Carrie Hruska, PhD, highlights how MBI improves dense breast cancer detection

In an interview with Contemporary OB/GYN, Carrie B. Hruska, PhD, medical physicist at Mayo Clinic, discussed ongoing challenges in breast cancer screening for women with dense breast tissue and the potential benefits of molecular breast imaging (MBI) as a complementary diagnostic tool.^1,2

Dense breast tissue, she explained, is a common and normal condition caused by a higher proportion of fibroglandular tissue in the breast. However, it poses a significant challenge for standard mammography and even newer technologies such as digital breast tomosynthesis.

Because both dense tissue and cancer appear white on X-ray images, overlapping tissue can obscure tumors, leading to missed cancers that may go undetected for years. Recent studies have shown that many breast cancers are not identified through mammography alone, underscoring the need for improved screening approaches that can detect malignancies earlier, when treatment is more effective.

MBI offers a promising solution by imaging the functional activity of breast tissue rather than its anatomy. The technique involves administering a radiopharmaceutical agent—commonly used in cardiac imaging—that accumulates in metabolically active, fast-growing cells such as cancer cells.

When imaged, these cancerous areas appear as bright spots, unaffected by tissue density. In a Mayo Clinic study, adding MBI to routine digital breast tomosynthesis screenings in women with dense breasts detected 2.5 times more invasive breast cancers than mammography alone, demonstrating MBI’s potential to uncover otherwise hidden tumors.

Hruska noted that the Mayo Clinic has incorporated MBI into clinical practice for over 15 years, primarily as a supplemental screening option for women with dense breasts. Unlike MRI, which can be complex and time-consuming, MBI is relatively simple, patient-friendly, and can be integrated directly into a breast imaging center. This accessibility allows women to undergo both mammography and MBI in a single visit.

Looking ahead, Hruska’s team aims to enhance MBI by reducing scan time from approximately 40 minutes and increasing patient comfort, building on strong satisfaction rates indicated by 97% of patients surveyed saying they would return for another MBI. She emphasized that while mammography remains vital for early detection, women with dense breasts should consider additional imaging tests such as MBI to improve diagnostic accuracy.

Importantly, the team’s research revealed that most cancers detected by MBI but missed by mammography were invasive and advanced, suggesting that broader use of MBI could significantly reduce breast cancer mortality by identifying the most aggressive tumors earlier.

No relevant disclosures.

References

1. Mayo Clinic. Mayo Clinic research improves dense breast cancer screening and early detection. Eurekalert. October 2, 2025. Accessed October 10, 2025. https://www.eurekalert.org/news-releases/1100598
2. Hruska CB, Hunt KN, Larson NB, et al. Molecular Breast Imaging and Digital Breast Tomosynthesis for Dense Breast Screening: The Density MATTERS Trial. Radiology. 2025;316(3). doi:https://doi.org/10.1148/radiol.243953