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- Kvernby, Sofia, et al.
(författare)
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Quantitative comparison of data-driven gating and external hardware gating for 18F-FDG PET-MRI in patients with esophageal tumors
- 2021
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Ingår i: European Journal of Hybrid Imaging. - : Springer Nature. - 2510-3636. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundRespiratory motion during PET imaging reduces image quality. Data-driven gating (DDG) based on principal component analysis (PCA) can be used to identify respiratory signals. The use of DDG, without need for external devices, would greatly increase the feasibility of using respiratory gating in a routine clinical setting. The objective of this study was to evaluate data-driven gating in relation to external hardware gating and regular static image acquisition on PET-MRI data with respect to SUVmax and lesion volumes.MethodsSixteen patients with esophageal or gastroesophageal cancer (Siewert I and II) underwent a 6-min PET scan on a Signa PET-MRI system (GE Healthcare) 1.5-2 h after injection of 4 MBq/kg F-18-FDG. External hardware gating was done using a respiratory bellow device, and DDG was performed using MotionFree (GE Healthcare). The DDG raw data files and the external hardware-gating raw files were created on a Matlab-based toolbox from the whole 6-min scan LIST-file. For comparison, two 3-min static raw files were created for each patient. Images were reconstructed using TF-OSEM with resolution recovery with 2 iterations, 28 subsets, and 3-mm post filter. SUVmax and lesion volume were measured in all visible lesions, and noise level was measured in the liver. Paired t-test, linear regression, Pearson correlation, and Bland-Altman analysis were used to investigate difference, correlation, and agreement between the methods.ResultsA total number of 30 lesions were included in the study. No significant differences between DDG and external hardware-gating SUVmax or lesion volumes were found, but the noise level was significantly reduced in the DDG images. Both DDG and external hardware gating demonstrated significantly higher SUVmax (9.4% for DDG, 10.3% for external hardware gating) and smaller lesion volume (- 5.4% for DDG, - 6.6% for external gating) in comparison with non-gated static images.ConclusionsData-driven gating with MotionFree for PET-MRI performed similar to external device gating for esophageal lesions with respect to SUVmax and lesion volume. Both gating methods significantly increased the SUVmax and reduced the lesion volume in comparison with non-gated static acquisition. DDG resulted in reduced image noise compared to external device gating and static images.
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| 3. |
- Linder, Gustav, et al.
(författare)
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F-18-FDG-PET/MRI in preoperative staging of oesophageal and gastroesophageal junctional cancer
- 2019
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Ingår i: Clinical Radiology. - : W B SAUNDERS CO LTD. - 0009-9260 .- 1365-229X. ; 74:9, s. 718-725
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To evaluate integrated 2-[F-18]-fluoro-2-deoxy-D-glucose (F-18-FDG) positron-emission tomography (PET)/magnetic resonance imaging (MRI), in comparison with the standard technique, integrated F-18-FDG-PET/computed tomography (CT), in preoperative staging of oesophageal or gastroesophageal junctional cancer.MATERIALS AND METHODS: In the preoperative staging of 16 patients with oesophageal or gastroesophageal junctional cancer, F-18-FDG-PET/MRI was performed immediately following the clinically indicated F-18-FDG-PET/CT. MRI-sequences included T1-weighted fat-water separation (Dixon's technique), T2-weighted, diffusion-weighted imaging (DWI), and gadolinium contrast-enhanced T1-weighted three-dimensional (3D) imaging. PET was performed with F-18-FDG. Two separate teams of radiologists conducted structured blinded readings of F-18-FDG-PET/MRI or F-18-FDG-PET/CT, which were then compared regarding tumour measurements and characteristics as well as assessment of inter-rater agreement (Cohen's kappa) for the clinical tumour, nodal and metastatic (TNM) stage.RESULTS: There were no medical complications. Comparison of tumour measurements revealed high correlations without significant differences between modalities. The maximum standardised uptake value (SUVmax) values of the primary tumour with F-18-FDG-PET/MRI had excellent correlation to those of F-18-FDG-PET/CT (0.912, Spearman's rho). Inter-rater agreement between the techniques regarding T-stage was only fair (Cohen's kappa, 0.333), arguably owing to relative over-classification of the T-stage using F-18-FDG-PET/CT. Agreements in the assessment of N- and M-stage were substantial (Cohen's kappa, 0.849 and 0.871 respectively).CONCLUSION: Preoperative staging with F-18-FDG-PET/MRI is safe and promising with the potential to enhance tissue resolution in the area of interest. F-18-FDG-PET/MRI and F-18-FDG-PET/CT correlated well for most of the measured values and discrepancies were seen mainly in the assessment of the T-stage. These results facilitate further studies investigating the role of F-18-FDG-PET/MRI in, e.g., predicting or determining the response to neoadjuvant therapy.
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