Some breast cancers hide in plain sight. In dense breast tissue, a tumor and the tissue around it can look identical on a standard mammogram, white on white. Contrast enhanced mammography, or CEM, tackles that problem by adding an iodine contrast agent that highlights areas with increased blood supply, the way tumors typically behave. The result is a mammogram that shows not only structure but also activity. This article explains how CEM works, when it is used, and what happens after CEM finds something that needs treatment.
CEM, sometimes called contrast enhanced spectral mammography or CESM, is a mammogram performed after an iodine based contrast agent is injected into a vein in the arm. Growing tumors recruit extra blood vessels, and the contrast agent accumulates where blood supply is increased. By taking two images at different X-ray energies and combining them, the system subtracts the normal tissue background and leaves an image in which enhancing areas stand out. A state of the art review in Radiology (doi: 10.1148/radiol.2021201948) describes how this functional information substantially improves cancer detection compared with standard mammography, particularly in dense breasts.
The exam feels much like a regular mammogram and takes about ten minutes longer. A small intravenous line is placed in the arm and the contrast agent is injected. After roughly two minutes, images of both breasts are taken in the usual positions. Each compression produces two exposures at different energies, which the system combines into a familiar looking mammogram plus a recombined image showing where contrast has accumulated. The intravenous line is removed and normal activities can resume immediately. Total radiation dose is somewhat higher than a standard mammogram but well within accepted limits.
Nearly half of women undergoing screening have dense breast tissue, which both raises breast cancer risk and lowers the sensitivity of standard mammography. This interaction between density and detection is explored in Breast Density and Tumor Localization. CEM is used when standard imaging leaves questions: to clarify an uncertain finding, to map the true extent of a known cancer before surgery, to look for additional tumors in the same or the other breast, and to monitor how a tumor responds to chemotherapy given before surgery. In each of these situations the functional image answers a question the standard mammogram cannot.
Breast MRI is the other exam that shows enhancement, and studies reviewed in Radiology (doi: 10.1148/radiol.2021201948) report that CEM approaches its sensitivity for many indications. The practical differences decide which is used: CEM is faster, more widely available, more comfortable for patients who find MRI claustrophobic, and less expensive, while MRI avoids radiation and iodine contrast and remains the standard for specific indications such as screening women at the highest risk. Both can serve as a roadmap for surgery, and MRI guided workflows are described in MRI Guided Localization in Breast Cancer. Imaging manufacturers such as GE HealthCare offer mammography systems on which contrast enhanced imaging is performed.
An enhancing area on CEM is not a diagnosis; tissue confirmation comes first. A biopsy is taken from the suspicious area, and during that biopsy a small marker is placed so the exact spot can always be found again, whatever later imaging shows. The role of that marker is explained in Clip Marker in Breast Cancer. If surgery follows, the marked lesion, often one that could never be felt by hand, must be located precisely in the operating room. That is the localization step described in Surgery for Non Palpable Breast Cancer: the better the imaging that found the tumor, the more important it becomes that surgery can find exactly the same spot.
The iodine based contrast used for CEM is the same type used for CT scans, with a long safety record. Mild reactions such as a warm feeling are common and brief. People with a previous reaction to iodine contrast or with reduced kidney function should mention this beforehand, as it may make MRI the better choice.
The dual energy technique adds roughly a fifth to a half to the dose of a standard mammogram, depending on the system and breast thickness. The total remains within international safety limits for mammography.
Yes. Contrast enhanced spectral mammography, contrast enhanced digital mammography and CEM all refer to the same technique of dual energy mammography after intravenous iodine contrast.
For women with dense tissue and a clinical question, CEM detects cancers that standard mammography can miss, because it shows blood supply rather than only structure. Whether it is appropriate in your situation is a decision for your radiologist.
No. CEM shows where suspicion is; only tissue sampling can confirm what an enhancing area is. CEM often makes the biopsy more targeted.
Better imaging finds smaller, earlier and less palpable tumors, which raises the bar for surgery: what imaging can see, the surgeon must be able to find. Sirius Medical developed the Pintuition System® for that step. After a suspicious finding is confirmed, the Pintuition Marker®, a non radioactive and permanent magnetic marker, is placed in the lesion under image guidance, and thanks to its long term implantation indication this can be done as early as the biopsy itself. During surgery GPSDetect™ technology gives the surgeon continuous distance and direction to the marker, independent of how the lesion was discovered. In the French 200 case series in Scientific Reports (doi: 10.1038/s41598-025-88430-5), 100 percent of lesions were successfully excised. The wider marking landscape is covered in Breast Localization Device and Implantable Markers.
Learn how Pintuition® can support precision, workflow efficiency and reliable excision in breast cancer surgery. Request demo or explore the clinical overview for more information.
Disclaimer
This article is intended for informational purposes only and should not be considered medical advice. Clinical decisions should always be made by qualified healthcare professionals based on individual patient needs and current guidelines.