Based on a study published online in the October issue of Radiology, analyzing breast density at CT of the chest could provide additional information on a patient's risk evaluation for breast cancer.
Mary Salvatore, MD, of the Mount Sinai School of Medicine in New York City, and her peers conducted a pilot study comparing radiologists’ reading of breast density at chest CT with breast density readings from mammography done for the very same patient(s). A subgroup of these readings were then compared with computer-derived measurements of breast density at CT.
The researchers chose two radiologists with impressive experience in analyzing, reading, and interpreting mammographic and CT findings to independently perform a retrospective review of mammograms and chest CT scans from 206 women aged 29 to 91.
The radiologists were also asked to categorize each case into one of the four breast density types, as defined by the Breast Imaging Reporting and Data System (BI-RADS) of the American College of Radiology. 
Computer-derived measurements were then used to identify the estimated breast region of interest (ROI). The computer-based breast density was based on the percentage of glandular tissue in the breast ROI and typified into one of the four CT density grades.
Statistical analysis was completed to find an agreement between the breast density type on the basis of the mammogram and chest CT scan for each radiologist. Intrareader agreement was determined, as well as the percentage agreement between the computer-derived measurements and the consensus-read CT scans.
Results eventually revealed that interreader agreement was higher for the CT density grades (0.79) than for the mammographic density types (0.62), which illustrates that the CT agreement was considerably more effective than the mammographic agreement.
The intrareader consistency of breast density grades on CT images was 0.88. The computer-derived breast density measurements were in agreement with those of the radiologists in 90 percent of the cases. When the four cases were manually adjusted for complex anatomy, agreement was discovered and recorded for all cases.
“CT breast density readings represent an opportunity to provide additional information about the risk of breast cancer that is readily available and currently not being used in a standardized manner,” wrote Salvatore and peers.
