Jeongin Yoo1, Jeong Min Lee2,3,4,5, Jeong Hee Yoon1,6, Ijin Joo1,6, Eun Sun Lee7, Sun Kyung Jeon1, Siwon Jang8. 1. Department of Radiology, Seoul National University Hospital, Seoul, Korea. 2. Department of Radiology, Seoul National University Hospital, Seoul, Korea. jmlshy2000@gmail.com. 3. Department of Radiology, Seoul National University College of Medicine, Seoul, Korea. jmlshy2000@gmail.com. 4. Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea. jmlshy2000@gmail.com. 5. Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Daehak-ro 101, Jongno-gu, Seoul, 03080, Korea. jmlshy2000@gmail.com. 6. Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea. 7. Department of Radiology, Chung-Ang University Hospital, Seoul, Korea. 8. Department of Radiology, Seoul National University Boramae Hospital, Seoul, Korea.
Abstract
PURPOSE: To compare lesion conspicuity and image quality of arterial phase images obtained from low kVp (90-kVp) and dual-energy (DE) scans for the evaluation of hypervascular hepatocellular carcinoma (HCC). METHODS: This retrospective study included 229 patients with HCC who underwent either 90 kVp (n = 106) or DE scan (80- and 150-kVp with a tin filter) (n = 123) during the arterial phase. DE scans were reconstructed into a linearly blended image with a mixed ratio of 0.6 (60% 80kVp and 40% 150 kVp) and post-processed for 40 keV and 50 keV images. The contrast-to-noise ratio (CNR) of HCC to the liver and image noise was measured. Lesion conspicuity, liver parenchymal image quality, and overall image preference were assessed qualitatively by three independent radiologists. RESULTS: DE 40 keV images had the highest CNR of HCC, and DE blended images had the lowest image noise among four image sets (p = 0.01 and p < 0.001, respectively). There was no significant difference in mean volume CT dose index and dose-length product between DE and low kVp scan (ps > 0.05). For qualitative analyses, DE blended images had the highest scores for image quality and overall image preference (ps < 0.001). CONCLUSION: At an equal radiation dose, DE 40 keV showed higher CNR of HCC and DE blended image showed higher image quality and image preference compared with low kVp CT.
PURPOSE: To compare lesion conspicuity and image quality of arterial phase images obtained from low kVp (90-kVp) and dual-energy (DE) scans for the evaluation of hypervascular hepatocellular carcinoma (HCC). METHODS: This retrospective study included 229 patients with HCC who underwent either 90 kVp (n = 106) or DE scan (80- and 150-kVp with a tin filter) (n = 123) during the arterial phase. DE scans were reconstructed into a linearly blended image with a mixed ratio of 0.6 (60% 80kVp and 40% 150 kVp) and post-processed for 40 keV and 50 keV images. The contrast-to-noise ratio (CNR) of HCC to the liver and image noise was measured. Lesion conspicuity, liver parenchymal image quality, and overall image preference were assessed qualitatively by three independent radiologists. RESULTS: DE 40 keV images had the highest CNR of HCC, and DE blended images had the lowest image noise among four image sets (p = 0.01 and p < 0.001, respectively). There was no significant difference in mean volume CT dose index and dose-length product between DE and low kVp scan (ps > 0.05). For qualitative analyses, DE blended images had the highest scores for image quality and overall image preference (ps < 0.001). CONCLUSION: At an equal radiation dose, DE 40 keV showed higher CNR of HCC and DE blended image showed higher image quality and image preference compared with low kVp CT.
Authors: W Dennis Foley; William P Shuman; Marilyn J Siegel; Dushyant V Sahani; Daniel T Boll; David N Bolus; Carlo N De Cecco; Ravi K Kaza; Desiree E Morgan; U Joseph Schoepf; Terri J Vrtiska; Benjamin M Yeh; Lincoln L Berland Journal: J Comput Assist Tomogr Date: 2016 Nov/Dec Impact factor: 1.826