The feasibility of contrast-enhanced spectral mammography immediately after contrast-enhanced CT.

Contrast-enhanced spectral mammography (CESM) is a digital mammography method that requires an intravenous injection of iodinated contrast material to detect hypervascular lesions. In patients undergoing evaluation for metastases before breast tumor surgery, a contrast material must be injected for computed tomography (CT) and CESM studies. The purpose of our study was to investigate the feasibility of performing CESM immediately after contrast-enhanced CT, without injecting additional contrast material. We enrolled 77 women with 88 breast carcinomas. Immediately after contrast-enhanced CT, we performed CESM without injecting additional contrast material. The patients were divided into two groups based on the length of the interval between contrast material injection and the start of mammography. In group A (n = 51), it was less, and in group B (n = 26) it was more than 7 min. We measured the tumor gland contrast of each tumor on the CESM images and recorded the tumor opacification on a 4-point visual scale. The mean interval between the start of contrast material injection for CT and the acquisition of mammograms in groups A and B was 5.41 and 10.40 min, respectively. All lesions were detectable on the CESM images. There was no significant difference in the visual evaluation between the two groups (p = 0.21). CESM immediately after contrast-enhanced CT without the injection of additional contrast material is feasible and cost-effective.