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Theranostics Dec 2013Positron Emission Tomography (PET) experienced accelerated development and has become an established method for medical research and clinical routine diagnostics on... (Review)
Review
Positron Emission Tomography (PET) experienced accelerated development and has become an established method for medical research and clinical routine diagnostics on patient individualized basis. Development and availability of new radiopharmaceuticals specific for particular diseases is one of the driving forces of the expansion of clinical PET. The future development of the ⁶⁸Ga-radiopharmaceuticals must be put in the context of several aspects such as role of PET in nuclear medicine, unmet medical needs, identification of new biomarkers, targets and corresponding ligands, production and availability of ⁶⁸Ga, automation of the radiopharmaceutical production, progress of positron emission tomography technologies and image analysis methodologies for improved quantitation accuracy, PET radiopharmaceutical regulations as well as advances in radiopharmaceutical chemistry. The review presents the prospects of the ⁶⁸Ga-based radiopharmaceutical development on the basis of the current status of these aspects as well as wide range and variety of imaging agents.
Topics: Animals; Drug Discovery; Gallium Radioisotopes; Humans; Positron-Emission Tomography; Radiopharmaceuticals
PubMed: 24396515
DOI: 10.7150/thno.7447 -
Deutsches Arzteblatt International Mar 2018Anatomical and molecular data can be acquired simultaneously through the use of positron emission tomography (PET) in combination with computed tomography (CT) or... (Review)
Review
BACKGROUND
Anatomical and molecular data can be acquired simultaneously through the use of positron emission tomography (PET) in combination with computed tomography (CT) or magnetic resonance imaging (MRI) as a hybrid technique. A variety of radiopharmaceuticals can be used to characterize various metabolic processes or to visualize the expression of receptors, enzymes, and other molecular target structures.
METHODS
This review is based on pertinent publications retrieved by a selective search in PubMed, as well as on guidelines from Germany and abroad and on systematic reviews and meta-analyses.
RESULTS
Established radiopharmaceuticals for PET, such as 2-[18F]fluoro-2- deoxyglucose ([18F]FDG), enable the visualization of physiological processes on the molecular level and can provide vital information for clinical decision-making. For example, PET can be used to evaluate pulmonary nodules for malignancy with 95% sensitivity and 82% specificity. It can be used both for initial staging and for the guidance of further treatment. Alongside the PET radiopharmaceuticals that have already been well studied and evaluated, newer ones are increasingly becoming available for the noninvasive phenotyping of tumor diseases, e.g., for analyzing the expression of prostate-specific membrane antigen (PSMA), of somatostatin receptors, or of chemokine receptors on tumor cells.
CONCLUSION
PET is an important component of diagnostic algorithms in oncology. It can help make diagnosis more precise and treatment more individualized. An increasing number of PET radiopharmaceuticals are now expanding the available options for imaging. Many radiopharmaceuticals can be used not only for noninvasive analysis of the expression of therapeutically relevant target structures, but also for the ensuing, target-directed treatment with radionuclides.
Topics: Germany; Half-Life; Humans; Magnetic Resonance Imaging; Molecular Imaging; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, X-Ray Computed
PubMed: 29607803
DOI: 10.3238/arztebl.2018.0175 -
Journal of Applied Clinical Medical... Oct 2022Time-of-flight (TOF) and resolution modeling (RM) algorithms are frequently used in clinical PET images, and inclusion of these corrections should measurably improve...
Time-of-flight (TOF) and resolution modeling (RM) algorithms are frequently used in clinical PET images, and inclusion of these corrections should measurably improve image quality. We quantified the effects of these correction algorithms on reconstructed images via the following metrics: recovery coefficients (RCs), contrast-to-noise ratio (CNR), noise-power spectrum (NPS), modulation transfer function (MTF), and the full width at half maximum (FWHM) of a point source. The goal of this experiment was to assess the effects of the correction algorithms when applied singly or together. Two different phantom tests were performed and analyzed by custom software. FWHM and MTF were measured using capillary tube point sources, while RCs, CNR, and NPS were measured using an image quality body phantom. Images were reconstructed with both TOF and RM, only TOF, only RM, or neither correction. The remaining reconstruction parameters used the standard clinical protocol. RM improved RCs, FWHM, and MTF, without increasing overall noise significantly. TOF improves CNR for small objects FWHM or MTF but did not decrease noise. RCs were not statistically improved by enabling these algorithms. Inclusion of both correction algorithms in image reconstruction provides an overall improvement to all metrics relative to the uncorrected image, but not by a significant margin in multiple aspects.
Topics: Humans; Image Processing, Computer-Assisted; Positron-Emission Tomography; Phantoms, Imaging; Algorithms
PubMed: 35976771
DOI: 10.1002/acm2.13751 -
Tomography (Ann Arbor, Mich.) Oct 2022The uptake of F-fluorothymidine (F-FLT) depends on cells' proliferative rates. We compared the characteristics of F-FLT positron emission tomography/computed tomography...
Comparison of F-fluorothymidine Positron Emission Tomography/Computed Tomography and F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Patients with Breast Cancer.
The uptake of F-fluorothymidine (F-FLT) depends on cells' proliferative rates. We compared the characteristics of F-FLT positron emission tomography/computed tomography (PET/CT) with those of F-fluorodeoxyglucose (F-FDG) PET/CT for breast cancer. We prospectively diagnosed patients with breast cancer who underwent F-FLT PET/CT and F-FDG PET/CT. Subsequently, significant differences and correlation coefficients of the maximum standardized uptake value (SUVmax) in primary breast cancer and axillary lymph nodes were statistically evaluated. We enrolled eight patients with breast cancer. In six treatment-naive patients, the SUVmax for primary lesions showed a significant difference (mean, 2.1 vs. 4.1, = 0.031) and a strong correlation ( = 0.969) between F-FLT and F-FDG. Further, although the SUVmax for the axillary lymph nodes did not show a significant difference between F-FLT and F-FDG (P = 0.246), there was a strong correlation between the two (r = 0.999). In a patient-by-patient study, there were cases in which only F-FDG uptake was observed in lymph nodes and normal breasts. Bone metastases demonstrated lower accumulation than bone marrow on the F-FLT PET/CT. In conclusion, a strong correlation was observed between the F-FLT PET/CT and F-FDG PET/CT uptake. Differences in the biochemical characteristics of F-FLT and F-FDG were reflected in the accumulation differences for breast cancer, metastatic lesions, and normal organs.
Topics: Humans; Female; Fluorodeoxyglucose F18; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Radiopharmaceuticals; Breast Neoplasms; Dideoxynucleosides
PubMed: 36287810
DOI: 10.3390/tomography8050211 -
Japanese Journal of Radiology Sep 2022Paraneoplastic dermatoses (PD) are defined as nonspecific skin disorders which are associated with internal neoplasms, but without direct association to primary tumors... (Review)
Review
Paraneoplastic dermatoses (PD) are defined as nonspecific skin disorders which are associated with internal neoplasms, but without direct association to primary tumors or metastases. Recognition of PD and the following surveillance may lead to the diagnosis of internal malignant neoplasms including early stage ones. Accurate imaging examinations in the following searching is essential in identifying the underlying neoplasms. Since whole-body 18-fluoro-2-deoxyglucose (F-18-FDG)-positron emission (PET)/computed tomography (CT) has been widely used in early diagnosis, staging of various malignant tumors, it may play a role for detection of underlying or occult malignant neoplasms in patients with PD. However, to date, only a few reports of FDG PET/CT findings of the associated neoplasms in PD patients have been cited in the literature. The present paper shows the cases of FDG-avid associated neoplasms in patients with PD in our 10-year experience in our institute, and reviews the well-known and/or relatively common PD and their associated neoplasms, and the previously reported cases of FDG-avid associated neoplasms in these patients.
Topics: Fluorodeoxyglucose F18; Humans; Neoplasms; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Radiopharmaceuticals; Skin Diseases; Tomography, X-Ray Computed
PubMed: 35713794
DOI: 10.1007/s11604-022-01286-x -
BMC Veterinary Research Jan 2020Positron emission tomography (PET) is increasingly being used as an imaging modality for clinical and research applications in veterinary medicine. Amyloid PET has...
BACKGROUND
Positron emission tomography (PET) is increasingly being used as an imaging modality for clinical and research applications in veterinary medicine. Amyloid PET has become a useful tool for diagnosing Alzheimer's disease (AD) in humans, by accurately identifying amyloid-beta (Aβ) plaques. Cognitive dysfunction syndrome in dogs shows cognitive and pathophysiologic characteristics similar to AD. Therefore, we assessed the physiologic characteristics of uptake of F-flutemetamol, an Aβ protein-binding PET tracer in clinical development, in normal dog brains, for distinguishing an abnormal state. Static and dynamic PET images of six adult healthy dogs were acquired after F-flutemetamol was administered intravenously at approximately 3.083 MBq/kg. For static images, PET data were acquired at 30, 60, and 90 min after injection. One week later, dynamic images were acquired for 120 min, from the time of tracer injection. PET data were reconstructed using an iterative technique, and corrections for attenuation and scatter were applied. Regions of interest were manually drawn over the frontal, parietal, temporal, occipital, anterior cingulate, posterior cingulate, and cerebellar cortices, cerebral white matter, midbrain, pons, and medulla oblongata. After calculating standardized uptake values with an established formula, standardized uptake value ratios (SUVRs) were obtained, using the cerebellar cortex as a reference region.
RESULTS
Among the six cerebral cortical regions, the cingulate cortices and frontal lobe showed the highest SUVRs. The lowest SUVR was observed in the occipital lobe. The average values of the cortical SUVRs were 1.25, 1.26, and 1.27 at 30, 60, and 90 min post-injection, respectively. Tracer uptake on dynamic scans was rapid, peaking within 4 min post-injection. After reaching this early maximum, cerebral cortical regions showed a curve with a steep descent, whereas cerebral white matter demonstrated a curve with a slow decline, resulting in a large gap between cerebral cortical regions and white matter.
CONCLUSION
This study provides normal baseline data of F-flutemetamol PET that can facilitate an objective diagnosis of cognitive dysfunction syndrome in dogs in future.
Topics: Amyloid; Aniline Compounds; Animals; Benzothiazoles; Brain; Cognitive Dysfunction; Dog Diseases; Dogs; Female; Fluorine Radioisotopes; Male; Positron-Emission Tomography
PubMed: 31952531
DOI: 10.1186/s12917-020-2240-y -
Journal of Cerebral Blood Flow and... May 2016Noninvasive imaging of cerebral blood flow provides critical information to understand normal brain physiology as well as to identify and manage patients with... (Comparative Study)
Comparative Study Review
Noninvasive imaging of cerebral blood flow provides critical information to understand normal brain physiology as well as to identify and manage patients with neurological disorders. To date, the reference standard for cerebral blood flow measurements is considered to be positron emission tomography using injection of the [(15)O]-water radiotracer. Although [(15)O]-water has been used to study brain perfusion under normal and pathological conditions, it is not widely used in clinical settings due to the need for an on-site cyclotron, the invasive nature of arterial blood sampling, and experimental complexity. As an alternative, arterial spin labeling is a promising magnetic resonance imaging technique that magnetically labels arterial blood as it flows into the brain to map cerebral blood flow. As arterial spin labeling becomes more widely adopted in research and clinical settings, efforts have sought to standardize the method and validate its cerebral blood flow values against positron emission tomography-based cerebral blood flow measurements. The purpose of this work is to critically review studies that performed both [(15)O]-water positron emission tomography and arterial spin labeling to measure brain perfusion, with the aim of better understanding the accuracy and reproducibility of arterial spin labeling relative to the positron emission tomography reference standard.
Topics: Arteries; Brain; Cerebrovascular Circulation; Humans; Magnetic Resonance Angiography; Oxygen Radioisotopes; Positron-Emission Tomography; Spin Labels; Water
PubMed: 26945019
DOI: 10.1177/0271678X16636393 -
Contrast Media & Molecular Imaging 2015Standard [(18) F]fluorination methods to form carbon-fluorine bonds can have some limitations such as low yield and the requirement for harsh reaction conditions.... (Review)
Review
Standard [(18) F]fluorination methods to form carbon-fluorine bonds can have some limitations such as low yield and the requirement for harsh reaction conditions. Inorganic approaches include the formation of boron-[(18) F]fluorine bonds and have the potential to give high specific activities at room temperature forming a bond that is stable in vivo. There is considerable potential in future applications, particularly in relation to multimodal imaging and the provision of rapid efficient labelling protocols.
Topics: Animals; Boron Compounds; Fluorine Radioisotopes; Humans; Positron-Emission Tomography
PubMed: 25103995
DOI: 10.1002/cmmi.1615 -
Ugeskrift For Laeger Feb 2023
Topics: Humans; Polymyalgia Rheumatica; Fluorodeoxyglucose F18; Positron Emission Tomography Computed Tomography; Giant Cell Arteritis; Positron-Emission Tomography
PubMed: 36762378
DOI: No ID Found -
Theranostics Oct 2013Positron emission tomography (PET) is used extensively in clinical oncology for tumor detection, staging and therapy response assessment. Quantitative measurements of... (Review)
Review
Positron emission tomography (PET) is used extensively in clinical oncology for tumor detection, staging and therapy response assessment. Quantitative measurements of tumor uptake, usually in the form of standardized uptake values (SUVs), have enhanced or replaced qualitative interpretation. In this paper we review the current status of tumor quantification methods and their applications to clinical oncology. Factors that impede quantitative assessment and limit its accuracy and reproducibility are summarized, with special emphasis on SUV analysis. We describe current efforts to improve the accuracy of tumor uptake measurements, characterize overall metabolic tumor burden and heterogeneity of tumor uptake, and account for the effects of image noise. We also summarize recent developments in PET instrumentation and image reconstruction and their impact on tumor quantification. Finally, we offer our assessment of the current development needs in PET tumor quantification, including practical techniques for fully quantitative, pharmacokinetic measurements.
Topics: Evaluation Studies as Topic; Image Processing, Computer-Assisted; Neoplasms; Positron-Emission Tomography; Treatment Outcome
PubMed: 24312151
DOI: 10.7150/thno.5629