Contrast-Enhanced Digital Mammography: Technique, Clinical Applications, and Pitfalls

Comparison of Performance in Diagnosis and Characterization of Breast Lesions: Contrast-Enhanced Mammography Versus Breast Magnetic Resonance Imaging

INTRODUCTION

In contemporary medical practice, magnetic resonance imaging (MRI) is the most sensitive modality for detecting breast cancer. Contrast-enhanced mammography (CEM), a relatively recent technology, represents another contrast-enhanced imaging technique that has the potential to serve as an alternative to breast MRI. Our main goal is to compare the diagnostic accuracy including assessment of sensitivity and specificity of these 2 contrast-enhanced breast imaging methods, CEM and MRI, in the diagnosis and characterization of breast lesions.

MATERIAL AND METHODS

Our prospective study included patients who were clinically suspected of malignancy and/or had suspicious findings detected by mammography or ultrasound. A total of 116 patients were included, and both CEM and MRI examinations were performed on all patients. All CEM examinations were conducted at our institution, while 56.89% of all MRI examinations were carried out at external centers. While histopathological results were accessible for all malignant lesions, the final diagnosis for 80.5% of benign lesions was established through typical imaging findings and adequate follow-up.

RESULTS

This study encompassed a total of 219 lesions, with 125 out of 219 (57.07%) malignant lesions and 94 out of 219 (42.92%) benign lesions. The sensitivity and specificity values were 98.40% and 81.91%, respectively, for CEM, and 100% and 75.33%, respectively, for MRI. Moreover, CEM showcased comparable performance to MRI in evaluating women with dense breasts.

CONCLUSION

CEM and MRI were compared for breast lesion diagnosis, with MRI showing higher sensitivity and CEM higher specificity; however, the differences were not statistically significant.

State-of-the-art for contrast-enhanced mammography

Contrast-enhanced mammography (CEM) is an emerging breast imaging technology with promise for breast cancer screening, diagnosis, and procedural guidance. However, best uses of CEM in comparison with other breast imaging modalities such as tomosynthesis, ultrasound, and MRI remain inconclusive in many clinical settings. This review article summarizes recent peer-reviewed literature, emphasizing retrospective reviews, prospective clinical trials, and meta-analyses published from 2020 to 2023. The intent of this article is to supplement prior comprehensive reviews and summarize the current state-of-the-art of CEM.

Contrast-enhanced Mammography Artifacts and Pitfalls: Tips and Tricks to Avoid Misinterpretation

Contrast-enhanced mammography (CEM) involves addition of intravenous iodinated contrast material at digital mammography, thus increasing the ability to detect breast cancer owing to tumor contrast enhancement. After image acquisition, interpretation includes careful assessment of the technique, artifacts, and pitfalls and reporting with a standard lexicon category and appropriate follow-up recommendations. Artifacts and pitfalls that may cause image misinterpretation should be detected and distinguished from pathologic conditions. Different artifacts apparent on CEM images are usually caused during image acquisition and include CEM-specific and contrast agent-related artifacts, apart from the typical digital mammography artifacts. The pitfalls are related to technical and diagnostic difficulties. One disadvantage of CEM that MRI does not have is a technical factor related to a mammography technique that consists of blind spots that may not be included in the imaging field of mammography views, including the axilla, medial region of the breast, or areas close to the breast wall. Normal breast tissue enhancement called background parenchymal enhancement is also present at CEM and may affect interpretation performance. Diagnostic pitfalls are caused by minimally enhancing lesions, such as invasive lobular carcinomas and mucinous carcinomas, which are difficult to detect with CEM, resulting in false-negative findings. Benign lesions can show enhancement at CEM and represent false-positive lesions that should also be recognized. The authors discuss image interpretation of CEM studies and focus on the artifacts and pitfalls that may be encountered. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Challenging Contrast-Enhanced Mammography-Guided Biopsies: Practical Approach Using Real-Time Multimodality Imaging and a Proposed Procedural Algorithm

Contrast-enhanced mammography (CEM) is an emerging functional breast imaging technique that entails the acquisition of dual-energy digital mammographic images after IV administration of iodine-based contrast material. CEM-guided biopsy technology was introduced in 2019 and approved by the U.S. FDA in 2020. This technology's availability enables direct sampling of suspicious enhancement seen only on or predominantly on recombined CEM images and addresses a major obstacle to the clinical implementation of CEM technology. The literature describing clinical indications and procedural techniques of CEM-guided biopsy is scarce. This article describes our initial experience in performing challenging CEM-guided biopsies and proposes a step-by-step procedural algorithm designed to proactively address anticipated technical difficulties and thereby increase the likelihood of achieving successful targeting.

Value of contrast-enhanced mammography combined with the Kaiser score for clinical decision-making regarding tomosynthesis BI-RADS 4A lesions

OBJECTIVES

To investigate the diagnostic performance of contrast-enhanced mammography (CEM) combined with the Kaiser score (KS) in digital breast tomosynthesis (DBT) BI-RADS 4A lesions to potentially reduce unnecessary breast biopsies.

METHODS

This retrospective study evaluated 106 patients with 109 DBT BI-RADS 4A lesions from June 2019 to June 2021. For the absence of enhancement on CEM, the lesions were downgraded to BI-RADS 3. For lesions with enhancement, the readers were asked to classify all enhancing lesions referring to the KS for breast MRI. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance. Two readers rated all cases and interreader agreement was assessed by Cohen's kappa coefficients.

RESULTS

There were ninety-five benign lesions and 14 malignant lesions. CEM combined with KS's accuracy, represented by the area under the curve (AUC), ranged between 0.880 and 0.906. The use of the KS improved the performance, with a significant difference relative to a single BI-RADS reading or US (p < 0.001). CEM with KS had higher specificity than CEM with BI-RADS or US (p < 0.001), without difference in sensitivity (p > 0.05). CEM combined with KS could have potentially obviated 72 (75.8%) to 78 (82.1%) unnecessary benign biopsies in 95 benign lesions previously DBT classified as BI-RADS 4A. The interreader agreement was substantial (kappa: 0.727) for KS.

CONCLUSIONS

CEM combined with KS may be used in DBT BI-RADS 4A lesions to substantially reduce unnecessary benign biopsies.

KEY POINTS

• CEM combined with the Kaiser scoring system shows high diagnostic performance for DBT BI-RADS 4A lesions. • The application of CEM combined with the Kaiser scoring system may avoid 75.8% to 82.1% of unnecessary benign breast biopsies. • CEM combined with the KS aids clinical decision-making in DBT BI-RADS 4A lesions.

Addressing Misinformation About the Canadian Breast Screening Guidelines

Screening mammography has been shown to reduce breast cancer mortality by 41% in screened women ages 40-69 years. There is misinformation about breast screening and the Canadian breast screening guidelines. This can decrease confidence in screening mammography and can lead to suboptimal recommendations. We review some of this misinformation to help radiologists and referring physicians navigate the varied international and provincial guidelines. We address the ages to start and stop breast screening. We explore how these recommendations may vary for specific populations such as patients who are at increased risk, transgender patients and minorities. We identify who would benefit from supplemental screening and review the available supplemental screening modalities including ultrasound, MRI, contrast-enhanced mammography and others. We describe emerging technologies including the potential use of artificial intelligence for breast screening. We provide background on why screening policies vary across the country between provinces and territories. This review is intended to help radiologists and referring physicians understand and navigate the varied international and provincial recommendations and guidelines and make the best recommendations for their patients.

Multimodality imaging of breast hematomas and their mimickers

While breast hematomas are common, their imaging features are often underrecognized or mistaken for other conditions.Diagnosis of acute hematomas is generally easy when associated with a recent history of breast trauma, surgery, or percutaneous biopsy. However, minor trauma might not always be remembered, and breast hematoma might have longlasting imaging manifestations when associated with fat necrosis. Also, because of the increasing use of breast MRI and FDG-PET/CT, breast hematomas are increasingly detected as incidentalomas and may mimic malignancies.Conversely, breast hematomas may also be associated with authentic malignant processes.In this pictorial review, we present the natural history of breast hematomas, their various imaging features, as well as their differential diagnoses, highlighting the situations requiring histopathological correlation.