Kwee Thomas C, Takahara Taro, Koh Dow-Mu, Nievelstein Rutger A J, Luijten Peter R
Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
J Magn Reson Imaging. 2008 Nov;28(5):1141-8. doi: 10.1002/jmri.21569.
To compare and determine the reproducibility of apparent diffusion coefficient (ADC) measurements of the normal liver parenchyma in breathhold, respiratory triggered, and free-breathing diffusion-weighted magnetic resonance imaging (DWI).
Eleven healthy volunteers underwent three series of DWI. Each DWI series consisted of one breathhold, one respiratory triggered, and two free-breathing (thick and thin slice acquisition) scans of the liver, at b-values of 0 and 500 s/mm2. ADCs of the liver parenchyma were compared by using nonparametric tests. Reproducibility was assessed by the Bland-Altman method.
Mean ADCs (in 10(-3) mm2/sec) in respiratory triggered DWI (2.07-2.27) were significantly higher than mean ADCs in breathhold DWI (1.57-1.62), thick slice free-breathing DWI (1.62-1.65), and thin slice free-breathing DWI (1.57-1.66) (P<0.005). Ranges of mean difference in ADC measurement+/-limits of agreement between two scans were -0.02-0.05+/-0.16-0.24 in breathhold DWI, -0.14-0.20+/-0.59-0.60 in respiratory triggered DWI, -0.03-0.03+/-0.20-0.29 in thick slice free-breathing DWI, and -0.01-0.09+/-0.21-0.29 in thin slice free-breathing DWI.
ADC measurements of the normal liver parenchyma in respiratory triggered DWI are significantly higher and less reproducible than in breathhold and free-breathing DWI.
比较并确定屏气、呼吸触发和自由呼吸的扩散加权磁共振成像（DWI）中正常肝实质表观扩散系数（ADC）测量值的可重复性。
11名健康志愿者接受了3组DWI检查。每组DWI检查包括一次屏气、一次呼吸触发以及两次自由呼吸（厚层和薄层采集）肝脏扫描，b值为0和500 s/mm²。采用非参数检验比较肝实质的ADC值。通过Bland-Altman方法评估可重复性。
呼吸触发DWI中平均ADC值（单位：10⁻³ mm²/秒，范围2.07 - 2.27）显著高于屏气DWI（1.57 - 1.62）、厚层自由呼吸DWI（1.62 - 1.65）和薄层自由呼吸DWI（1.57 - 1.66）中的平均ADC值（P < 0.005）。两次扫描之间ADC测量平均差值±一致性界限范围在屏气DWI中为 -0.02 - 0.05 ± 0.16 - 0.24，呼吸触发DWI中为 -0.14 - 0.20 ± 0.59 - 0.60，厚层自由呼吸DWI中为 -0.03 - 0.03 ± 0.20 - 0.29，薄层自由呼吸DWI中为 -0.01 - 0.09 ± 0.21 - 0.29。
呼吸触发DWI中正常肝实质的ADC测量值显著高于屏气和自由呼吸DWI，且可重复性较差。
