Department of Radiology, Shenzhen Traditional Chinese Medicine Hospital (The Fourth Clinical Medical College of Guangzhou University of Chinese Medicine), Shenzhen, China.
MR Collaborations, Siemens Healthcare Ltd., Shenzhen, China.
Diagn Interv Radiol. 2022 Jan;28(1):5-11. doi: 10.5152/dir.2021.21471.
We aimed to evaluate the diagnostic performance of apparent diffusion coefficient (ADC) in assessing liver fibrosis after correcting for the effects of hepatic steatosis or iron deposition.
Seventy-three patients with chronic hepatitis B (CHB) were included in this retrospective study. The aspartate aminotransferase-to-platelet ratio index (APRI) was calculated for classification of the fibrosis grade. Significant fibrosis and cirrhosis were diagnosed with the APRI. The proton density fat fraction (PDFF), R2*, and ADC values were measured. The impact of the PDFF and R2* on the ADC was analyzed. The PDFF- and R2*-corrected ADC values (ADCPDFF and ADCR2*) were calculated according to linear regression equations. The diagnostic performance of uncorrected ADC (ADCu), ADCPDFF and ADCR2* in predicting significant fibrosis and cirrhosis was assessed, and the area under the curve (AUC) values were compared.
Among the 73 patients in this study, the mean ADC was 0.866 ± 0.084×10-3 mm2/s, the mean R2* was 60.24 (42.77, 85.37) 1/s, and the mean PDFF was 2.90% (1.60%- 4.80%). The ADC was negatively correlated with the PDFF (r= -0.298, P = .010) and R2* (r = -0.457, P < .001). Linear regression analysis showed that the PDFF and R2* were independent factors of the ADC (β= -0.315, P = .007, R2= 0.099 and β= -0.493, P < .001, R2= 0.243, respectively). Compared with the uncorrected ADC (r= -0.307, P = .022), the correlation between the ADCPDFF and fibrosis grade increased (r= -0.513, P < .001), and the correlation between the ADCR2* and fibrosis grade decreased (r=-0.168, P = .215). The AUC of the ADCPDFF was significantly larger than that of the ADCu in the diagnosis of significant fibrosis and cirrhosis, which increased from 0.68 to 0.81 (P = .003) for predicting significant fibrosis and from 0.75 to 0.84 (P = .009) for predicting cirrhosis. The AUCs for the ADCR2* in the diagnosis of significant fibrosis and cirrhosis were both lower than that for the uncorrected ADC (P = .206 and P = .109, respectively).
After correcting for the effects of steatosis, the diagnostic performance of the ADC for signifi-cant fibrosis and cirrhosis increased. The ADC corrected for the effects of steatosis may be more reliable for identifying liver fibrosis.
本研究旨在评估表观扩散系数（ADC）校正肝脂肪变性或铁沉积影响后在评估肝纤维化中的诊断性能。
本回顾性研究纳入了 73 例慢性乙型肝炎（CHB）患者。采用天冬氨酸氨基转移酶-血小板比值指数（APRI）对纤维化程度进行分类。采用 APRI 诊断显著纤维化和肝硬化。测量质子密度脂肪分数（PDFF）、R2和 ADC 值。分析 PDFF 和 R2对 ADC 的影响。根据线性回归方程计算 PDFF 和 R2校正的 ADC 值（ADCPDFF 和 ADCR2）。评估校正 ADC（ADCu）、ADCPDFF 和 ADCR2*在预测显著纤维化和肝硬化中的诊断性能，并比较曲线下面积（AUC）值。
在这项研究中的 73 例患者中，平均 ADC 为 0.866±0.084×10-3mm2/s，平均 R2为 60.24（42.77，85.37）1/s，平均 PDFF 为 2.90%（1.60%-4.80%）。ADC 与 PDFF（r=-0.298，P=0.010）和 R2（r=-0.457，P<0.001）呈负相关。线性回归分析显示，PDFF 和 R2是 ADC 的独立影响因素（β=-0.315，P=0.007，R2=0.099 和 β=-0.493，P<0.001，R2=0.243）。与未校正 ADC（r=-0.307，P=0.022）相比，ADCPDFF 与纤维化程度的相关性增加（r=-0.513，P<0.001），而 ADCR2与纤维化程度的相关性降低（r=-0.168，P=0.215）。ADCPDFF 在诊断显著纤维化和肝硬化中的 AUC 显著大于 ADCu，AUC 从 0.68 增加到 0.81（P=0.003）用于预测显著纤维化，从 0.75 增加到 0.84（P=0.009）用于预测肝硬化。ADCR2*在诊断显著纤维化和肝硬化中的 AUC 均低于未校正 ADC（P=0.206 和 P=0.109）。
校正脂肪变性的影响后，ADC 对显著纤维化和肝硬化的诊断性能提高。校正脂肪变性影响后的 ADC 可能更可靠地识别肝纤维化。
