Digital Mammography: Computed Radiography Detects Fewer Cancers

A new study published in Radiology found that direct digital radiography (DDR), is the more effective digital mammography option when compared to computed radiography (CR). DDR is also equivalent to screen-film mammography (SFM), though the latter is used less frequently these days. Research shows that both DDR and SFM are able to detect a significantly greater number of cancers than CR.

DDR and CR have evolved to be the most widely implemented digital breast imaging systems. DDR is an online system that includes a detector as an integral part of the mammographic unit to allow reading of the digital image in real time. CR is an offline system using a cassette-based removable detector and an external reading device to generate the digital image. Until recently, it was believed that both systems detected breast cancers at an equal rate. However, data from the Ontario Breast Screening Program showed that while DDR and SFM had similar detection rates, CR was 21 percent less effective than DDR.  According to the lead investigators, this could result in 10 fewer breast cancers detected for every 10,000 women screened.

At UCSF, we use full-field digital mammography (FFDM), a type of DDR system. In addition to detecting more cancers, FFDM is also the faster alternative. While CR involves a cassette that needs to be fed through an external reading device in order to get the digital image to the workstation, FFDM has the advantage of directly transmitting digital images to the workstation for radiologists to view.

The UCSF Department of Radiology views DDR as a more viable option for effective breast cancer screening.  As recommended by the study authors, those screening programs that use both types of digital mammography should monitor the performance of CR separately and inform women of the potentially lower cancer detection rates.

We encourage you to speak to your doctor about which type of digital radiology system is being used for your breast cancer screening.

For more information on breast cancer screening at UCSF, please see here.