Article

Clarity for Breast Cancer: Giving Doctors a Clear Answer

Doctors are often left with results from conventional mammogram exams that create uncertainty when it comes to clarifying breast cancer diagnosis, particularly for women with dense tissue. With the introduction of contrast-enhanced mammography (CEM), doctors are now able to provide patients with a much more exact image of their cancer and therefore, a firmer answer to this potentially life-altering moment. With this level of certainty, patients will now be able to better understand their care journey  and why it must begin immediately, and thus, saving precious time.

Before CEM was introduced, magnetic resonance imaging (MRI), and its associated costs as well as accessibility and scheduling challenges, had been the only contrast-based option for evaluating women with dense breast tissue.1 Conventional mammography visualizations are morphological with limitations related to accuracy especially in dense tissue assessment where the addition of functional data from a contrast agent could improve diagnostic accuracy.1

Diagnostic clarity with dual-energy contrast enhancement

Contrast-enhanced mammography is an imaging method where low-energy and high-energy images are acquired 90 to 120 seconds after injecting the patient with an iodine-based contrast medium.2 Placement of the patient in the scanner for acquisition of the low-energy image is similar to a full-field digital mammography (FFDM) exam and includes conventional mediolateral oblique and craniocaudal views.1,2,3 A second high-energy image is acquired in order to display uptake of the iodine that visualizes vascular data such as angiogenesis that is often associated with cancer.1,2 Enhanced images in additional views can be obtained up to 7 to 10 minutes following contrast administration.3

Once image acquisition is complete, the contrast-enhanced subtraction images are produced using a weighted logarithmic subtraction of the low-energy image from the high-energy image.3 This dual-energy subtraction technique increases the visibility of the iodine while virtually eliminating visibility of the background tissue because the difference in iodine absorption between the images is larger than the difference in tissue absorption.3 The final set of two images are sent to a workstation for review and interpretation by the radiologist.3

Greater clarity for imaging facilities with limited resources

Indications for both contrast-based imaging methods are comparable, however there are fewer contraindications for CEM. Patient contraindications associated with MRI include renal impairment, comfort, weight, and claustrophobia, among others, such as high cost, inaccessible equipment, and scheduling wait times.1 On the other hand, CEM is contraindicated for patients with renal impairment and for those who are pregnant because it is otherwise considered to be easily accessible, cost-effective, and uses the same equipment as conventional mammography.1

Contrast-enhanced mammography is also currently being used is in assessing the extent of disease for presurgical planning.1 Some radiologists are looking for CEM's potential for monitoring neoadjuvant therapy and evaluation for tumor recurrence.1

Future CEM research of interest to radiologists includes using contrast-enhanced mammography as a replacement for breast MRI in certain indications and whether the protocol can optimized for different indications.2

References:

  1. Contrast-enhanced mammography effective in detecting breast lesions. Aunt Minnie Europe https://www.auntminnieeurope.com/index.aspx?sec=sup&sub=wom&pag=dis&ItemID=609784 Accessed 10/20/2019
  2. Contrast-enhanced mammography prepares to enter clinical mainstream. Aunt Minnie https://www.auntminnieeurope.com/index.aspx?sec=rca&sub=ecr_2018&pag=dis&ItemID=615596 Accessed 10/20/2019
  3. Contrast Enhanced Digital Mammography. Society of Breast Imaging https://www.sbi-online.org/RESOURCES/WhitePapers/TabId/595/ArtMID/1617/ArticleID/601/Contrast-Enhanced-Digital-Mammography.aspx Accessed 10/20/2019