Image quality and quantification accuracy dependence on patient body mass in 89Zr PET/CT imaging

Abstract Background This study was conducted to clarify how patient body mass affects the image quality and quantification accuracy of images obtained using 89Zr PET/CT. 89Zr PET/CT images from time-of-flight (TOF) PET/CT and semiconductor (SC) PET/CT were obtained using three types (M, L, LL; corresponding to increasing patient body weight) of custom-made body phantoms designed similarly to the National Electrical Manufacturers Association (NEMA) IEC body phantom. The phantom data were analyzed visually and quantitatively to derive image quality metrics, namely detectability of the 10-mm-diameter hot sphere, percent contrast for the 10-mm-diameter hot sphere (QH,10 mm), percent background variability (N10mm), contrast-to-noise ratio (QH,10 mm/N10mm), and coefficient of variation of the background area (CVBG). Results Visual assessment revealed that all the 10-mm-diameter hot spheres of the three types of phantoms were identifiable on both SC and TOF PET/CT images. The N10mm and CVBG values were within the proposed reference levels, and decreased with acquisition duration for both PET/CT types. At 10-min acquisition, the QH,10 mm/N10mm of SC PET/CT was greater than the proposed reference level in all phantoms. However, the QH,10 mm/N10mm of TOF PET/CT was greater than the proposed reference level in M-type phantom alone. All the SUVBG values were within 1.00 ± 0.05 for both PET/CT types. Conclusions This study showed that the image quality and quantification accuracy depend on the patient’s body mass, suggesting that acquisition time on 89Zr PET/CT should be changed according to the patient’s body mass.

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The Role of Activity, Scan Duration and Patient's Body Mass Index in the Optimization of 18FDG Imaging Protocols on a TOF-PET/CT Scanner

10.21203/rs.3.rs-136005/v1 ◽

2020 ◽

Author(s):

Roberta Matheoud ◽

Naema Al-Maymani ◽

Alessia Oldani ◽

Gian Mauro Sacchetti ◽

Marco Brambilla ◽

...

Keyword(s):

Body Mass Index ◽

Image Quality ◽

Body Mass ◽

Activity Concentration ◽

Background Activity ◽

Whole Body ◽

Internal Diameter ◽

Ct Scanner ◽

Pet Ct ◽

Tof Pet

Abstract BackgroundTime-of-flight (TOF) PET technology determines a reduction in the noise and improves the reconstructed image quality in low counts acquisitions, such as in overweight patients, allowing a reduction of administered activity and/or imaging time. However, international guidelines and recommendations on 18F-fluoro-2-deoxyglucose (FDG) activity administration scheme are old or only partially account for TOF technology and advanced reconstruction modalities. The aim of this study was to optimize FDG whole-body studies on a TOF PET/CT scanner by using a multivariate approach to quantify how physical figures of merit related to image quality change with acquisition/reconstruction/patient-dependent parameters in a phantom experiment. MethodsThe NEMA-IQ phantom was used to evaluate contrast recovery coefficient (CRC), background variability (BV) and contrast-to-noise ratio (CNR) as a function of changing emission scan duration (ESD), activity concentration (AC), target internal diameter (ID), target-background activity ratio (TBR), and body mass index (BMI). The phantom was filled with an average concentration of 5.3 kBq/mL of FDG solution and the spheres with TBR of 21.2, 8.8, and 5.0 in 3 different sessions. Images were acquired at varying background activity concentration from 5.1 to 1.3 kBq/mL and images were reconstructed for ESD of 30-151 seconds per bed position with and without Point Spread Function (PSF) correction. The parameters were all considered in a single analysis using multiple linear regression methods. ResultsAs expected, CRC depended only on sphere ID and on PSF application, while BV depended on sphere ID, ESD, AC and BMI of the phantom, in order of decreasing relevance. Noteworthy, ESD and AC resulted as the most significant predictors of CNR variability with a similar relevance, followed by the weight of the patient and TBR of the lesion. ConclusionsAC and ESD proved to be effective tools in modulating CNR. ESD could be increased rather than AC to improve image quality in overweight/obese patients to fulfil ALARA principles.

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Clinical evaluation of PET image quality as a function of acquisition time in a new TOF-PET/MR compared to TOF-PET/CT - initial results

EJNMMI Physics ◽

10.1186/2197-7364-2-s1-a76 ◽

2015 ◽

Vol 2 (S1) ◽

Cited By ~ 3

Author(s):

Konstantinos Zeimpekis ◽

Martin Huellner ◽

Felipe De Galiza Barbosa ◽

Edwin Ter Voert ◽

Helen Davison ◽

...

Keyword(s):

Image Quality ◽

Clinical Evaluation ◽

Acquisition Time ◽

Pet Ct ◽

Initial Results ◽

Tof Pet

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Clinical Evaluation of PET Image Quality as a Function of Acquisition Time in a New TOF-PET/MRI Compared to TOF-PET/CT—Initial Results

Molecular Imaging and Biology ◽

10.1007/s11307-015-0845-5 ◽

2015 ◽

Vol 17 (5) ◽

pp. 735-744 ◽

Cited By ~ 15

Author(s):

Konstantinos G. Zeimpekis ◽

Felipe Barbosa ◽

Martin Hüllner ◽

Edwin ter Voert ◽

Helen Davison ◽

...

Keyword(s):

Image Quality ◽

Clinical Evaluation ◽

Acquisition Time ◽

Pet Ct ◽

Initial Results ◽

Tof Pet

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The role of activity, scan duration and patient’s body mass index in the optimization of FDG imaging protocols on a TOF-PET/CT scanner

EJNMMI Physics ◽

10.1186/s40658-021-00380-9 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Roberta Matheoud ◽

Naema Al-Maymani ◽

Alessia Oldani ◽

Gian Mauro Sacchetti ◽

Marco Brambilla ◽

...

Keyword(s):

Body Mass Index ◽

Image Quality ◽

Body Mass ◽

Activity Concentration ◽

Background Activity ◽

Whole Body ◽

Internal Diameter ◽

Ct Scanner ◽

Pet Ct ◽

Tof Pet

Abstract Background Time-of-flight (TOF) PET technology determines a reduction in the noise and improves the reconstructed image quality in low count acquisitions, such as in overweight patients, allowing a reduction of administered activity and/or imaging time. However, international guidelines and recommendations on the 18F-fluoro-2-deoxyglucose (FDG) activity administration scheme are old or only partially account for TOF technology and advanced reconstruction modalities. The aim of this study was to optimize FDG whole-body studies on a TOF-PET/CT scanner by using a multivariate approach to quantify how physical figures of merit related to image quality change with acquisition/reconstruction/patient-dependent parameters in a phantom experiment. Methods The NEMA-IQ phantom was used to evaluate contrast recovery coefficient (CRC), background variability (BV) and contrast-to-noise ratio (CNR) as a function of changing emission scan duration (ESD), activity concentration (AC), target internal diameter (ID), target-background activity ratio (TBR) and body mass index (BMI). The phantom was filled with an average concentration of 5.3 kBq/ml of FDG solution and the spheres with TBR of 21.2, 8.8 and 5.0 in 3 different sessions. Images were acquired at varying background activity concentration from 5.1 to 1.3 kBq/ml, and images were reconstructed for ESD of 30–151 s per bed position with and without point spread function (PSF) correction. The parameters were all considered in a single analysis using multiple linear regression methods. Results As expected, CRC depended only on sphere ID and on PSF application, while BV depended on sphere ID, ESD, AC and BMI of the phantom, in order of decreasing relevance. Noteworthy, ESD and AC resulted as the most significant predictors of CNR variability with a similar relevance, followed by the BMI of the patient and TBR of the lesion. Conclusions AC and ESD proved to be effective tools in modulating CNR. ESD could be increased rather than AC to improve image quality in overweight/obese patients to fulfil ALARA principles.

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Minimisation of Acquisition Time in a TOF PET/CT Scanner Without Compromising Image Quality

VipIMAGE 2017 - Lecture Notes in Computational Vision and Biomechanics ◽

10.1007/978-3-319-68195-5_4 ◽

2017 ◽

pp. 27-42

Author(s):

J. Oliveira ◽

R. Parafita ◽

S. Branco

Keyword(s):

Image Quality ◽

Acquisition Time ◽

Ct Scanner ◽

Pet Ct ◽

Tof Pet

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Investigation of acquisition time for harmonization of image quality between PET/CT and PET/MRI systems: A phantom study

Optik ◽

10.1016/j.ijleo.2021.167594 ◽

2021 ◽

pp. 167594

Author(s):

Seok Hwan Yoon ◽

Chan Rok Park

Keyword(s):

Image Quality ◽

Phantom Study ◽

Acquisition Time ◽

Pet Ct

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Acquisition Protocols to Optimize 68Ga-DOTA-NOC Position Emission Tomography/Computer Tomography Image Quality Based on Patient Body Mass Index and Injected Dose

Journal of Medical Imaging and Health Informatics ◽

10.1166/jmihi.2020.2968 ◽

2020 ◽

Vol 10 (2) ◽

pp. 508-514

Author(s):

Lei Xu ◽

Lei Lei Zhou ◽

Zhenyu Zhao ◽

Qingle Meng ◽

Rui Yang ◽

...

Keyword(s):

Image Quality ◽

Dose Group ◽

Group Versus ◽

Normal Weight ◽

Emission Tomography ◽

Acquisition Time ◽

Position Emission Tomography ◽

Weight Group ◽

Pet Ct ◽

Overweight Group

Background: The choice of 68Ga-DOTA-1-Nal3-octreotide (68Ga-DOTA-NOC) injected dose and Position emission tomography/computer tomography (PET/CT) acquisition time is still a challenge for obtaining consistently high-quality PET image. Objective: To determine the optimal acquisition protocols based on patient body mass index (BMI) and the injected dose per kilogram for 68Ga-DOTA-NOC PET/CT imaging. Patients and Methods: This was a retrospective analysis of 51 patients (21 males and 30 females) who underwent clinical 68Ga-DOTANOC PET/CT imaging from November 2016 to March 2018 in Nanjing first hospital, the average BMI of these patients was 23.18 ± 3.45 kg/m2 with injected dose of 39.55–110.11 MBq. The study population was classified into groups based on Chinese standard BMI and injected dose. PET image quality and acquisition time were evaluated by coefficient of variance (CV) in the liver slice. Results: (1) The CV significantly increased with increasing weight and BMI (r = 0.647, 0.483, all P < 0.01), and significantly decreased with increasing injected dose per kilogram (r = 0 695, P < 0.01). (2) The CV differed significantly among 4 BMI-based groups, except for normal-weight group versus overweight group and overweight group versus obese group (P < 0.01), and the ratio of overweight group and obese group to normal weight group was approximately 1.1 and 1.2, respectively. Meanwhile, the CV had a significant statistical difference among 3 injected dose per kilogram groups (P < 0.01), and the ratio of that for low dose group and high dose group to moderate dose group was approximately 1.2 and 0.8. Conclusion: The findings showed a feasibility of obtaining consistently high-quality PET image at low injected dose and shorter acquisition time. Estimation of optimal acquisition time and injected dose using CV is valid in improving PET image quality, which can provide reference for the establishment and promotion of 68Ga-DOTA-NOC imaging protocols in China.

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PET/CT BiographTM Sensation 16

Nuklearmedizin ◽

10.1055/s-0038-1625926 ◽

2006 ◽

Vol 45 (03) ◽

pp. 126-133 ◽

Cited By ~ 18

Author(s):

Y. Bercier ◽

M. Schwaiger ◽

S. I. Ziegler ◽

M.-J. Martínez

Keyword(s):

Image Quality ◽

Count Rate ◽

Signal To Noise Ratio ◽

Reconstruction Algorithm ◽

Considerable Change ◽

Acquisition Time ◽

Average Increase ◽

Scatter Fraction ◽

Pet Ct ◽

Before And After

SummaryAim: The new PET/CT Biograph Sensation 16 (BS16) tomographs have faster detector electronics which allow a reduced timing coincidence window and an increased lower energy threshold (from 350 to 400 keV). This paper evaluates the performance of the BS16 PET scanner before and after the Pico-3D electronics upgrade. Methods: Four NEMA NU 2–2001 protocols, (i) spatial resolution, (ii) scatter fraction, count losses and random measurement, (iii) sensitivity, and (iv) image quality, have been performed. Results: A considerable change in both PET count-rate performance and image quality is observed after electronics upgrade. The new scatter fraction obtained using Pico-3D electronics showed a 14% decrease compared to that obtained with the previous electronics. At the typical patient background activity (5.3 kBq/ml), the new scatter fraction was approximately 0.42. The noise equivalent count-rate (RNEC) performance was also improved. The value at which the RNEC curve peaked, increased from 3.7·104s-1 at 14 kBq/ml to 6.4·104s-1 at 21 kBq/ml (2R-NEC rate). Likewise, the peak true count-rate value increased from 1.9·105s-1 at 22 kBq/ml to 3.4·105s-1 at 33 kBq/ml. An average increase of 45% in contrast was observed for hot spheres when using AW-OSEM (4ix8s) as the reconstruction algorithm. For cold spheres, the average increase was 12%. Conclusion: The performance of the PET scanners in the BS16 tomographs is improved by the optimization of the signal processing. The narrower energy and timing coincidence windows lead to a considerable increase of signal- to-noise ratio. The existing combination of fast detectors and adapted electronics in the BS16 tomographs allow imaging protocols with reduced acquisition time, providing higher patient throughput.

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