Breast cancer is the most common cause of cancer-related death among women globally. Screening facilitates early detection of breast cancers, which is essential for reducing breast cancer-related mortality. Guidelines from major medical organizations generally support initiating screening mammography at the age of 40 years for average-risk women, although variability remains regarding the recommended screening interval and the age at which to stop screening. ^,,,

While 2-dimensional digital mammography (DM) continues to be the cornerstone of breast cancer screening, and is the only imaging modality with a proven mortality benefit, it is not without limitations, particularly in the setting of dense breast tissue. ^,,,, Digital breast tomosynthesis (DBT), which was approved for clinical use by the US Food and Drug Administration (FDA) in 2011 and offers a quasi-3-dimensional (3D) view of the breast, has largely supplanted DM as the standard of care in the United States. Additional modalities used in screening include whole-breast ultrasound (WBUS) for women with dense breast tissue and MR imaging for those at high-risk for breast cancer. Emerging technologies, such as contrast-enhanced mammography (CEM), molecular breast imaging (MBI), and artificial intelligence (AI), continue to expand the armamentarium of screening tools.

This article provides an updated review of breast cancer screening guidelines and examines the evolving role of both established and emerging imaging technologies. It evaluates the evidence supporting each modality, outlines their strengths and limitations, and discusses the growing impact of AI in breast imaging. Future directions are also considered in the ongoing effort to enhance screening effectiveness, minimize false-positives, and improve outcomes for all women.

Breast cancer screening is essential for early detection. While there is growing consensus about initiating screening at the age of 40 years, recommendations regarding how frequently to screen and the age at which to stop still vary among major medical organizations ( Table 1 ). In recent years, increasing attention has also been given to risk-based screening approaches that aim to personalize care based on individual risk profile.

Per the American College of Radiology (ACR) and Society of Breast Imaging (SBI) guidelines, annual mammographic screening should begin at the age of 40 years for women at average risk and should continue if she remains in good health and is willing to be treated if a breast cancer is diagnosed. In alignment with ACR and SBI guidelines, the National Comprehensive Cancer Network (NCCN) supports annual mammography starting at the age of 40 years for women at average risk.

The US Preventive Services Task Force (USPSTF) changed its screening guidelines in 2024. The USPSTF now recommends that biennial mammographic screening begin at the age of 40 years for women at average risk, which reflects a shift from its previous recommendation to initiate screening at the age of 50 years. The Task Force states that evidence is not sufficient to evaluate the benefits and harms of mammographic screening in women aged 75 years and older, leaving decisions in this age group to clinical judgment and individual preferences.

The American Cancer Society (ACS) offers a hybrid recommendation. Per ACS guidelines, women aged 40 to 44 years should have the opportunity to begin annual screening mammography, while those aged 45 to 54 years should undergo annual mammographic screening. Women aged 55 years and older should undergo biennial mammographic screening, though women may continue annual screening based on personal preference and health status. Screening mammography should continue if she remains in good health and her life expectancy is 10 or more years.

For women at high risk of breast cancer, the ACR, NCCN, and ACS recommend annual screening MR imaging in addition to annual screening mammography. ^,, Per the ACR, specific indications for high-risk screening include women with known genetic mutations (eg, breast cancer gene 1 [ BRCA1 ] and breast cancer gene 2 [ BRCA2 ]) and their untested first-degree relatives; women with a calculated lifetime breast cancer risk of 20% or greater; women with a history of cumulative chest radiation therapy of 10 Gy or greater by the age of 30 years; women diagnosed with breast cancer before the age of 50 years; and, women with a personal history of breast cancer and dense breast tissue. The ACR also emphasizes the importance of risk assessment by the age of 25 years to identify women who may benefit from earlier or supplemental screening.

DM remains the foundation of breast cancer screening and is, to date, the only imaging modality with a demonstrated mortality benefit. Large-scale randomized controlled trials, including the Health Insurance Plan of Greater New York study and trials conducted in Sweden and the United Kingdom, have shown that routine mammographic screening reduces breast cancer-related mortality by approximately 20% to 40%. ^,,,, Despite its established benefits, DM has known limitations, particularly in women with dense breast tissue, where cancers may be obscured by overlapping fibroglandular tissue.

DBT, approved by the US FDA in 2011, was developed to overcome some of these limitations. DBT acquires multiple low-dose projection images from different angles and reconstructs them into thin slices, offering a quasi-3D view of the breast. This tomographic approach reduces the masking effect of overlapping tissue and enhances lesion visibility ( Fig. 1 ).

A 51 year old woman presented for screening mammography and was found to have architectural distortion in the right breast. ( A ) Craniocaudal 2-dimensional digital mammographic view, ( B ) craniocaudal tomosynthesis image, ( C ) mediolateral oblique 2-dimensional digital mammographic view, and ( D ) mediolateral oblique tomosynthesis image show that the area of architectural distortion in the upper inner quadrant at middle depth (circles) is better visualized on DBT views than on DM views. ( E ) Targeted ultrasound shows a corresponding 7-mm irregular hypoechoic mass ( arrow ), which was biopsied under ultrasound guidance and revealed grade 1 invasive ductal carcinoma.

Multiple studies have shown that DBT in combination with DM improves cancer detection rates, especially for invasive cancers, and reduces false-positive rates compared to DM alone. ^,,,, As a result of these benefits, DBT has been widely adopted across the United States. However, while improvements in cancer detection and recall metrics are well documented, long-term data demonstrating a mortality benefit of DBT are not yet available. The Tomosynthesis Mammographic Imaging Screening Trial is an ongoing randomized trial comparing DBT to DM, with the primary goal of determining whether DBT reduces advanced breast cancer incidence.

WBUS, which involves neither ionizing radiation nor intravenous contrast, is increasingly used as an adjunctive imaging modality for breast cancer screening. Its growing use is driven, in part, by breast density notification legislation and heightened awareness of the limitations of mammography in detecting breast cancer in dense tissue. WBUS may be performed as handheld ultrasound (HHUS), either by a radiologist or a technologist, or as automated breast ultrasound (ABUS), which standardizes image acquisition and reduces operator variability.

A 2019 review article reported that, for women with dense breast tissue, the incremental cancer detection rate from supplemental ultrasound screening is 2.0 per 1000 (range, 0–6.8) for HHUS performed by physicians, 2.5 per 1000 (range, 2.0–3.8) for ABUS, and 2.7 per 1000 (range, 1.8–4.1) for HHUS performed by technologists. Approximately 88% of cancers detected solely by ultrasound are invasive. During the initial (prevalence) screening round, about 3% of women will undergo biopsy based on ultrasound findings, with malignancy rates for ultrasound-detected lesions ranging from 2% to 30%.

More recently, the performance of WBUS has been assessed in prospective multicenter studies involving women undergoing screening with DBT. A study of technologist-performed ultrasound after DBT in women with dense breast tissue reported a modest added cancer detection rate of 1.1 per 1000 screens (19 cancers in 17,552 screens; confidence interval: 0.5–1.6) with supplemental ultrasound after DBT. In the ASTOUND-2 trial which compared screening with DBT versus ultrasound in women with dense breast tissue and negative DM, the incremental cancer detection rate was 4.9 per 1000 (CI: 3.2–7.2) for ultrasound versus 2.8 per 1000 (CI: 1.6–4.7) for DBT ( P =.015). While ultrasound detected more cancers, it also led to more false-positives.

In addition to high false-positive and recall rates, other limitations of WBUS include its time-intensive nature in the handheld format and its operator dependence. According to the ACR, breast MR imaging is the preferred supplemental screening modality for women with dense breast tissue who desire additional screening. However, for individuals who qualify for but are unable to undergo MR imaging, ultrasound or CEM may be considered as alternative options.

MR imaging is the most sensitive breast imaging modality and is recommended for screening high-risk women ( Figs. 2 and 3 ). One of the first large prospective studies to compare MR imaging with mammography for high-risk breast cancer screening was the United Kingdom-based MARIBS study. The study included 649 women aged 35 to 49 years with a strong family history or a high likelihood of carrying BRCA1 , BRCA2 , or TP53 mutations. The results showed that MR imaging had significantly higher sensitivity than mammography (77% vs 40%, P =.01), particularly among BRCA1 carriers (92% vs 23%, P =.004). MR imaging, however, had lower specificity than mammography (81% vs 93%, P <.001).

A 41 year old woman with a family history of breast cancer presented for a baseline high-risk screening MR imaging examination and was found to have a mass in the right breast. ( A ) Axial and ( B ) sagittal postcontrast fat-saturated T1-weighted images demonstrate a 6-mm enhancing mass in the central inner right breast at middle depth ( arrows ). ( C ) Axial and ( D ) sagittal images with overlying kinetic maps demonstrate that the mass has mixed delayed kinetics ( arrows ). Targeted ultrasound and ultrasound-guided biopsy were recommended. Since the mass was not identified on ultrasound, MR imaging-guided biopsy was performed and yielded invasive ductal carcinoma.

A 46 year old woman with a family history of breast cancer presented for a high-risk screening MR imaging examination and was found to have non–mass enhancement in the right breast. ( A ) Axial and ( B ) sagittal postcontrast fat-saturated T1-weighted images demonstrate a 28–mm area of focal non-mass enhancement in the upper central right breast at posterior depth ( arrows ). ( C ) Axial and ( D ) sagittal images with overlying kinetic maps demonstrate that the non–mass enhancement has mixed delayed kinetics ( arrows ). MR imaging-guided biopsy was performed and yielded grade 3 invasive ductal carcinoma.

Despite its proven benefit of early cancer detection, breast MR imaging remains underutilized, with several barriers limiting widespread adoption. These barriers include high cost, limited access to MR imaging facilities, patient anxiety or claustrophobia, and concerns related to gadolinium-based contrast agents. To address some of these challenges, abbreviated breast MR imaging (AB-MRI) protocols have been developed as a cost-efficient and time-efficient alternative to conventional full-protocol breast MR imaging. AB-MRI typically consists of a single precontrast and one postcontrast T1-weighted sequence, in addition to a subtracted image or maximum intensity projection. Total acquisition times are generally under 10 minutes.

Several studies have shown that AB-MRI retains the high diagnostic accuracy of full breast MR imaging protocols. The EA1141 trial, a multicenter prospective study, demonstrated that AB-MRI achieved significantly higher cancer detection rates compared to DBT in women with dense breast tissue (invasive cancer detection rate of 11.8 vs 4.8 per 1000 women, P =.002), while maintaining acceptable specificity. The shorter scan time and reduced cost of AB-MRI increase its potential for broader implementation, particularly among intermediate-risk women who may not meet criteria for full-protocol MR imaging under current guidelines but could still benefit from supplemental screening. As technology advances and abbreviated protocols become more standardized, MR imaging may play an increasing role not only in high-risk populations but also in tailored screening strategies for women at intermediate risk. Continued research is needed to evaluate the long-term outcomes of AB-MRI, optimize patient selection, and determine screening intervals based on individualized risk.