scholarly journals Neurological update: neuroimaging in dementia

2020 ◽  
Vol 267 (11) ◽  
pp. 3429-3435
Author(s):  
Timothy Rittman
Keyword(s):  
Artificial Intelligence ◽  
Positron Emission Tomography ◽  
Clinical Practice ◽  
Imaging Techniques ◽  
Emission Tomography ◽  
Structural Imaging ◽  
Regulatory Issues ◽  
Positron Emission ◽  
Remarkable Progress

Abstract Neuroimaging for dementia has made remarkable progress in recent years, shedding light on diagnostic subtypes of dementia, predicting prognosis and monitoring pathology. This review covers some updates in the understanding of dementia using structural imaging, positron emission tomography (PET), structural and functional connectivity, and using big data and artificial intelligence. Progress with neuroimaging methods allows neuropathology to be examined in vivo, providing a suite of biomarkers for understanding neurodegeneration and for application in clinical trials. In addition, we highlight quantitative susceptibility imaging as an exciting new technique that may prove to be a sensitive biomarker for a range of neurodegenerative diseases. There are challenges in translating novel imaging techniques to clinical practice, particularly in developing standard methodologies and overcoming regulatory issues. It is likely that clinicians will need to lead the way if these obstacles are to be overcome. Continued efforts applying neuroimaging to understand mechanisms of neurodegeneration and translating them to clinical practice will complete a revolution in neuroimaging.

New Perspectives on Alzheimer's Disease: Studies with Positron Emission Tomography

1991 ◽  
Vol 3 (S1) ◽  
pp. 61-67
Author(s):  
P. J. Tyrrell ◽  
R. S. J. Frackowiak
Keyword(s):  
Positron Emission Tomography ◽  
Dopaminergic System ◽  
Cerebral Metabolism ◽  
Imaging Techniques ◽  
Cognitive Disorders ◽  
Emission Tomography ◽  
Alzheimer Type ◽  
Positron Emission ◽  
Abnormal Metabolism

Positron Emission Tomography (PET) is a quantitative technique which can be used to measure regional values of cerebral metabolism, or uptake of radio-labeled tracers, in the living human. While structural scans (CT or MRI) may be normal in the degenerative dementias, or show generalized atrophy, functional imaging techniques allow differentiation of subtypes of dementias according to patterns of abnormal metabolism. This paper describes some of the variety of alterations in patterns of energy metabolism that may be observed in degenerative cognitive disorders and their correlations with clinical subtypes, together with an in vivo study of the dopaminergic system in subtypes of patients with dementia of the Alzheimer type (DAT).

scholarly journals Diagnosis of Pancreatic Ductal Adenocarcinoma by Immuno-Positron Emission Tomography

2021 ◽  
Vol 10 (6) ◽  
pp. 1151
Author(s):  
Ruth González-Gómez ◽  
Roberto A. Pazo-Cid ◽  
Luis Sarría ◽  
Miguel Ángel Morcillo ◽  
Alberto J. Schuhmacher
Keyword(s):  
Positron Emission Tomography ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Imaging Techniques ◽  
Metastatic Tumor ◽  
Emission Tomography ◽  
Whole Body ◽  
Ductal Adenocarcinoma ◽  
Non Invasive ◽  
Positron Emission

Diagnosis of pancreatic ductal adenocarcinoma (PDAC) by current imaging techniques is useful and widely used in the clinic but presents several limitations and challenges, especially in small lesions that frequently cause radiological tumors infra-staging, false-positive diagnosis of metastatic tumor recurrence, and common occult micro-metastatic disease. The revolution in cancer multi-“omics” and bioinformatics has uncovered clinically relevant alterations in PDAC that still need to be integrated into patients’ clinical management, urging the development of non-invasive imaging techniques against principal biomarkers to assess and incorporate this information into the clinical practice. “Immuno-PET” merges the high target selectivity and specificity of antibodies and engineered fragments toward a given tumor cell surface marker with the high spatial resolution, sensitivity, and quantitative capabilities of positron emission tomography (PET) imaging techniques. In this review, we detail and provide examples of the clinical limitations of current imaging techniques for diagnosing PDAC. Furthermore, we define the different components of immuno-PET and summarize the existing applications of this technique in PDAC. The development of novel immuno-PET methods will make it possible to conduct the non-invasive diagnosis and monitoring of patients over time using in vivo, integrated, quantifiable, 3D, whole body immunohistochemistry working like a “virtual biopsy”.

scholarly journals Development of a blood sample detector for multi-tracer positron emission tomography using gamma spectroscopy

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Carlos Velasco ◽  
Adriana Mota-Cobián ◽  
Jesús Mateo ◽  
Samuel España
Keyword(s):  
Positron Emission Tomography ◽  
Blood Sample ◽  
Pet Imaging ◽  
Spectroscopic Analysis ◽  
Gamma Spectroscopy ◽  
Emission Tomography ◽  
Blood Samples ◽  
Positron Emission

Abstract Background Multi-tracer positron emission tomography (PET) imaging can be accomplished by applying multi-tracer compartment modeling. Recently, a method has been proposed in which the arterial input functions (AIFs) of the multi-tracer PET scan are explicitly derived. For that purpose, a gamma spectroscopic analysis is performed on blood samples manually withdrawn from the patient when at least one of the co-injected tracers is based on a non-pure positron emitter. Alternatively, these blood samples required for the spectroscopic analysis may be obtained and analyzed on site by an automated detection device, thus minimizing analysis time and radiation exposure of the operating personnel. In this work, a new automated blood sample detector based on silicon photomultipliers (SiPMs) for single- and multi-tracer PET imaging is presented, characterized, and tested in vitro and in vivo. Results The detector presented in this work stores and analyzes on-the-fly single and coincidence detected events. A sensitivity of 22.6 cps/(kBq/mL) and 1.7 cps/(kBq/mL) was obtained for single and coincidence events respectively. An energy resolution of 35% full-width-half-maximum (FWHM) at 511 keV and a minimum detectable activity of 0.30 ± 0.08 kBq/mL in single mode were obtained. The in vivo AIFs obtained with the detector show an excellent Pearson’s correlation (r = 0.996, p < 0.0001) with the ones obtained from well counter analysis of discrete blood samples. Moreover, in vitro experiments demonstrate the capability of the detector to apply the gamma spectroscopic analysis on a mixture of 68Ga and 18F and separate the individual signal emitted from each one. Conclusions Characterization and in vivo evaluation under realistic experimental conditions showed that the detector proposed in this work offers excellent sensibility and stability. The device also showed to successfully separate individual signals emitted from a mixture of radioisotopes. Therefore, the blood sample detector presented in this study allows fully automatic AIFs measurements during single- and multi-tracer PET studies.

scholarly journals Correction to: In vivo imaging of early stages of rheumatoid arthritis by α5β1-integrin-targeted positron emission tomography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Johannes Notni ◽  
Florian T. Gassert ◽  
Katja Steiger ◽  
Peter Sommer ◽  
Wilko Weichert ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Positron Emission Tomography ◽  
In Vivo Imaging ◽  
Emission Tomography ◽  
Early Stages ◽  
Positron Emission ◽  
Α5β1 Integrin

Following publication of the original article [1], the authors have reported an error in the ‘Histopathology’ (under ‘Materials and methods’) section of the article that compromises the reproducibility of the paper.

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