The accuracy of titanium contrast-enhanced mammography: a retrospective multicentric study

BACKGROUND: Recently, a new mammography system to perform contrast-enhanced mammography has become available in the market. For the high-energy acquisition, it uses a titanium filter instead of a copper one, reducing the tube load while maintaining image quality.

PURPOSE: To retrospectively evaluate the accuracy of contrast-enhanced mammography with a titanium filter (TiCEM) in three readers with different grades of experience.

MATERIAL AND METHODS: IRB-approved retrospective multicentric lesion by lesion study with 200 lesions, all of them initially classified as BI-RADS categories 0/3/4/5 on mammography and/or ultrasound and with pathological confirmation, in 135 patients. Three readers with different levels of experience (expert, resident, intermediate) blinded to the final diagnosis, retrospectively evaluated the low-energy (LE) images and the combination of LE and recombined (subtracted) images and classified the lesions according to the BI-RADS categories. Reader 1 also categorized the breast density. ROC curves were performed for each reader.

RESULTS: Out of the 200 lesions, 82 were benign and 118 malignant (20 DCIS, 10 ILC, 88 IDC). The AUCs of LE versus TiCEM for were: Reader 1: 0.7 vs. 0.88, P < 0.001; Reader 2: 0.63 vs. 0.83, P < 0.001; and Reader 3: 0.63 vs. 0.84, P < 0.001. For the three readers, the AUCs of LE versus TiCEM were significantly superior in both dense and non-dense breasts (P < 0.001). Comparing the AUC of LE for Reader 1 (expert) versus the AUC of TiCEM for Reader 2 (resident) there were significant differences (0.7 vs. 0.83, P < 0.001).

CONCLUSION: The accuracy of TiCEM was significantly better for all the readers, in both dense and non-dense breasts. The accuracy of a resident reading a TiCEM study was better than the accuracy of an expert radiologist reading LE images.