PT  - JOURNAL ARTICLE
AU  - Burger, Irene A.
AU  - Wurnig, Moritz C.
AU  - Becker, Anton S.
AU  - Kenkel, David
AU  - Delso, Gaspar
AU  - Veit-Haibach, Patrick
AU  - Boss, Andreas
TI  - Hybrid PET/MR Imaging: An Algorithm to Reduce Metal Artifacts from Dental Implants in Dixon-Based Attenuation Map Generation Using a Multiacquisition Variable-Resonance Image Combination Sequence
AID  - 10.2967/jnumed.114.145862
DP  - 2015 Jan 01
TA  - Journal of Nuclear Medicine
PG  - 93--97
VI  - 56
IP  - 1
4099  - http://jnm.snmjournals.org/content/56/1/93.short
4100  - http://jnm.snmjournals.org/content/56/1/93.full
SO  - J Nucl Med2015 Jan 01; 56
AB  - It was the aim of this study to implement an algorithm modifying Dixon-based MR imaging datasets for attenuation correction in hybrid PET/MR imaging with a multiacquisition variable resonance image combination (MAVRIC) sequence to reduce metal artifacts. Methods: After ethics approval, in 8 oncologic patients with dental implants data were acquired in a trimodality setup with PET/CT and MR imaging. The protocol included a whole-body 3-dimensional dual gradient-echo sequence (Dixon) used for MR imaging–based PET attenuation correction and a high-resolution MAVRIC sequence, applied in the oral area compromised by dental implants. An algorithm was implemented correcting the Dixon-based μ maps using the MAVRIC in areas of Dixon signal voids. The artifact size of the corrected μ maps was compared with the uncorrected MR imaging μ maps. Results: The algorithm was robust in all patients. There was a significant reduction in mean artifact size of 70.5% between uncorrected and corrected μ maps from 697 ± 589 mm2 to 202 ± 119 mm2 (P = 0.016). Conclusion: The proposed algorithm could improve MR imaging–based attenuation correction in critical areas, when standard attenuation correction is hampered by metal artifacts, using a MAVRIC.