feasible, highly reliable technique for lesion targeting, avoiding contrast agent administration.

• DWI allows a precise localization of both biopsy needle device and site marker.

Recent Progress for the Techniques of MRI-Guided Breast Interventions and their applications on Surgical Strategy

With a high sensitivity of breast lesions, MRI can detect suspicious lesions which are occult in traditional breast examination equipment. However, the lower and variable specificity of MRI makes the MRI-guided intervention, including biopsies and localizations, necessary before surgery, especially for patients who need the treatment of breast-conserving surgery (BCS). MRI techniques and patient preparation should be first carefully considered before the intervention to avoid lengthening the procedure time and compromising targeting accuracy. Doctors and radiologists need to reconfirm the target of the lesion and be very familiar with the process approach and equipment techniques involving the computer-aided diagnosis (CAD) tools and the biopsy system and follow a correct way. The basic steps of MRI-guided biopsy and localization are nearly the same regardless of the vendor or platform, and this article systematically introduces detailed methods and techniques of MRI-guided intervention. The two interventions both face different challenging situations during procedures with solutions given in the article. Post-operative statistics show that the complications of MRI-guided intervention are infrequent and mild, and MRI-guided biopsy provides the pathological information for the subsequent surgical decisions and MRI-guided localization fully prepared for follow-up surgical biopsy. New techniques for MRI-guided intervention are also elaborated in the article, which leads to future development. In a word, MRI-guided intervention is a safe, accurate, and effective technique with a low complication rate and successful MRI-guided intervention is truly teamwork with efforts from patients to surgeons, radiologists, MRI technologists, and nurses.

Solving the preoperative breast MRI conundrum: design and protocol of the MIPA study

Despite its high diagnostic performance, the use of breast MRI in the preoperative setting is controversial. It has the potential for personalized surgical management in breast cancer patients, but two of three randomized controlled trials did not show results in favor of its introduction for assessing the disease extent before surgery. Meta-analyses showed a higher mastectomy rate in women undergoing preoperative MRI compared to those who do not. Nevertheless, preoperative breast MRI is increasingly used and a survey from the American Society of Breast Surgeons showed that 41% of respondents ask for it in daily practice. In this context, a large-scale observational multicenter international prospective analysis (MIPA study) was proposed under the guidance of the European Network for the Assessment of Imaging in Medicine (EuroAIM). The aims were (1) to prospectively and systematically collect data on consecutive women with a newly diagnosed breast cancer, not candidates for neoadjuvant therapy, who are offered or not offered breast MRI before surgery according to local practice; (2) to compare these two groups in terms of surgical and clinical endpoints, adjusting for covariates. The underlying hypotheses are that MRI does not cause additional mastectomies compared to conventional imaging, while reducing the reoperation rate in all or in subgroups of patients. Ninety-six centers applied to a web-based call; 36 were initially selected based on volume and quality standards; 27 were active for enrollment. On November 2018, the target of 7000 enrolled patients was reached. The MIPA study is presently at the analytic phase. Key Points • Breast MRI has a high diagnostic performance but its utility in the preoperative setting is controversial. • A large-scale observational multicenter prospective study was launched to compare women receiving with those not receiving preoperative MRI. • Twenty-seven centers enrolled more than 7000 patients. The study is presently at the analytic phase.

MRI-guided vacuum-assisted breast biopsy: experience of a single tertiary referral cancer centre and prospects for the future

MRI-guided vacuum-assisted breast biopsy (VABB) is used for suspicious breast cancer (BC) lesions which are detectable only with MRI: because the high sensitivity but limited specificity of breast MRI it is a fundamental tool in breast imaging divisions. We analyse our experience of MRI-guided VABB and critically discuss the potentialities of diffusion-weighted imaging (DWI) and artificial intelligence (AI) in this matter. We retrospectively analysed a population of consecutive women underwent VABB at our tertiary referral BC centre from 01/2011 to 01/2019. Reference standard was histological diagnosis or at least 1-year negative follow-up. McNemar, Mann-Whitney and χ² tests at 95% level of significance were used as statistical exams. 217 women (mean age = 52, 18-72 years) underwent MRI-guided VABB; 11 were excluded and 208 MRI-guided VABB lesions were performed: 34/208 invasive carcinomas, 32/208 DCIS, 8/208 LCIS, 3/208 high-risk lesions and 131/208 benign lesions were reported. Accuracy of MRI-guided VABB was 97%. The predictive features for malignancy were mass with irregular shape (OR 8.4; 95% CI 0.59-31.6), size of the lesion (OR 4.4; 95% CI 1.69-9.7) and mass with irregular/spiculated margins (OR 5.4; 95% CI 6.8-31.1). Six-month follow-up showed 4 false-negative cases (1.9%). Invasive BC showed a statistically significant higher hyperintense signal at DWI compared to benign lesions (p = 0.03). No major complications occurred. MR-guided VABB showed high accuracy. Benign-concordant lesions should be followed up with breast MRI in 6-12 months due to the risk of false-negative results. DWI and AI applications showed potential benefit as support tools for radiologists.

Both a biopsy method and a therapeutic procedure in BI-RADS 4A and 4B lesions: Ultrasound-guided vacuum-assisted breast biopsy

Objectives

This study aimed to evaluate outcomes, complications, and follow-up results of ultrasound-guided vacuum-assisted breast biopsy (UG-VABB) in BI-RADS 4 A and B lesions.

Material and Methods

Between Agust 2014 to January 2018, fifty BI-RADS 4A and BI-RADS 4B lesions of 41 patients biopsied with 10G vacuum needle by a single radiologist were retrospectively evaluated.

Results

All patients were females and mean age of the 41 patients was 50.12 ± 8.63. Of all lesions, 84% was benign, 6% was ADH, 4% was in-situ cancer, and 6% was diagnosed as malign. Follow-up duration after VABB was 0-51 months and mean was 20.92 months. Complications were as vasovagal-induced seizure in 3 patients (7.3%) and intramammary hematoma in 16 patients (39%). Hematoma was diagnosed in 3 patients (7.3%) at the 6th month follow-up and it was resolved in all patients at the 12th month follow-up. Higher breast density resulted in higher hematoma rates. There was no relationship between lesion BI-RADS subgroups, lesion size or sample number and hematoma development. During the follow-up, residue lesion in 1 (2.4%) patient and scar tissue in 2 (4.9%) patients was detected.

Conclusion

US-guided VABB, with low complication rates and low scar development, is also a therapeutic excision method without remaining residue, which should be primarily preferred in smaller than 2 cm BI-RADS 4A and 4B lesions whose malignancy rates are relatively low. Hematoma, which is the most frequent complication, resorbed entirely in the 12th month in all patients.

Clinical Application and Feasibility of MRI-Guided Breast Biopsy of Breast Minimal Lesions in Chinese Population

Objectives: Some breast lesions are not visible on mammography or ultrasonography, and magnetic resonance imaging (MRI) become the only way to monitor these lesions. The purpose of this study was to evaluate the clinical application of MRI-guided biopsy and MRI-guided wire localization of breast minimal lesions in Chinese population.

Methods: We evaluated 95 patients (the most patients of known in China) from August 2013 to December 2017. All the patients were scanned with a 1.5-Tesla MRI system (GE Medical Systems, America) in the prone position using a bilateral 8-channel phased-array breast coil and underwent MRI-guided wire localization or MRI-guided biopsy.

Results: MRI-guided wire localization and MRI-guided biopsy were successfully performed in 87 patients with 88 lesions (100%, 88/88). After biopsy or surgery, 36 of 88 lesions (40.91%) were malignant, and 52 of 88 lesions (59.09%) were benign. Thirty-nine of 88 lesions (44.32%) were masses, and 49 of 88 (55.68%) showed non-mass enhancement. Statistical analysis showed there was no significant correlation between the malignancy rate and the type of lesion on MRI (P = 0.27). In this study, the rate of malignancy for Breast Imaging-Reporting and Data System (BI-RADS) 5 lesions was 100% (2 of 2) compared with 44.44% for BI-RADS 4C lesions (4 of 9), 42.42% for BI-RADS 4B lesions (14 of 33), and 36.36% for BI-RADS 4A lesions (16 of 44).

Conclusions: MRI-guided wire localization with subsequent surgical biopsy and MRI-guided biopsy are safe and effective tools for breast minimal lesions.

Image-guided breast biopsy and localisation: recommendations for information to women and referring physicians by the European Society of Breast Imaging

We summarise here the information to be provided to women and referring physicians about percutaneous breast biopsy and lesion localisation under imaging guidance. After explaining why a preoperative diagnosis with a percutaneous biopsy is preferred to surgical biopsy, we illustrate the criteria used by radiologists for choosing the most appropriate combination of device type for sampling and imaging technique for guidance. Then, we describe the commonly used devices, from fine-needle sampling to tissue biopsy with larger needles, namely core needle biopsy and vacuum-assisted biopsy, and how mammography, digital breast tomosynthesis, ultrasound, or magnetic resonance imaging work for targeting the lesion for sampling or localisation. The differences among the techniques available for localisation (carbon marking, metallic wire, radiotracer injection, radioactive seed, and magnetic seed localisation) are illustrated. Type and rate of possible complications are described and the issue of concomitant antiplatelet or anticoagulant therapy is also addressed. The importance of pathological-radiological correlation is highlighted: when evaluating the results of any needle sampling, the radiologist must check the concordance between the cytology/pathology report of the sample and the radiological appearance of the biopsied lesion. We recommend that special attention is paid to a proper and tactful approach when communicating to the woman the need for tissue sampling as well as the possibility of cancer diagnosis, repeat tissue sampling, and or even surgery when tissue sampling shows a lesion with uncertain malignant potential (also referred to as "high-risk" or B3 lesions). Finally, seven frequently asked questions are answered.

Association of Retrospective Peer Review and Positive Predictive Value of Magnetic Resonance Imaging-Guided Vacuum-Assisted Needle Biopsies of Breast

Objective

To evaluate the association between retrospective peer review of breast magnetic resonance imaging-guided vacuum-assisted needle biopsies and positive predictive value of subsequent magnetic resonance imaging-guided biopsies.

Materials and Methods

In January, 2015, a weekly conference was initiated in our institution to evaluate all breast magnetic resonance imaging-guided vacuum-assisted needle biopsies performed over January 1, 2014-December 31, 2015. During this weekly conferences, breast dynamic contrast-enhanced magnetic resonance imaging findings of 6 anonymized cases were discussed and then the faculty voted on whether they agree with the biopsy indication, accurate sampling and radiology-pathology correlation. We retrospectively reviewed and compared the magnetic resonance imaging indication, benign or malignant pathology rates, lesion types and the positive predictive value of magnetic resonance imaging-guided vacuum-assisted needle biopsy in the years before and after initiating this group peer review.

Results

The number of dynamic contrast-enhanced magnetic resonance imaging and magnetic resonance imaging-guided vacuum-assisted needle biopsies before and after initiating the review were 1447 vs 1596 (p=0.0002), and 253 (17.5%) vs 203 (12.7%) (p=0.04), respectively. There was a significant decrease in the number of benign biopsies in 2015 (n=104) compared to 2014 (n=154, p=0.04). The positive predictive value of magnetic resonance imaging-guided biopsy significantly increased after group review was implemented (Positive predictive value in 2014=%39.1 and positive predictive value in 2015=%48.8) (p=0.03), although the indications (p=0.49), history of breast cancer (p=0.14), biopsied magnetic resonance imaging lesion types (p=0.53) were not different. Less surgical excision was performed on magnetic resonance imaging-guided vacuum-assisted needle biopsy identified high-risk lesions in 2015 (p=0.25).

Conclusion

Our study showed an association between retrospective peer review of past biopsies and increased positive predictive value of magnetic resonance imaging-guided vacuum-assisted needle biopsies in our institution.

MRI-detected breast lesions: clinical implications and evaluation based on MRI/ultrasonography fusion technology

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.

Interobserver variability and likelihood of malignancy for fifth edition BI-RADS MRI descriptors in non-mass breast lesions

Objective

Non-mass enhancement (NME) in breast MRI is the most common feature of ductal carcinoma in situ (DCIS). We sought to evaluate the interobserver variability and positive predictive value (PPV) for malignancy of NME descriptors using the fifth edition BI-RADS lexicon focusing on the newly introduced “clustered ring enhancement” pattern.

Materials and methods

Breast MRIs of 129 patients who had undergone MRI-guided vacuum-assisted biopsy (VAB) in our institution were reviewed. Studies assessed as NME were classified according to the fifth edition BI-RADS lexicon by two breast radiologists. Consensus was reached by involving a third radiologist. Interobserver variability and PPV for malignancy were assessed.

Results

Seventy-two of 129 studies were assessed as NME. The disagreement rate in the first assessment step (mass vs. NME) was low at 9.3% (ĸ = 0.81, 95% confidence interval [CI] 0.71–0.91). The disagreement rate for distribution patterns was 23.6% (ĸ = 0.67, 95% CI 0.54–0.80) and 22.2% (ĸ = 0.69, 95% CI 0.56–0.81) for internal enhancement patterns. Clustered ring enhancement (PPV 53.85, p = 0.038) and segmental distribution (PPV 62.5%, p = 0.028) had the highest malignancy rates among internal enhancement and distribution patterns with a significant result; the combination of clustered ring enhancement and segmental distribution raised the malignancy rate by approximately 4% (PPV 66.67%, p = 0.049).

Conclusion

There was a high agreement rate among readers when differentiating NME from mass lesions. The agreement rate was lower when assessing the distribution and internal enhancement pattern descriptors, but still substantial. The descriptors clustered ring enhancement and segmental distribution were significant predictors of malignancy.

Key Points

• Non-mass enhancement is a common morphological feature of non-invasive breast cancer (DCIS) in MRI. Differentiation between potentially malignant and benign changes may be very challenging.

• Since clustered ring enhancement and segmental distribution are both significant predictors of malignancy, the awareness of this important finding, combined with high-quality image interpretation skills, may improve the tumor detection rate.

• The combination of clustered ring enhancement and segmental distribution increases the positive predictive value for malignancy, which may be relevant for clinical practice.

Do benign-concordant breast MRI biopsy results require short interval follow-up imaging? Report of longitudinal study and review of the literature

OBJECTIVE

The objectives of this study were to examine the frequency and outcomes of short interval imaging follow up of benign, concordant breast MRI biopsies and review the published literature on this topic.

MATERIALS AND METHODS

This was an IRB-approved, HIPAA compliant retrospective review of women undergoing MRI-guided breast biopsies between October 1, 2008 and December 31, 2014. Patients with malignant or high risk lesions with recommendation for excision, discordant cases, and those undergoing breast conservation therapy in same quadrant, chemotherapy or mastectomy were excluded. At least 2 years imaging and/or clinical follow-up without development of cancer in the same quadrant as the biopsy was set as the benchmark to confirm benign etiology. A PubMed search of similar articles through 2018 was also performed for the literature review.

RESULTS

943 consecutive MRI-guided biopsies were performed in 785 women. Of these, 378/943 (40.1%) were benign and met inclusion criteria. Eleven cases were recommended for and underwent repeat MRI-guided biopsy or excision, 2 of which were malignant. The overall false negative rate for benign concordant MRI-guided biopsy was 2/378, 0.5% (95% CI 0.02 to 2.0%). Literature search demonstrated five articles with similar methodologies yielding 628 additional cases of benign concordant breast biopsies. Nine of these cases were eventually diagnosed as malignancy with a false negative rate of 1.4%. Combined with our data, the overall false negative rate is 1.1%.

CONCLUSIONS

Short interval follow-up exams for benign concordant MRI-guided breast biopsies may not be necessary given the low malignancy rate.

Magnetic resonance imaging-guided vacuum-assisted breast biopsy: experience and preliminary results of 205 procedures

Objective

To demonstrate the frequency of malignancy and histological characteristics of lesions in patients submitted to vacuum-assisted breast biopsy guided by magnetic resonance imaging (MRI).

Materials and Methods

This was a retrospective study of MRI-guided vacuum-assisted breast biopsies performed between April 2008 and December 2016, in which we analyzed clinical and epidemiological data, as well as the BI-RADS classification and histopathological results. We compared nodules and non-nodular enhancements, in terms of their correlation with malignancy, using chi-square test.

Results

Among 215 cases referred for MRI-guided vacuum-assisted breast biopsy, the procedure was contraindicated in 10 cases (5%) and was technically feasible in the remaining 205 (95%). Non-nodular enhancements were observed in 135 cases (66%), and nodules were observed in 70 (34%), with a mean diameter of 2.2 cm (range, 0.5-9.6 cm) and 0.97 cm (range, 0.5-2.2 cm), respectively. Of the 205 lesions analyzed, 43 (21%) were malignant, 129 (63%) were benign, and 33 (16%) were classified as high-risk lesions. The most common histological findings were invasive ductal carcinoma and, in high-risk cases, lobular neoplasia. There was no significant difference between nodules and non-nodular enhancements in terms of the rate of malignancy (p = 0.725).

Conclusion

In our sample, the overall malignancy rate was 21%. However, to improve the assessment of these results, it is necessary to correlate them with the surgical data and with data from the follow-up of benign cases.

Understanding indications and defining guidelines for breast magnetic resonance imaging

Magnetic resonance imaging (MRI) of the breast is the most sensitive imaging modality for detecting cancer. With improved scan resolution and correctly applied clinical indications, the specificity of breast MRI has markedly improved in recent years. Current literature indicates an overall sensitivity for breast MRI of 98% - 100% and specificity of 88%. By comparison, the sensitivity and specificity for mammography is in the region of 71% and 98%, respectively. In particular, the very high negative predictive value (NPV) of breast MRI, which approaches 100%, is hugely useful in establishing absence of disease. Furthermore, the ability to accurately delineate viable cancer by way of combining both morphological and functional (contrast enhancement) capabilities means that MRI is the best tool we have in terms of local cancer staging and identifying residual or recurrent disease. The high NPV also means that breast MRI is uniquely capable of ruling out cancer or high-grade ductal carcinoma in situ in appropriate circumstances. I hope that the following guidelines that are based on those of the American College of Radiology and the European Society of Breast Imaging in addition to multiple review articles will provide some assistance to radiologists in terms of the correct indications for breast MRI. There are few formal guidelines in South Africa for the usage of breast MRI. In fact, there is a general paucity of guidelines in the international radiology world. The role of breast MRI in high-risk screening and identification of the primary in occult breast cancer is universally accepted. Thereafter, there is little consensus. By using some general guidelines, and bringing MRI into the discussion of multidisciplinary breast cancer management, good clinical practice and consistent decision-making can be established.

Lesion characteristics, histopathologic results, and follow-up of breast lesions after MRI-guided biopsy

PURPOSE

We aimed to assess the effectiveness of magnetic resonance imaging (MRI)-guided vacuum-assisted breast biopsy (VABB), evaluate and compare the characteristics and histopathologic findings of lesions, and overview the follow-up results of benign lesions.

METHODS

MRI findings and histopathologic results of breast lesions biopsied by MRI-guided VABB between 2013 and 2016 were retrospectively analyzed. MRI findings closely related with malignancy were investigated in particular. Follow-up results of benign lesions were evaluated.

RESULTS

MRI-guided VABB was applied to 116 lesions of 112 women. Of the lesions, 75 (65%) were benign, while 41 (35%) were malignant. Segmental (94%), clustered (89%), and clustered ring (67%) non-mass-like enhancement patterns were found to be more related with malignancy. False-negative rate of MRI-guided VABB was 12%, underestimation rate was 21%. One of the 54 followed-up benign lesions had a malignant result.

CONCLUSION

MRI-guided VABB is a reliable method for the diagnosis of breast lesions that are positive only on MRI. Follow-up results show that cancer detection rate is low for radio-pathologically concordant lesions. Further multicenter studies with larger patient population are needed to elucidate these results.

A survey by the European Society of Breast Imaging on the utilisation of breast MRI in clinical practice

OBJECTIVES

While magnetic resonance imaging (MRI) is considered a helpful diagnostic tool in breast imaging, discussions are ongoing about appropriate protocols and indications. The European Society of Breast Imaging (EUSOBI) launched a survey to evaluate the utilisation of breast MRI in clinical practice.

METHODS

An online survey reviewed by the EUSOBI board and committees was distributed amongst members. The questions encompassed: training and experience; annual breast MRI and MRI-guided-intervention workload; examination protocols; indications; reporting habits and preferences. Data were summarised and subgroups compared using χ² test.

RESULTS

Of 647 EUSOBI members, 177 (27.4%) answered the survey. The majority were radiologists (90.5%), half of them based in academic centres (51.9%). Common indications for MRI included cancer staging, treatment monitoring, high-risk screening and problem-solving, and differed significantly between countries (p≤0.03). Structured reporting and BI-RADS were mostly used. Breast radiologists with ≤10 years of experience preferred inclusion of additional techniques, such as T2/STIR (p=0.03) and DWI (p=0.08) in the scan protocol. MRI-guided interventions were performed by a minority of participants (35.4%).

CONCLUSIONS

The utilisation of breast MRI in clinical practice is generally in line with international recommendations. There are substantial differences between countries. MRI-guided interventions and functional MRI parameters are not widely available.

KEY POINTS

• MRI is commonly used for the detection and characterisation of breast lesions. • Clinical practice standards are generally in line with current recommendations. • Standardised criteria and diagnostic categories (mainly BI-RADS) are widely adopted. • Younger radiologists value additional techniques, such as T2/STIR and DWI. • MRI-guided breast biopsy is not widely available.

Second-look US Using Real-time Virtual Sonography, a Coordinated Breast US and MRI System with Electromagnetic Tracking Technology: A Pilot Study

Our aim was to retrospectively evaluate the utility of second-look ultrasound (US) using real-time virtual sonography (RVS) for detection of conventional B-mode (cB-mode) occult magnetic resonance imaging (MRI)-detected breast lesions. Between July 2011 and May 2015, 53 consecutive patients who underwent second-look US to identify lesions detected by prone MRI were enrolled in this study. Second-look US using RVS was performed for cB-mode occult MRI-detected breast lesions after an additional supine MRI. In the 53 patients, 59 lesions were initially detected by prone MRI, followed by second-look US. Of the 59 lesions, 20 (34%) were identified by second-look US using cB-mode. Of the 39 (66%) cB-mode occult lesions, 38 (97%) were detected in supine MRI and 33 (85%) were detected by second-look US using RVS. MRI morphology types of the 33 lesions were as follows: mass, 16; non-mass enhancement, 5; and focus, 12. US-guided biopsy under RVS or excisional biopsy demonstrated that of the 33 lesions, 8 (24%) were malignant and the remaining 25 (76%) were benign. A total of 53 (90%) MRI-detected lesions were sonographically identified using both cB-mode and RVS (p < 0.001). All five remaining US-occult lesions could be followed up under RVS after the enhancing area was marked on the breast surface using RVS. Although further prospective studies are required, the findings of our pilot study suggest that second-look US using RVS with additional supine MRI may improve the sonographic and histopathologic detection rate of cB-mode occult MRI-detected breast lesions.

A simple classification system (the Tree flowchart) for breast MRI can reduce the number of unnecessary biopsies in MRI-only lesions

OBJECTIVES

To assess whether using the Tree flowchart obviates unnecessary magnetic resonance imaging (MRI)-guided biopsies in breast lesions only visible on MRI.

METHODS

This retrospective IRB-approved study evaluated consecutive suspicious (BI-RADS 4) breast lesions only visible on MRI that were referred to our institution for MRI-guided biopsy. All lesions were evaluated according to the Tree flowchart for breast MRI by experienced readers. The Tree flowchart is a decision rule that assigns levels of suspicion to specific combinations of diagnostic criteria. Receiver operating characteristic (ROC) curve analysis was used to evaluate diagnostic accuracy. To assess reproducibility by kappa statistics, a second reader rated a subset of 82 patients.

RESULTS

There were 454 patients with 469 histopathologically verified lesions included (98 malignant, 371 benign lesions). The area under the curve (AUC) of the Tree flowchart was 0.873 (95% CI: 0.839-0.901). The inter-reader agreement was almost perfect (kappa: 0.944; 95% CI 0.889-0.998). ROC analysis revealed exclusively benign lesions if the Tree node was ≤2, potentially avoiding unnecessary biopsies in 103 cases (27.8%).

CONCLUSIONS

Using the Tree flowchart in breast lesions only visible on MRI, more than 25% of biopsies could be avoided without missing any breast cancer.

KEY POINTS

• The Tree flowchart may obviate >25% of unnecessary MRI-guided breast biopsies. • This decrease in MRI-guided biopsies does not cause any false-negative cases. • The Tree flowchart predicts 30.6% of malignancies with >98% specificity. • The Tree's high specificity aids in decision-making after benign biopsy results.

MRI-guided breast interventions

Magnetic resonance imaging (MRI)-guided interventions, including biopsies and wire localizations, are fundamental to any breast imaging practice due to the high sensitivity but limited specificity of breast MRI. The basic steps of MRI-guided biopsies are similar regardless of the vendor or platform, and technical considerations include approach planning, patient preparation and positioning, lesion targeting, and directional sampling using a vacuum-assisted biopsy technique. Unique challenges related to MRI-guided biopsies include vanishing lesions due to contrast washout, obscuration of the biopsy site due to susceptibility artifacts, and limited access to posteromedial lesions. A careful approach to planning, patient positioning, and lesion targeting will maximize the chances for a successful biopsy. Due to overlapping imaging features between benign and malignant lesions, radiologic-pathologic concordance is difficult and essential for further patient management.

LEVEL OF EVIDENCE

5 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2017;46:631-645.