Wang Min, Chen Hongyu, Ma Yue, Bai Ruobing, Gao Sizhe, Yang Linlin, Guo Wenli, Zhang Cong, Kang Chengjun, Lan Yu, Sun Yanqiu, Zhang Yonggao, Xiao Xigang, Hou Yang
Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, P.R. China.
Department of Radiology, Qinghai Provincial People's Hospital, Qinghai, P.R. China.
Insights Imaging. 2024 Aug 15;15(1):210. doi: 10.1186/s13244-024-01716-6.
To evaluate the diagnostic accuracy of liver dual-layer spectral-detector CT (SDCT) derived parameters of liver parenchyma for grading steatosis with reference to magnetic resonance imaging-based proton density fat fraction (MRI-PDFF).
Altogether, 320 consecutive subjects who underwent MRI-PDFF and liver SDCT examinations were recruited and prospectively enrolled from four Chinese hospital centers. Participants were classified into normal (n = 152), mild steatosis (n = 110), and moderate/severe(mod/sev) steatosis (n = 58) groups based on MRI-PDFF. SDCT liver parameters were evaluated using conventional polychromatic CT images (CT), virtual mono-energetic images at 40 keV (CT), the slope of the spectral attenuation curve (λ), the effective atomic number (Zeff), and liver to spleen attenuation ratio (L/S ratio). Linearity between SDCT liver parameters and MRI-PDFF was examined using Spearman correlation. Cutoff values for SDCT liver parameters in determining steatosis grades were identified using the area under the receiver-operating characteristic curve analyses.
SDCT liver parameters demonstrated a strong correlation with PDFF, particularly Zeff (r = -0.856; p < 0.001). Zeff achieved an area under the curve (AUC) of 0.930 for detecting the presence of steatosis with a sensitivity of 89.4%, a specificity of 82.4%, and an AUC of 0.983 for detecting mod/sev steatosis with a sensitivity of 93.1%, a specificity of 93.5%, the corresponding cutoff values were 7.12 and 6.94, respectively. Zeff also exhibited good diagnostic performance for liver steatosis grading in subgroups, independent of body mass index.
SDCT liver parameters, particularly Zeff, exhibit excellent diagnostic accuracy for grading steatosis.
Dual-layer SDCT parameter, Zeff, as a more convenient and accurate imaging biomarker may serve as an alternative indicator for MRI-based proton density fat fraction, exploring the stage and prognosis of liver steatosis, and even metabolic risk assessment.
Liver biopsy is the standard for grading liver steatosis, but is limited by its invasive nature. The diagnostic performance of liver steatosis using SDCT-Zeff outperforms conventional CT parameters. SDCT-Zeff accurately and noninvasively assessed the grade of liver steatosis.
参照基于磁共振成像的质子密度脂肪分数（MRI-PDFF），评估肝脏双层光谱探测器CT（SDCT）得出的肝实质参数对脂肪变性分级的诊断准确性。
共招募了320名连续接受MRI-PDFF和肝脏SDCT检查的受试者，并前瞻性地纳入了四个中国医院中心。根据MRI-PDFF将参与者分为正常组（n = 152）、轻度脂肪变性组（n = 110）和中度/重度脂肪变性组（n = 58）。使用传统的多色CT图像（CT）、40 keV的虚拟单能图像（CT）、光谱衰减曲线的斜率（λ）、有效原子序数（Zeff）和肝脾衰减比（L/S比）评估SDCT肝脏参数。使用Spearman相关性检验SDCT肝脏参数与MRI-PDFF之间的线性关系。使用受试者操作特征曲线分析下的面积确定SDCT肝脏参数在确定脂肪变性分级时的临界值。
SDCT肝脏参数与PDFF显示出很强的相关性，尤其是Zeff（r = -0.856；p < 0.001）。Zeff检测脂肪变性存在时的曲线下面积（AUC）为0.930，灵敏度为89.4%，特异性为82.4%；检测中度/重度脂肪变性时的AUC为0.983，灵敏度为93.1%，特异性为93.5%，相应的临界值分别为7.12和6.94。Zeff在亚组中对肝脏脂肪变性分级也表现出良好的诊断性能，且独立于体重指数。
SDCT肝脏参数，尤其是Zeff，在脂肪变性分级方面表现出优异的诊断准确性。
双层SDCT参数Zeff作为一种更方便、准确的成像生物标志物，可作为基于MRI的质子密度脂肪分数的替代指标，用于探索肝脏脂肪变性的阶段和预后，甚至代谢风险评估。
肝活检是肝脏脂肪变性分级的标准，但受其侵入性的限制。使用SDCT-Zeff对肝脏脂肪变性的诊断性能优于传统CT参数。SDCT-Zeff准确、无创地评估了肝脏脂肪变性的分级。
