title: Ischemia-reperfusion injury in rat skeletal muscle assessed with T2-weighted and dynamic contrast-enhanced MRI.
abstract: Pressure ulcers are localized areas of soft tissue breakdown due to mechanical loading. Susceptible individuals are subjected to pressure relief strategies to prevent long loading periods. Therefore, ischemia-reperfusion injury may play an important role in the etiology of pressure ulcers. To investigate the inter-relation between postischemic perfusion and changes in skeletal muscle integrity, the hindlimbs of Brown Norway rats were subjected to 4-h ischemia followed by 2-h reperfusion. Dynamic contrast-enhanced MRI was used to examine perfusion, and changes in skeletal muscle integrity were monitored with T2-weighted MRI. The dynamic contrast-enhanced MRI data showed a heterogeneous postischemic profile in the hindlimb, consisting of areas with increased contrast enhancement (14-76% of the hindlimb) and regions with no-reflow (5-77%). For T2, a gradual increase in the complete leg was observed during the 4-h ischemic period (from 34 to 41 msec). During the reperfusion phase, a heterogeneous distribution of T2 was observed. Areas with increased contrast enhancement were associated with a decrease in T2 (to 38 msec) toward preischemic levels, whereas no-reflow areas exhibited a further increase in T2 (to 42 msec). These results show that reperfusion after prolonged ischemia may not be complete, thereby continuing the ischemic condition and aggravating tissue damage.
authors.affiliation: Soft Tissue Biomechanics and Engineering, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands. s.loerakker@tue.nl
authors.forename: S
authors.initials: S
authors.lastname: Loerakker
authors.forename: C W J
authors.initials: CW
authors.lastname: Oomens
authors.forename: E
authors.initials: E
authors.lastname: Manders
authors.forename: T
authors.initials: T
authors.lastname: Schakel
authors.forename: D L
authors.initials: DL
authors.lastname: Bader
authors.forename: F P T
authors.initials: FP
authors.lastname: Baaijens
authors.forename: K
authors.initials: K
authors.lastname: Nicolay
authors.forename: G J
authors.initials: GJ
authors.lastname: Strijkers
mesh_terms: D000818:Animals; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006571:Heterocyclic Compounds; D008279:Magnetic Resonance Imaging / Q000379:methods*; D018482:Muscle, Skeletal / Q000473:pathology*; D009135:Muscular Diseases / Q000473:pathology*; D009942:Organometallic Compounds; D003668:Pressure Ulcer / Q000473:pathology*; D051381:Rats; D015427:Reperfusion Injury / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; D005682:Gadolinium