Klinik Fur Nuklearmedizin

Germany

Klinik Fur Nuklearmedizin

Germany

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Gould K.L.,University of Houston | Johnson N.P.,University of Houston | Bateman T.M.,University of Missouri - Kansas City | Beanlands R.S.,University of Ottawa | And 23 more authors.
Journal of the American College of Cardiology | Year: 2013

Angiographic severity of coronary artery stenosis has historically been the primary guide to revascularization or medical management of coronary artery disease. However, physiologic severity defined by coronary pressure and/or flow has resurged into clinical prominence as a potential, fundamental change from anatomically to physiologically guided management. This review addresses clinical coronary physiology - pressure and flow - as clinical tools for treating patients. We clarify the basic concepts that hold true for whatever technology measures coronary physiology directly and reliably, here focusing on positron emission tomography and its interplay with intracoronary measurements. © 2013 by the American College of Cardiology Foundation Published by Elsevier Inc.


Muller S.,Allgemein | Poehnert D.,Allgemein | Muller J.A.,Klinik fur Nuklearmedizin | Scheumann G.W.F.,Allgemein | And 2 more authors.
World Journal of Surgery | Year: 2010

Background: Immunological response of the human body is controlled by the suppressive characteristics of regulatory T cells (Tregs). In various diseases a change in the number of Tregs is evident. For example, whereas Tregs are reduced in auto-immunological processes, an increase of Tregs is found with various malignant tumors. Regarding medullary thyroid carcinoma (MTC) no such studies have been performed to date. Methods: Expression of CD4 and CD25 in CD45+ leukocytes from blood and lymph nodes was studied by flow cytometry in patients with MTC and patients with benign goiter. We also examined the marker forkhead box P3 (FoxP3), an intracellular transcription factor, which is supposed to be the most specific marker for Tregs. Immunohistochemical staining for FoxP3 was performed on lymph node and thyroid tissue. Results: The number of FoxP3+ lymphocytes in peripheral blood was significantly higher in patients with MTC than in controls (p = 0.02). This result was confirmed immunohistochemically in lymph node and thyroid tissue, as well as in carcinoma tissue. No difference in CD4+CD25+ lymphocytes was observed between the two groups. After clinical staging (International Union against Cancer-UICC-stages) of MTC patients, triplication of FoxP3+ lymphocytes could be observed from MTC < UICC II to MTC > UICC II. Conclusions: An increase of FoxP3+ lymphocytes could be shown in peripheral blood of patients with MTC but not in patients with benign goiter; this increase also correlates with findings in lymph nodes and thyroid gland. The number of FoxP3+ cells correlated with the patients' prognosis. Therefore, FoxP3+ lymphocytes are a good diagnostic criterion for malignancy in patients with medullary thyroid carcinoma, and their presence at staging may influence therapeutic decisions. © 2010 Société Internationale de Chirurgie.


Hellwig D.,Universitatsklinikum des Saarlandes | Krause B.-J.,TU Munich | Schirrmeister H.,Klinik fur Nuklearmedizin | Freesmeyer M.,Universitatsklinikum Jena
NuklearMedizin | Year: 2010

In nuclear medicine, bone scanning is based on the principle of scintigraphy using bone-seeking radiopharmaceuticals which accumulate in sites of increased bone formation. From a historical point of view, 18F-fluoride was one of the first osteotropic tracers which was replaced by 99mTc-labelled polyphosphonates. With the development of modern PET equipment the superior diagnostic performance of 18F- fluoride PET for the detection and characterization of osseous lesions was proven in comparison to conventional bone scanning. Recently, its importance as a substitute of conventional skeletal scintigraphy increased in a time with limited availability of 99Mo/ 99mTc. To ensure health care during this period, 18F- fluoride PET currently became part of common outpatient care. This guideline comprehends recommendations on indications, protocols, interpretation and reporting of 18F-fluoride PET and PET/CT. © Schattauer 2010.


Romer W.,Klinik fur Nuklearmedizin
DoctorConsult - The Journal. Wissen fur Klinik und Praxis | Year: 2010

Bone scintigraphy enables the visualisation of the bone metabolism. It can be used to detect bone metastases or primary bone tumours as well as for diagnosing degenerative or inflammatory lesions of the bone. Furthermore, traumatic lesions can be detected due to an enhanced bone metabolism. Nowadays bone scintigraphy is performed by using Technetium-99m-labeled diphosphonates which are able to visualize the bone metabolism with a high lesion-to-background contrast. Using SPECT technology, lesions with an altered bone metabolism can be precisely localised. The advantages of bone scintigraphy are its high sensitivity and the opportunity to scan the whole body in one session with an acceptable radiation exposure. On the other hand, its specificity is limited and thus additional imaging may be necessary. However, hybrid imaging with SPECT/CT is used increasingly and helps to improve the specificity. © 2010 Published by Elsevier GmbH.


Linke R.,Klinik fur Nuklearmedizin | Gelse K.,Friedrich - Alexander - University, Erlangen - Nuremberg | Schuch F.,Rheumatologische Schwerpunktpraxis Erlangen
Zeitschrift fur Rheumatologie | Year: 2011

Radiosynovectomy or radiosynoviorthesis (RSO), the intra-articular injection of beta-emitting radionuclides (e.g. colloidal preparations of 90-Yttrium, 186-Rhenium or 169-Erbium), is an approved, reliable and easily performed therapy for the treatment of chronic synovitis without harmful side effects. The best clinical results have been obtained in patients with predominantly inflammatory joint disease such as rheumatoid arthritis or reactive arthritis. But RSO is also established to treat pain and persistent effusions after total knee replacement. It also represents an adjuvant therapy in patients with pigmented villonodular synovitis to protect against recurrence following synovectomy. In patients with hemophilia and arthropathy a reduction in joint bleeding is seen and the use of coagulation factor is reduced. The indication for RSO should be made in close cooperation between the referring physician, the rheumatologist and the nuclear medicine expert in the context of a multimodal therapy concept. In this way, success rates of over 80%, with only few side effects, can be achieved, particularly in rheumatoid arthritis, reactive arthritis and hemophilic arthropathy. © 2011 Springer-Verlag.


In contrast to positron emission tomography/computed tomography (PET/CT), the currently available single photon emission computed tomography/computed tomography (SPECT/CT) systems are very heterogeneous. On the side of the gamma cameras, dual-head systems are established, which are not very different from one manufacturer to the other. For the CT component, there are low dose tubes on the one side and flat detector-based cone beam CT and multislice-CT on the other. The CT image data can be used for anatomic correlation of suspicious findings as well as for attenuation correction of SPECT data. Attenuation correction enables on the one hand enhancement of SPECT image quality and on the other hand quantification of the radioactivity concentration becomes possible. Modern iterative reconstruction algorithms allow scatter correction and attenuation correction of SPECT data using the density values from CT. It still has to be shown to what extent attenuation-corrected whole body SPECT/CT studies will be able to improve the sensitivity of scintigraphy studies. As SPECT/CT primarily aims at morphologic correlation and not detection of additional lesions, an attempt should be made to balance the necessary anatomic information and the additional radiation exposure. Besides SPECT-guided CT all technical possibilities for dose reduction should be exhausted. © Springer-Verlag 2012.


Caobelli F.,Klinik fur Nuklearmedizin | Thackeray J.T.,Klinik fur Nuklearmedizin | Soffientini A.,Fondazione Poliambulanza | Bengel F.M.,Klinik fur Nuklearmedizin | And 2 more authors.
European Journal of Nuclear Medicine and Molecular Imaging | Year: 2015

Purpose: IQ-SPECT, an add-on to general purpose cameras based on multifocal collimation, can reduce myocardial perfusion imaging (MPI) acquisition times to one-fourth that of standard procedures (to 12 s/view). In a phantom study, a reduction of the acquisition time to one-eighth of the standard time (to 6 s/view) was demonstrated as feasible. It remains unclear whether such a reduction could be extended to clinical practice. Methods: Fifty patients with suspected or diagnosed CAD underwent a 2-day stress–rest 99mTc-sestamibi MPI protocol. Two consecutive SPECT acquisitions (6 and 12 s/view) were performed. Electrocardiogram-gated images were reconstructed with and without attenuation correction (AC). Polar maps were generated and visually scored by two blinded observers for image quality and perfusion in 17 segments. Global and regional summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) were determined. Left ventricular volumes and ejection fraction were calculated based on automated contour detection. Results: Image quality was scored higher with the 12 s/view acquisition, both with and without AC. Summed scores were statistically comparable between the 6 s/view and the 12 s/view acquisition, both globally and in individual coronary territories (e.g. in images with AC, SSS were 6.6 ± 8.3 and 6.2 ± 8.2 with 6 s and 12 s/view, respectively, p = 0.10; SRS were 3.9 ± 5.6 and 3.5 ± 5.3, respectively, p = 0.19; and SDS were 2.8 ± 5.7 and 2.6 ± 5.7, respectively, p = 0.59). Both acquisitions allowed MPI-based diagnosis of CAD in 25 of the 50 patients (with AC). Calculated end-diastolic volume (EDV) and end-systolic volume (ESV) were modestly higher with the 6 s/view acquisition than with the 12 s/view acquisition (EDV +4.8 ml at rest and +3.7 ml after stress, p = 0.003; ESV +4.1 ml at rest and +2.6 ml after stress, p = 0.01), whereas the ejection fraction did not differ (−1.2 % at rest, p = 0.20, and −0.9 % after stress, p = 0.27). Conclusion: Image quality and LV functional parameters obtained with a one-eighth acquisition time were statistically comparable to the previously validated one-fourth time protocol using IQ-SPECT. Shorter acquisition times without loss of diagnostic accuracy provide improved patient comfort and streamlined departmental efficiency. © 2015, Springer-Verlag Berlin Heidelberg.


Bengel F.M.,Klinik fur Nuklearmedizin
Journal of Nuclear Medicine | Year: 2011

The usefulness of imaging the cardiac sympathetic nervous system is increasingly supported by prospective clinical studies. The future success of this molecular imaging technique, however, will depend on careful design of additional trials. But preclinical and clinical use requires a thorough understanding of the underlying biology, which defines the relationship between neuronal tracer kinetics, disease mechanisms, and appropriate study interpretation. This review focuses on basic methodologic aspects considered relevant for successful continuation of the translation of cardiac neuronal imaging from a research tool toward a clinical test. Copyright © 2011 by the Society of Nuclear Medicine, Inc.


Positron emission tomography (PET) using F-18-fluoro-deoxyglucose (FDG) is suitable for many indications in oncology and can also be used in rheumatology to search for inflammatory foci and benign lesions with increased glucose metabolism in, for example soft tissue and joints (arthritis, vasculitis etc.) and fever of unknown origin. Usually a whole-body scanning technique is used for data acquisition in the search for foci of unknown localization or for the characterization of glucose metabolism of one or more known lesions - also for observation of the effect of, for example pharmacotherapy. Patients are admitted under fasting conditions and acquisition starts 1 h after i.v. injection of FDG with an acquisition time of 30-60 min. The method is sensitive and can measure glucose metabolism in an objective manner, but is not specific for inflammatory diseases (FDG also accumulates in malignant diseases).


Thackeray J.T.,Klinik fur Nuklearmedizin | Bengel F.M.,Klinik fur Nuklearmedizin
Journal of Nuclear Cardiology | Year: 2013

The autonomic nervous system is the primary extrinsic control of cardiac performance, and altered autonomic activity has been recognized as an important factor in the progression of various cardiac pathologies. Molecular imaging techniques have been developed for global and regional interrogation of pre- and postsynaptic targets of the cardiac autonomic nervous system. Building on established work with the guanethidine analogue 123I-metaiodobenzylguanidine (MIBG) for single-photon emission tomography (SPECT), development of radiotracers and protocols for positron emission tomography (PET) investigation of autonomic signaling has expanded. PET is limited in availability and requires specialized centers for radiosynthesis and interpretation, but the higher resolution allows for improved regional analysis and kinetic modeling provides more true quantification than is possible with SPECT. A wider array of radiolabeled catecholamines, analogues of catecholamines, and receptor ligands have been characterized and evaluated. Sympathetic neuronal PET tracers have shown promise in the identification of several cardiac pathologies. In particular, recent studies have elucidated a mechanistic role for heterogeneous sympathetic innervation in the development of lethal ventricular arrhythmias. Evaluation of cardiomyocyte adrenergic receptor expression and the parasympathetic nervous system has been slower to develop, with clinical studies beginning to emerge. This review summarizes the clinical and the experimental PET tracers currently available for autonomic imaging and discusses their application in health and cardiovascular disease, with particular emphasis on the major findings of the last decade. Copyright © 2012 American Society of Nuclear Cardiology.

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