en Medical Physics Medical Physics تحقيق بديع Original Research <div style="text-align: justify;">Background: The objective was to explore the value of the CT value difference (△HU) and CT value ratio (CVR) between the hepatic arterial (AP), portal (PP), and delayed phases (DP) to differentiate the small Hepatocellular Carcinoma (SHCC, &le; 3 cm) from the small Focal nodular hyperplasia (SFNH, &le; 3 cm). Materials and Methods: All the lesions were confirmed by clinically and/or pathologically and all the patients underwent triple-phase enhanced CT scans. The lesions&rsquo; CT values (LCV) and the surrounding normal liver parenchyma (NCV) of the enhancement phases were measured separately, the △HU and CVR were calculated. Results: The median age and the male/female ratios of the SHCC and SFNH have statistically significant, and the size haven&rsquo;t statistically significant. The △HU and CVR of the AP, PP, and DP of the SHCCs and SFNHs were statistically significant, respectively. The area under curve of △HU and CVR of AP, PP and DP were increased gradually. When the △HU and CVR of the AP, PP and DP were 105.800HU vs. 1.516, -12.600HU vs. 0.949, -19.750 HU vs. 0.951, obtained the maximum You-den indexes. The corresponding sensitivity and specificity were 80.6 % and 90.1 % vs. 88.90% and 72.1%, 100% and 81.1% vs. 100% and 81.1%, 94.4 % and 96.4% vs. 94.4 % and 96.4%, respectively. Conclusion: The SHCC was highly suggested when △HU and CVR are no greater than 105.800HU and 1.516, -12.600HU and 0.949, -19.750 HU and 0.951 of the AP, PP, and DP in the middle-aged and elderly male patients, especially in the DP.</div> Computerized Tomography-value, Liver cancer, hepatocytes, Liver, focal nodular hyperplasia. 641 646 http://ijrr.com/browse.php?a_code=A-10-2055-48&slc_lang=en&sid=1 X.H. Ge 7900319475328460017359 7900319475328460017359 No Department of Radiology, The Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, China J.F. Zhang 570396920@qq.com 7900319475328460017360 7900319475328460017360 Yes Department of Radiology, the First Affiliated Hospital, College of Medicine, Zhejiang University, China