Kakite Suguru, Dyvorne Hadrien, Besa Cecilia, Cooper Nancy, Facciuto Marcelo, Donnerhack Claudia, Taouli Bachir
Department of Radiology/Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
J Magn Reson Imaging. 2015 Jan;41(1):149-56. doi: 10.1002/jmri.24538. Epub 2014 Jan 10.
To evaluate short-term test-retest and interobserver reproducibility of IVIM (intravoxel incoherent motion) diffusion parameters and ADC (apparent diffusion coefficient) of hepatocellular carcinoma (HCC) and liver parenchyma at 3.0T.
In this prospective Institutional Review Board (IRB)-approved study, 11 patients were scanned twice using a free-breathing single-shot echo-planar-imaging, diffusion-weighted imaging (DWI) sequence using 4 b values (b = 0, 50, 500, 1000 s/mm(2)) and IVIM DWI using 16 b values (0-800 s/mm(2)) at 3.0T. IVIM parameters (D: true diffusion coefficient, D*: pseudodiffusion coefficient, PF: perfusion fraction) and ADC (using 4 b and 16 b) were calculated. Short-term test-retest and interobserver reproducibility of IVIM parameters and ADC were assessed by measuring correlation coefficient, coefficient of variation (CV), and Bland-Altman limits of agreements (BA-LA).
Fifteen HCCs were assessed in 10 patients. Reproducibility of IVIM metrics in HCC was poor for D* and PF (mean CV 60.6% and 37.3%, BA-LA: -161.6% to 135.3% and -66.2% to 101.0%, for D* and PF, respectively), good for D and ADC (CV 19.7% and <16%, BA-LA -57.4% to 36.3% and -38.2 to 34.1%, for D and ADC, respectively). Interobserver reproducibility was on the same order of test-retest reproducibility except for PF in HCC. Reproducibility of diffusion parameters was better in liver parenchyma compared to HCC.
Poor reproducibility of D*/PF and good reproducibility for D/ADC were observed in HCC and liver parenchyma. These findings may have implications for trials using DWI in HCC.
评估3.0T磁共振成像下肝细胞癌（HCC）及肝实质的体素内不相干运动（IVIM）扩散参数和表观扩散系数（ADC）的短期重测及观察者间的可重复性。
在这项经机构审查委员会（IRB）批准的前瞻性研究中，11例患者使用自由呼吸单次激发回波平面成像、扩散加权成像（DWI）序列进行了两次扫描，该序列在3.0T下使用4个b值（b = 0、50、500、1000 s/mm²）以及使用16个b值（0 - 800 s/mm²）的IVIM DWI。计算IVIM参数（D：真实扩散系数，D*：伪扩散系数，PF：灌注分数）和ADC（使用4个b值和16个b值）。通过测量相关系数、变异系数（CV）和Bland-Altman一致性界限（BA-LA）来评估IVIM参数和ADC的短期重测及观察者间的可重复性。
对10例患者中的15个HCC进行了评估。HCC中IVIM指标的可重复性对于D和PF较差（D和PF的平均CV分别为60.6%和37.3%，BA-LA分别为-161.6%至135.3%和-66.2%至101.0%），对于D和ADC良好（D和ADC的CV分别为19.7%和<16%，BA-LA分别为-57.4%至36.3%和-38.2至34.1%）。除HCC中的PF外，观察者间的可重复性与重测可重复性处于同一水平。与HCC相比，肝实质中扩散参数的可重复性更好。
在HCC和肝实质中观察到D*/PF的可重复性较差，而D/ADC的可重复性良好。这些发现可能对HCC中使用DWI的试验有影响。
