scholarly journals Monitoring internal contamination from OEW of an 18F-FDG production plant: WBC or head counting setup?

2019 ◽  
Vol 7 (3A) ◽  
Author(s):  
Bruno Melo Mendes ◽  
Bruno Machado Trindade ◽  
Telma Cristina Ferreira Fonseca ◽  
Tarcisio Passos Ribeiro de Campos
Keyword(s):  
Great Influence ◽  
Calibration Coefficient ◽  
Whole Body ◽  
Production Plant ◽  
Counting System ◽  
Internal Contamination ◽  
Positron Emission ◽  
18F Fdg ◽  
Future Work

The production 18F-FDG for positron emission tomography (PET) has consistently increased over the past two decades. The risk of internal contamination at 18F-FDG production facilities exists. A setup for evaluation of the 18F-FDG activity incorporated into the OEW brain, called Head Counting System (HCS), was presented in previous works. In this study, the whole body counter setup (WBC) was evaluated for monitoring 18F incorporations. The Monte Carlo Virtual Software (VMC in-vivo) and the MCNPx code were used to assess the system calibration coefficient (CC). Three 18F distributions were simulated: i) uniformly distributed in soft tissue (UDST); ii) Na18F biodistribution (NAFB); and iii) 18F-FDG biodistribution (FDGB). The calibration coefficient of WBC was compared to the current head counting system CC under the same biodistribution conditions. The ICRP male reference voxelized phantoms (RCP_AM) was used in the simulations. The results showed that the WBC setup was more efficient than the head counter for all the studied 18F distributions: UDST = 1060 %, FDGB = 488 % and NAFB = 340 %. Despite this, especially for 18F-FDG, the possibility of bladder voiding before measurement can lead to considerable uncertainties when the WBC setup is used.  On the other hand, bladder activity does not show great influence the calibration coefficient of the head counting system. Future work will evaluate the WBC sources of uncertainties in the measurement of 18F incorporated activity.

Abstract T MP46: Stroke-Related Neuroplasticity During Steering of Human Gait

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Caroline Paquette ◽  
Jean-Paul Soucy
Keyword(s):  
Brain Plasticity ◽  
Brain Activity ◽  
Brain Regions ◽  
Whole Body ◽  
Human Gait ◽  
Stroke Survivors ◽  
Post Stroke ◽  
Positron Emission ◽  
18F Fdg

Background: The risk of falling is higher in stroke survivors than among the general population. These falls are more frequent during walking and transfers or during turning. The neuronal substrates involved in steering of locomotion are poorly understood due to methodological limitations in quantifying brain activations during whole-body movements. Thus, no data is currently available to study the mechanisms of post-stroke brain plasticity for steering of gait. This study tested the hypothesis that stroke-induced neuroplastic changes for steering of gait can be quantified using 18F- fluorodesoxy-glucose (18F-FDG) Positron Emission Tomography (PET) in-vivo in humans Methods: PET imaging with 18F-FDG tracer was used to quantify cerebral glucose metabolism (CMRGlc) during two locomotor tasks (straight walking and turning) measured on separate days. Immediately prior to each walking task, a 5 mCi bolus of 18F-FDG was injected. Subjects walked for 40 minutes (duration of 18F-FDG uptake). Subjects were scanned on an ECAT HR+ scan (20min emission followed by 10min transmission) within 10 minutes of completing the walking task, well within reaching the 2h half-life of 18F. Images obtained during straight walking were subtracted from the ones acquired during steering Results: Subjects post-stroke showed an asymmetrical pattern of CMRGlc in sensorimotor areas and superior parietal lobule where the affected hemisphere shows no increase in CMRGlc. Differences between groups were also observed in the cerebellum where CMRGlc was increased in the vermis for controls, an area predominant for the control of trunk and gait. Stroke subjects, in contrast, showed increased CMRGlc in the hemishperes, associated with goal-directed leg movements. Conclusions: Neuroplasticity in complex locomotor tasks such as steering can be quantified using 18F-FDG PET in subjects post-stroke. This study showed that changes affect several brain regions remote to the infarct. Understanding stroke-related changes in brain activity during steering of locomotion is crucial for improving rehabilitative strategies to minimize falls and injuries in stroke survivors.

POSITRON EMISSION TOMOGRAPHY WITH 18F -FDG IN THE DIAGNOSIS OF PROSTHETIC HEART VALVE ENDOCARDITIS

2021 ◽  
Vol 5 (1) ◽  
pp. 1151-1160
Author(s):  
A.S. Lukashevich ◽  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Fdg Pet ◽  
Prosthetic Heart Valve ◽  
Emission Tomography ◽  
Whole Body ◽  
Positron Emission ◽  
Pet Ct ◽  
18F Fdg ◽  
Fdg Pet Ct

Purpose. The purpose of the article is to evaluate the diagnostic significance of positron emission tomography / computed tomography with 18F -fluorodeoxyglucose (18F -FDG PET/CT) for the diagnosis of prosthetic endocarditis. Methods of research. The study included 82 patients with suspected prosthetic endocarditis in accordance with the criteria proposed by Duke University [1-5]. The patients received hospital treatment at the State Institution RSPC "Cardiology" from January 2016 to March 2021. The study was of a prospective, non-randomized, single-center cohort design. The duration of the monitor period was 12 months from the moment of patients’ inclusion in the study. Whole-body positron emission tomography / computed tomography (PET/CT) examinations were performed in 82 patients. 27 patients were selected for surgical treatment. Conservative treatment group included 16 patients. 27 patients were selected into the observation group, they were suspected to have prosthetic heart valve infection in the primary referral and underwent PET/CT scanning, according to which the diagnosis of prosthetic endocarditis was excluded. The event under the study did not develop in this group during the year of observation. Results and conclusion. The history of infective endocarditis was not statistically significant and did not increase the risk of developing prosthetic endocarditis in the sample presented. The Duke criteria are less reliable in establishing the diagnosis of prosthetic endocarditis. The median number of days from the date of the first prosthesis implantation to the onset of prosthetic endocarditis was about 4 years. This study revealed that the development of the infectious process in the area of the prosthesis was noted in a more distant postoperative period compared to literature data. Histological confirmation of infection was noted in 100% (27 patients) of cases in reoperated patients. The presence of a more formidable complication such as valve ring abscess located mainly in the projection of the aortic valve ring was quite common in both groups. Presepsin and Interleukin-6 have a statistically significant (U = 394,50 p = 0,01 and U = 94,50 p = 0.004) value in the prognosis of prosthetic endocarditis. Considering the data obtained from ROC analysis, it can be said that the cut-off point at which it is possible to diagnose prosthetic endocarditis based on PETCT is 2.85. The presented methods for the interpretation of whole-body FDG-PET/CT images of patients with suspected infectious complications after cardiac surgery, as well as with the presence of prosthetic endocarditis, show high sensitivity and specificity.

scholarly journals Cervical Cancer: Associations between Metabolic Parameters and Whole Lesion Histogram Analysis Derived from Simultaneous 18F-FDG-PET/MRI

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hans-Jonas Meyer ◽  
Sandra Purz ◽  
Osama Sabri ◽  
Alexey Surov
Keyword(s):  
Cervical Cancer ◽  
Fdg Pet ◽  
Metabolic Tumor Volume ◽  
Total Lesion Glycolysis ◽  
Histogram Analysis ◽  
Whole Body ◽  
Standardized Uptake Values ◽  
Positron Emission ◽  
18F Fdg ◽  
Magnetic Resonance Imaging Mri

Multimodal imaging has been increasingly used in oncology, especially in cervical cancer. By using a simultaneous positron emission (PET) and magnetic resonance imaging (MRI, PET/MRI) approach, PET and MRI can be obtained at the same time which minimizes motion artefacts and allows an exact imaging fusion, which is especially important in anatomically complex regions like the pelvis. The associations between functional parameters from MRI and 18F-FDG-PET reflecting different tumor aspects are complex with inconclusive results in cervical cancer. The present study correlates histogram analysis and 18F-FDG-PET parameters derived from simultaneous FDG-PET/MRI in cervical cancer. Overall, 18 female patients (age range: 32–79 years) with histopathologically confirmed squamous cell cervical carcinoma were retrospectively enrolled. All 18 patients underwent a whole-body simultaneous 18F-FDG-PET/MRI, including diffusion-weighted imaging (DWI) using b-values 0 and 1000 s/mm2. Apparent diffusion coefficient (ADC) histogram parameters included several percentiles, mean, min, max, mode, median, skewness, kurtosis, and entropy. Furthermore, mean and maximum standardized uptake values (SUVmean and SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were estimated. No statistically significant correlations were observed between SUVmax or SUVmean and ADC histogram parameters. TLG correlated inversely with p25 (r=−0.486,P=0.041), p75 (r=−0.490,P=0.039), p90 (r=−0.513,P=0.029), ADC median (r=−0.497,P=0.036), and ADC mode (r=−0.546,P=0.019). MTV also showed significant correlations with several ADC parameters: mean (r=−0.546,P=0.019), p10 (r=−0.473,P=0.047), p25 (r=−0.569,P=0.014), p75 (r=−0.576,P=0.012), p90 (r=−0.585,P=0.011), ADC median (r=−0.577,P=0.012), and ADC mode (r=−0.597,P=0.009). ADC histogram analysis and volume-based metabolic 18F-FDG-PET parameters are related to each other in cervical cancer.

Abstract 35: DVT Inflammation Assessed by 18F-FDG-PET/CT Predicts Subsequent Vein Wall Scarring

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Chase W Kessinger ◽  
Ahmed Tawakol ◽  
Gregory R Wojtkiewicz ◽  
Peter K Henke ◽  
Ralph Weissleder ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Vena Cava ◽  
Standard Uptake Value ◽  
Vein Wall ◽  
Positron Emission ◽  
Pet Ct ◽  
18F Fdg ◽  
The Right ◽  
Fdg Pet Ct

Objective: While venous thrombosis (VT)-induced inflammation facilitates thrombus resolution, inflammation causes vein wall scarring (VWS). Recently, statins have shown to improve VT resolution and reduce VT inflammatory components. In this study, we hypothesized that early VT inflammation detected by 18F-FDG positron emission tomography/computed tomography (PET/CT) could predict subsequent late stage VWS, and would be attenuated by statin therapy. Methods: Stasis VT was induced in 8-12 week old male C57BL/6 mice (n=31) in either the right jugular vein (n=13) or inferior vena cava (IVC,n=18). Animals in the IVC VT cohort were randomized to statin (n=8) or control (n=10) treatment. Statin, rosuvastatin (5mg/kg), was administered by oral gavage, daily starting 24 hours prior to VT induction; control mice received saline. All mice underwent survival FDG-PET/CT venography imaging on day 2. FDG inflammation signals (standard uptake value=SUV) were measured in the thrombosed vein and compared to the sham-operated venous segments or treatment control. On day 14, mice were sacrificed and VT tissue was resected. Picrosirius red staining allowed measurement of collagen and vein wall thickness in VT sections. Results: FDG-PET/CT at day 2 revealed increased inflammation signal activity in jugular VT (SUV 1.43 ± 0.3 VT vs. 0.81 ± 0.3 contralateral vein, p<0.0001). Statin-treated mice showed a trend of decreased inflammation signal at day 2 in the IVC VT models (SUV 1.02 ± 0.1 statin VT vs. 1.42 ± 0.2 control VT, p=0.07). Day 14 histological analysis revealed significantly reduced vein wall injury in statin-treated animals (thickness, 32±9.4 μm statin; vs. 56.2±14.7 μm control, p=0.02). Day 2 FDG-PET inflammation in VT correlated positively with the magnitude of day 14 VWS (jugular VT, Spearman r=0.62, p=0.02; IVC VT r=0.74, p<0.001, respectively). Conclusions: Quantitative FDG-PET/CT imaging demonstrates that early in vivo VT inflammation predicts subsequent VWS, a driver of post-thrombotic syndrome (PTS). The overall findings strengthen: (i) the link between inflammation and PTS; (ii) the translational potential of FDG-PET inflammation to predict VWS and PTS; and (iii) the concept that statins and other anti-inflammatory therapies could reduce VWS and PTS.

scholarly journals Comparison of the Diagnostic Value of MRI and Whole Body 18F-FDG PET/CT in Diagnosis of Spondylodiscitis

2020 ◽  
Vol 9 (5) ◽  
pp. 1581
Author(s):  
Corinna Altini ◽  
Valentina Lavelli ◽  
Artor Niccoli-Asabella ◽  
Angela Sardaro ◽  
Alessia Branca ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Diagnostic Value ◽  
Whole Body ◽  
Spine Infection ◽  
Positron Emission ◽  
Pet Ct ◽  
18F Fdg ◽  
Sensitivity Specificity ◽  
Fdg Pet Ct ◽  
Ct And Mri

Spondylodiscitis is a spine infection for which a diagnosis by a magnetic resonance imaging (MRI) is considered the most appropriate imaging technique. The aim of this study was to compare the role of an 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and an MRI in this field. For 56 patients with suspected spondylodiscitis for whom MRI and 18F-FDG PET/CT were performed, we retrospectively analyzed the results. Cohen’s κ was applied to evaluate the agreement between the two techniques in all patients and in subgroups with a different number of spinal districts analyzed by the MRI. Sensitivity, specificity, and accuracy were also evaluated. The agreements of the 18F-FDG PET/CT and MRI in the evaluation of the entire population, whole-spine MRI, and two-districts MRI were moderate (κ = 0.456, κ = 0.432, and κ = 0.429, respectively). In patients for whom one-district MRI was performed, 18F-FDG PET/CT and MRI were both positive and completely concordant (κ = 1). We also separately evaluated patients with suspected spondylodiscitis caused by Mycobacterium tuberculosis for whom the MRI and 18F-FDG PET/CT were always concordant excepting in 2 of the 18 (11%) patients. Sensitivity, specificity, and accuracy of the MRI and 18F-FDG PET/CT were 100%, 60%, 97%, and 92%, 100%, and 94%, respectively. Our results confirmed the 18F-FDG PET/CT diagnostic value in the diagnosis of spondylodiscitis is comparable to that of MRI for the entire spine evaluation. This could be considered a complementary technique or a valid alternative to MRI.

scholarly journals Positron Emission Tomography (PET) Radiopharmaceuticals in Multiple Myeloma

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 134 ◽  
Author(s):  
Christos Sachpekidis ◽  
Hartmut Goldschmidt ◽  
Antonia Dimitrakopoulou-Strauss
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Multiple Myeloma ◽  
Bone Marrow ◽  
Bone Disease ◽  
Emission Tomography ◽  
Whole Body ◽  
Positron Emission ◽  
Pet Ct ◽  
18F Fdg

Multiple myeloma (MM) is a plasma cell disorder, characterized by clonal proliferation of malignant plasma cells in the bone marrow. Bone disease is the most frequent feature and an end-organ defining indicator of MM. In this context, imaging plays a pivotal role in the management of the malignancy. For several decades whole-body X-ray survey (WBXR) has been applied for the diagnosis and staging of bone disease in MM. However, the serious drawbacks of WBXR have led to its gradual replacement from novel imaging modalities, such as computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT). PET/CT, with the tracer 18F-fluorodeoxyglucose (18F-FDG), is now considered a powerful diagnostic tool for the detection of medullary and extramedullary disease at the time of diagnosis, a reliable predictor of survival as well as the most robust modality for treatment response evaluation in MM. On the other hand, 18F-FDG carries its own limitations as a radiopharmaceutical, including a rather poor sensitivity for the detection of diffuse bone marrow infiltration, a relatively low specificity, and the lack of widely applied, established criteria for image interpretation. This has led to the development of several alternative PET tracers, some of which with promising results regarding MM detection. The aim of this review article is to outline the major applications of PET/CT with different radiopharmaceuticals in the clinical practice of MM.

scholarly journals The Influence of Genetic Variants on Striatal Dopamine Transporter and D2 Receptor Binding after TB

2014 ◽  
Vol 34 (8) ◽  
pp. 1328-1339 ◽  
Author(s):  
Amy K Wagner ◽  
Joelle M Scanion ◽  
Carl R Becker ◽  
Anne C Ritter ◽  
Christian Niyonkuru ◽  
...  
Keyword(s):  
Genetic Variants ◽  
Ventral Striatum ◽  
D2 Receptor ◽  
Variable Number ◽  
Small Sample ◽  
Post Injury ◽  
Positron Emission ◽  
Small Sample Sizes ◽  
Future Work

Dopamine (DA) neurotransmission influences cognition and recovery after traumatic brain injury (TBI). We explored whether functional genetic variants affecting the DA transporter (DAT) and D2 receptor (DRD2) impacted in vivo dopaminergic binding with positron emission tomography (PET) using [11C]βCFT and [11C]raclopride. We examined subjects with moderate/severe TBI ( N = 12) ~1 year post injury and similarly matched healthy controls ( N = 13). The variable number of tandem repeat polymorphism within the DAT gene and the Taql restriction fragment length polymorphism near the DRD2 gene were assessed. TBI subjects had age-adjusted DAT-binding reductions in the caudate, putamen, and ventral striatum, and modestly increased D2 binding in ventral striatum versus controls. Despite small sample sizes, multivariate analysis showed lower caudate and putamen DAT binding among DAT 9-allele carriers and DRD2 A2/A2 homozygotes with TBI versus controls with the same genotype. Among TBI subjects, 9-allele carriers had lower caudate and putamen binding than 10/10 homozygotes. This PET study suggests a hypodopaminergic environment and altered DRD2 autoreceptor DAT interactions that may influence DA transmission after TBI. Future work will relate these findings to cognitive performance; future studies are required to determine how DRD2/DAT1 genotype and DA-ligand binding are associated with neurostimulant response and TBI recovery.

Numerical model of detector for in vivo internal dosimetry in radiological incidents

2012 ◽  
Vol 18 (2) ◽  
pp. 29-39
Author(s):  
Jakub Ośko ◽  
Katarzyna Tymińska
Keyword(s):  
Numerical Model ◽  
Dose Rate ◽  
Human Body ◽  
Radioactive Isotopes ◽  
Whole Body ◽  
Internal Dosimetry ◽  
Internal Contamination ◽  
Contaminated Area ◽  
Selection Of

The aim of this work was to create a numerical model of scintillation detector and to check whether such detector can be used for the measurements of internal contamination in emergency conditions. The purpose of the measurements would be only detection of possible contamination, without identification of radioactive isotopes, and hence without estimation of effective dose. However, in emergency conditions, it is sufficient for the rapid selection of a group of contaminated persons, who should be subjected to careful inspection in the laboratory conditions. The calculations were performed for three detector positions relatively to the phantom. The distribution of dose rate was also calculated, in order to find the best geometry for dose rate measurements around human body. Another problem under consideration was the possible influence of radioactive contamination in the environment on the registration of the gamma spectrum emitted from the whole body phantom. Performed calculations showed that there is a possibility to measure internal contamination outside laboratory, even in contaminated area.

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