Automatic assessment of dynamic contrast-enhanced MRI in an ischemic rat hindlimb model: an exploratory study of transplanted multipotent progenitor cells

NMR Biomed. 2008 Feb;21(2):111-9. doi: 10.1002/nbm.1166.

Abstract

This study presents computerized automatic image analysis for quantitatively evaluating dynamic contrast-enhanced MRI in an ischemic rat hindlimb model. MRI at 7 T was performed on animals in a blinded placebo-controlled experiment comparing multipotent adult progenitor cell-derived progenitor cell (MDPC)-treated, phosphate buffered saline (PBS)-injected, and sham-operated rats. Ischemic and non-ischemic limb regions of interest were automatically segmented from time-series images for detecting changes in perfusion and late enhancement. In correlation analysis of the time-signal intensity histograms, the MDPC-treated limbs correlated well with their corresponding non-ischemic limbs. However, the correlation coefficient of the PBS control group was significantly lower than that of the MDPC-treated and sham-operated groups. In semi-quantitative parametric maps of contrast enhancement, there was no significant difference in hypo-enhanced area between the MDPC and PBS groups at early perfusion-dependent time frames. However, the late-enhancement area was significantly larger in the PBS than the MDPC group. The results of this exploratory study show that MDPC-treated rats could be objectively distinguished from PBS controls. The differences were primarily determined by late contrast enhancement of PBS-treated limbs. These computerized methods appear promising for assessing perfusion and late enhancement in dynamic contrast-enhanced MRI.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Adult Stem Cells / transplantation
  • Animals
  • Contrast Media
  • Control Groups
  • Disease Models, Animal
  • Echo-Planar Imaging / methods*
  • Hindlimb / pathology*
  • Hindlimb / transplantation
  • Image Enhancement / methods*
  • Image Interpretation, Computer-Assisted / methods
  • Ischemia / pathology*
  • Male
  • Multipotent Stem Cells / transplantation*
  • Rats
  • Single-Blind Method
  • Transplants

Substances

  • Contrast Media