Klaus P. Schäfers

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Motion is a source of degradation in positron emission tomography (PET)/computed tomography (CT) images. As the PET images represent the sum of information over the whole respiratory cycle, attenuation correction with the help of CT images may lead to false staging or quantification of the radioactive uptake especially in the case of small tumors. We(More)
BACKGROUND Matrix metalloproteinases (MMPs) are enzymes involved in the proteolytic degradation of extracellular matrix. They play an important role in several disease processes, such as inflammation, cancer, and atherosclerosis. METHODS AND RESULTS In this study, we have used the broad-spectrum MMP inhibitor CGS 27023A to develop the radioligand(More)
BACKGROUND Coronary endothelial function and vasomotion are impaired in smokers without coronary disease, and this is thought to be due to increased oxidative stress. METHODS AND RESULTS We used positron emission tomography to measure the coronary flow reserve, an integrated measure of coronary flow, through both the large epicardial coronary arteries and(More)
UNLABELLED PET has become an important noninvasive imaging technique in cardiovascular research for the characterization of mouse models in vivo. This modality offers unique insight into biochemical changes on a molecular level, with excellent sensitivity. However, morphologic and functional changes may be of equal importance for a thorough assessment of(More)
AIMS Patients with atrial fibrillation (AF) present with symptoms of myocardial ischaemia despite exclusion of coronary artery disease. A small vessel disease has been suggested. We quantified myocardial perfusion, perfusion reserve, and coronary vascular resistance (CVR) in AF patients using positron emission tomography (PET). METHODS AND RESULTS(More)
In clinical and research studies, images obtained using carrier-added meta-[123I]iodobenzylguanidine (c.a. [123I]MIBG) have shown quite variable quality, with varying levels of uptake in lung, liver and mediastinum; this is a significant problem for quantification of the myocardial uptake by means of region ratios. First experimental and preliminary human(More)
UNLABELLED Reliable, repeatable, and time-efficient noninvasive measurement of infarct size in mice with PET would benefit studies aimed at the exploration of biochemical and functional changes associated with acute myocardial infarction (MI). PET with the radioactively labeled glucose derivative (18)F-FDG is used in humans to distinguish between viable but(More)
Use of iodine-123-α-methyl tyrosine (123I-IMT) allows investigation of the amino acid transport rate in gliomas. It was the aim of this study to compare the value of measurement of glucose metabolism with that of measurement of123I-IMT uptake for the non-invasive grading of brain tumours. The study population comprised 23 patients with histopathologically(More)
Respiratory gating is used for reducing the effects of breathing motion in a wide range of applications from radiotherapy treatment to diagnostical imaging. Different methods are feasible for respiratory gating. In this study seven gating methods were developed and tested on positron emission tomography (PET) listmode data. The results of seven patient(More)
UNLABELLED Recently, integrated small-animal PET/MRI prototypes that provide isochronous and coregistered datasets of morphology and function through the simultaneous acquisition of PET and MRI data have been developed. However, the need for MRI compatibility can constrain the technical design of the PET components and may lead to a lower sensitivity and(More)