Modeling tracer kinetics in dynamic Gd-DTPA MR imaging

J Magn Reson Imaging. Jan-Feb 1997;7(1):91-101. doi: 10.1002/jmri.1880070113.

Abstract

Three major models (from Tofts, Larsson, and Brix) for collecting and analyzing dynamic MRI gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) data are examined. All models use compartments representing the blood plasma and the abnormal extravascular extracellular space (EES), and they are intercompatible. All measure combinations of three parameters; (1) kPSp is the influx volume transfer constant (min-1), or permeability surface area product per unit volume of tissue, between plasma and EES; (2) ve is the volume of EES space per unit volume of tissue (0 < ve < 1); and (3) K(ep), the efflux rate constant (min-1), is the ratio of the first two parameters (k(ep) = kPSp/ve). The ratio K(ep) is the simplest to measure, requiring only signal linearity with Gd tracer concentration or, alternatively, a measurement of T1 before injection of Gd (T10). To measure the physiologic parameters kPSp and ve separately requires knowledge of T10 and of the tissue relaxivity R1 (approximately in vitro value).

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Contrast Media / pharmacokinetics*
  • Extracellular Space / metabolism
  • Gadolinium DTPA
  • Humans
  • Image Enhancement / methods*
  • Magnetic Resonance Imaging / methods*
  • Models, Biological
  • Organometallic Compounds / pharmacokinetics*
  • Pentetic Acid / analogs & derivatives*
  • Pentetic Acid / pharmacokinetics
  • Permeability
  • Radioactive Tracers
  • Reproducibility of Results

Substances

  • Contrast Media
  • Organometallic Compounds
  • Radioactive Tracers
  • Pentetic Acid
  • Gadolinium DTPA