title: Assessment of micronecrotic tumor tissue using dynamic contrast-enhanced magnetic resonance imaging.
abstract: Compartmental models for evaluation of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) datasets assume a homogeneous interstitital volume distribution and homogeneous contrast agent (CA) distribution within each compartment, neglecting effects of CA diffusion within the compartments. When necrotic or micronecrotic tumor tissue is present, these assumptions may no longer be valid. Therefore, the present study investigates the validity of three compartmental models in assessing tumors with necrotic components. The general diffusion equation for inhomogeneous tissue was used to simulate the extravasation of a low-molecular-weight contrast agent from a feeding vessel into the interstitial space. The simulated concentration-time curves were evaluated using the extended Tofts model, a parallel 3-compartment model, and a sequential 3-compartment model. The extended Tofts model overestimated the interstitial volume fraction by a median of 6.9% resp. 10.0% and the parallel 3-compartment model by 8.6% resp. 15.5%, while the sequential 3-compartment model overestimated it by 0.2% resp. underestimated it by 18.8% when simulating a mean vessel distance of 100μm resp. 150μm. Overall, the sequential 3-compartment model provided more reliable results both for the total fractional interstitial volume and for the interstitial subcompartments.
authors.affiliation: Department of Radiation Therapy, Hufelandstr. 55, Universitätsklinikum Essen, 45147 Essen, Germany.
authors.forename: Olga
authors.initials: O
authors.lastname: Schimpf
authors.affiliation: Department of Radiation Therapy, Hufelandstr. 55, Universitätsklinikum Essen, 45147 Essen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hindel
authors.affiliation: Department of Radiation Therapy, Hufelandstr. 55, Universitätsklinikum Essen, 45147 Essen, Germany. Electronic address: lutz.luedemann@uk-essen.de.
authors.forename: Lutz
authors.initials: L
authors.lastname: Lüdemann
mesh_terms: D001692:Biological Transport; D003287:Contrast Media / Q000378:metabolism; D004058:Diffusion; D008279:Magnetic Resonance Imaging; D008954:Models, Biological; D009336:Necrosis / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*
chemical_list: D003287:Contrast Media
keywords: Contrast agent; DCE-MRI; Diffusion; Interstitium; Necrotic tissue; Tumor