title: Automatic assessment of dynamic contrast-enhanced MRI in an ischemic rat hindlimb model: an exploratory study of transplanted multipotent progenitor cells.
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.
authors.affiliation: National Heart Lung and Blood Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892-1061, USA.
authors.forename: Li-Yueh
authors.initials: LY
authors.lastname: Hsu
authors.forename: Andrew
authors.initials: A
authors.lastname: Wragg
authors.forename: Stasia A
authors.initials: SA
authors.lastname: Anderson
authors.forename: Robert S
authors.initials: RS
authors.lastname: Balaban
authors.forename: Manfred
authors.initials: M
authors.lastname: Boehm
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Arai
mesh_terms: D053687:Adult Stem Cells / Q000637:transplantation; D000818:Animals; D003287:Contrast Media; D035061:Control Groups; D004195:Disease Models, Animal; D017352:Echo-Planar Imaging / Q000379:methods*; D006614:Hindlimb / Q000473:pathology* / Q000637:transplantation; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007511:Ischemia / Q000473:pathology*; D008297:Male; D039902:Multipotent Stem Cells / Q000637:transplantation*; D051381:Rats; D016037:Single-Blind Method; D019737:Transplants
chemical_list: D003287:Contrast Media