Assessment of the dentin-pulp complex response to caries by ADC mapping

NMR Biomed. 2012 Sep;25(9):1056-62. doi: 10.1002/nbm.2770. Epub 2012 Jan 16.

Abstract

The prognostic potential of apparent diffusion coefficient (ADC) mapping was studied as complemented by high-resolution 3D T(1)-weighted MRI in the assessment of dentin-pulp complex response to caries. Twenty-six extracted human teeth, with or without caries lesions of different grades in accord with the International Caries Detection and Assessment System (ICDAS), were analyzed by high-resolution MRI at 2.35 T. A signal rise in demineralized hard dental tissues in high-resolution T(1)-weighted MR images enabled assessment of the demineralization depth over the whole range of ICDAS scores. ADC maps of the teeth were calculated from corresponding diffusion-weighted images of four different b values: 0, 132, 317, 635 s/mm(2). These maps enabled reliable differentiation between intact (ADC > 1.0·10(-9) m(2)/s) and affected (ADC < 1.0·10(-9) m(2)/s) regions of dental pulp. Linear regression analyses of demineralization depth in relation to ICDAS score and then also to average ADC of dental pulp showed that a demineralization depth increase of one millimeter corresponds to an ICDAS score increase of 1.2 and an average ADC decrease of 0.07·10(-9) m(2)/s. Results of the study indicate that the average ADC value of dental pulp could be used as a potential marker to assess tissue response to caries comparable to that of ICDAS scoring.

MeSH terms

  • Dental Caries / pathology*
  • Dental Pulp / pathology*
  • Dentin / pathology*
  • Diffusion
  • Humans
  • Imaging, Three-Dimensional
  • Magnetic Resonance Imaging / methods*
  • Signal Processing, Computer-Assisted
  • Tooth Demineralization