Pediatric MRI: Should stainless steel crowns be removed?

Congress:

ECR 2019

Poster Number:

C-2189

Type:

Scientific Exhibit

Keywords:

Artifacts, Safety, Removal, Audit and standards, MR, Paediatric, Neuroradiology brain, MR physics

Authors:

A. Heinrich¹, P. Kaleth², C. Finke², F. V. Güttler¹, M. de Bucourt², U. K. M. Teichgräber¹; ¹Jena/DE, ²Berlin/DE

DOI:

10.26044/ecr2019/C-2189

DOI-Link:

https://dx.doi.org/10.26044/ecr2019/C-2189

Fig. 1: Crowns in untreated (a), trimmed (b) and bent (c) condition.

Fig. 2: The maximum artifact size was measured with the software MR-Susceptibility...

Fig. 3: The total signal loss of three stainless steel crowns (A: 3M Espe, B: Acero XT,...

Fig. 4: The distances from the maxillary left second deciduous molar to anatomic...

Aims and objectives

The purpose of this study was to measure susceptibility artifacts in pediatric stainless steel crowns according to standardized test methods of the American Society for Testing and Materials (ASTM) at 1.5 T and 3 T MRI to clarify if the crown needs to be removed for the examination.

Methods and materials

For this study different pre-fabricated pediatric stainless steel crowns (type 304, 316, 316L, see Fig. 1) for the maxillary left first and second deciduous molars from three manufacturers (3M Espe, Acero XT, Denovo Dental) were compared on a 1.5 T and 3 T MRI (Magnetom Avanto and Prisma, Siemens, Erlangen, Germany). The signal loss was measured according to ASTM F2119-07 [1] for a TSE (TR 500 ms, TE 20 ms) and GRE (TR 100 ms, TE 15 ms) sequence. The evaluation was performed with the...

Results

There are significant differences in susceptibility artifacts dependent on material composition of the crowns (see Fig. 3). The total signal loss was 27-to-35 ± 4 mm for TSE sequences and 35-to-46 ± 5 mm for GRE sequences. The distances from the maxillary left second deciduous molar to anatomic structures (see Fig. 4) were 36-to-44 ± 5 mm (orbital rim), 39-to-53 ± 6 mm (gyrus temporalis inferior), 70-to-81 ± 5 mm (lower margin of cerebellum) and 109-to-126 ± 7 mm (lateral ventricle).

Conclusion

In general, pediatric stainless steel crowns do not have to be removed before a MRI examination. However, materials with lower artifact size should be preferred. Mechanical modifications of the crown margins do not result in significantly larger artifacts and can as a rule thus be ignored.

Personal information

Andreas Heinrich, medical physicists Department of Radiology, University Hospital Jena, Friedrich Schiller University, Germany Am Klinikum 1 07747 Jena, Germany Fon: +49 3641 9 - 324 898 Fax: +49 3641 9 - 324 832 e-mail: [email protected]

References

ASTM F2119-07, ASTM F2119-07, Standard Test Method for Evaluation of MR Image Artifacts from Passive Implants. 2013, ASTM International: West Conshohocken, PA. Heinrich, A., U.K. Teichgräber, and F.V. Güttler, Measurement of susceptibility artifacts with histogram-based reference value on magnetic resonance images according to standard ASTM F2119. Biomedical Engineering/Biomedizinische Technik, 2015. 60(6): p. 541-549. Heinrich, A., et al., In vitro stent assessment by MRI: visibility of lumen and artifacts for 27 modern stents. Biomedical Engineering/Biomedizinische Technik, 2017. 62(6): p. 565-573.