title: Collagen composition and content-dependent contrast in porcine annulus fibrosus achieved by using double quantum and magnetization transfer filtered UTE MRI.
abstract: OBJECTIVE
  To test the potential of combining double quantum and magnetization transfer filtered ultra-short echo time (DQF-MT-UTE) MRI to obtain information about the macromolecular composition and characteristics of connective tissues.
  
  
  METHODS
  A DQF-MT-UTE pulse sequence was implemented on a 14.1 T AVANCE III Bruker spectrometer equipped with a Bruker micro2.5-imaging gradient system to obtain images of porcine annulus fibrosus.
  
  
  RESULTS
  The DQF-MT-UTE MRI of the annulus fibrosus of porcine intervertebral disc, where the creation time of the double quantum coherence filtering (DQF) was on a time scale appropriate for excitation of macromolecules, showed stronger signal from the outer layers of the disc than from the inner layers closer to the nucleus pulposus. Similarly, spectroscopic studies showed the same trend in the efficiency of the magnetization transfer (MT) from collagen to water.
  
  
  CONCLUSIONS
  DQF-MT filtered UTE MRI of the annulus fibrosus provides new contrast parameters that depend on the concentration of the collagen and on the rate and efficiency of MT of its protons to water. The latter parameters appear to be different for collagen types I and II in the annulus fibrosus.
authors: School of Chemistry, Tel Aviv University, Tel Aviv, Israel.
authors: Uzi
authors: U
authors: Eliav
authors: Michal E
authors: ME
authors: Komlosh
authors: Peter J
authors: PJ
authors: Basser
authors: Gil
authors: G
authors: Navon
mesh_terms: D000465:Algorithms; D000818:Animals; D003094:Collagen / Q000378:metabolism*; D003287:Contrast Media; D005240:Feasibility Studies; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D066298:In Vitro Techniques; D007403:Intervertebral Disc / Q000033:anatomy & histology* / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine
chemical_list: D003287:Contrast Media; D003094:Collagen
keywords: annulus fibrosus; collagen type I; collagen type II; double quantum filter; interverterbral disc; magnetization transfer; ultra-short TE