Magnetic resonance imaging (MRI) remains the gold standard for breast cancer screening in women at increased risk, but it has notable limitations. Wendie Berg, MD, PhD, professor of radiology at the University of Pittsburgh School of Medicine, explains that MRI access is limited and many patients experience claustrophobia, making it unsuitable for some.
Contrast-enhanced mammography (CEM) is emerging as a promising alternative. After injecting iodinated contrast material intravenously, CEM uses updated mammography equipment to capture both low- and high-energy images. These produce subtraction images with enhanced findings similar to contrast-enhanced MRI, while the low-energy images resemble standard mammograms.
Accessibility and Operational Benefits of CEM
CEM is not restricted by breast density and uses widely available mammography units. According to Dr. Berg, since mammography technology is more common and familiar to patients, CEM can be a convenient option. The contrast agent is relatively inexpensive, and the procedure itself is cost-effective.
Fiona Gilbert, MBChB, FRCR, professor of radiology at the University of Cambridge, highlights CEM’s quick acquisition time—often just 15 to 20 minutes—which is shorter than MRI, and faster image reading times. Additionally, CEM exams can be scheduled during a routine breast imaging visit, making it a practical “one-stop-shop” for patients.
Patient Preference and Practical Considerations
Although CEM requires staff trained in intravenous contrast administration and managing potential allergic reactions (which occur in about 0.8% of cases), roughly 70% of women who have experienced both CEM and MRI prefer CEM. Dr. Berg notes that avoiding claustrophobia and combining cancer detection with mammographic evaluation in one exam are key reasons for this preference.
While CEM adds tasks such as allergy checks, renal function evaluation, and intravenous setup for staff, its impact on workflow is manageable. Importantly, biopsy decisions can often be made immediately from CEM images, eliminating extra diagnostic visits.
Evidence Supporting CEM Versus MRI
Although the U.S. Food and Drug Administration has not yet approved CEM for screening, ongoing research aims to address the data gap. A recent Radiology study co-authored by Dr. Berg evaluated adding CEM to digital breast tomosynthesis (DBT) in women eligible for MRI screening.
Among 601 women mostly with dense breasts, 12 cancers were detected, including six cancers identified only by CEM, representing an additional detection rate of 10 per 1000. These cancers were early-stage, mostly node-negative, and small in size, highlighting CEM’s diagnostic value.
Professor Gilbert points to the BRAID randomized trial that showed CEM matched or slightly outperformed abbreviated and full-protocol MRI in sensitivity and specificity. The trial noted that invasive cancers detected by CEM and abbreviated MRI were smaller compared to those found by ultrasound.
False Positives and Ongoing Improvements
Despite promising results, false positive rates are a concern. In the Radiology study, 13.4% of women without cancer who underwent CEM were recalled for further testing, on top of those recalled by DBT alone. False positives were more frequent in perimenopausal women.
The BRAID trial showed recall rates for CEM and abbreviated MRI were double those for whole breast ultrasound. Some of these false positives stem from the learning curve with newer CEM technology. Subsequent studies show the false positive rate decreases with experience. AI tools are in development to help reduce this issue further.
Conclusion
Dr. Berg emphasizes that although initial data are encouraging, more long-term research is critical. Multiple rounds of CEM screening need assessment to demonstrate sustained benefits such as reduced symptomatic interval cancers and better stage distribution at diagnosis.
Current Breast Cancer Research Foundation-funded studies and continuing BRAID and C-MIST trials in the U.S. and U.K. will provide data on repeated CEM screening rounds, especially in women with dense breasts or a personal cancer history.
Researchers are also exploring optimal screening intervals, such as every 18 or 24 months, which could reduce overall patient and system burden while maintaining effectiveness.
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