Institute of Nuclear Medicine

Vienna, Austria

Institute of Nuclear Medicine

Vienna, Austria
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Brammen L.,Medical University of Vienna | Granegger S.,Institute of Nuclear Medicine | Sinzinger H.,Institute of Nuclear Medicine
Hellenic Journal of Nuclear Medicine | Year: 2016

Objective: Platelet labeling is used to study platelets in vivo in terms of diagnosing intravascular thrombosis, as well as studyi ng their role and biological activity in atherosclerosis. A low labeling efficiency (LE) can negatively impair testing results. Labeling efficiency dependson various factors, including low-den- sity-lipoprotein (LDL)-cholesterol levels in the blood. Lipoprotein(a) (Lp(a)) is a lipoprotein subclass that when elevated, is frequently associated with the premature development of cardiovascular disease through activation of different signaling path way sand eel I surf ace receptors. Subjects and Methods:We retrospectively studied 51 patients with isolated elevated Lp(a) (>50 mg/dl, ranging up to 440 mg/dl) compared to patients with normal lipid profiles who underwent autologous radioactive platelet labeling during the time period of January 2001-September 2013 at the Vienna General Hospital. Platelets were radiolabeled according to ISORBE consensus. Results: LE was decreased in patients with elevated Lp(a). Cross-incubation of hyper-Lp(a) patients with normal Lp(a) plasma and vice versa demonstrated that platelets themselves and not the plasmatic environment are accountable for the decline in LE. Furthermore, LE positively cor related with an increase in platelet incubation time.thehighest LE being seen after 30 minutes. Condusion: This study determined that extremely elevated Lp(a) profiles, especially values greater than 150 mg/dL, may significantly impair platelets function such as labeling results. Platelets are responsiblefor the decrease in LE in hyper-Lp(a) patients. Non-HDL-Lp is the most informative parameter of impaired LE. We thus recommend to indude Lp(a) in the list of parameters that need to be taken into consideration in studying autologousradiolabeledplatelets.

Ben-Haim S.,University College London | Ben-Haim S.,Institute of Nuclear Medicine | Almukhailed O.,University College London | Neill J.,Royal Victoria Hospital | And 5 more authors.
Journal of Nuclear Cardiology | Year: 2014

Purpose. We have assessed whether additional upright imaging increases the confidence of interpretation of stress only supine myocardial perfusion imaging (MPI) in obese patients. Methods and results. Tc-MIBI stress MPI of 101 consecutive patients (M = 49, 62 ± 12 years) with BMI ≥30 scanned on the D-SPECT cardiac camera were assessed. Images were interpreted as diagnostic or equivocal and the need for a rest study was recorded. Stress supine MPI was interpreted first, then gated and finally upright data were added. Defects on supine but not on upright were defined as artefacts and defects seen on both as abnormal. The total perfusion deficit (TPD) was also quantified. There were 27 normal, 22 abnormal, and 52 equivocal supine scans. The median EF was 52%, unaffecting the need for rest imaging. Upright imaging reclassified 32/52 (62%) equivocal studies as normal and 6/52 (11%) as abnormal (P < 0.001). Rest scan was deemed needed in 74/101 patients on supine vs 42/101 on supine/upright (P < 0.001). Supine TPD was normal in 53 and supine/upright TPD was normal in 70 patients (P < 0.001). Conclusion. Supine stress MPI is inadequate in obese patients. The addition of upright imaging significantly increases the ability to interpret scans as diagnostic and may reduce considerably the need for rest imaging. © 2014 American Society of Nuclear Cardiology.

PubMed | Hematology Unit, Institute of Nuclear Medicine, University of Udine, University of Bologna and 6 more.
Type: Journal Article | Journal: Leukemia | Year: 2016

Identification of patient sub-groups with smoldering multiple myeloma (SMM) at high risk of progression to active disease (MM) is an important goal. 18F-FDG PET/CT (positron emission tomography (PET) integrated with computed tomography (PET/CT) using glucose labelled with the positron-emitting radionuclide (18)F) allows for assessing early skeletal involvement. Identification of osteolytic lesions by this technique has recently been incorporated into the updated International Myeloma Working Group criteria for MM diagnosis. However, no data are available regarding the impact of focal lesions (FLs) without underlying osteolysis on time to progression (TTP) to MM. We hence prospectively studied a cohort of 120 SMM patients with PET/CT. PET/CT was positive in 16% of patients (1 FL: 8, 2 FLs: 3, >3 FLs: 6, diffuse bone marrow involvement: 2). With a median follow-up of 2.2 years, 38% of patients progressed to MM, in a median time of 4 years, including 21% with skeletal involvement. The risk of progression of those with positive PET/CT was 3.00 (95% confidence interval 1.58-5.69, P=0.001), with a median TTP of 1.1 versus 4.5 years for PET/CT-negative patients. The probability of progression within 2 years was 58% for positive versus 33% for negative patients. In conclusion, PET/CT positivity significantly increased the risk of progression of SMM to MM. PET/CT could become a new tool to define high-risk SMM.

Holman B.F.,Institute of Nuclear Medicine | Cuplov V.,Institute of Nuclear Medicine | Millner L.,Institute of Nuclear Medicine | Hutton B.F.,Institute of Nuclear Medicine | And 4 more authors.
Physics in Medicine and Biology | Year: 2015

Recently, there has been an increased interest in imaging different pulmonary disorders using PET techniques. Previous work has shown, for static PET/CT, that air content in the lung influences reconstructed image values and that it is vital to correct for this 'tissue fraction effect' (TFE). In this paper, we extend this work to include the blood component and also investigate the TFE in dynamic imaging. CT imaging and PET kinetic modelling are used to determine fractional air and blood voxel volumes in six patients with idiopathic pulmonary fibrosis. These values are used to illustrate best and worst case scenarios when interpreting images without correcting for the TFE. In addition, the fractional volumes were used to determine correction factors for the SUV and the kinetic parameters. These were then applied to the patient images. The kinetic parameters K1 and Ki along with the static parameter SUV were all found to be affected by the TFE with both air and blood providing a significant contribution to the errors. Without corrections, errors range from 34-80% in the best case and 29-96% in the worst case. In the patient data, without correcting for the TFE, regions of high density (fibrosis) appeared to have a higher uptake than lower density (normal appearing tissue), however this was reversed after air and blood correction. The proposed correction methods are vital for quantitative and relative accuracy. Without these corrections, images may be misinterpreted. © 2015 Institute of Physics and Engineering in Medicine.

Lawrence Y.R.,Thomas Jefferson University | Pokroy R.,Ford Motor Company | Berlowitz D.,Institute of Radiology | Aharoni D.,Imaging Centers Ltd. | And 2 more authors.
Israel Medical Association Journal | Year: 2010

Background: Osler taught that splenic infarction presents with left upper abdominal quadrant pain, tenderness and swelling accompanied by a peritoneal friction rub. Splenic infarction is classically associated with bacterial endocarditis and sickle cell disease. Objectives: To describe the contemporary experience of splenic infarction. Methods: We conducted a chart review of inpatients diagnosed with splenic infarction in a Jerusalem hospital between 1990 and 2003. Results: We identified 26 cases with a mean age of 52 years. Common causes were hematologic malignancy (six cases) and intracardiac thrombus (five cases). Only three cases were associated with bacterial endocarditis. In 21 cases the splenic infarction brought a previously undiagnosed underlying disease to attention. Only half the subjects complained of localized left-sided abdominal pain, 36% had left-sided abdominal tenderness; 31% had no signs or symptoms localized to the splenic area, 36% had fever, 56% had leukocytosis and 71% had elevated lactate dehydrogenase levels. One splenectomy was performed and all patients survived to discharge. A post hoc analysis demonstrated that single infarcts were more likely to be associated with fever (20% vs. 63%, p < 0.05) and leukocytosis (75% vs. 33%, p = 0.06) Conclusions: The clinical presentation of splenic infarction in the modern era differs greatly from the classical teaching, regarding etiology, signs and symptoms. In patients with unexplained splenic infarction, investigation frequently uncovers a new underlying diagnosis.

PubMed | University of Udine, Institute of Nuclear Medicine, University of Bologna, University of Turin and 2 more.
Type: Journal Article | Journal: Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation | Year: 2015

Positron emission tomography (PET) integrated with computed tomography (PET/CT) has been reported to be useful for screening myelomatous lesions at diagnosis in patients with multiple myeloma (MM) and for monitoring response to autologous stem cell transplantation (auto-SCT). The aim of the study was to evaluate the prognostic significance of PET/CT in MM patients who received allogeneic stem cell transplantation (allo-SCT). Patients who underwent upfront auto-SCT followed by allo-SCT, either as consolidation or salvage treatment, were studied with PET/CT before and/or within 6 months after allo-SCT. The number, the maximum standard uptake value (SUV), and the location (medullary or extramedullary) of focal lesions (FLs) were recorded and investigated as predictors of progression-free survival (PFS) and overall survival (OS) by univariate and multivariate analyses. Fifty-four patients had a PET/CT scan before allo-SCT. Of these, 22 patients (41%) had a negative PET/CT scan, 11 patients (20%) showed 1 to 3 FLs, and 21 patients (39%) had either a diffuse bone marrow involvement or more than 3 FLs. SUV was >4.2 in 21 patients (39%) and extramedullary disease (EMD) was present in 6 patients (11%). Multivariate analysis of prognostic factors before allo-SCT showed that persistence of EMD at transplantation was an independent predictor of poor PFS, whereas OS was negatively influenced by unrelated donor and SUV > 4.2. Fifty-nine patients had a PET/CT scan within 6 months after allo-SCT. Multivariate analysis of post-treatment variables showed that persistence of EMD and failure to obtain complete response or very good partial response after allo-SCT were strongly associated with shorter PFS and OS. Of the 46 patients with evaluable PET/CT scans both before and 6 months after allo-SCT, the 23 patients who maintained or reached a PET complete remission showed a significantly prolonged PFS and OS compared with the 23 patients with persistence of any PET positivity (2-year PFS: 51% versus 25%, P= .03; 2-year OS: 81% versus 47%, P= .001). This study indicates that PET/CT imaging before and after allo-SCT is significantly associated with the outcome, suggesting the utility of this technique for MM staging before allo-SCT and for response monitoring after the transplantation.

Levy S.,The Academic College of Tel-Aviv-Yaffo | Segev M.,The Academic College of Tel-Aviv-Yaffo | Reicher-Atir R.,The Academic College of Tel-Aviv-Yaffo | Steinmetz A.,Institute of Nuclear Medicine | And 4 more authors.
European Journal of Gastroenterology and Hepatology | Year: 2014

Objective: To compare perceptions of patients and gastroenterologists regarding irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Methods: The Illness Perception Questionnaire-Revised was sent to 150 randomly selected hospital-based and community-based gastroenterologists nationwide. Participants were instructed to refer their responses to either IBS or IBD. Patients were recruited during a regular visit to the Gastroenterology Department of a tertiary medical center and completed the same questionnaire. Findings were analyzed according to illness and group. Results: Questionnaires were returned by 55 physicians (29 referred to IBS, 26 to IBD) and 58 patients. Physicians and patients stated that IBD has more severe consequences and benefits more from medical treatment (P<0.05), and that patient coherence is higher for IBD than IBS (P<0.05). Physicians stated that psychological attributes and accidents/injuries play a greater causative role in IBS than in IBD (P<0.01 and P<0.05, respectively). Conversely, patients found no such difference. More patients than physicians attributed both illnesses to risk factors (P=0.07). Both groups believed that the immune system is a more important causative factor in IBD than IBS (P<0.01). Conclusion: The different views of gastroenterologists and patients in terms of the involvement of psychological attributes, risk factors, and accidents/injuries in IBD and IBS could affect the patient-health provider relationship and adversely impact treatment outcome. Copyright ©2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.

PubMed | University Hospital, Institute of Nuclear Medicine and University of Ulm
Type: | Journal: Journal of nuclear medicine : official publication, Society of Nuclear Medicine | Year: 2016

We aimed to assess the risk of developing diabetes mellitus and its effects on all-cause mortality after radiopeptide therapy for neuroendocrine tumors (NET).NET patients received somatostatin radiopeptide therapy with yttrium-90-DOTATOC and/or lutetium-177-DOTATOC. The incidence of diabetes mellitus and its mortality were assessed using univariate and multivariate regression.Overall, 1535 NET patients were enrolled, and received 3807 treatment cycles. After treatment, 72 patients developed diabetes mellitus, including 47 cases after yttrium-90-DOTATOC and 25 cases after combined treatment. The diabetes mellitus risk was higher before than after DOTATOC (Estimate: 0.0032, P < 0.001), and overall survival was similar in patients with and without diabetes mellitus (HR: 1.13, 95%CI: 0.91-1.39, n = 1535, P = 0.27).Radiopeptide therapy does not appear to increase the risk of developing diabetes mellitus in NET patients, while diabetes mellitus does not appear to increase the mortality of NET patients undergoing receptor-targeted radiopeptide therapy.

PubMed | Institute of Nuclear Medicine and University of Duisburg - Essen
Type: Journal Article | Journal: European journal of nuclear medicine and molecular imaging | Year: 2016

Therapy with the alpha-emitter radium-223 chloride (In 11 patients receiving Lymphocyte proliferation and the production of interferon- and interleukin-10 towards mitogens and antigens remained unchanged after therapy. Consistent with these in vitro data, we did not observe infectious complications after treatment.The results argue against an impairment of lymphocyte function after

PubMed | Institute of Nuclear Medicine
Type: Journal Article | Journal: Physics in medicine and biology | Year: 2016

Accurate PET quantitation requires a matched attenuation map. Obtaining matched CT attenuation maps in the thorax is difficult due to the respiratory cycle which causes both motion and density changes. Unlike with motion, little attention has been given to the effects of density changes in the lung on PET quantitation. This work aims to explore the extent of the errors caused by pulmonary density attenuation map mismatch on dynamic and static parameter estimates. Dynamic XCAT phantoms were utilised using clinically relevant (18)F-FDG and (18)F-FMISO time activity curves for all organs within the thorax to estimate the expected parameter errors. The simulations were then validated with PET data from 5 patients suffering from idiopathic pulmonary fibrosis who underwent PET/Cine-CT. The PET data were reconstructed with three gates obtained from the Cine-CT and the average Cine-CT. The lung TACs clearly displayed differences between true and measured curves with error depending on global activity distribution at the time of measurement. The density errors from using a mismatched attenuation map were found to have a considerable impact on PET quantitative accuracy. Maximum errors due to density mismatch were found to be as high as 25% in the XCAT simulation. Differences in patient derived kinetic parameter estimates and static concentration between the extreme gates were found to be as high as 31% and 14%, respectively. Overall our results show that respiratory associated density errors in the attenuation map affect quantitation throughout the lung, not just regions near boundaries. The extent of this error is dependent on the activity distribution in the thorax and hence on the tracer and time of acquisition. Consequently there may be a significant impact on estimated kinetic parameters throughout the lung.

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