IVIM analysis of brain tumors: an investigation of the relaxation effects of CSF, blood, and tumor tissue on the estimated perfusion fraction

MAGMA. 2015 Aug;28(4):377-83. doi: 10.1007/s10334-014-0474-z. Epub 2014 Dec 5.


Object: We sought to investigate the dependence of intravoxel incoherent motion (IVIM)-related perfusion fraction (f) estimates on the transverse relaxation of brain tissue, blood, and cerebrospinal fluid (CSF), attempting to overcome the influence of CSF on conventional f maps.

Materials and methods: Eighteen patients with gliomas underwent DWI with 14 b-values (0-1,300 s/mm(2)) and two distinct echo times (TEs). Regions of interest representing tumour and normal brain tissue were analysed by calculating the f values for both TEs. A mask for pixels with relevant CSF partial volume was subsequently created. The f values were tested for significant differences.

Results: We found statistically significant differences between the two TEs in the f values for cortical and juxtacortical structures and non-enhancing areas of the tumour /oedema. Normal white matter and gadolinium-enhancing tumour tissue appeared insensitive to TE variation. In all tissue types examined, the masking of voxels with considerable CSF content was able to overcome issues of erroneous f estimation and calculation of f values insensitive to TE changes was feasible.

Conclusion: Due to the complex interaction in the relaxation rates of CSF, blood, and tumour tissue, the estimation of f values is affected by the choice of TE. Only f values in normal white matter and tumour tissue--which largely comprise blood voxels with minor CSF partial volume--may be clinically applicable in the present form of IVIM-based DWI analysis. Going a step further, and after removing voxels with heavily TE-susceptible f values, we were able to obtain accurate and TE-independent f values in contrast-enhancing tumour tissue, white matter, and grey matter, which were essentially consistent with those reported in the literature.

MeSH terms

  • Adult
  • Aged
  • Brain Neoplasms / blood
  • Brain Neoplasms / cerebrospinal fluid
  • Brain Neoplasms / pathology*
  • Contrast Media
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Glioma / blood
  • Glioma / cerebrospinal fluid
  • Glioma / pathology*
  • Humans
  • Image Interpretation, Computer-Assisted
  • Male
  • Middle Aged
  • Motion
  • Organometallic Compounds
  • Signal-To-Noise Ratio


  • Contrast Media
  • Organometallic Compounds
  • gadobutrol