title: Dynamic Measurement of Tumor Vascular Permeability and Perfusion using a Hybrid System for Simultaneous Magnetic Resonance and Fluorescence Imaging.
abstract: OBJECTIVE
  Assessing tumor vascular features including permeability and perfusion is essential for diagnostic and therapeutic purposes. The aim of this study was to compare fluorescence and magnetic resonance imaging (MRI)-based vascular readouts in subcutaneously implanted tumors in mice by simultaneous dynamic measurement of tracer uptake using a hybrid fluorescence molecular tomography (FMT)/MRI system.
  
  
  METHODS
  Vascular permeability was measured using a mixture of extravascular imaging agents, GdDOTA and the dye Cy5.5, and perfusion using a mixture of intravascular agents, Endorem and a fluorescent probe (Angiosense). Dynamic fluorescence reflectance imaging (dFRI) was integrated into the hybrid system for high temporal resolution.
  
  
  RESULTS
  Excellent correspondence between uptake curves of Cy5.5/GdDOTA and Endorem/Angiosense has been found with correlation coefficients R > 0.98. The two modalities revealed good agreement regarding permeability coefficients and centers-of-gravity of the imaging agent distribution.
  
  
  CONCLUSIONS
  The FMT/dFRI protocol presented is able to accurately map physiological processes and poses an attractive alternative to MRI for characterizing tumor neoangiogenesis.
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland.
authors.forename: Wuwei
authors.initials: W
authors.lastname: Ren
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Elmer
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Buehlmann
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland.
authors.forename: Mark-Aurel
authors.initials: MA
authors.lastname: Augath
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland.
authors.forename: Divya
authors.initials: D
authors.lastname: Vats
authors.affiliation: Department of Bioengineering, Universidad Carlos III of Madrid, 28911, Madrid, Spain.|Medical Imaging Laboratory, Hospital General Gregorio Marañón, Madrid, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Ripoll
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland. rudin@biomed.ee.ethz.ch.|Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland. rudin@biomed.ee.ethz.ch.|Experimental and Clinical Imaging Technologies (EXCITE), Zürich, Switzerland. rudin@biomed.ee.ethz.ch.
authors.forename: Markus
authors.initials: M
authors.lastname: Rudin
mesh_terms: D000818:Animals; D002199:Capillary Permeability; D005260:Female; D005453:Fluorescence; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000098:blood supply* / Q000473:pathology; D010477:Perfusion
keywords: Fluorescence molecular tomography; MRI; Perfusion; Simultaneous hybrid measurements; Tumor angiogenesis; Vascular permeability