Taguchi Hidetoshi, Imamura Akihiro, Sekiguchi Kotaro, Okada Hiroaki, Funatsu Hiroyuki, Takano Hideyuki, Suzuki Kojiro
Department of Diagnostic Imaging Division, Chiba Cancer Center, Chiba, Japan.
Department of Radiology, Aichi Medical University, Nagakute, Japan.
Acta Radiol Open. 2025 Jul 19;14(7):20584601251360347. doi: 10.1177/20584601251360347. eCollection 2025 Jul.
As CT pulmonary angiography (CTPA) is not performed in routine contrast-enhanced CT, it is important to improve the accuracy of embolism detection from the portal-venous phase images that are generally obtained.
To assess the diagnostic performance of virtual monochromatic images (VMIs) obtained from portal phase dual-energy CT (PP-DECT) by qualitative and quantitative evaluation of contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) compared with those of CTPA.
Included were 45 oncology patients who had been diagnosed with pulmonary embolism based on CTPA. Two radiologists evaluated conventional PP-DECT images and VMIs created from PP-DECT at 40, 55, 70, and 85 keV with the window width and level fixed at 400/70. The energy with the highest diagnostic accuracy was determined, and the image was re-evaluated under conditions where the window could be freely set. Quantitative evaluation was based on CNR and SNR.
Under the condition of fixed window width and level, the energy with the highest accuracy was 55 keV for both radiologists. When the window was set freely in the 55 keV image, accuracy rates were 96.0% and 96.3%; and were 98.5% and 98.1% when limited to the main pulmonary artery or lobar level. CNR and SNR were highest at 40 keV, and were similar to those of CTPA.
Compared to original PP-DECT images, 55 keV images created from PP-DECT appear more useful for detecting pulmonary embolism.
由于常规增强CT不进行CT肺动脉造影（CTPA），因此提高从通常获取的门静脉期图像中检测栓塞的准确性很重要。
通过与CTPA的对比噪声比（CNR）和信噪比（SNR）进行定性和定量评估，来评估门静脉期双能量CT（PP-DECT）获得的虚拟单色图像（VMI）的诊断性能。
纳入45例经CTPA诊断为肺栓塞的肿瘤患者。两名放射科医生评估了常规PP-DECT图像以及在40、55、70和85keV下由PP-DECT生成的VMI，窗宽和窗位固定为400/70。确定诊断准确性最高的能量，并在可自由设置窗宽的条件下重新评估图像。定量评估基于CNR和SNR。
在固定窗宽和窗位的条件下，两名放射科医生诊断准确性最高的能量均为55keV。在55keV图像中自由设置窗宽时，准确率分别为96.0%和96.3%；仅限于主肺动脉或叶水平时，准确率分别为98.5%和98.1%。CNR和SNR在40keV时最高，与CTPA相似。
与原始PP-DECT图像相比，由PP-DECT生成的55keV图像在检测肺栓塞方面似乎更有用。
