Dual-energy computed tomography for evaluation of breast cancer. Value of virtual monoenergetic images reconstructed with a noise-reduced monoenergetic reconstruction algorithm

To evaluate the image quality and lesion visibility of virtual monoenergetic images (VMIs) reconstructed using a new monoenergetic reconstruction algorithm (nMERA) for evaluation of breast cancer. Forty-two patients with 46 breast cancers who underwent 4-phasic breast contrast-enhanced computed tomography (CT) using dual-energy CT (DECT) were enrolled. We selected the peak enhancement phase of the lesion in each patient. The selected phase images were generated by 120-kVp-equivalent linear blended (M120) and monoenergetic reconstructions from 40 to 80 keV using the standard reconstruction algorithm (sMERA: 40, 50, 60, 70, 80) and nMERA (40+, 50+, 60+, 70+, 80+). The contrast-to-noise ratio (CNR) was calculated and objectively analyzed. Two independent readers subjectively scored tumor visibility and image quality each on a 5-point scale. The CNR at 40+ and tumor visibility scores at 40+ and 50+ were significantly higher than those on M120. The CNR at 50+ was not significantly different from that on M120, However, the overall image quality score at 40+ was significantly lower than that at 50 + and on M 120 (40 + vs M120, P < 0.0001 and 40+ vs 50+, P=0.0001). (author)