title: Characterization of tumor microvascular structure and permeability: comparison between magnetic resonance imaging and intravital confocal imaging.
abstract: Solid tumors are characterized by abnormal blood vessel organization, structure, and function. These abnormalities give rise to enhanced vascular permeability and may predict therapeutic responses. The permeability and architecture of the microvasculature in human osteosarcoma tumors growing in dorsal window chambers in athymic mice were measured by confocal laser scanning microscopy (CLSM) and dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). Dextran (40 kDa) and Gadomer were used as molecular tracers for CLSM and DCE-MRI, respectively. A significant correlation was found between permeability indicators. The extravasation rate K(i) as measured by CLSM correlated positively with DCE-MRI parameters, such as the volume transfer constant K(trans) and the initial slope of the contrast agent concentration-time curve. This demonstrates that these two techniques give complementary information. Extravasation was further related to microvascular structure and was found to correlate with the fractal dimension and vascular density. The structural parameter values that were obtained from CLSM images were higher for abnormal tumor vasculature than for normal vessels.
authors.affiliation: Norwegian University of Science and Technology, Department of Physics, Hogskoleringen 5, N-7491 Trondheim, Norway. nina.reitan@ntnu.no
authors.forename: Nina Kristine
authors.initials: NK
authors.lastname: Reitan
authors.forename: Marte
authors.initials: M
authors.lastname: Thuen
authors.forename: Pål Erik
authors.initials: PE
authors.lastname: Goa
authors.forename: Catharina
authors.initials: C
authors.lastname: de Lange Davies
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000098:blood supply*; D002199:Capillary Permeability; D003287:Contrast Media; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D018613:Microscopy, Confocal / Q000379:methods*; D055806:Microvessels / Q000378:metabolism* / Q000473:pathology*; D009389:Neovascularization, Pathologic / Q000473:pathology; D012516:Osteosarcoma / Q000098:blood supply*; D013329:Structure-Activity Relationship; D014183:Transplantation, Heterologous
chemical_list: D003287:Contrast Media