Quantitative Transmission Imaging Compared With MRI as Supplemental Screening for High Lifetime Risk of Breast Cancer

In this prospective feasibility study, 25-30 women over the age of 18 years of age with a high lifetime risk of breast cancer >20% (as calculated by a risk assessment model such as Tyrer-Cuzick) and scheduled for a clinically ordered contrast-enhanced breast MRI were included. Exclusion criteria included pregnant or lactating patients, patients with open breast wounds or nipple discharge, patients heavier than 350 pounds, patients unable to lie prone for more than 15 minutes, and patients with a bra size larger than DDD. Enrolled patients were scheduled for a QT examination within 30 days of their clinical MRI. No additional follow-up appointments were required after the QTI exam.

Images from both imaging modalities were reviewed in consensus by four breast radiologists with 2-24 years of experience. Each interpretation was read without the benefit of prior history. The radiologists knew only that the breast MRI was a clinically indicated high-risk screening breast MRI. Since it was possible that one of the radiologists may have interpreted a breast MRI in the study, recall bias was mitigated by waiting about two months before interpreting the cases. The QTI scans were read in a randomized order. Later that same day, the MRI scans were read in randomized order. Up to three findings per breast could be reported for each imaging modality. For each finding, imaging characteristics, size, and location were recorded. A Breast Imaging Reporting and Data System (BI-RADS) score was assigned for each finding.

Weighted Cohen's kappa evaluated agreement between MRI and QTI BI-RADS scores. Unweighted Cohen's kappa used after dichotomizing scores into negative (BI-RADS 1-2) vs positive (BI-RADS 3-5) categories.

Inclusion criteria

• Women 18+ years of age
• High lifetime risk of breast cancer as determined by a risk assessment tool such a Tyrer-Cuzick model
• Clinical ordered screening MRI.

• MRI and QTI performed within 30 days of each other
• Breasts that will fit in the quantitate transmission (QT) Ultrasound Breast Scanner (e.g. bra cup size less than DDD)

Exclusion criteria

• Pregnant patients
• Lactating patients
• Patients with open wounds or discharge
• Patients < 18 years of age
• Patients who are > 350 lbs
• Patients who are unable to lay prone for >15 minutes