title: Magnetic resonance imaging relaxation times and gadolinium-DTPA relaxivity values in human cerebrospinal fluid.
abstract: OBJECTIVE
  This study was conducted to prove the feasibility of using cerebrospinal fluid (CSF) T1 and T2 measurements to assess the blood-brain barrier integrity in disease states not noted for focal blood-brain barrier disruption, such as Alzheimer's disease.
  
  
  METHODS
  T1 and T2 of human CSF samples were measured with and without gadolinium Gd-DTPA over a concentration range of 1.98 x 10(-3) to 6.32 mM, in a GE 1.5-T Signa scanner.
  
  
  RESULTS
  T1 and T2 of human CSF without Gd-DTPA were measured as 2.39 and 0.23 s. K1 and K2 were calculated as 6.25 and 6.74 mM(-1) s(-1). The lowest Gd-DTPA concentration with measurable T1 and T2 was 1.98 x 10(-3) mM. There is no statistically significant difference in T2 and K2 at different repetition times.
  
  
  CONCLUSIONS
  This work demonstrates that a single measurement of relaxation times after contrast-enhanced magnetic resonance imaging could be used to determine the Gd-DTPA concentration in CSF. It may thus be feasible, using this technique, to measure intersubject and intraregional variability in the quantity of Gd-DTPA transferred across the blood-brain barrier after intravenous injection of contrast agent.
authors.affiliation: Institute for Brain Aging and Dementia, University of California and Irvine, 92697-4540, USA. mibrahim@mrrc.bio.uci.edu
authors.forename: M A
authors.initials: MA
authors.lastname: Ibrahim
authors.forename: J F
authors.initials: JF
authors.lastname: Emerson
authors.forename: C W
authors.initials: CW
authors.lastname: Cotman
mesh_terms: D001812:Blood-Brain Barrier / Q000502:physiology; D002555:Cerebrospinal Fluid / Q000502:physiology*; D019786:Gadolinium DTPA; D006801:Humans; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging; D015203:Reproducibility of Results
chemical_list: D019786:Gadolinium DTPA