Search results for " Emission"

Projection and Pinhole-Based Data Acquisition for Small-Animal SPECT Using Storage Phosphor Technology

2007

Three-dimensional Single Photon Emission Computed Tomography (SPECT) can provide high-resolution insight into biomolecular distribution and pharmacokinetics. However, instrument availability and distribution is limited at present,and imaging times can be considerable. To evaluate the large array of novel agents which are becoming available,we find that storage phosphor-based in vivo imaging can provide an important,rapid-throughput transition from the traditional ex vivo sacrifice/gamma counting and autoradiography to full-time course SPECT.

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…

Comparison of the quantitative first pass myocardial perfusion MRI with and without prospective slice tracking: Comparison between breath-hold and fr…

2010

Physiologic motion of the heart is one of the major problems of myocardial blood flow quantification using first pass perfusion-MRI method. To overcome these problems, a perfusion pulse sequence with prospective slice tracking was developed. Cardiac motion was monitored by a navigator directly positioned at heart's basis to overcome no additional underlying model calculations connecting diaphragm and cardiac motion. Additional prescans were used before the perfusion measurement to detect slice displacements caused by remaining cardiac motion between navigator and the perfusion slice readout. The pulse sequence and subsequent quantification of myocardial blood flow was tested in healthy pigs…

A Knowledge-Based System for the Diagnosis of Alzheimer’s Disease

2003

Therapies to slow down the progression of Alzheimer’s disease are most effective when applied in its initial stages. Therefore it is important to develop methods to diagnose the disease as early as possible. It is also desirable to establish standards which can be used generally by physicians who may not be experts in diagnosis of the disease. One possible method to obtain an early diagnosis is the evaluation of the glucose metabolism of the brain. In this paper we present a prototype of an expert system that automatically diagnoses Alzheimer’s disease on the basis of positron emission tomography images displaying the metabolic activity in the brain.

2020

Background: ABCB1 (P-glycoprotein) and ABCG2 (breast cancer resistance protein) are co-localized at the blood-brain barrier (BBB), where they restrict the brain distribution of many different drugs. Moreover, ABCB1 and possibly ABCG2 play a role in Alzheimer’s disease (AD) by mediating the brain clearance of beta-amyloid (Aβ) across the BBB. This study aimed to compare the abundance and activity of ABCG2 in a commonly used β-amyloidosis mouse model (APP/PS1-21) with age-matched wild-type mice. Methods: The abundance of ABCG2 was assessed by semi-quantitative immunohistochemical analysis of brain slices of APP/PS1-21 and wild-type mice aged 6 months. Moreover, the brain distribution of two d…

Verbesserte Auswertbarkeit transitorisch evozierter otoakustischer Emissionen durch Korrelationsfilterung

1993

Hearing screening as well as evaluation of cochlear function under therapy with ototoxic agents or patients with various diseases is increasingly done by registration of transient evoked otoacoustic emissions (TEOAE). Usually the standard system ILO 88 Otodynamic Analyser is used, where until now emissions were analyzed subjectively. However, evaluation of signals may be difficult mainly in the hearing threshold area. In this article we describe a method to mathematically analyze registered emissions by correlation-filtering. This allows to better identify small specific responses, to further increase the sensitivity of TEOAE, and offers a more objective means for audiologic diagnoses.

016: Evidence of systemic plaque vulnerability in acute coronary syndromes with FDG-positron emission tomography and computed tomographic angiography…

2013

PurposeAtherosclerotic plaque vulnerability is a systemic phenomenon and is often associated with severe plaque infiltration with inflammatory cells. 18-Fluoro-deoxyglucose (FDG) accumulates in inflammatory cells of atherosclerotic plaques. The aim of this study was to assess whether 1) FDG uptake in the aorta and carotid arteries measured by positron emission tomography (PET) is higher in patients with acute coronary syndromes (ACS) than in patients with stable coronary artery disease (CAD) and; 2) associated with morphological markers of plaque instability detected with computed tomography angiography (CTA).MethodsPatients with ACS (n=50) or stable CAD (n=28) underwent a PET 90 minutes af…

Role of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography in gastrointestinal cancers

2015

AbstractFluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a routine imaging modality for many malignancies and its use is currently increasing. In the present review article, we will summarize the evidence for FDG-PET/CT use in digestive cancers (excluding neuroendocrine tumours), and review the existing recommendations. While PET/CT is nowadays considered to be an important tool in the initial workup of oesophageal and anal cancers, new data are emerging regarding its use in assessing therapeutic efficacy, radiotherapy treatment planning, and detection of recurrence in case of isolated tumour marker elevation. Moreover, PET/CT may help …