Impact of free-breathing CT on quantitative measurements of static and quiescent period-gated PET Images

Meier, Joseph; Einstein, Samuel A.; Diab, Radwan; Erasmus, Lauren J; Xu, Guofang; Mawlawi, Osama

doi:10.1088/1361-6560/ab1cdd

Cited by 8 publications

(11 citation statements)

References 20 publications

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“…While images from the two modalities were often closely aligned, there were occasions where the CT exposure occurred at a different respiratory phase leading to mis-alignment of the images and the introduction of well recognised attenuation and scatter correction artefacts. Application of quiescent period gating in such a manner is known to cause changes in the magnitude of these artefacts with corresponding changes in lesion quantification (21). While this does not confound our comparison of DDG-retro for the PET data), it is a confounding factor for comparison of gated images and non-gated images, and hence the quantitative comparison we performed is subject to this caveat.…”

Section: Discussionmentioning

confidence: 99%

Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical ¹⁸F-FDG PET/CT

et al. 2020

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Methods 144 whole-body 18 F-FDG PET/CT examinations were acquired using a Discovery D690 or D710 PET/CT scanner (GE Healthcare), with a respiratory gating waveform recorded by an external, device-based respiratory gating system. In each examination, two of the bed positions covering the liver and lung bases were acquired with duration of 6 minutes. Quiescent period gating retaining ~50% of coincidences was then able to produce images with an effective duration of 3 minutes for these two bed positions, matching the other bed positions. For each exam, 4 reconstructions were performed and compared: data-driven gating (DDG-retro), external devicebased gating (RPM-gated), no gating but using only the first 3 minutes of data (Ungated matched), and no gating retaining all coincidences (Ungated full). Lesions in the images were quantified and image quality was scored by a radiologist, blinded to the method of data processing. Results The use of DDG-retro was found to increase SUV max and to decrease the threshold-defined lesion volume in comparison to each of the other reconstruction options. Compared to RPMgated, DDG-retro gave an average increase in SUV max of 0.66±0.1 g/mL (n=87,p<0.0005). Although results from the blinded image evaluation were most commonly equivalent, DDG-retro was preferred over RPM-gated in 13% of exams while the opposite occurred in just 2% of exams. This was a significant preference for DDG-retro (p=0.008,n=121). Liver lesions were identified in 23 exams. Considering this subset of data, DDG-retro was ranked superior to Ungated full in 6/23 (26%) of cases. Gated reconstruction using the external device failed in 16% of exams, while DDG-retro always provided a clinically acceptable image. Conclusion In this clinical evaluation, the data-driven respiratory gating technique provided superior performance as compared to the external device-based system. For the majority of exams the performance was equivalent, but data-driven respiratory gating had superior performance in 13% of exams, leading to a significant preference overall.

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Section: Discussionmentioning

confidence: 99%

Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical ¹⁸F-FDG PET/CT

et al. 2020

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“…An important theme discussed in prior studies of DDG-PET is the acknowledgement that misregistration between DDG-PET and helical CT may have been present in some fraction of cases studied [ 11 , 15 ]. Meier et al showed previously that different CT phases being used for attenuation correction can lead to significant changes in PET quantitation, with the impact even more severe for DDG-PET than static PET [ 27 ]. However, to our knowledge, no previous work attempted to correct DDG-PET and CT misregistration before analyzing the impact of DDG-PET for the purposes of their study.…”

Section: Introductionmentioning

confidence: 99%

Data-driven gated PET/CT: implications for lesion segmentation and quantitation

Thomas

Pan

2021

EJNMMI Phys

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Background Data-driven gating (DDG) can improve PET quantitation and alleviate many issues with patient motion. However, misregistration between DDG-PET and CT may occur due to the distinct temporal resolutions of PET and CT and can be mitigated by DDG-CT. Here, the effects of misregistration and respiratory motion on PET quantitation and lesion segmentation were assessed with a new DDG-PET/CT method. Methods A low-dose cine-CT was acquired in misregistered regions to enable both average CT (ACT) and DDG-CT. The following were compared: (1) baseline PET/CT, (2) PET/ACT (attenuation correction, AC = ACT), (3) DDG-PET (AC = helical CT), and (4) DDG-PET/CT (AC = DDG-CT). For DDG-PET, end-expiration (EE) data were derived from 50% of the total PET data at 30% from end-inspiration. For DDG-CT, EE phase CT data were extracted from cine-CT data by lung Hounsfield unit (HU) value and body contour. A total of 91 lesions from 16 consecutive patients were assessed for changes in standard uptake value (SUV), lesion glycolysis (LG), lesion volume, centroid-to-centroid distance (CCD), and DICE coefficients. Results Relative to baseline PET/CT, median changes in SUVmax ± σ for all 91 lesions were 20 ± 43%, 26 ± 23%, and 66 ± 66%, respectively, for PET/ACT, DDG-PET, and DDG-PET/CT. Median changes in lesion volume were 0 ± 58%, − 36 ± 26%, and − 26 ± 40%. LG for individual lesions increased for PET/ACT and decreased for DDG-PET, but was not different for DDG-PET/CT. Changes in mean HU from baseline PET/CT were dramatic for most lesions in both PET/ACT and DDG-PET/CT, especially for lesions with mean HU < 0 at baseline. CCD and DICE were both affected more by motion correction with DDG-PET than improved registration with ACT or DDG-CT. Conclusion As misregistration becomes more prominent, the impact of motion correction with DDG-PET is diminished. The potential benefits of DDG-PET toward accurate lesion segmentation and quantitation could only be fully realized when combined with DDG-CT. These results impress upon the necessity of ensuring both misregistration and motion correction are accounted for together to optimize the clinical utility of PET/CT.

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“…Several authors have suggested methods to select part of the PET data where the patient is in the same respiratory state as during the CT (Chang et al 2010, Meier et al 2019, Hamill et al 2020. However, in the context of motion correction, such an approach can not be used to generate phase-matched gated PET.…”

Section: Attenuation Correction Issuesmentioning

confidence: 99%

PET respiratory motion correction: quo vadis?

Lamare¹,

Bousse²,

Thielemans³

et al. 2022

Phys. Med. Biol.

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Positron emission tomography (PET) respiratory motion correction has been a subject of great interest for the last twenty years, prompted mainly by the development of multimodality imaging devices such as PET/computed tomography (CT) and PET/magnetic resonance imaging (MRI). PET respiratory motion correction involves a number of steps including acquisition synchronization, motion estimation and finally motion correction. The synchronization steps include the use of different external device systems or data driven approaches which have been gaining ground over the last few years. Patient specific or generic motion models using the respiratory synchronized datasets can be subsequently derived and used for correction either in the image space or within the image reconstruction process. Similar overall approaches can be considered and have been proposed for both PET/CT and PET/MRI devices. Certain variations in the case of PET/MRI include the use of MRI specific sequences for the registration of respiratory motion information. The proposed review includes a comprehensive coverage of all these areas of development in field of PET respiratory motion for different multimodality imaging devices and approaches in terms of synchronization, estimation and subsequent motion correction. Finally, a section on perspectives including the potential clinical usage of these approaches is included.

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Impact of free-breathing CT on quantitative measurements of static and quiescent period-gated PET Images

Cited by 8 publications

References 20 publications

Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical ¹⁸F-FDG PET/CT

Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical ¹⁸F-FDG PET/CT

Data-driven gated PET/CT: implications for lesion segmentation and quantitation

PET respiratory motion correction: quo vadis?

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Impact of free-breathing CT on quantitative measurements of static and quiescent period-gated PET Images

Cited by 8 publications

References 20 publications

Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical 18F-FDG PET/CT

Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical 18F-FDG PET/CT

Data-driven gated PET/CT: implications for lesion segmentation and quantitation

PET respiratory motion correction: quo vadis?

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Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical ¹⁸F-FDG PET/CT

Data-Driven Respiratory Gating Outperforms Device-Based Gating for Clinical ¹⁸F-FDG PET/CT