Scan time minimization in hepatic diffusion-weighted imaging: evaluation of the simultaneous multislice acceleration technique with different acceleration factors and gradient preparation schemes

MAGMA. 2016 Oct;29(5):739-49. doi: 10.1007/s10334-016-0553-4. Epub 2016 Apr 2.

Abstract

Objective: To evaluate simultaneous multislice (sms) accelerated diffusion-weighted imaging (DWI) of the liver in comparison to conventional sequences.

Materials and methods: Ten volunteers underwent DWI of the liver at 1.5 T. Four different sms-accelerated sequences with monopolar and bipolar gradient preparation (MP, BP) and acceleration factors 2 and 3 (sms2-DWI, sms3-DWI) were compared to conventional DWI (c-DWI). Image quality criteria rated on a 5-point Likert scale (5 = excellent), image quality sum scores (maximum 120), and ADC were compared using Friedman test and Dunn-Bonferroni post hoc test. Bland-Altman plots were calculated for ADC comparison. p values <0.05 were considered significant.

Results: Sms2-DWI offered scan time minimization of 67 % without significant difference in image quality (sum score: sms2-DWI MP/BP: 97 ± 8/92 ± 9; c-DWI MP/BP: 99 ± 8/97 ± 8). Sms3-DWI offered slight additional scan time minimization with significantly inferior image quality (sum score: sms3-DWI MP/BP: 75 ± 14/69 ± 14; p < 0.001). MP preparation provided slightly higher image quality in sms-DWI without statistical significance. ADC in sms-DWI were significantly lower (sms2-DWI MP 1.01 × 10(-3) mm(2)/s; c-DWI MP 1.20 × 10(-3) mm(2)/s; p < 0.001).

Conclusion: Sms2-DWI provides considerable scan time minimization without significant shortcomings in image quality. Sms3-DWI provides significantly inferior image quality without further scan time minimization. Potentially lower ADC in sms-DWI should be considered in clinical routine.

Keywords: Bipolar; Diffusion-weighted imaging; Liver; Monopolar; Scan time minimization; Simultaneous multislice.

MeSH terms

  • Adult
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Healthy Volunteers
  • Humans
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods
  • Image Processing, Computer-Assisted / methods*
  • Liver / diagnostic imaging*
  • Male
  • Reproducibility of Results
  • Time Factors