Amide proton transfer imaging of brain tumors using a self-corrected 3D fast spin-echo dixon method: Comparison With separate B 0 correction

Magn Reson Med. 2017 Jun;77(6):2272-2279. doi: 10.1002/mrm.26322. Epub 2016 Jul 6.


Purpose: To assess the quantitative performance of three-dimensional (3D) fast spin-echo (FSE) Dixon amide proton transfer (APT) imaging of brain tumors compared with B0 correction with separate mapping methods.

Methods: Twenty-two patients with brain tumors (54.2 ± 18.7 years old, 12 males and 10 females) were scanned at 3 Tesla (T). Z-spectra were obtained at seven different frequency offsets at ±3.1 ppm, ± 3.5 ppm, ± 3.9 ppm, and -1560 ppm. The scan was repeated three times at +3.5 ppm with echo shifts for Dixon B0 mapping. The APT image corrected by a three-point Dixon-type B0 map from the same scan (3D-Dixon) or a separate B0 map (2D-separate and 3D-separate), and an uncorrected APT image (3D-uncorrected) were generated. We compared the APT-weighted signals within a tumor obtained with each 3D method with those obtained with 2D-separate as a reference standard.

Results: Excellent agreements and correlations with the 2D-separate were obtained by the 3D-Dixon method for both mean (ICC = 0.964, r = 0.93, P < 0.0001) and 90th-percentile (ICC = 0.972, r = 0.95, P < 0.0001) APT-weighted signals. These agreements and correlations for 3D-Dixon were better than those obtained by the 3D-uncorrected and 3D-separate methods.

Conclusion: The 3D FSE Dixon APT method with intrinsic B0 correction offers a quantitative performance that is similar to that of established two-dimensional (2D) methods. Magn Reson Med 77:2272-2279, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Keywords: Dixon; amide proton transfer (APT) imaging; brain tumor; chemical exchange saturation transfer (CEST).

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Amides / metabolism*
  • Artifacts*
  • Biomarkers, Tumor / metabolism*
  • Brain Neoplasms / diagnostic imaging*
  • Brain Neoplasms / metabolism*
  • Female
  • Humans
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods
  • Imaging, Three-Dimensional / methods*
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Molecular Imaging / methods
  • Protons
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Signal Processing, Computer-Assisted
  • Spin Labels
  • Tissue Distribution


  • Amides
  • Biomarkers, Tumor
  • Protons
  • Spin Labels