Evaluation of image quality of DWIBS versus DWI sequences in thoracic MRI at 3T

Magn Reson Imaging. 2014 Dec;32(10):1237-41. doi: 10.1016/j.mri.2014.08.015. Epub 2014 Aug 23.


Purpose: To compare diffusion weighted imaging with background suppression (DWIBS) sequence with classic spectral diffusion sequence (DWI) with and without respiratory gating in mediastinal lymph node analysis at 3T.

Materials and methods: 26 patients scheduled for mediastinoscopic lymph node analysis, prospectively undergone a thoracic 3T MRI with DWIBS (FatSat=STIR; TR/TE=6674.1/44.7ms; IR=260 ms) and DWI sequences (FatSat=SPIR; TR/TE=1291/59.6 ms) (b=0-400-800 s/mm2) with and without (free breathing) respiratory gating. Images at b=800 were analyzed by two radiologists. They performed qualitative analysis of fat-sat homogeneity and motion artifacts, rated from 0 to 4, and quantitative evaluation by studying signal to background (STB) of lymph nodes.

Results: Quality of fat suppression was significantly higher for DWIBS than for DWI both for free-breathing (score 3.48±0.65 vs. 1.76±0.96, p<0.0001) and respiratory-gated scans (3.17±0.77 vs. 1.72±0.73, p=0.0001). Similarly, artifacts were reduced with DWIBS (3.16±0.47 vs. 1.76±0.59, p<0.0001; 3.0±0.73 vs. 2.04±0.53, p=0.0001). Quantitative analysis showed higher STB with DWIBS (3.26±1.83 vs. 0.98±0.44, p<0.0001; 3.56±, 2.09 vs. 0.92±0.59, p<0.0001). Gating did not improve image quality and STB on DWIBS (p>0.05).

Conclusion: In thoracic MRI, ungated DWIBS sequence improves fat-sat homogeneity, reduces motion artifacts and increases STB of lymph nodes. Respiratory gating does not improve DWIBS image quality.

Keywords: DWIBS; Diffusion; Lymph node; MR imaging; Mediastinal.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / pathology
  • Adult
  • Aged
  • Artifacts
  • Diffusion Magnetic Resonance Imaging*
  • Female
  • Humans
  • Image Processing, Computer-Assisted*
  • Lymph Nodes / pathology*
  • Magnetic Resonance Imaging*
  • Male
  • Mediastinum / pathology*
  • Middle Aged
  • Motion
  • Prospective Studies
  • Radiology
  • Respiration
  • Water / chemistry


  • Water