A pharmacokinetic model for quantitative evaluation of spinal cord injury with dynamic contrast-enhanced magnetic resonance imaging.

A multicompartment pharmacokinetic model was proposed to quantitatively describe the distribution of the contrast agent gadopentetate-dimeglumine (Gd) in an experimental spinal cord injury (SCI). Concentration of Gd was measured in different compartments with in vivo dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the acute phase of injury. The concentration data for each rat was fitted to the model to estimate transfer rates between different compartments. The results indicate: 1) lack of uptake of Gd in normal cord tissue, 2) rapid exchange of Gd between plasma and cerebrospinal fluid in both normal and injured cord tissues, and 3) slower uptake of Gd in injured cord. With this approach, it is possible to quantify the integrity of the blood-spinal cord barrier (BSCB) in vivo, evaluate the pathobiology of injured cord, assess the efficacy of interventions, and monitor the progression of injury with postinjury time.