scholarly journals Feasibility and Initial Performance of Simultaneous SPECT-CT Imaging Using a Commercial Multi-Modality Preclinical Imaging System

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Dustin R. Osborne ◽  
Derek W. Austin
Keyword(s):  
Image Quality ◽  
System Performance ◽  
Imaging System ◽  
Tomographic Imaging ◽  
Ct Scans ◽  
Preclinical Imaging ◽  
Temporal Alignment ◽  
Pet Ct ◽  
The Individual ◽  
Improve Correlation

Multi-modality imaging provides coregistered PET-CT and SPECT-CT images; however such multi-modality workflows usually consist of sequential scans from the individual imaging components for each modality. This typical workflow may result in long scan times limiting throughput of the imaging system. Conversely, acquiring multi-modality data simultaneously may improve correlation and registration of images, improve temporal alignment of the acquired data, increase imaging throughput, and benefit the scanned subject by minimizing time under anesthetic. In this work, we demonstrate the feasibility and procedure for modifying a commercially available preclinical SPECT-CT platform to enable simultaneous SPECT-CT acquisition. We also evaluate the performance of simultaneous SPECT-CT tomographic imaging with this modified system. Performance was accessed using a 57Co source and image quality was evaluated with Tc99m phantoms in a series of simultaneous SPECT-CT scans.

scholarly journals Comparison of Image Quality and Spatial Resolution Between 18F, 68Ga and 64Cu Phantom Measurements Using a Digital Biograph Vision PET/CT

2022 ◽  
Author(s):  
Anja Braune ◽  
Liane Oehme ◽  
Robert Freudenberg ◽  
Frank Hofheinz ◽  
Jörg van den Hoff ◽  
...  
Keyword(s):  
Image Quality ◽  
Spatial Resolution ◽  
Ct Scans ◽  
Reconstruction Method ◽  
Recovery Coefficient ◽  
Positron Energy ◽  
Pet Ct ◽  
The Individual ◽  
The Impact

Abstract Background: The PET nuclide and reconstruction method can have a considerable influence on spatial resolution and image quality of PET/CT scans, which can, for example, influence the diagnosis in oncology. The individual impact of the positron energy of 18F, 68Ga and 64Cu on spatial resolution and image quality of PET/CT scans acquired using a clinical, digital scanner was compared. Furthermore, the impact of different reconstruction parameters on image quality and spatial resolution was evaluated for 18F-FDG PET/CT scans acquired with a scanner of the newest generation. Methods: PET/CT scans of a Jaszczak phantom and a NEMA PET body phantom, filled with 18F-FDG, 68Ga-HCl and 64Cu-HCl, respectively, were performed on a Siemens Biograph Vision. Images were assessed using spatial resolution and image quality (Recovery Coefficients (RC), coefficient of variation within the background, Contrast Recovery Coefficient (CRC), Contrast-Noise-Ratio (CNR), and relative count error in lung insert). In a subsequent analysis, the scan of the NEMA PET body phantom filled with 18F-FDG was reconstructed applying different parameters (with/without the application of Point Spread Function (PSF), Time of Flight (ToF) or post-filtering; matrix size). Spatial resolution and quantitative image quality were compared between reconstructions. Results: We found that image quality was comparable between 18F-FDG and 64Cu-HCl PET/CT measurements featuring similar maximal endpoint energy. In comparison, RC, CRC and CNR were worse in 68Ga-HCl data, despite similar count rates. Spatial resolution was up to 18 % worse in 68Ga-HCl compared to 18F-FDG images. Post-filtering of 18F-FDG acquisitions changed image quality the most and reduced spatial resolution by 52 % if a Gaussian filter with 5 mm FWHM was applied. ToF measurements especially improved the recovery of the smallest lesion (RCmean = 1.07 compared to 0.65 without ToF) and improved spatial resolution by 29 %.Conclusions: The positron energy of PET nuclides influences spatial resolution and image quality of digital PET/CT scans. Image quality of 68Ga-HCl PET/CT images was worse compared to 18F-FDG and 64Cu-HCl, respectively, despite similar count rates. Reconstruction parameters have a high impact on image quality and spatial resolution and should be considered when comparing images of different scanners or centers.

Imaging system performance analysis and optimization using objective image quality criteria

1999 ◽  
Author(s):  
Volodymyr N. Borovytsky ◽  
Valery V. Fesenko ◽  
Anatoly V. Molodyk ◽  
Pavel A. Zavorotny
Keyword(s):  
Performance Analysis ◽  
Image Quality ◽  
System Performance ◽  
Imaging System ◽  
Quality Criteria

Lesion concordance, image quality and artefacts in PET/CT

2010 ◽  
Vol 49 (04) ◽  
pp. 129-137 ◽  
Author(s):  
B. J. Krause ◽  
S. M. Eschmann ◽  
K. U. Juergens ◽  
H. Kuehl ◽  
A. C. Pfannenberg ◽  
...  
Keyword(s):  
Image Quality ◽  
Fdg Pet ◽  
Whole Body ◽  
Ct Scans ◽  
Intravenous Contrast ◽  
Metal Implants ◽  
Body Regions ◽  
Pet Ct ◽  
Fdg Pet Ct ◽  
Attenuation Corrected

Summary Aim: This study had three major objectives: 1.) to record the number of concordant (both in PET and CT) pathological lesions in different body regions/organs, 2.) to evaluate the image quality and 3.) to determine both, the quantity and the quality of artefacts in whole body FDG PET/CT scans. Patients, methods: Routine whole body scans of 353 patients referred to FDG-PET/ CT exams at 4 university hospitals were employed. All potentially malignant lesions in 13 different body regions/organs were classified as either concordant or suspicious in FDG-PET or CT only. In the latter case the diagnostic relevance of this disparity was judged. The image quality in PET and CT was rated as a whole and separately in 5 different body regions. Furthermore we investigated the frequency and site of artefacts caused by metal implants and oral or intravenous contrast media as well as the subjective co-registration quality (in 4 body regions) and the diagnostic impact of such artefacts or misalignment. In addition, the readers rated the diagnostic gain of adding the information from the other tomographic method. Results: In total 1941 lesions (5.5 per patient) were identified, 1094 (56%) out of which were concordant. 602 (71%) out of the 847 remaining lesions were detected only with CT, 245 (29%) were only PET-positive. As expected, CT particularly depicted the majority of lesions in the lungs and abdominal organs. However, the diagnostic relevance was greater with PET-only positive lesions. Most of the PET/CT scans were performed with full diagnostic CT including administration of oral and intravenous contrast media (> 80%). The image quality in PET and CT was rated excellent. Artefacts occurred in more than 60% of the scans and were mainly due to (dental) metal implants and contrast agent. Nevertheless there was almost no impact on diagnostic confidence if reading of the non attenuation corrected PET was included. The co-registration quality in general was also rated as excellent. Misalignment mostly occurred due to patient motion and breathing and led to diagnostic challenges in about 4% of all exams. The diagnostic gain of adding PET to a CT investigation was rated higher than vice versa. Conclusions: As the image quality in both PET and CT was more than satisfying, CT-artefacts almost never led to diagnostic uncertainties and serious misalignment rarely occurred, PET/CT can be considered as suitable for routine use and may replace single PET- and CT-scans. However, additional reading of the non attenuation corrected PET is mandatory to assure best possible diagnostic confidence in PET. Since approximately half of all lesions found in PET/CT were not concordant, at least in a setting with a diagnostic CT the exams need to be reported by both a nuclear medicine physician and a radiologist in consensus.

scholarly journals High Throughput PET/CT Imaging Using a Multiple Mouse Imaging System

2019 ◽  
Author(s):  
Hannah E. Greenwood ◽  
Zoltan Nyitrai ◽  
Gabor Mocsai ◽  
Sandor Hobor ◽  
Timothy H. Witney
Keyword(s):  
Image Quality ◽  
Fdg Pet ◽  
Imaging System ◽  
Small Animal ◽  
Ct Imaging ◽  
Small Animal Pet ◽  
Pet Ct ◽  
Fdg Pet Ct ◽  
The Cost

AbstractA considerable limitation of current small animal positron emission tomography/computed tomography (PET/CT) imaging is the low throughput of image acquisitions. Subsequently, to design sufficiently-powered studies, high costs accumulate. Together with Mediso Medical Imaging Systems, a four-bed mouse ‘hotel’ was developed to simultaneously image up to four mice, thereby reducing the cost and maximising radiotracer usage when compared to scans performed with a single mouse bed.MethodsFor physiological evaluation of the four-bed mouse hotel, temperature and anaesthesia were tested for uniformity, followed by [18F]fluorodeoxyglucose (FDG) PET/CT imaging of ‘mini’ image quality (IQ) phantoms specifically designed to fit the new imaging system. Post-reconstruction, National Electrical Manufacturers Association (NEMA) NU-4 tests examined uniformity, recovery coefficients (RCs) and spill-over ratios (SORs). To evaluate the bed under standard in vivo imaging conditions, four mice were simultaneously scanned by dynamic [18F]FDG PET/CT over 60 minutes using the four-bed mouse hotel, with quantified images compared to those acquired using a single mouse bed.ResultsThe bed maintained a constant temperature of 36.8°C ± 0.4°C (n = 4), with anaesthesia distributed evenly to each nose cone (2.9 ± 0.1 L/min, n = 4). The NEMA tests performed on reconstructed mini IQ phantom images acquired using the four-bed mouse hotel revealed values within the tolerable limits for uniformity, RC values in >2mm rods, and SORs in the non-radioactive water- and air-filled chambers. There was low variability in radiotracer uptake in all major organs of mice scanned using the four-animal bed versus those imaged using a single bed imaging platform.ConclusionAnalysis of images acquired using the four-bed mouse hotel confirmed its utility to increase the throughput of small animal PET imaging without considerable loss of image quality and quantitative precision. In comparison to a single mouse bed, the cost and time associated with each scan were substantially reduced.

scholarly journals Validation of CARE kV automated tube voltage selection for PET-CT: PET quantification and CT radiation dose reduction in phantoms

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Natalie A. Bebbington ◽  
Troels Jørgensen ◽  
Erik Dupont ◽  
Mille A. Micheelsen
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Activity Concentration ◽  
Ct Scans ◽  
Reference Image ◽  
Tube Voltage ◽  
Pet Quantification ◽  
Measured Activity ◽  
Ct Radiation ◽  
The Individual

Abstract Background Applied tube voltage (kilovolts, kV) and tube current (milliampere seconds, mAs) affect CT radiation dose and image quality and should be optimised for the individual patient. CARE kV determines the kV and mAs providing the lowest dose to the patient, whilst maintaining user-defined reference image quality. Given that kV changes affect CT values which are used to obtain attenuation maps, the aim was to evaluate the effect of kV changes on PET quantification and CT radiation dose using phantoms. Method Four phantoms (‘Lungman’, ‘Lungman plus fat’, ‘Esser’ and ‘NEMA image quality’ (NEMA IQ)) containing F-18 sources underwent 1 PET and 5 CT scans, with CARE kV on (automatic kV selection and mAs modulation) and in semi mode with specified tube voltages of 140, 120, 100 and 80 kV (mAs modulation only). A CARE kV image quality reference of 120 kV/50 mAs was used. Impact on PET quantification was determined by comparing measured activity concentrations for PET reconstructions from different CT scans with the reconstruction using the 120 kV reference, and dose (DLP, CTDIvol) differences calculated by comparing doses from all kV settings with the 120 kV reference. Results CARE kV-determined optimal tube voltage and CARE kV ‘on’ dose (DLP) savings compared with the 120 kV reference were: Lungman, 100 kV, 2.0%; Lungman plus fat, 120 kV, 0%; Esser, 100 kV, 9.3%; NEMA IQ, 100 kV, 3.4%. Using tube voltages in CARE kV ‘semi’ mode which were not advised by CARE kV ‘on’ resulted in dose increases ≤ 65% compared with the 120 kV reference (greatest difference Lungman plus fat, 80 kV). Clinically insignificant differences in PET activity quantification of up to 0.7% (Lungman, 100 kV, mean measured activity concentration) were observed when using the optimal tube voltage advised by CARE kV. Differences in PET quantification of up to 4.0% (Lungman, 140 kV, maximum measured activity concentration) were found over the full selection of tube voltages in semi mode, with the greatest differences seen at the most suboptimal kV for each phantom. However, most differences were within 1%. Conclusions CARE kV on can provide CT radiation dose savings without concern over changes in PET quantification.

The Value of PET-CT Scans in Patients with Ventricular Assist Devices

2016 ◽  
Vol 64 (S 01) ◽  
Author(s):  
A. Bernhardt ◽  
M. Barten ◽  
A. Schäfer ◽  
B. Sill ◽  
F. Wagner ◽  
...  
Keyword(s):  
Ventricular Assist Devices ◽  
Ct Scans ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Pet Ct

scholarly journals Alavi–Carlsen Calcification Score (ACCS): A Simple Measure of Global Cardiac Atherosclerosis Burden

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1421
Author(s):  
Babak Saboury ◽  
Lars Edenbrandt ◽  
Reza Piri ◽  
Oke Gerke ◽  
Tom Werner ◽  
...  
Keyword(s):  
Arterial Wall ◽  
Cardiac Ct ◽  
Standardized Uptake Value ◽  
Coronary Calcification ◽  
High Affinity ◽  
Maximum Standardized Uptake Value ◽  
Atherosclerotic Burden ◽  
Calcification Score ◽  
Pet Ct ◽  
The Individual

Multislice cardiac CT characterizes late stage macrocalcification in epicardial arteries as opposed to PET/CT, which mirrors early phase arterial wall changes in epicardial and transmural coronary arteries. With regard to tracer, there has been a shift from using mainly 18F-fluorodeoxyglucose (FDG), indicating inflammation, to applying predominantly 18F-sodium fluoride (NaF) due to its high affinity for arterial wall microcalcification and more consistent association with cardiovascular risk factors. To make NaF-PET/CT an indispensable adjunct to clinical assessment of cardiac atherosclerosis, the Alavi–Carlsen Calcification Score (ACCS) has been proposed. It constitutes a global assessment of cardiac atherosclerosis burden in the individual patient, supported by an artificial intelligence (AI)-based approach for fast observer-independent segmentation. Common measures for characterizing epicardial coronary atherosclerosis by NaF-PET/CT as the maximum standardized uptake value (SUV) or target-to-background ratio are more versatile, error prone, and less reproducible than the ACCS, which equals the average cardiac SUV. The AI-based approach ensures a quick and easy delineation of the entire heart in 3D to obtain the ACCS expressing ongoing global cardiac atherosclerosis, even before it gives rise to CT-detectable coronary calcification. The quantification of global cardiac atherosclerotic burden by the ACCS is suited for management triage and monitoring of disease progression with and without intervention.

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