Itaya Shunsuke, Matsui Takeshi, Kamiyama Tetsuya, Yoshino Hiroyuki
Department of Medical Radiation Technology, Teine-Keijinkai Hospital.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2016;72(11):1084-1090. doi: 10.6009/jjrt.2016_JSRT_72.11.1084.
Recently, the number of patients with nonalcoholic fatty liver disease (NAFLD) has been increasing, and some of them progresses to cirrhosis and hepatocellular carcinoma. Dual energy CT allows the discrimination of substance using monochromatic image (MI), and steatosis exhibit specifically the CT value of each energy level. The purpose is to evaluate the fat quantification in the liver using spectral HU curve and CT value compare to a conventional image diagnosis.
Dual energy CT and liver biopsy were performed in 54 patients between October 2014 and April 2016. The CT value of 40 keV MI was measured by spectral HU curve setting 3 points ROI on the right and left liver. The CT value of 40 keV MI was compared with steatosis area and the NAFLD activity score (NAS). Additionally, steatosis area was compared with the conventional CT value scan and hepatorenal echo contrast value.
The CT value of 40 keV MI exhibited a negative correlation for the stenosis area (R=0.619), and NAS (R=0.147). Steatosis area exhibited correlation for the conventional CT value (R=0.407), and hepatorenal echo contrast (R=0.135). This study suggests that the evaluation of the fat quantification in the liver using the spectral HU curve and CT value improved in comparison to the conventional image diagnosis.
近年来，非酒精性脂肪性肝病（NAFLD）患者数量不断增加，其中部分患者会进展为肝硬化和肝细胞癌。双能量CT可通过单色图像（MI）鉴别物质，脂肪变性在各能量水平的CT值上有特异性表现。目的是利用光谱HU曲线和CT值评估肝脏脂肪定量，并与传统图像诊断进行比较。
2014年10月至2016年4月期间，对54例患者进行了双能量CT和肝活检。通过在左右肝脏设置3个感兴趣区（ROI）的光谱HU曲线测量40 keV MI的CT值。将40 keV MI的CT值与脂肪变性面积和NAFLD活动评分（NAS）进行比较。此外，还将脂肪变性面积与传统CT值扫描及肝肾回声对比值进行比较。
40 keV MI的CT值与狭窄面积（R = 0.619）和NAS（R = 0.147）呈负相关。脂肪变性面积与传统CT值（R = 0.407）和肝肾回声对比（R = 0.135）呈相关。本研究表明，与传统图像诊断相比，利用光谱HU曲线和CT值评估肝脏脂肪定量有所改善。
