Contrast Enhanced Mammograms
The Breast Institute New Zealand is the first in New Zealand to offer contrast-enhanced mammography.
What is it?
Contrast-enhanced mammography (CEM) is also known as contrast-enhanced spectral mammography (CESM) or contrast-enhanced digital mammography (CEDM). CEM uses a standard iodinated intravenous (IV) contrast agent, such as would be used for a typical CT scan, in combination with mammography. Some cancers that may not be visible on standard mammograms will show up because of contrast enhancement.
Similar to a CT scan, the contrast is injected into an arm vein. CEM can be used for problem solving and to assess the extent of disease in women with newly diagnosed breast cancer.
How it works:
Positioning is like a standard mammogram, with the breast compressed. Beginning about two minutes after contrast injection, two exposures are taken in each view: one at low energy that mimics a standard mammogram, and one at higher energy that is absorbed by iodine; subtraction is performed to create an “iodine-only” image which is reviewed together with the low-energy image. Just as for breast MRI, which is also done with contrast, cancers typically take up more of the contrast agent than does the surrounding normal tissue. The contrast agent contains iodine, which absorbs x-rays, causing the cancer to show up white on the mammogram. Normal breast tissue (dense and non-dense) and benign (noncancerous) lesions will mostly appear dark on CEM, though some benign lesions and background tissue can show enhancement.
Benefits:
In multiple studies, CEM equaled or nearly equaled MRI in its ability to detect breast cancer and was superior to the combination of standard mammography and breast ultrasound .
Considerations:
CEM requires that an IV be placed into the arm for injection of the contrast agent. There is a small increase in the amount of radiation, about 50% more than for a standard mammogram, but less than that from combined 2D and 3D mammography.
Contrast agents carry some risks. Women with poor kidney function or history of prior contrast reaction should avoid it. Mild allergic reactions, such as those resulting in hives, occur in about 1% of patients.
How much does it cost?
A contrast mammogram costs $700 and may be covered by your Health Insurance provider.