Applicability of three-dimensional ultra-short echo time magnetic resonance imaging for in vivo assessment of caries lesions and early demineralization
The objective of this thesis was to investigate the potential of a new magnetic resonance imaging (MRI) technique at a high-field (3Tesla) whole-body clinical system for the assessment of caries lesions and early demineralization. In an initial in-vitro study it could be shown that with adjusted imaging parameters of the ultra-short echo time (UTE) sequence a clear delineation between the different hard dental tissues was feasible. In the following clinical study the aim was to investigate the transfer to patients. On the basis of two different MRI sequences for dental applications, one conventional multi-slice turbo spin-echo (MS-TSE) and one 3D ultra-short echo time (3D-UTE) sequence, the applicability for the detection of caries lesions was evaluated. The results were compared to the findings in existing conventional intra-oral X-ray images and four of the examined patients volunteered for additional in-situ documentation. In all cases, the dimensions of the caries lesions identified by 3D-UTE MRI were significantly larger than the respective dimensions in the X-ray images. Furthermore, the lesion extensions from the in-situ documentations confirm the lesion size in the 3D-UTE images and the respective underestimation in the X-ray images. In direct comparison of the two investigated MRI techniques, there was no advantage for the MS-TSE technique at any time, yet the 3D-UTE technique showed a much higher level of sensitivity than the MS-TSE technique. In summary, this clinical study enabled to obtain a sensitivity of 97.5 % for 3D-UTE, 85 % for X-ray and 17 % for MS-TSE.
Subject HeadingsKaries [GND]
Dental caries [MeSH]
Magnetic resonance imaging, dental [MeSH]
Tooth demineralization [MeSH]