Search results for "POSITRON EMISSION TOMOGRAPHY"
showing 10 items of 235 documents
The role of 18F-FDG PET/CT in early infectious discitis: a case report after a negative MRI
2019
We present the case of a 70 years old woman with infectious discitis which was detected using Fluorine fluodeoxiglucose positron emission tomography/computed tomography (18F-FDG PET/CT), after a negative magnetic resonance imaging. A Streptococuss gallolyticus (bovis gender bacteria) grow on culture. In addition 18F-FDG PET also demonstrated infectious endocarditis which was confirmed by transesophageal echocardiography and a colonic neoplasm. Here we have highlighted the potential role of 18F-FDG PET/CT study in patients with a clinical history suggestive of infectious discitis with a negative or indifferent magnetic resonance imaging. Keywords: 18F-FDG PET/TC, Spondylodiscitis, Pyogenic v…
Locked-in Syndrome and 18F-fluorodeoxyglucose-positron Emission Tomography/Computed Tomography: Observations from a Case of Basilar Artery Thrombosis
2018
We report the case of a 59-year-old male patient suffering from locked-in syndrome (LIS) following basilar artery thrombosis despite an attempt of thrombolysis. Neurological examination showed quadriplegia and aphonia and a state of coma requiring mechanical ventilation was diagnosed. The use of 18F-fluorodeoxyglucose (18F-FDG)-positron emission tomography (PET) allowed to detect a normal 18F-FDG uptake in the main cerebral cortical areas and a significant reduction of 18F-FDG uptake in both cerebellar hemispheres, compatible with a functional deafferentation, helping confirming the clinical suspicion of LIS. The diagnosis of LIS, according to literature, is based on the clinical assessment…
Direct radiofluorination of [18F]MH.MZ for 5-HT2A receptor molecular imaging with PET
2012
Imaging the serotonin 2A neuroreceptor with positron emission tomography has been carried out with [11C]MDL 100907 and [18F]altanserin for years. Recently, the MDL 100907 analogue [18F]MH.MZ was developed by combining the increased selectivity profile of MDL 100907 and the favourable radiophysical properties of fluorine-18. Here, we want to report the synthesis of [18F]MH.MZ via direct radiofluorination. Unfortunately, the direct radiofluorination did not have any significant benefits over the indirect labelling method. This is mainly because the precursor for the direct labelling approach is not completely stable and slowly decomposes. However, only one HPLC separation is necessary for the…
Segmentation of Positron Emission Tomography Images Using Multi-atlas Anatomical Magnetic Resonance Imaging (MRI)
2021
Positron emission tomography (PET), is a medical imaging technique, it provides information about the body’s cellular function rather than its anatomy. However, due to the functional nature of PET images, locating the anatomical structures in such an image remains a challenging task, indeed, PET images only provide very little anatomical information. Segmentation of PET images, therefore, requires the intervention of a medical expert. The expert proceeds to a manual segmentation of a volume slice by slice, which turns out to be very tedious and costly in terms of time. In this article, we present, evaluate, and make available a multi-atlas approach for automatically segmenting human brain P…
Evaluation of MRI and cannabinoid type 1 receptor PET templates constructed using DARTEL for spatial normalization of rat brains
2015
Purpose: Image registration is one prerequisite for the analysis of brain regions in magnetic-resonance-imaging (MRI) or positron-emission-tomography (PET) studies. Diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL) is a nonlinear, diffeomorphic algorithm for image registration and construction of image templates. The goal of this small animal study was (1) the evaluation of a MRI and calculation of several cannabinoid type 1 (CB1) receptor PET templates constructed using DARTEL and (2) the analysis of the image registration accuracy of MR and PET images to their DARTEL templates with reference to analytical and iterative PET reconstruction algorithms. Methods:…
An automatic method for metabolic evaluation of gamma knife treatments
2015
Lesion volume delineation of Positron Emission Tomography images is challenging because of the low spatial resolution and high noise level. Aim of this work is the development of an operator independent segmentation method of metabolic images. For this purpose, an algorithm for the biological tumor volume delineation based on random walks on graphs has been used. Twenty-four cerebral tumors are segmented to evaluate the functional follow-up after Gamma Knife radiotherapy treatment. Experimental results show that the segmentation algorithm is accurate and has real-time performance. In addition, it can reflect metabolic changes useful to evaluate radiotherapy response in treated patients.
A methodical 68Ga-labelling study of DO2A-(butyl- l-tyrosine)2 with cation-exchanger post-processed 68Ga: practical aspects of radiolabelling
2011
Positron emission tomography (PET) with 68Ga is a fast-growing field in molecular imaging, both in research and in clinical routine. The availability of 68Ga via the 68Ge/68Ga radionuclide generator facilitates the development and production of radiopharmaceuticals independent of a cyclotron. The presented work shows a complete 68Ga labelling study exemplified on [68Ga]DO2A-(butyl- l-tyrosine)2, a potential tumour tracer for PET. A methodical sequence is followed to optimize the 68Ga-labelling reaction. Practical aspects are described and the different parameters contributing to the labelling yield are demonstrated. The influence of temperature, time, amount of labelling precursor and pH va…
Kinetic analysis of functional images: The case for a practical approach to performance prediction
1999
We present the first parallel medical application for the analysis of dynamic positron emission tomography (PET) images together with a practical performance model. The parallel application may improve the diagnosis for a patient (e. g. in epilepsy surgery) because it enables the fast computation of parametric images on a pixed level as opposed to the traditionally used region of interest (ROI) approach which is applied to determine an average parametric value for a particular anatomic region of the brain. We derive the performance model from the application context and show its relation to abstract machine models. We demonstrate the accuracy of the model to predict the runtime of the appli…
Tropane-derived11C-labelled and18F-labelled DAT ligands
2013
Radiolabelling of cocaine-derived 3-phenyltropanes for dopamine transporter positron emission tomography with 18F and 11C is reviewed. Copyright © 2013 John Wiley & Sons, Ltd.
Cerebrospinal Fluid Tau Protein Levels and <sup>18</sup>F-Fluorodeoxyglucose Positron Emission Tomography in the Differential Diagnosis o…
2010
<i>Aims:</i> In this study, we aimed to compare cerebrospinal fluid (CSF) levels of total tau (t-tau), phosphorylated tau (p-tau<sub>181</sub>) and positron emission tomography with <sup>18</sup>F-fluorodeoxyglucose (FDG-PET) in the differential diagnosis of Alzheimer’s disease (AD) under clinical conditions. <i>Method:</i> In a cross-sectional, blinded, single-center study, we examined a sample of 75 unselected memory clinic patients with clinical diagnoses of dementia of Alzheimer type (DAT; n = 24), amnestic mild cognitive impairment (MCI; n = 16), other dementias (n = 13) and nondemented controls (n = 22). Discriminative accuracy, sensitiv…