@article {Knesaurek494, author = {Karin Knesaurek and Josef Machac and David Izquierdo-Garcia and Zahi Fayad}, title = {Investigation of dental filling artifacts in head and neck PET/MRI imaging. Comparison with PET/CT images}, volume = {52}, number = {supplement 1}, pages = {494--494}, year = {2011}, publisher = {Society of Nuclear Medicine}, abstract = {494 Objectives The purpose of our study was to explore the influence of dental filing artifacts in head and neck PET/MRI imaging. Methods In ongoing study, several patients were imaged on a GE DLS 16 slice PET/CT system. Approximately 20 minutes later, the same patient was imaged at a Philips PET/MRI system. The data were reconstructed using vendors{\textquoteright} software. For PET/MRI data a binary attenuation map was created from MRI images and applied for attenuation correction (AC). The data were transferred to a common platform and compared using in house software. Two approaches were used to match PET data. First, MRI and CT data were coregistrated and the transformation was saved and used to match the PET data. The second approach was a direct match of the PET data. In both cases, matching was done using maximization of mutual information (Viola and Wells, Int. J. Com. Vis., 137-154, 1997). Results The differences in CT and MRI generated attenuation maps were significant, more than 30\% of average values. However, the differences in the reconstructed images were 20\% or less of the average activity area and did not cause major diagnostic problem. Conclusions Our results indicate, that PET clinical images are not significantly affected by dental filling artifacts, when MRI derived AC is used in head and neck PET/MRI imaging}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/52/supplement_1/494}, eprint = {https://jnm.snmjournals.org/content}, journal = {Journal of Nuclear Medicine} }