Retrospective Study
Copyright ©The Author(s) 2017.
World J Hepatol. May 18, 2017; 9(14): 657-666
Published online May 18, 2017. doi: 10.4254/wjh.v9.i14.657
Table 1 Details of magnetic resonance parameters
Imaging techniqueFB-DWIRT-DWI
Spin echo single-shot EPISpin echo single-shot EPI
SENSE factor22
TR/TE (ms)6250/561877/55
Flip angle (degree)90°90°
Field of view (mm2)380 × 299380 × 299
Matrix (frequency × phase)112 × 176112 × 68
Slice thickness (mm)77
Slice gap (mm)11
No. of slice2525
No. of excitations22
b-value (s/mm2)0.500 and 1.0000.500 and 1.000
Respiratory compensationFree-breathing without navigator echoRespiratory-triggered with navigator echo
SPAIR delay (ms)100
SPAIR TR (ms)250
Frequency offset (Hz)250180
EPI factor7525
Band width (Hz/pixel)4050.44438.5
Scan time (min:s)3:323:201
Table 2 Image quality scores of sharpness of the liver contour, distortion and chemical shift artifacts
ScoreSharpness of the liver contourDistortion and chemical shift artifacts
1Unclear liver contourSevere distortion or artifacts compromise the diagnostic capability of DWI in the whole liver
2The liver contour is partially unclearDistortion or artifacts are moderate, and they compromise the diagnostic capability of DWI in 50% or more of the liver
3The liver contour is mostly clearDistortion or artifacts are mild, and they compromise the diagnostic capability of DWI in less than 50% of the liver
4The entire liver contour is clearNo distortion or artifacts; the diagnostic capability of DWI is not compromised
Table 3 Results of qualitative assessment of the free-breathing diffusion-weighted imaging and respiratory-triggering-diffusion-weighted imaging results
Sharpness of the liver contour
Chemical shift artifacts
Observer 13.08 ± 0.812.33 ± 0.65a2.94 ± 0.502.81 ± 0.56a3.38 ± 0.602.92 ± 0.59a
Observer 22.98 ± 0.732.37 ± 0.74a2.71 ± 0.702.25 ± 0.74a3.15 ± 1.072.21 ± 0.85a
Observer 33.54 ± 0.752.75 ± 0.81a3.27 ± 0.532.96 ± 0.71a3.21 ± 0.852.77 ± 1.08a