OTHER BREAST IMAGING IN DEVELOPMENT: Contrast-Enhanced Digital Mammography (CEDM)
What is it? CEDM uses a standard iodinated IV contrast agent, such as would be used for a typical CT scan, in combination with mammography, to make cancers that are not visible on standard mammograms show up as enhancing areas. The contrast is injected into an arm vein.
How it works: Just as on a breast MRI, which is also done with contrast, the cancer takes up more of the contrast agent than does the surrounding normal tissue. The contrast agent contains iodine, which blocks x-rays, causing the cancer to show up as a white area on the mammogram.
Benefits: In multiple studies, CEDM equaled MRI in its ability to detect breast cancer and is superior to both standard mammography and breast ultrasound. Compared to MRI, CEDM uses much less expensive equipment so it can be performed at less cost. It is also a shorter examination, lasting about 5 minutes, versus 30-40 minutes for an MRI.
Considerations: CEDM requires that an IV be placed into the arm for injection of the contrast agent. There is a small amount of radiation, about 50% more than for a standard mammogram. There is no direct method to biopsy abnormalities seen only on contrast-enhanced mammography. The Iodinated contrast agents carry some risks. Women with poor kidney function or prior contrast reaction should avoid it. Mild allergic reactions, such as those resulting in hives, occur in about 1% of patients. Severe allergic reactions resulting in anaphylaxis and even death are rare, but can occur. The risk of death from a reaction is estimated to be 1 in 100,000 to 1 in 200,000.
Courtesy of Dr. John Lewin
Figure 19. Contrast-Enhanced Mammography. Top: digital mammogram with cancer (yellow arrows), Bottom: contrast-enhanced mammogram in same patient; cancer (red circles) displays more visibly.
Lewin JM, Isaacs PK, Vance V, Larke FJ. Dual-energy contrast-enhanced digital subtraction mammography: feasibility. Radiology 2003; 229:261-268
Jochelson MS, Dershaw DD, Sung JS, et al. Bilateral Contrast-enhanced Dual-Energy Digital Mammography: Feasibility and Comparison with Conventional Digital Mammography and MR Imaging in Women with Known Breast Carcinoma. Radiology 2013; 266:743-751
McDonald, RJ, McDonald, JS, Kallmes, DF, et al. (2015). Intracranial gadolinium deposition after contrast-enhanced MR imaging. Radiology. Retrieved from: http://dx.doi.org/10.1148/radiol.15150025