title: Structure and Size-selective Permeability of the Synovial Membrane of the Temporomandibular Joint of the Mouse Measured by MR Imaging at 7T.
abstract: OBJECTIVE
  We analyzed the anatomical structure of the temporomandibular joint (TMJ) and molecular weight dependency of synovial membrane permeability in mice using 7-tesla magnetic resonance (MR) imaging.
  
  
  METHODS
  We obtained 3-dimensional (3D) T1-weighted gradient echo (3D-T1W) and 3D T2-weighted rapid acquisition with relaxation enhancement (3D-T2W RARE) MR images of the TMJ of male C57BL6 mice with voxel resolution of 65 µm. Two-dimensional (2D) T1w images were measured every 45 s before and after bolus intravenous (IV) injection of contrast reagents: gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA; 0.5 kDa); oligomer-based contrast agent (CH3-DTPA-Gd; 2.1 kDa); gadolinium-labeled polylysine (Gd-polylysine; 10 kDa); and gadolinium-labeled albumin (Gd-albumin; 74 kDa).
  
  
  RESULTS
  T1W images depicted the temporal bone and mandibular condyle as regions with lower signal intensity and the disc as a region of intermediate intensity. In the Gd-DTPA-enhanced T1W and T2W images, the articular disc could be identified as a region with lower signal intensity than that of the upper and lower joint cavities. After IV injection of Gd-DTPA or CH3-DTPA-Gd, the signal intensity of the joint cavities increased within 10 min, but this increase was not shown with Gd-polylysine and Gd-albumin.
  
  
  CONCLUSIONS
  The structural findings obtained by MR imaging agreed with those obtained by hematoxylin-eosin staining under light microscopy. Contrast-enhanced MR imaging suggested that smaller (<2.1 kDa) but not larger (>10 kDa) molecules can permeate the synovial membrane. Our results suggest the utility of MR imaging for analyzing the structure of the TMJ as well as permeability of the synovial membrane.
authors.affiliation: Department of Maxillofacial Surgery, Nihon University School of Dentistry at Matsudo.
authors.forename: Fumie
authors.initials: F
authors.lastname: Yamazaki
authors.forename: Kaori
authors.initials: K
authors.lastname: Satoh
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Seo
mesh_terms: D000418:Albumins / Q000008:administration & dosage / Q000493:pharmacokinetics; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics; D019786:Gadolinium DTPA / Q000008:administration & dosage / Q000493:pharmacokinetics; D021621:Imaging, Three-Dimensional / Q000379:methods; D007275:Injections, Intravenous; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008335:Mandibular Condyle / Q000033:anatomy & histology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D010539:Permeability; D011107:Polylysine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D013583:Synovial Membrane / Q000033:anatomy & histology* / Q000378:metabolism; D013701:Temporal Bone / Q000033:anatomy & histology / Q000378:metabolism; D013704:Temporomandibular Joint / Q000033:anatomy & histology* / Q000378:metabolism; D019224:Temporomandibular Joint Disc / Q000033:anatomy & histology / Q000378:metabolism
chemical_list: D000418:Albumins; D003287:Contrast Media; C058946:albumin-(gadolinium-DTPA); C068674:polylysine-(Gd-DTPA); D011107:Polylysine; D019786:Gadolinium DTPA