scholarly journals Influence of the scintillation crystal option on the detector response of pet devices

2014 ◽  
Vol 29 (1) ◽  
pp. 40-45
Author(s):  
Vojislav Antic ◽  
Koviljka Stankovic ◽  
Milos Vujisic ◽  
Predrag Osmokrovic
Keyword(s):  
Positron Emission Tomography ◽  
Medical Image ◽  
Radioactive Tracer ◽  
The Body ◽  
Emission Tomography ◽  
Detector Response ◽  
Biochemical Activity ◽  
Scintillation Crystal ◽  
Positron Emission ◽  
Scintillation Decay Time

Positron emission tomography is a technology that provides unique and exquisite possibilities in functional diagnostics, in the sense that it is the most efficient and most reliable method for obtaining information about biochemical activity and cellular metabolism in the body, by determining exact localization and performing semi-quantitative assessment of the distribution of a radioactive tracer. This paper compares the characteristics of recently introduced lutetium based crystals to those of conventionally used bismuth-ortho-germanate scintillators; both options are used as scintillation detectors within the positron emission tomography systems. Energy resolution and scintillation decay time of lutetium based crystals and bis-muth-ortho-germanate crystals was experimentally tested. Main scintillation detector parameters which affect the resulting detector response are considered and analyzed, since they serve as the basis for a positron emission tomography medical image.

scholarly journals Subsecond total-body imaging using ultrasensitive positron emission tomography

2020 ◽  
Vol 117 (5) ◽  
pp. 2265-2267 ◽  
Author(s):  
Xuezhu Zhang ◽  
Simon R. Cherry ◽  
Zhaoheng Xie ◽  
Hongcheng Shi ◽  
Ramsey D. Badawi ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Motion Tracking ◽  
The Body ◽  
Body Motion ◽  
Emission Tomography ◽  
Ct Scanner ◽  
External Monitoring ◽  
Time Motion ◽  
Positron Emission ◽  
Total Body

A 194-cm-long total-body positron emission tomography/computed tomography (PET/CT) scanner (uEXPLORER), has been constructed to offer a transformative platform for human radiotracer imaging in clinical research and healthcare. Its total-body coverage and exceptional sensitivity provide opportunities for innovative studies of physiology, biochemistry, and pharmacology. The objective of this study is to develop a method to perform ultrahigh (100 ms) temporal resolution dynamic PET imaging by combining advanced dynamic image reconstruction paradigms with the uEXPLORER scanner. We aim to capture the fast dynamics of initial radiotracer distribution, as well as cardiac motion, in the human body. The results show that we can visualize radiotracer transport in the body on timescales of 100 ms and obtain motion-frozen images with superior image quality compared to conventional methods. The proposed method has applications in studying fast tracer dynamics, such as blood flow and the dynamic response to neural modulation, as well as performing real-time motion tracking (e.g., cardiac and respiratory motion, and gross body motion) without any external monitoring device (e.g., electrocardiogram, breathing belt, or optical trackers).

scholarly journals Positron Emission Tomography in Parkinson’s Disease

1992 ◽  
Vol 19 (S1) ◽  
pp. 138-141 ◽  
Author(s):  
Barry J. Snow
Keyword(s):  
Parkinson’S Disease ◽  
Positron Emission Tomography ◽  
Parkinson's Disease ◽  
Blood Flow ◽  
D2 Receptor ◽  
The Body ◽  
Emission Tomography ◽  
Motor Tasks ◽  
Positron Emission ◽  
Ligand Interactions

ABSTRACT:Positron emission tomography (PET) allows the study of physiological and neurochemical processes which would otherwise be inaccessible, using radioactive labels on biological compounds to follow their fate in the body. By analysing changes of concentration with time we can measure blood flow, neuronal metabolism and receptor ligand interactions. In Parkinson’s disease (PD), PET has been used to examine the dopaminergic deficit and its relationship to motor performance. It has also been shown to detect asymptomatic dopaminergic lesions that have implications for the etiology of PD. In untreated PD there is increased density of D2 binding sites, while in chronically treated PD with motor fluctuations, D2 receptor density is reduced. [18F]-fluorodeoxyglucose studies of demented PD patients show a pattern of cortical metabolism similar to Alzheimer’s disease. Activation studies, which measure changes in blood flow during the performance of motor tasks, show reduced activation of medial frontal areas in PD.

EFFECTS OF THE SCAN RANGE ON RADIATION DOSE IN THE COMPUTED TOMOGRAPHY COMPONENT OF ONCOLOGY POSITRON EMISSION TOMOGRAPHY/COMPUTED TOMOGRAPHY

2018 ◽  
Vol 185 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Yusuke Inoue ◽  
Kazunori Nagahara ◽  
Hiroko Kudo ◽  
Hiroyasu Itoh
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Radiation Dose ◽  
Effective Dose ◽  
The Body ◽  
Emission Tomography ◽  
Whole Body ◽  
Computed Tomography Images ◽  
Positron Emission ◽  
Proximal Thigh

Abstract We performed phantom experiments to investigate radiation dose in the computed tomography component of oncology positron emission tomography/computed tomography in relation to the scan range. Computed tomography images of an anthropomorphic whole-body phantom were obtained from the head top to the feet, from the head top to the proximal thigh or from the skull base to the proximal thigh. Automatic exposure control using the posteroanterior and lateral scout images offered reasonable tube current modulation corresponding to the body thickness. However, when the posteroanterior scout alone was used, unexpectedly high current was applied in the head and upper chest. When effective dose was calculated on a region-by-region basis, it did not differ greatly irrespective of the scan range. In contrary, when effective dose was estimated simply by multiplying the scanner-derived dose-length product by a single conversion factor, estimates increased definitely with the scan range, indicating severe overestimation in whole-body imaging.

Positron Emission Tomography: A Technology Assessment

1986 ◽  
Vol 2 (4) ◽  
pp. 577-594 ◽  
Author(s):  
Nora D. Volkow ◽  
Laurence R. Tancredi
Keyword(s):  
Positron Emission Tomography ◽  
The Body ◽  
Emission Tomography ◽  
Positron Emission ◽  
Neurological Patients ◽  
Technological Assessment ◽  
A New Technique ◽  
First Time ◽  
Nuclear Medicine Technique ◽  
The Brain

Positron emission tomography (PET) is a new nuclear medicine technique that has recently entered the clinical realm of medicine. Although it is a technique that can be utilized for assessment of biochemical and physiological parameters of any organ in the body, it has particular utility in the investigation of the brain. PET poses unique advantages over previous imaging devices. For the first time, it is feasible to investigate directly various biological parameters of the brain in a noninvasive way. PET allows for investigating the functional, biochemical, physiological, and pharmacological characteristics of various areas within the brains of normal and psychiatric or neurological patients. Although it has already started to give promising results, it is too new a technique to obtain an accurate appraisal of its true potentials. This is a problem that seems always to surface when one tries to evaluate the utility of a new technique in a new area of research. The problem is accentuated in the case of PET where there is no other technique available with which to compare results. This paper will discuss the basic principles of PET, its relationship to other existing imaging devices, and the issues to be considered when making a technological assessment of positron emission tomography.

scholarly journals [68Ga]ABY-028: an albumin-binding domain (ABD) protein-based imaging tracer for positron emission tomography (PET) studies of altered vascular permeability and predictions of albumin-drug conjugate transport

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Emma Jussing ◽  
Li Lu ◽  
Jonas Grafström ◽  
Tetyana Tegnebratt ◽  
Fabian Arnberg ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Vascular Permeability ◽  
Ex Vivo ◽  
Circulatory System ◽  
Binding Domain ◽  
The Body ◽  
Emission Tomography ◽  
Albumin Binding ◽  
Positron Emission

Abstract Background Albumin is commonly used as a carrier platform for drugs to extend their circulatory half-lives and influence their uptake into tissues that have altered permeability to the plasma protein. The albumin-binding domain (ABD) protein, which binds in vivo to serum albumin with high affinity, has proven to be a versatile scaffold for engineering biopharmaceuticals with a range of binding capabilities. In this study, the ABD protein equipped with a mal-DOTA chelator (denoted ABY-028) was radiolabeled with gallium-68 (68Ga). This novel radiotracer was then used together with positron emission tomography (PET) imaging to examine variations in the uptake of the ABD-albumin conjugate with variations in endothelial permeability. Results ABY-028, produced by peptide synthesis in excellent purity and stored at − 20 °C, was stable for 24 months (end of study). [68Ga]ABY-028 could be obtained with labeling yields of > 80% and approximately 95% radiochemical purity. [68Ga]ABY-028 distributed in vivo with the plasma pool, with highest radioactivity in the heart ventricles and major vessels of the body, a gradual transport over time from the circulatory system into tissues and elimination via the kidneys. Early [68Ga]ABY-028 uptake differed in xenografts with different vascular properties: mean standard uptake values (SUVmean) were initially 5 times larger in FaDu than in A431 xenografts, but the difference decreased to 3 after 1 h. Cutaneously administered, vasoactive nitroglycerin increased radioactivity in the A431 xenografts. Heterogeneity in the levels and rates of increases of radioactivity uptake was observed in sub-regions of individual MMTV-PyMT mammary tumors and in FaDu xenografts. Higher uptake early after tracer administration could be observed in lower metabolic regions. Fluctuations in the increased permeability for the tracer across the blood-brain-barrier (BBB) direct after experimentally induced stroke were monitored by PET and the increased uptake was confirmed by ex vivo phosphorimaging. Conclusions [68Ga]ABY-028 is a promising new tracer for visualization of changes in albumin uptake due to disease- and pharmacologically altered vascular permeability and their potential effects on the passive uptake of targeting therapeutics based on the ABD protein technology.

scholarly journals Pancreatic serous cystoadenoma (CSA) showing increased tracer uptake at 68-GaDOTA-peptide Positron Emission Tomography (68Ga-DOTA-peptide PET-CT): a case report

BMC Surgery ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Gennaro Nappo ◽  
Niccola Funel ◽  
Simone Giudici ◽  
Paola Spaggiari ◽  
Giovanni Capretti ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Somatostatin Receptors ◽  
The Body ◽  
Emission Tomography ◽  
Neuroendocrine Neoplasm ◽  
Unexpected Finding ◽  
Pancreatic Lesion ◽  
Positron Emission ◽  
Pet Ct ◽  
Pancreatic Neuroendocrine Neoplasm

Abstract Background Serous cysto-adenoma (SCA) is a rare benign neoplasm of the pancreas. SCA can mimic other pancreatic lesions, such as neuroendocrine tumours. 68Gallium-DOTA-peptide Positron Emission Tomography (PET) is able to image in vivo the over-expression of the somatostatin receptors, playing an important role for the identification of neuroendocrine neoplasms. Case presentation We reported a case of 63-year-old man, with a solid lesion of 7 cm of diameter of the body–tail of the pancreas. Two fine-needle-aspirations (FNA) were inconclusive. A 68Ga-DOTA-peptide PET-CT revealed a pathological uptake of the pancreatic lesion. The diagnosis of a pancreatic neuroendocrine neoplasm was established and a laparoscopic distal splenopancreatectomy and cholecystectomy was performed. Final histopathological report revealed the presence of a micro-cystic SCA. Conclusions The current case firstly reports a pancreatic SCA showing increased radiopharmaceutical uptake at 68Ga-DOTA-peptide PET-CT images. This unexpected finding should be taken into account during the diagnostic algorithm of a pancreatic lesion, in order to minimize the risk of misdiagnosis and overtreatment of SCA.

scholarly journals Determination of [11C]Rifampin Pharmacokinetics within Mycobacterium tuberculosis-Infected Mice by Using Dynamic Positron Emission Tomography Bioimaging

2015 ◽  
Vol 59 (9) ◽  
pp. 5768-5774 ◽  
Author(s):  
Vincent P. DeMarco ◽  
Alvaro A. Ordonez ◽  
Mariah Klunk ◽  
Brendan Prideaux ◽  
Hui Wang ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Mycobacterium Tuberculosis ◽  
Ex Vivo ◽  
The Body ◽  
Emission Tomography ◽  
Time Curve ◽  
Content Type ◽  
Dynamic Positron Emission Tomography ◽  
Standardized Uptake Values ◽  
Positron Emission

ABSTRACTInformation about intralesional pharmacokinetics (PK) and spatial distribution of tuberculosis (TB) drugs is limited and has not been used to optimize dosing recommendations for new or existing drugs. While new techniques can detect drugs and their metabolites within TB granulomas, they are invasive, rely on accurate resection of tissues, and do not capture dynamic drug distribution in the tissues of interest. In this study, we assessed thein situdistribution of11C-labeled rifampin in live,Mycobacterium tuberculosis-infected mice that develop necrotic lesions akin to human disease. Dynamic positron emission tomography (PET) imaging was performed over 60 min after injection of [11C]rifampin as a microdose, standardized uptake values (SUV) were calculated, and noncompartmental analysis was used to estimate PK parameters in compartments of interest. [11C]rifampin was rapidly distributed to all parts of the body and quickly localized to the liver. Areas under the concentration-time curve for the first 60 min (AUC0–60) in infected and uninfected mice were similar for liver, blood, and brain compartments (P> 0.53) and were uniformly low in brain (10 to 20% of blood values). However, lower concentrations were noted in necrotic lung tissues of infected mice than in healthy lungs (P= 0.03).Ex vivotwo-dimensional matrix-assisted laser desorption ionization (MALDI) imaging confirmed restricted penetration of rifampin into necrotic lung lesions. Noninvasive bioimaging can be used to assess the distribution of drugs into compartments of interest, with potential applications for TB drug regimen development.

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