title: Imaging human teeth by phosphorus magnetic resonance with nuclear Overhauser enhancement.
abstract: Three-dimensional phosphorus MR images ((31)P MRI) of teeth are obtained at a nominal resolution of 0.5 mm in less than 15 minutes using acquisition pulse sequences sensitive to ultra-short transversal relaxation times. The images directly reflect the spatially resolved phosphorus content of mineral tissue in dentin and enamel; they show a lack of signal from pulp tissue and reduced signal from de-mineralized carious lesions. We demonstrate for the first time that the signal in (31)P MR images of mineralized tissue is enhanced by a (1)H-(31)P nuclear Overhauser effect (NOE). Using teeth as a model for imaging mineralized human tissue, graded differences in signal enhancement are observed that correlate well with known mineral content. From solid-state NMR experiments we conclude that the NOE is facilitated by spin diffusion and that the NOE difference can be assigned to a higher water content and a different micro-structure of dentin. Thus, a novel method for imaging mineral content without ionizing radiation is proposed. This method has potential use in the assessment of de-mineralization states in humans, such as caries of teeth and osteoporosis of bones.
authors: Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein zuid 10, 6586 GA Nijmegen The Netherlands.
authors: Yi
authors: Y
authors: Sun
authors: Solid State NMR, Institute of Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands.
authors: Ole
authors: O
authors: Brauckmann
authors: Division of TMD and Orofacial Pain Department of Diagnostic and Biological Sciences, University of Minnesota, 515 Delaware St. SE, Minneapolis, MN 55455, United States.
authors: Donald R
authors: DR
authors: Nixdorf
authors: Solid State NMR, Institute of Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ Nijmegen, The Netherlands.
authors: Arno
authors: A
authors: Kentgens
authors: Center for Magnetic Resonance Research, University of Minnesota, 2021 Sixth Street SE, Minneapolis, MN 55455, United States.
authors: Michael
authors: M
authors: Garwood
authors: Center for Magnetic Resonance Research, University of Minnesota, 2021 Sixth Street SE, Minneapolis, MN 55455, United States.
authors: Djaudat
authors: D
authors: Idiyatullin
authors: Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein zuid 10, 6586 GA Nijmegen The Netherlands.
authors: Arend
authors: A
authors: Heerschap
mesh_terms: D003743:Dental Enamel / Q000737:chemistry / Q000000981:diagnostic imaging; D003804:Dentin / Q000737:chemistry / Q000000981:diagnostic imaging; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D010758:Phosphorus / Q000737:chemistry*; D014070:Tooth / Q000737:chemistry / Q000000981:diagnostic imaging*
chemical_list: D010758:Phosphorus