title: Comparing dynamic parameters of tumor vascularization in nude mice revealed by magnetic resonance imaging and contrast-enhanced intermittent power Doppler sonography.
abstract: BACKGROUND
  Angiogenesis is essential for spread and growth of malignant tumors. Because noninvasive methods for observing tumor vascularization are limited, most of previous results were based on histologic findings alone. In this study, dynamic parameters obtained using intermittent contrast-enhanced Doppler sonography and dynamic MRI were compared and correlated with microvessel density.
  
  
  METHODS
  Eleven tumor-bearing nude mice were examined with dynamic T(1)-weighted sequences using Gd-DTPA in a 1.5 T magnetic resonance (MR) scanner and with intermittent power Doppler sonography after a single bolus of galactose based contrast agent. After examination 6 tumors were harvested for immunofluorescence microscopy using a CD31 stain. Using a 2-compartment model, the MR parameters amplitude (reflecting plasma volume) and k(ep) (influenced by the vessel permeability) were calculated and compared with maximal enhancement (max) and perfusion P measured with ultrasound.
  
  
  RESULTS
  The MR amplitude correlated with the ultrasound parameter max significantly (r = 0.61; P = 0.01). Max (r = 0.67; P = 0.01), amplitude (r = 0.72; P = 0.01), and perfusion (r = 0.62; P = 0.05) correlated with the microvessel density. k(ep) moderately correlated with max, but not with perfusion and microvessel density.
  
  
  CONCLUSIONS
  Dynamic MRI and contrast enhanced ultrasound are supplementing methods for examining perfusion and vascularity of experimental tumors.
authors.affiliation: Division of Oncological Diagnostics and Therapy, German Cancer Research Center, Heidelberg, Germany. F.Kiessling@dkfz.de
authors.forename: Fabian
authors.initials: F
authors.lastname: Kiessling
authors.forename: Martin
authors.initials: M
authors.lastname: Krix
authors.forename: Melanie
authors.initials: M
authors.lastname: Heilmann
authors.forename: Silvia
authors.initials: S
authors.lastname: Vosseler
authors.forename: Matthias
authors.initials: M
authors.lastname: Lichy
authors.forename: Christian
authors.initials: C
authors.lastname: Fink
authors.forename: Nabeel
authors.initials: N
authors.lastname: Farhan
authors.forename: Katharina
authors.initials: K
authors.lastname: Kleinschmidt
authors.forename: Lothar
authors.initials: L
authors.lastname: Schad
authors.forename: Norbert E
authors.initials: NE
authors.lastname: Fusenig
authors.forename: Stefan
authors.initials: S
authors.lastname: Delorme
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D019786:Gadolinium DTPA / Q000008:administration & dosage; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D051379:Mice; D008819:Mice, Nude; D009369:Neoplasms / Q000098:blood supply*; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging*; D018617:Ultrasonography, Doppler, Pulsed
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA