Pontificia Universidad Católica de Chile Pontificia Universidad Católica de Chile
Aizaz M., van der Pol J., Schneider A., Munoz C., Holtackers R., van Cauteren Y., van Langen H., Meeder J., Rahel B., Wierts R., Botnar R., Prieto C., Moonen R., Kooi M. (2024)

Extended MRI-based PET motion correction for cardiac PET/MRI

Revista : EJNMMI Physics
Volumen : 11
Número : 1
Tipo de publicación : ISI Ir a publicación

Abstract

Purpose: A 2D image navigator (iNAV) based 3D whole-heart sequence has been used to perform MRI and PET non-rigid respiratory motion correction for hybrid PET/MRI. However, only the PET data acquired during the acquisition of the 3D whole-heart MRI is corrected for respiratory motion. This study introduces and evaluates an MRI-based respiratory motion correction method of the complete PET data.nMethods: Twelve oncology patients scheduled for an additional cardiac F-18-Fluorodeoxyglucose (F-18-FDG) PET/MRI and 15 patients with coronary artery disease (CAD) scheduled for cardiac F-18-Choline (F-18-FCH) PET/MRI were included. A 2D iNAV recorded the respiratory motion of the myocardium during the 3D whole-heart coronary MR angiography (CMRA) acquisition (similar to 10 min). A respiratory belt was used to record the respiratory motion throughout the entire PET/MRI examination (similar to 30-90 min). The simultaneously acquired iNAV and respiratory belt signal were used to divide the acquired PET data into 4 bins. The binning was then extended for the complete respiratory belt signal. Data acquired at each bin was reconstructed and combined using iNAV-based motion fields to create a respiratory motion-corrected PET image. Motion-corrected (MC) and non-motion-corrected (NMC) datasets were compared. Gating was also performed to correct cardiac motion. The SUVmax and TBRmax values were calculated for the myocardial wall or a vulnerable coronary plaque for the F-18-FDG and F-18-FCH datasets, respectively.nResults: A pair-wise comparison showed that the SUVmax and TBRmax values of the motion corrected (MC) datasets were significantly higher than those for the non-motion-corrected (NMC) datasets (8.2 +/- 1.0 vs 7.5 +/- 1.0, p < 0.01 and 1.9 +/- 0.2 vs 1.2 +/- 0.2, p < 0.01, respectively). In addition, the SUVmax and TBRmax of the motion corrected and gated (MC_G) reconstructions were also higher than that of the non-motion-corrected but gated (NMC_G) datasets, although for the TBRmax this difference was not statistically significant (9.6 +/- 1.3 vs 9.1 +/- 1.2, p = 0.02 and 2.6 +/- 0.3 vs 2.4 +/- 0.3, p = 0.16, respectively). The respiratory motion-correction did not lead to a change in the signal to noise ratio.nConclusion: The proposed respiratory motion correction method for hybrid PET/MRI improved the image quality of cardiovascular PET scans by increased SUVmax and TBRmax values while maintaining the signal-to-noise ratio.