The impact of time-of-flight, resolution recovery, and noise modelling in reconstruction algorithms in non-solid-state detectors PET/CT scanners: – multi-centric comparison of activity recovery in a 68Ge phantom

2020 ◽  
Vol 75 ◽  
pp. 85-91
Author(s):  
Stephane Chauvie ◽  
Fabrizio Bergesio ◽  
Elena De Ponti ◽  
Sabrina Morzenti ◽  
Adriano De Maggi ◽  
...  
Keyword(s):  
Solid State ◽  
Time Of Flight ◽  
Reconstruction Algorithms ◽  
Resolution Recovery ◽  
Solid State Detectors ◽  
Activity Recovery ◽  
Pet Ct ◽  
Ct Scanners ◽  
The Impact

scholarly journals The impact of reconstruction algorithms and time of flight information on PET/CT image quality

2015 ◽  
Vol 49 (3) ◽  
pp. 227-233 ◽  
Author(s):  
Alen Suljic ◽  
Petra Tomse ◽  
Luka Jensterle ◽  
Damijan Skrk
Keyword(s):  
Image Quality ◽  
Spatial Resolution ◽  
Time Of Flight ◽  
Triple Line ◽  
Internal Diameter ◽  
Ct Image ◽  
Reconstruction Algorithms ◽  
Pet Ct ◽  
Ct Image Quality ◽  
The Impact

Abstract Background. The aim of the study was to explore the influence of various time-of-flight (TOF) and non-TOF reconstruction algorithms on positron emission tomography/computer tomography (PET/CT) image quality. Materials and methods. Measurements were performed with a triple line source phantom, consisting of capillaries with internal diameter of ~ 1 mm and standard Jaszczak phantom. Each of the data sets was reconstructed using analytical filtered back projection (FBP) algorithm, iterative ordered subsets expectation maximization (OSEM) algorithm (4 iterations, 24 subsets) and iterative True-X algorithm incorporating a specific point spread function (PSF) correction (4 iterations, 21 subsets). Baseline OSEM (2 iterations, 8 subsets) was included for comparison. Procedures were undertaken following the National Electrical Manufacturers Association (NEMA) NU-2-2001 protocol. Results. Measurement of spatial resolution in full width at half maximum (FWHM) was 5.2 mm, 4.5 mm and 2.9 mm for FBP, OSEM and True-X; and 5.1 mm, 4.5 mm and 2.9 mm for FBP+TOF, OSEM+TOF and True-X+TOF respectively. Assessment of reconstructed Jaszczak images at different concentration ratios showed that incorporation of TOF information improves cold contrast, while hot contrast only slightly, however the most prominent improvement could be seen in background variability - noise reduction. Conclusions. On the basis of the results of investigation we concluded, that incorporation of TOF information in reconstruction algorithm mostly affects reduction of the background variability (levels of noise in the image), while the improvement of spatial resolution due to incorporation of TOF information is negligible. Comparison of traditional and modern reconstruction algorithms showed that analytical FBP yields comparable results in some parameter measurements, such as cold contrast and relative count error. Iterative methods show highest levels of hot contrast, when TOF and PSF corrections were applied simultaneously.

scholarly journals Phantom and clinical assessment of small pulmonary nodules using Q.Clear reconstruction on a silicon-photomultiplier-based time-of-flight PET/CT system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhifang Wu ◽  
Binwei Guo ◽  
Bin Huang ◽  
Xinzhong Hao ◽  
Ping Wu ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Pulmonary Nodules ◽  
Medium Size ◽  
Ct Reconstruction ◽  
Reconstruction Algorithms ◽  
Silicon Photomultiplier ◽  
Standardized Uptake Values ◽  
Pet Ct ◽  
Quantification Accuracy ◽  
Small Pulmonary Nodules

AbstractTo evaluate the quantification accuracy of different positron emission tomography-computed tomography (PET/CT) reconstruction algorithms, we measured the recovery coefficient (RC) and contrast recovery (CR) in phantom studies. The results played a guiding role in the partial-volume-effect correction (PVC) for following clinical evaluations. The PET images were reconstructed with four different methods: ordered subsets expectation maximization (OSEM), OSEM with time-of-flight (TOF), OSEM with TOF and point spread function (PSF), and Bayesian penalized likelihood (BPL, known as Q.Clear in the PET/CT of GE Healthcare). In clinical studies, SUVmax and SUVmean (the maximum and mean of the standardized uptake values, SUVs) of 75 small pulmonary nodules (sub-centimeter group: < 10 mm and medium-size group: 10–25 mm) were measured from 26 patients. Results show that Q.Clear produced higher RC and CR values, which can improve quantification accuracy compared with other methods (P < 0.05), except for the RC of 37 mm sphere (P > 0.05). The SUVs of sub-centimeter fludeoxyglucose (FDG)-avid pulmonary nodules with Q.Clear illustrated highly significant differences from those reconstructed with other algorithms (P < 0.001). After performing the PVC, highly significant differences (P < 0.001) still existed in the SUVmean measured by Q.Clear comparing with those measured by the other algorithms. Our results suggest that the Q.Clear reconstruction algorithm improved the quantification accuracy towards the true uptake, which potentially promotes the diagnostic confidence and treatment response evaluations with PET/CT imaging, especially for the sub-centimeter pulmonary nodules. For small lesions, PVC is essential.

scholarly journals An Assessment of the Impact of Incorporating Time-of-Flight Information into Clinical PET/CT Imaging

2010 ◽  
Vol 51 (2) ◽  
pp. 237-245 ◽  
Author(s):  
C. Lois ◽  
B. W. Jakoby ◽  
M. J. Long ◽  
K. F. Hubner ◽  
D. W. Barker ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Ct Imaging ◽  
Pet Ct ◽  
The Impact

scholarly journals Single scan parameterization of space-variant point spread functions in image space via a printed array: the impact for two PET/CT scanners

2011 ◽  
Vol 56 (10) ◽  
pp. 2917-2942 ◽  
Author(s):  
F A Kotasidis ◽  
J C Matthews ◽  
G I Angelis ◽  
P J Noonan ◽  
A Jackson ◽  
...  
Keyword(s):  
Image Space ◽  
Point Spread Functions ◽  
Point Spread ◽  
Pet Ct ◽  
Ct Scanners ◽  
The Impact ◽  
Space Variant

A Prospective, Matched Comparison Study of SUV Measurements From Time-of-Flight Versus Non–Time-of-Flight PET/CT Scanners

2016 ◽  
Vol 41 (7) ◽  
pp. e323-e326 ◽  
Author(s):  
Holly M. Thompson ◽  
Ryogo Minamimoto ◽  
Mehran Jamali ◽  
Amir Barkhodari ◽  
Rie von Eyben ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Comparison Study ◽  
Pet Ct ◽  
Ct Scanners ◽  
Matched Comparison

18 F-FDG-PET/CT assessment of Takayasu arteritis and effect of time-of-flight reconstruction: an observational study

2020 ◽  
Author(s):  
shuichi yanai ◽  
junichi tsuchiya ◽  
shinichi taura ◽  
ukihide tateishi
Keyword(s):  
Takayasu Arteritis ◽  
Time Of Flight ◽  
Sign Test ◽  
Visual Grade ◽  
Fdg Uptake ◽  
Uptake Pattern ◽  
Pet Ct ◽  
Expectation Maximisation ◽  
The Impact ◽  
Tof Pet

Abstract Background To assess the impact of time-of-flight (TOF) positron emission tomography (PET)/computed tomography (CT) image reconstruction on assessment of Takayasu arteritis (TKA). We reviewed 14 patients (15 cases) who underwent TOF-PET/CT. PET images were reconstructed using ordered-subsets expectation maximisation ± TOF. Uptake in 10 vascular regions was assessed using the four-point visual grading system (3, higher than liver uptake; 0, no uptake). The grades in the TOF-PET/CT and non-TOF-PET/CT groups were compared using the sign test. Relationships between visual grade and arterial FDG uptake pattern in the 10 regions and clinical findings were assessed. Results Except for the highest visual grade, the visual grades in all regions were significantly higher in the TOF-PET/CT group (p=0.003). FDG uptake pattern and region were not significant determinants of the effect of TOF reconstruction. Assessment of disease activity was inconsistent between the groups in 6 (4%) of 150 regions when grade 2/3 was defined as active and in 5 (3.3%) of 150 when grade 3 was defined as active. Conclusions Visual grades were significantly higher in all regions when assessed by TOF-PET/CT. Use of the same reconstruction algorithm before and after treatment is recommended when evaluating the response to treatment.

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