title: Diffusion-weighted MRI, dynamic susceptibility contrast MRI and ultrasound perfusion quantification of denervated muscle in rabbits.
abstract: OBJECTIVE
  The purpose of this study was to assess denervated muscle perfusion using dynamic susceptibility contrast MRI (DSCMRI) and contrast-enhanced ultrasound (CEUS), and to measure denervated muscle apparent diffusion coefficient (ADC) on b1000 diffusion-weighted MRI (DWMRI) at 3 T in order to clarify whether muscle denervation leads to an increase in the extracellular extravascular space, or an increase in blood flow-or both.
  
  
  METHODS
  Axotomy of the right sciatic nerve of six white rabbits was performed at day 0. At day 9, hind limb muscles MRI and CEUS were performed to assess the consequences of denervation and both semimembranosus muscles of each rabbit were explanted for histological studies. Signal intensity on T2- and T1-weighted MRI, ADC on DWMRI, maximum signal drop (MSD) on DSCMRI and the area under the curve (AUC) on CEUS were measured over circular regions of interest (ROI), in both semimembranosus muscles. Non-parametric Wilcoxon matched-pairs tests were used to assess the mean differences between denervated and normal muscles.
  
  
  RESULTS
  T2 fat-saturated (FS) MRI studies showed a strong signal in the right semimembranosus muscles compared with the left side, and gadolinium enhancement was observed on T1 FS MRI. Denervated muscles show a significant increase in ADC on DWMRI (p < 0.01) and a significant signal enhancement on DSCMR imaging (p < 0.05) and on first-pass CEUS (p < 0.05).
  
  
  CONCLUSIONS
  The results of this study--based on perfusion- and diffusion-weighted images--suggest that, after denervation, both increased blood flow through muscle tissue and expansion of the extracellular water volume are present.
authors.affiliation: Department of Cardiovascular imaging, Cardiologic Hospital, University Hospital, 59037, Lille, Cedex, France. gillesgoyault@gmail.com
authors.forename: G
authors.initials: G
authors.lastname: Goyault
authors.forename: G
authors.initials: G
authors.lastname: Bierry
authors.forename: N
authors.initials: N
authors.lastname: Holl
authors.forename: B
authors.initials: B
authors.lastname: Lhermitte
authors.forename: J L
authors.initials: JL
authors.lastname: Dietemann
authors.forename: J P
authors.initials: JP
authors.lastname: Beregi
authors.forename: S
authors.initials: S
authors.lastname: Kremer
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018482:Muscle, Skeletal / Q000294:innervation* / Q000473:pathology / Q000503:physiopathology*; D055420:Perfusion Imaging / Q000379:methods*; D011817:Rabbits; D015203:Reproducibility of Results; D012584:Sciatic Nerve / Q000502:physiology* / Q000601:surgery*; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media