NMR Imaging in Dentistry: Relaxation and Diffusion Studies

Abstract

Magnetic resonance imaging has been widely used for medical diagnosis in recent years. The knowledge of the proton spin-lattice relaxation time, T₁, represents the basis for NMR imaging. In the present study, we measured T₁ in saliva, gingival fluid, gingival blood, and inflamed gingiva by means of a pulsed NMR Fourier-transform spectrometer. From several measurements, we found the following average T₁ values: in saliva, T₁ = 2550 msec; in gingival fluid, T₁ = 2085 msec; in gingival blood, T₁ = 1515 msec; and in inflamed gingiva samples, T₁ = 840 msec.

In addition, electron paramagnetic resonance imaging was used to demonstrate the in vitro diffusion processes of spin-labeled molecules into tooth enamel by application of the linear magnetic field gradient to a conventional EPR spectrometer. The diffusion coefficient for the nitroxide spin-labeled molecules into tooth enamel was evaluated as D = 10^-7 cm² sec^-1.

Get full access to this article

View all access options for this article.

References

Aguayo, J.B. ; Blackband, S.J. ; Schoeniger, J. ; Mat-Tingly, M.A. ; and Hinterman, M. (1986): Nuclear Magnetic Resonance Imaging of a Single Cell, Nature 322:190-191.

Andrew, E.R. (1985): Nuclear Magnetic Resonance Imaging in Medicine: Physical Principles, Proc R Soc Lond B 225:399-410.

Cavezian, R. ; Cabanis, E.A. ; Pasquet, G. ; Iba-Zizen, M. Th.; Lebihan, D. ; Tamraz, J. ; and Roger, B.M. (1986): Imagerie par Resonance Magnetique : Principes Physiques, Applications Biomedicales Actuelles, Perspectives a 1'etage Maxillo-facial , Actual Odontostomatol 154:219-232.

Demsar, F. ; Cevc, P. ; and Schara, M. (1986): Diffusion of Spin Probes in Tissues Measured by Field-gradient EPR, J Magnet Reson 69:258-263.

Descouts, P. (1984): Trends in Nuclear Magnetic Resonance Imaging Systems . In: Progress in Nuclear Medicine, Vol. 8, M.A. Hopf and F.W. Smith , Eds., Basel: Karger, pp. 15-27.

Funduk, N. ; Kydon, D.W. ; Schreiner, L.J. ; Peemoeller, H. ; Miljkovic, L. ; and Pintar, M.M. (1984): Composition and Relaxation of the Proton Magnetization of Human Enamel and its Contribution to the Tooth NMR Image, Magnet Reson Med 1:66-75.

Funduk, N. ; Lahajnar, G. ; Miljkovic, L. ; Skocajic, S. ; Kydon, D.W. ; Schreiner, L.J. ; and Pintar, M.M. (1986): A Comparative NMR Study of Proton Groups in Dentine of 20 and 50 Years Old Donors, Zobozdrav Vestn 41 (Suppl I): 139-160.

Grodd, W. ; Lenz, M. ; Baumann, R. ; and Schroth, G. (1984): Kemspintomographische Unlersuchungen des Gesichtsschadels , Fortschr Rontgenstr 141:517-524.

Harms, S.E. ; Wilk, R.M. ; Wolford, L.M. ; Chiles, D.G. ; and Milam, S.B. (1985): The Temporomandibular Joint: Magnetic Resonance Imaging Using Surface Coils, Radiology 157:133-136.

10.

Lauterbur, P.C. (1973): Image Formation by Induced Local Interactions : Examples Employing Nuclear Magnetic Resonance, Nature 242:190-191.

11.

Mallard, J.R. (1986): Nuclear Magnetic Resonance Imaging in Medicine: Medical and Biological Applications and Problems, Proc R Soc Lond B 226:391-419.

12.

Mansfield, P. and Maudsley, A.A. (1977): Medical Imaging by NMR, Br J Radiol 50:188-194.

13.

Paushter, D.M. ; Modic, M.T. ; Borkowski, G.P. ; Wein-Stein, M.A. ; and Zeman, R.K. (1984): Magnetic Resonance: Principles and Applications , Med Clin N Amer- Radiology 68 :1393-1421.

14.

Roberts, D. ; Schenck, J. ; Joseph, P. ; Foster, T. ; Hart, H. ; Pettigrew, J. ; Kundel, H.L. ; Edelstein, W. ; and Ha-Ber, B. (1985): Temporomandibular Joint: Magnetic Resonance Imaging , Radiology 154:829-830.

15.

Skaleric, U. and Dolinsek, J. (1986): Proton Spin Lattice Relaxation Time T, in Gingival Fluid, Zobozdrav Vestn 41 (Suppl I):179-185.

16.

Steiner, R.E. (1986): Present and Future Clinical Position of Magnetic Resonance Imaging, Magnet Reson Med 3:473-490.

17.

Unger, J.M. (1985): The Oral Cavity and Tongue: Magnetic Resonance Imaging, Radiology 155:151-153.