Contrast Mammography

While ‘mammography’ or a mammogram has long been the gold standard for imaging breasts, for some women, particularly those with dense breast tissue, a standard mammogram can be difficult to interpret. 

A contrast mammogram is a conventional 3D mammogram (tomosynthesis) which is performed once intravenous contrast is given. The advantage of this technique is the contrast ‘enhances’ any cancerous lesions in the breast, making it much easier to identify. The contrast agent injected into the drip is an iodinated contrast dye (contrast that has iodine). It works by highlighting new blood vessels that form when cancers grow. 

There are several scenarios where your doctor may recommend a contrast mammogram: 

• as a screening test if you have no symptoms but have a higher risk of getting breast cancer. It can also be useful in women who have dense breasts as a screening tool; 

• to help diagnose breast symptoms; 

• to gather more information about a tumour you already know you have and to identify if there are any additional hidden tumours; 

• to assess the response your cancer may be having to neoadjuvant treatment (e.g. chemotherapy or anti-Her 2 therapy). 

Advantages 

Contrast mammograms can identify cancers that are difficult to locate on conventional mammograms or ultrasound. Often such cancers will be small with an excellent outlook. 

Risks 

• Radiation: there is only slightly more radiation given with a contrast mammogram compared to a conventional mammogram. The extra radiation dose is equivalent to having one extra mammogram picture taken. To put this in perspective, an average dose level for a regular mammogram is the equivalent background radiation dose received when catching a return international flight from Australia to London. Such a small risk is far outweighed by the better prognosis of detecting an early breast cancer. The risk of developing cancer from a mammogram is no greater than developing cancer from exposure to the natural background radiation accumulated from the normal environment in one year. 

• IV contrast: occasionally there may be leakage of the contrast agent around the blood vessel the cannula is inserted into (extravasation). This is treated with ice and compression. Some patients report feeling nauseous at the time of contrast injection. This is temporary. Minor reactions include rash and swelling to the face which may need treatment with medication occur in 1 in 100 patients. Severe reactions are rare and occur in less than 1 in 100,000 patients. This may include death. 

• Pregnancy and breastfeeding: contrast mammography is generally not the preferred breast imaging option for those who are pregnant or breastfeeding. 

• Effects on the kidneys: temporary worsening of kidney function may be seen if you already have diabetes or impaired kidney function. 

• Ability to biopsy: technology to perform a breast biopsy on a lesion visible only on contrast mammography is currently not available in Australia (but will soon be coming). If a lesion is found, you will require imaging with another modality such as ultrasound or MRI to identify its location and perform a biopsy. 

• Breast implants: if you still have your natural breast tissue and also have implants, you may still have a mammogram. There is a very small risk of implant rupture and your radiographer should be made aware of the implants’ presence to factor them into the compression and perform a ‘push-back’ view. 

For more information on preparation and logistics of having a contrast mammogram, please refer to i-med’s information page https://i-med.com.au/procedures/contrast-mammography#gsc.tab=0