Sanaz Javadi1, Sherif Elsherif2, Priya Bhosale3, Corey T Jensen3, Rick R Layman4, Megan C Jacobsen4, Ott Le3, Sun Jia5, Rajan J Parikh6, Eric P Tamm3. 1. Department of Abdominal Imaging, The University of Texas MD Anderson Cancer Center, 1400 Pressler St. Unit 1437, Houston, TX, 77030, USA. sanaz.javadi@mdanderson.org. 2. Department of Internal Medicine, Weiss Memorial Hospital, Affiliate of the University of Illinois, Chicago, Chicago, IL, USA. 3. Department of Abdominal Imaging, The University of Texas MD Anderson Cancer Center, 1400 Pressler St. Unit 1437, Houston, TX, 77030, USA. 4. Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. 5. Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. 6. Department of Bioengineering, The University of California, Berkeley, CA, USA.
Abstract
PURPOSE: To evaluate the quantitative attenuation and reliability of virtual non-contrast (VNC) images of the abdomen acquired from multiphasic scans with a dual-energy computed tomography (DECT) system and compare it with that of true non-enhanced images (TNC) on second- (Flash) and third- (Force) generation DECT scanners. METHODS: This retrospective study was approved by the institutional review board and included 123 patients with pancreatic cancer who had undergone routine clinical multiphasic DECT examinations at our institution using Flash and Force scanners between March and August 2017. VNC images of the abdomen were reconstructed from late arterial phase images. For every patient, regions-of-interest were defined in the aorta, fluid-containing structures (gallbladder, pleural effusion, and renal cysts > 10 mm), paravertebral muscles, subcutaneous fat, spleen, pancreas, renal cortex, and liver (eight locations) on TNC and VNC images. The mean attenuation of VNC was compared with TNC by organ for each CT scanner using an equivalence test and the Bland-Altman plot. The mean attenuations for TNC or VNC were compared between the Force and Flash CT scanners using a two-sample t test. RESULTS: The VNC attenuation of organs on the Force scanner was lower than was that on the Flash, and the mean attenuation difference in different organs on the Force was closer to 0. The estimated means of TNC and VNC were equivalent for an equivalence margin of 10 on the Force scanner. CONCLUSION: VNC images in DECT are a promising alternative to TNC images. In clinical scenarios in which non-enhanced CT images are required but are not available for accurate diagnosis, VNC images can potentially serve as an alternative to TNC images without the radiation exposure risks.
PURPOSE: To evaluate the quantitative attenuation and reliability of virtual non-contrast (VNC) images of the abdomen acquired from multiphasic scans with a dual-energy computed tomography (DECT) system and compare it with that of true non-enhanced images (TNC) on second- (Flash) and third- (Force) generation DECT scanners. METHODS: This retrospective study was approved by the institutional review board and included 123 patients with pancreatic cancer who had undergone routine clinical multiphasic DECT examinations at our institution using Flash and Force scanners between March and August 2017. VNC images of the abdomen were reconstructed from late arterial phase images. For every patient, regions-of-interest were defined in the aorta, fluid-containing structures (gallbladder, pleural effusion, and renal cysts > 10 mm), paravertebral muscles, subcutaneous fat, spleen, pancreas, renal cortex, and liver (eight locations) on TNC and VNC images. The mean attenuation of VNC was compared with TNC by organ for each CT scanner using an equivalence test and the Bland-Altman plot. The mean attenuations for TNC or VNC were compared between the Force and Flash CT scanners using a two-sample t test. RESULTS: The VNC attenuation of organs on the Force scanner was lower than was that on the Flash, and the mean attenuation difference in different organs on the Force was closer to 0. The estimated means of TNC and VNC were equivalent for an equivalence margin of 10 on the Force scanner. CONCLUSION: VNC images in DECT are a promising alternative to TNC images. In clinical scenarios in which non-enhanced CT images are required but are not available for accurate diagnosis, VNC images can potentially serve as an alternative to TNC images without the radiation exposure risks.
Authors: Sarah C Scharm; Cornelia Schaefer-Prokop; Moritz Willmann; Jens Vogel-Claussen; Lars Knudsen; Danny Jonigk; Jan Fuge; Tobias Welte; Frank Wacker; Antje Prasse; Hoen-Oh Shin Journal: Eur Radiol Date: 2022-03-31 Impact factor: 7.034