title: In vivo quantification of delayed gadolinium enhancement in the nucleus pulposus of human intervertebral disc.
abstract: OBJECTIVE
  To quantify the delayed contrast agent enhancement in the nucleus pulposus of the intervertebral disc by means by T1 relaxation time measurements, and to correlate the enhancement with visual grading of disc degeneration. Diffusion of nutrients through the endplate is a key factor in tissue viability in the intervertebral disc. It can be simulated in vivo using magnetic resonance imaging (MRI) by measuring delayed gadolinium (Gd) enhancement of the disc.
  
  
  METHODS
  Twenty male volunteers underwent a lumbar spine examination at 1.5T. T2-weighted sagittal images were used to score disc degeneration. T1 relaxation times were measured before and 90 minutes after intravenous administration of Gd-DTPA-BMA by applying a series of sagittal single-slice inversion-recovery fast spin-echo (IR-FSE) scans.
  
  
  RESULTS
  A total of 93 discs were analyzed. A statistically significant decrease in the T1 relaxation time of the nucleus pulposus was observed as a result of contrast-agent intake. The percentage change in the T1 relaxation rate for individual discs was up to 126%. A positive trend was observed between the change in the T1 relaxation rate and the grading of disc degeneration.
  
  
  CONCLUSIONS
  Quantification of delayed enhancement of the intervertebral disc may provide a new means of studying alterations in degenerative disc disease (DDD) that explain the variation in diffusion into the intervertebral disc.
authors.affiliation: Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland. jaakko.niinimaki@oulu.fi
authors.forename: Jaakko L
authors.initials: JL
authors.lastname: Niinimäki
authors.forename: Outi
authors.initials: O
authors.lastname: Parviainen
authors.forename: Jyrki
authors.initials: J
authors.lastname: Ruohonen
authors.forename: Risto O
authors.initials: RO
authors.lastname: Ojala
authors.forename: Mauno
authors.initials: M
authors.lastname: Kurunlahti
authors.forename: Jaro
authors.initials: J
authors.lastname: Karppinen
authors.forename: Osmo
authors.initials: O
authors.lastname: Tervonen
authors.forename: Miika T
authors.initials: MT
authors.lastname: Nieminen
mesh_terms: D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D007403:Intervertebral Disc / Q000033:anatomy & histology*; D007405:Intervertebral Disc Displacement / Q000175:diagnosis; D016014:Linear Models; D008159:Lumbar Vertebrae / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA