Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, Lyon, France.
Radiology Department, Hospices Civils de Lyon, CHU Louis Pradel, 59 Boulevard Pinel, 69500, Bron, France.
Eur Radiol. 2019 Dec;29(12):6762-6771. doi: 10.1007/s00330-019-06322-5. Epub 2019 Jul 1.
To assess whether virtual non-contrast (VNC) images derived from contrast dual-layer dual-energy computed tomography (DL-DECT) images could replace true non-contrast (TNC) images for aortic intramural hematoma (IMH) diagnosis in acute aortic syndrome (AAS) imaging protocols by performing quantitative as well as qualitative phantom and clinical studies.
Patients with confirmed IMH were included retrospectively in two centers. For in vitro imaging, a custom-made phantom of IMH was placed in a semi-anthropomorphic thorax phantom (QRM GmbH) and imaged on a DL-DECT at 120 kVp under various conditions of patient size, radiation exposure, and reconstruction modes. For in vivo imaging, 21 patients (70 ± 13 years) who underwent AAS imaging protocols at 120 kVp were included. In both studies, contrast-to-noise ratio (CNR) between hematoma and lumen was compared using a paired t test. Diagnostic confidence (1 = non-diagnostic, 4 = exemplary) for VNC and TNC images was rated by two radiologists and compared. Effective radiation doses for each acquisition were calculated.
In both the phantom and clinical studies, we observed that the CNRs were similar between the VNC and TNC images. Moreover, both methods allowed differentiating the hyper-attenuation within the hematoma from the blood. Finally, we obtained equivalent high diagnostic confidence with both VNC and TNC images (VNC = 3.2 ± 0.7, TNC = 3.1 ± 0.7; p = 0.3). Finally, by suppressing TNC acquisition and using VNC, the mean effective dose reduction would be 40%.
DL-DECT offers similar performances with VNC and TNC images for IMH diagnosis without compromise in diagnostic image quality.
• Dual-layer dual-energy CT enables virtual non-contrast imaging from a contrast-enhanced acquisition. • Virtual non-contrast imaging with dual-layer dual-energy CT reduces the number of acquisitions and radiation exposure in acute aortic syndrome imaging protocol. • Dual-layer dual-energy CT has the potential to become a suitable imaging tool for acute aortic syndrome.
通过进行定量和定性的体模和临床研究，评估对比双能量双层 CT（DL-DECT）图像的虚拟非对比（VNC）图像是否可以替代急性主动脉综合征（AAS）成像方案中的真实非对比（TNC）图像用于诊断主动脉壁内血肿（IMH）。
在两个中心回顾性纳入经证实的 IMH 患者。对于体外成像，将 IMH 定制体模放置在半拟人胸部体模（QRM GmbH）中，并在 120 kVp 下以不同的患者体型、辐射暴露和重建模式条件下对 DL-DECT 进行成像。对于体内成像，纳入 21 例（70 ± 13 岁）在 120 kVp 下进行 AAS 成像方案的患者。在这两项研究中，使用配对 t 检验比较血肿和管腔之间的对比噪声比（CNR）。两名放射科医生对 VNC 和 TNC 图像的诊断信心（1=无诊断价值，4=典型）进行评分并进行比较。计算每次采集的有效辐射剂量。
在体模和临床研究中，我们观察到 VNC 和 TNC 图像之间的 CNR 相似。此外，这两种方法都可以区分血肿内的高信号与血液。最后，我们使用 VNC 和 TNC 图像都获得了等效的高诊断信心（VNC=3.2 ± 0.7，TNC=3.1 ± 0.7；p=0.3）。最后，通过抑制 TNC 采集并使用 VNC，平均有效剂量减少 40%。
DL-DECT 为 IMH 诊断提供了与 VNC 和 TNC 图像相似的性能，而不会影响诊断图像质量。
• 双层双能 CT 可从对比增强采集获得虚拟非对比成像。
• 在急性主动脉综合征成像方案中，双层双能 CT 的虚拟非对比成像减少了采集次数和辐射暴露。
• 双层双能 CT 有可能成为急性主动脉综合征的合适成像工具。
