Image quality enhancement of CT hepatic portal venography using dual energy blending with computer determined parameters

Article type: Research Article

Authors: Wang, Tao^{a; b; c; d; 1} | Han, Yuxin^{a; b; c; d; 1} | Lin, Liying^e | Yu, Changlu^{a; b; c; d} | Lv, Rong^{a; b; c; d} | Han, Li^{f; g; *}

Affiliations: [a] Department of Radiology, Tianjin Third Central Hospital, Tianjin, China | [b] Tianjin Institute of Hepatobiliary Disease, Tianjin, China | [c] Tianjin Key Laboratory of Artificial Cell, Tianjin, China | [d] Artificial Cell Engineering Technology Research Center of Public Health Ministry, Tianjin, China | [e] First Central Clinical College, Tianjin Medical University, Tianjin, China | [f] School of Medical Imaging, Tianjin Medical University, Tianjin, China | [g] Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China

Correspondence: [*] Corresponding author: Li Han, PhD, School of Medical Imaging, Tianjin Medical University, #1 Guangdong Road, Hexi, Tianjin 300110, China. E-mail: [email protected].

Note: [1] Tao Wang and Yuxin Han contributed equally as joint first authors to this work.

Abstract: BACKGROUND:Previous studies have shown that using some post-processing methods, such as nonlinear-blending and linear blending techniques, has potential to improve dual-energy computed (DECT) image quality. OBJECTIVE:To improve DECT image quality of hepatic portal venography (CTPV) using a new non-linear blending method with computer-determined parameters, and to compare the results to additional linear and non-linear blending techniques. METHODS:DECT images of 60 patients who were clinically diagnosed with liver cirrhosis were selected and studied. Dual-energy scanning (80 kVp and Sn140 kVp) of CTPV was utilized in the portal venous phase through a dual-source CT scanner. For image processing, four protocols were utilized including linear blending with a weighing factor of 0.3 (protocol A) and 1.0 (protocol B), non-linear blending with fixed blending width of 200 HU and set blending center of 150HU (protocol C), and computer-based blending (protocol D). Several image quality indicators, including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and contrast of hepatic portal vein and hepatic parenchyma, were evaluated using the paired-sample t-test. A 5-grade scale scoring system was also utilized for subjective analysis. RESULTS:SNR of protocols A-D were 9.1±2.1, 12.1±3.0, 11.6±2.8 and 14.4±3.2, respectively. CNR of protocols A-D were 4.6±1.3, 8.0±2.3, 7.0±2.0 and 9.8±2.4, respectively. The contrast of protocols A-D were 37.7±11.6, 91.9±21.0, 66.2±19.0 and 107.7±21.3, respectively. The differences between protocol D and other three protocols were significant (P < 0.01). In subjective evaluation, the modes of protocols A, B, C, and D were rated poor, good, generally acceptable, and excellent, respectively. CONCLUSION:The non-linear blending technique of protocol D with computer-determined blending parameters can help improve imaging quality of CTPV and contribute to a diagnosis of liver disease.

Keywords: Non-linear blending, linear blending, dual-energy computed tomography (DECT), CT portal venography (CTPV), hepatic portal vein, signal-to-noise ratio, contrast-to-noise ratio

DOI: 10.3233/XST-210967

Journal: Journal of X-Ray Science and Technology, vol. 30, no. 2, pp. 307-317, 2022