Song Danlei, Wang Pingping, Han Jiahao, Chen Huihui, Gao Ruixia, Li Ling, Li Jia
Department of Ultrasound, Zhongda Hospital, Medical School, Southeast University, Nanjing, China.
Department of Endocrinology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China.
Insights Imaging. 2024 Oct 22;15(1):254. doi: 10.1186/s13244-024-01834-1.
Steatotic liver disease (SLD) has become the most common cause of chronic liver disease. Nevertheless, the non-invasive quantitative diagnosis of steatosis is still lacking in clinical practice. This study aimed to evaluate the reproducibility of the new parameter for steatosis quantification named ultrasound-derived fat fraction (UDFF).
The UDFF values were independently executed by two operators in two periods. In the process, repeated measurements of the same patient were performed by the same operator under different conditions (liver segments, respiration, positions, and dietary). Finally, the results of some subjects (28) were compared with the MRI-derived proton density fat fraction (PDFF). The concordance analysis was mainly achieved by the intraclass correlation coefficient (ICC) and Bland-Altman.
One hundred-five participants were included in the study. UDFF had good reliability in measuring the adult liver (ICC = 0.96, ICC = 0.94). Meanwhile, the ICC of the two operators increased over time. The variable measurement states did not influence the UDFF values on the surface, but they affected the coefficient of variation (Cov) of the results. Segment 8 (S8), end-expiratory, supine, and fasting images had the most minor variability. On the other hand, the UDFF value of S8 displayed satisfied consistency with PDFF (mean difference, -0.24 ± 1.44), and the results of both S5 (mean difference: -0.56 ± 3.95) and S8 (mean difference: 0.73 ± 1.87) agreed well with the whole-liver PDFF.
UDFF measurements had good reproducibility. Furthermore, the state of S8, end-expiration, supine, and fasting might be the more stable measurement approach.
UDFF is the quantitative ultrasound parameter of hepatic steatosis and has good reproducibility. It can show more robust performance under specific measurement conditions (S8, end-expiratory, supine, and fasting).
The research protocol was registered at the Chinese Clinical Trial Registry on October 9, 2023 ( http://www.chictr.org.cn/ ). The registration number is ChiCTR 2300076457.
There is a lack of non-invasive quantitative measurement options for hepatic steatosis. UDFF demonstrated excellent reproducibility in measuring hepatic steatosis. S8, end-expiratory, supine, and fasting may be the more stable measuring condition. Training could improve the operators' measurement stability. Variable measurement state affects the repeatability of the UDFF values (Cov).
脂肪性肝病（SLD）已成为慢性肝病最常见的病因。然而，临床上仍缺乏对肝脂肪变性的非侵入性定量诊断方法。本研究旨在评估一种名为超声衍生脂肪分数（UDFF）的肝脂肪变性定量新参数的可重复性。
UDFF值由两名操作人员在两个时间段独立测量。在此过程中，同一名操作人员在不同条件下（肝段、呼吸、体位和饮食）对同一患者进行重复测量。最后，将部分受试者（28例）的结果与磁共振成像衍生的质子密度脂肪分数（PDFF）进行比较。一致性分析主要通过组内相关系数（ICC）和Bland-Altman分析来完成。
本研究共纳入105名参与者。UDFF在测量成人肝脏时具有良好的可靠性（ICC = 0.96，ICC = 0.94）。同时，两名操作人员的ICC随时间增加。不同的测量状态表面上不影响UDFF值，但会影响结果的变异系数（Cov）。肝段8（S8）、呼气末、仰卧位和禁食状态下的图像变异性最小。另一方面，S8的UDFF值与PDFF显示出良好的一致性（平均差值，-0.24±1.44），S5（平均差值：-0.56±3.95）和S8（平均差值：0.73±1.87）的结果与全肝PDFF均吻合良好。
UDFF测量具有良好的可重复性。此外，S8、呼气末、仰卧位和禁食状态可能是更稳定的测量方法。
UDFF是肝脂肪变性的定量超声参数，具有良好的可重复性。在特定测量条件下（S8、呼气末、仰卧位和禁食），它能表现出更强的性能。
本研究方案于2023年10月9日在中国临床试验注册中心注册（http://www.chictr.org.cn/）注册号为ChiCTR 2300076457。
目前缺乏肝脂肪变性的非侵入性定量测量方法。UDFF在测量肝脂肪变性方面表现出优异的可重复性。S8、呼气末、仰卧位和禁食状态可能是更稳定的测量条件。培训可提高操作人员的测量稳定性。不同的测量状态会影响UDFF值的可重复性（Cov）。
