title: Quantitative and qualitative comparison of MR imaging of the temporomandibular joint at 1.5 and 3.0 T using an optimized high-resolution protocol.
abstract: OBJECTIVE
  To quantitatively and qualitatively compare MRI of the temporomandibular joint (TMJ) using an optimized high-resolution protocol at 3.0 T and a clinical standard protocol at 1.5 T.
  
  
  METHODS
  A phantom and 12 asymptomatic volunteers were MR imaged using a 2-channel surface coil (standard TMJ coil) at 1.5 and 3.0 T (Philips Achieva and Philips Ingenia, respectively; Philips Healthcare, Best, Netherlands). Imaging protocol consisted of coronal and oblique sagittal proton density-weighted turbo spin echo sequences. For quantitative evaluation, a spherical phantom was imaged. Signal-to-noise ratio (SNR) maps were calculated on a voxelwise basis. For qualitative evaluation, all volunteers underwent MRI of the TMJ with the jaw in closed position. Two readers independently assessed visibility and delineation of anatomical structures of the TMJ and overall image quality on a 5-point Likert scale. Quantitative and qualitative measurements were compared between field strengths.
  
  
  RESULTS
  The quantitative analysis showed similar SNR for the high-resolution protocol at 3.0 T compared with the clinical protocol at 1.5 T. The qualitative analysis showed significantly better visibility and delineation of clinically relevant anatomical structures of the TMJ, including the TMJ disc and pterygoid muscle as well as better overall image quality at 3.0 T than at 1.5 T.
  
  
  CONCLUSIONS
  The presented results indicate that expected gains in SNR at 3.0 T can be used to increase the spatial resolution when imaging the TMJ, which translates into increased visibility and delineation of anatomical structures of the TMJ. Therefore, imaging at 3.0 T should be preferred over 1.5 T for imaging the TMJ.
authors.affiliation: 1 Department of Radiology, Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.|2 Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Andrei
authors.identifier: http://orcid.org/0000-0003-1230-5752
authors.initials: A
authors.lastname: Manoliu
authors.affiliation: 2 Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Georg
authors.initials: G
authors.lastname: Spinner
authors.affiliation: 2 Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Wyss
authors.affiliation: 3 Center of Dental Medicine of the University of Zurich, Zurich, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Erni
authors.affiliation: 3 Center of Dental Medicine of the University of Zurich, Zurich, Switzerland.
authors.forename: Dominik A
authors.initials: DA
authors.lastname: Ettlin
authors.affiliation: 1 Department of Radiology, Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Nanz
authors.affiliation: 1 Department of Radiology, Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Ulbrich
authors.affiliation: 3 Center of Dental Medicine of the University of Zurich, Zurich, Switzerland.
authors.forename: Luigi M
authors.initials: LM
authors.lastname: Gallo
authors.affiliation: 1 Department of Radiology, Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
authors.forename: Gustav
authors.initials: G
authors.lastname: Andreisek
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D011626:Pterygoid Muscles / Q000033:anatomy & histology; D012815:Signal Processing, Computer-Assisted; D013704:Temporomandibular Joint / Q000033:anatomy & histology*; D019224:Temporomandibular Joint Disc / Q000033:anatomy & histology; D055815:Young Adult
keywords: magnetic resonance imaging (MRI); signal-to-noise ratio (SNR); temporomandibular joint; temporomandibular joint disc; temporomandibular joint disorders