双层 CT (DLCT) 可以在各种单色 X 射线能量下，特别是在低 keV 水平下，创建具有高对比度噪声比的虚拟单色图像 (VMI)。本研究的目的是评估对比增强胸部 DLCT 和低 keV VMI 与乳腺 MRI 相比用于术前乳腺癌分期的临床可行性。共有 152 名患有 155 个指数乳腺癌的患者参加了该研究。 VMI 是通过 40 keV 的对比增强胸部 DLCT 生成的，并对双侧乳房区域进行了三维 (3D) 重建的最大强度投影 (MIP)。两名放射科医生在 3 个月的清除期的单独会议中一致审查了胸部 DLCT 与 VMI 和乳房 MRI 的 3D MIP 图像。比较胸部 DLCT VMI 和乳腺 MRI 的检出率和平均肿瘤大小。此外，还评估了两种成像方式之间肿瘤大小测量的一致性。在所有指标癌症中，84.5% (131/155) 在采用 VMI 的胸部 DLCT 中检出，而 88.4% (137/155) 在乳腺中检出MRI（P = 0.210）。胸部 DLCT 与 VMI 和乳腺 MRI 之间的 Bland-Altman 一致性为 -0.05 cm，95% 一致性限度为 -1.29 至 1.19 cm。胸部 DLCT VMI 肿瘤大小 (2.3 ± 1.7 cm) 与乳腺 MRI 肿瘤大小 (2.4 ± 1.6 cm) 无显着差异 (P = 0.106)。 论证了胸部 DLCT VMI 术前肿瘤分期的可行性在乳腺癌患者中，与乳腺 MRI 相比，显示出可比的癌症检测能力和肿瘤大小测量的良好一致性。这表明胸部 DLCT 结合 VMI 可以作为有乳腺 MRI 禁忌症的患者的潜在替代方案。版权所有 © 2024 韩国放射学会。

Dual-layer CT (DLCT) can create virtual monochromatic images (VMIs) at various monochromatic X-ray energies, particularly at low keV levels, with high contrast-to-noise ratio. The purpose of this study was to assess the clinical feasibility of contrast-enhanced chest DLCT with a low keV VMI for preoperative breast cancer staging, in comparison to breast MRI.A total of 152 patients with 155 index breast cancers were enrolled in the study. VMIs were generated from contrast-enhanced chest DLCT at 40 keV and maximum intensity projection (MIP) with three-dimensional (3D) reconstruction was performed for both bilateral breast areas. Two radiologists reviewed in consensus the 3D MIP images of the chest DLCT with VMI and breast MRI in separate sessions with a 3-month wash-out period. The detection rate and mean tumor size of the index cancer were compared between the chest DLCT with VMI and breast MRI. Additionally, the agreement of tumor size measurement between the two imaging modalities were evaluated.Of all index cancers, 84.5% (131/155) were detected in the chest DLCT with VMI, while 88.4% (137/155) were detected in the breast MRI (P = 0.210). The Bland-Altman agreement between the chest DLCT with VMI and breast MRI was a mean difference of -0.05 cm with 95% limits of agreement of -1.29 to 1.19 cm. The tumor size in the chest DLCT with VMI (2.3 ± 1.7 cm) was not significantly different from that in the breast MRI (2.4 ± 1.6 cm) (P = 0.106).The feasibility of chest DLCT with VMI was demonstrated for preoperative tumor staging in breast cancer patients, showing comparable cancer detectability and good agreement in tumor size measurement compared to breast MRI. This suggests that chest DLCT with VMI can serve as a potential alternative for patients who have contraindications to breast MRI.Copyright © 2024 The Korean Society of Radiology.