Pieter De Bondt

Intracoronary Injection of CD133-Positive Enriched Bone Marrow Progenitor Cells Promotes Cardiac Recovery After Recent Myocardial Infarction Feasibility and Safety

Background—Bone marrow CD133-postive (CD133+) cells possess high hematopoietic and angiogenic capacity. We tested the feasibility, safety, and functional effects of the use of enriched CD133+ progenitor cells after intracoronary administration in patients with recent myocardial infarction. Methods and Results—Among 35 patients with acute myocardial infarction treated with stenting, 19 underwent intracoronary administration of CD133+ progenitor cells (12.6±2.2×106 cells) 11.6±1.4 days later (group 1) and 16 did not (group 2). At 4 months, left ventricular ejection fraction increased significantly in group 1 (from 45.0±2.6% to 52.1±3.5%, P<0.05), but only tended to increase in case-matched group 2 patients (from 44.3±3.1% to 48.6±3.6%, P=NS). Likewise, left ventricular regional chordae shortening increased in group 1 (from 11.5±1.0% to 16.1±1.3%, P<0.05) but remained unchanged in group 2 patients (from 11.1±1.1% to 12.7±1.3%, P=NS). This was paralleled by reduction in the perfusion defect in group 1 (from 28.0±4.1% to 22.5±4.1%, P<0.05) and no change in group 2 (from 25.0±3.0% to 22.6±4.1%, P=NS). In group 1, two patients developed in-stent reocclusion, 7 developed in-stent restenosis, and 2 developed significant de novo lesion of the infarct-related artery. In group 2, four patients showed in-stent restenosis. In group 1 patients without reocclusion, glucose uptake shown by positron emission tomography with 18fluorodeoxyglucose in the infarct-related territory increased from 51.2±2.6% to 57.5±3.5% (P<0.05). No stem cell-related arrhythmias were noted, either clinically or during programmed stimulation studies at 4 months. Conclusion—In patients with recent myocardial infarction, intracoronary administration of enriched CD133+ cells is feasible but was associated with increased incidence of coronary events. Nevertheless, it seems to be associated with improved left ventricular performance paralleled with increased myocardial perfusion and viability.

EANM procedural guidelines for radionuclide myocardial perfusion imaging with SPECT and SPECT/CT : 2015 revision

Since the publication of the European Association of Nuclear Medicine (EANM) procedural guidelines for radionuclide myocardial perfusion imaging (MPI) in 2005, many small and some larger steps of progress have been made, improving MPI procedures. In this paper, the major changes from the updated 2015 procedural guidelines are highlighted, focusing on the important changes related to new instrumentation with improved image information and the possibility to reduce radiation exposure, which is further discussed in relation to the recent developments of new International Commission on Radiological Protection (ICRP) models. Introduction of the selective coronary vasodilator regadenoson and the use of coronary CT-contrast agents for hybrid imaging with SPECT/CT angiography are other important areas for nuclear cardiology that were not included in the previous guidelines. A large number of minor changes have been described in more detail in the fully revised version available at the EANM home page: http://eanm.org/publications/guidelines/2015_07_EANM_FINAL_myocardial_perfusion_guideline.pdf.

Coincidence camera FDG imaging for the diagnosis of chronic orthopedic infections: a feasibility study.

Purpose Results of dedicated [18F]fluoro-2-deoxy-d-glucose (FDG) PET imaging in patients with suspected orthopedic infections are promising. This study evaluates the feasibility of dual-head gamma-camera coincidence (DHC) imaging in this population. Method Twenty-four patients, referred for the confirmation or exclusion of orthopedic infection, were prospectively studied with consecutive FDG-dedicated PET and FDG DHC imaging. Images were read by two blinded readers experienced with FDG PET and compared with the final diagnosis, obtained by microbiologic proof in 11 patients and clinical follow-up of at least 9 months in 13 patients. Results Nine patients had osseous infection on final diagnosis. Sensitivity, specificity, and accuracy in this limited series were (Reader 1/Reader 2), respectively, 100/100, 86/86, and 92/92% for FDG-dedicated PET and 89/89, 100/93, and 96/92% for FDG DHC imaging. Conclusion Despite lower image quality for FDG DHC imaging, results in this limited series were comparable with the results of FDG-dedicated PET. Further studies are needed to confirm the utility of FDG DHC imaging in suspected chronic orthopedic infections in larger patient groups.

Prevalence of Potential Candidates for Biventricular Pacing Among Patients with Known Coronary Artery Disease: A Prospective Registry from a Single Center

A Prospective Registry from a Single Center. New forms of ventricular pacing are increasingly studied as an option in the management of patients with heart failure. Coronary artery disease (CAD) is the most frequent cause of heart failure, and patients with complete left or right bundle branch block (LBBB and RBBB) and a reduced left ventricular ejection fraction (LVEF) are the best candidates for this new therapy. However, the prevalence of this clinical presentation is uncertain. During a 1‐year period, 433 patients with documented CAD (mean age 64 ± 10 years, 79% men) who were referred for myocardial perfusion imaging were prospectively studied. All patients underwent a 2‐day stress‐rest gated 99mTc‐Tetrofosmin SPECT study with evaluation of resting LV enddiastolic (LVEDV) and endsystolic (LVESV) volumes and LVEF. The resting ECG was examined in all patients for the presence of complete LBBB or RBBB. Of the 433 patients with CAD 36 patients (8.3%) had LBBB (n = 14) or RBBB (n = 22) and a QRS width >120 ms. These 36 patients were in general older and more frequently had diabetes and atrial fibrillation. Patients with LBBB or RBBB had a significantly lower LVEF (41 ± 16%vs 48 ± 14%, P < 0.01) and significantly higher LV volumes compared to patients without LBBB or RBBB (177 ± 79 mL vs 131 ± 53 mL, P < 0.001 for LVEDV and 116 ± 76 mL vs 73 ± 49 mL, P < 0.001 for LVESV). In total, 112 /433 (26%) had an LVEF ≤ 40%; 16 had also a LBBB or RBBB (3.7% of the whole population, 14% of the patients with a LVEF ≤ 40%). Within the group of patients with a LVEF ≥ 40%, patients with BBB had comparable LVEF (26 ± 9% vs 30 ± 8%, P = NS) but significantly higher LVEDV and LVESV (230 ± 70 mL vs 190 ± 64 mL, P < 0.05 for LVEDV and 170 ± 65 mL vs 135 ± 56 mL, P < 0.05 for LVESV). In this prospective registry 3.7% of all patients with known CAD had LBBB or RBBB in combination with a LVEF ≤ 40%. This represented 14% of all patients with a LVEF ≥ 40%. These limited numbers should be kept in mind when considering biventricular pacing as a new therapeutic options in patients with heart failure.

Aseptic loosening of a knee prosthesis as imaged on FDG positron emission tomography.

FDG positron emission tomography (PET) has been presented as a highly accurate technique (n = 51; accuracy 96%, no false-positive results) for diagnosing chronic osteomyelitis. The authors report a case of high FDG uptake in aseptic loosening of a knee prosthesis. The FDG uptake mechanism in infection is related to increased tracer accumulation in activated macrophages, leukocytes, and fibroblasts. Macrophages and fibroblasts also play a role in aseptic loosening. This may be reflected in an elevated FDG uptake. Although promising, FDG PET probably will not be able to distinguish infection from inflammation. Further investigation is needed to determine its value in loosened prostheses.

Agreement between four available algorithms to evaluate global systolic left and right ventricular function from tomographic radionuclide ventriculography and comparison with planar imaging.

Background and aimLeft and right ventricular ejection fractions (LVEF and RVEF) and end-diastolic and end-systolic volumes (LVEDV, RVEDV, LVESV and RVESV) can be calculated from tomographic radionuclide ventriculography (TRV). The aim of this study was to validate and compare these parameters obtained using four different TRV software programs (QBS, QUBE, 4D-MSPECT and BP-SPECT). MethodsLVEF obtained from planar radionuclide ventriculography (PRV) was compared with LVEF obtained from TRV using the four different software programs in 166 patients. Furthermore, ventricular volumes obtained using TRV (QBS, QUBE and 4D-MSPECT) were compared with those obtained using BP-SPECT, the latter being the only method with the validation of ventricular volumes in the literature. ResultsThe correlation of LVEF between PRV and TRV was good for all methods: 0.81 for QBS, 0.79 for QUBE, 0.71 for 4D-MSPECT and 0.79 for BP-SPECT. The mean differences±standard deviation (SD) were 3.16±9.88, 10.72±10.92, 3.43±11.79 and 2.91±10.39, respectively. The correlation of RVEF between BP-SPECT and QUBE and QBS was poor: 0.33 and 0.38, respectively. LV volumes calculated using QBS, QUBE and 4D-MSPECT correlated well with those obtained using BP-SPECT (0.98, 0.90 and 0.98, respectively), with mean differences±SD of 7.31±42.94, −22.09±36.07 and −40.55±39.36, respectively. RV volumes showed poorer correlation between QBS and BP-SPECT and between QUBE and BP-SPECT (0.82 and 0.57, respectively). ConclusionLVEF calculated using TRV correlates well with that calculated using PRV, but is not interchangeable with the value obtained using PRV. Volume calculations (for left and right ventricle) and RVEF require further validation before they can be used in clinical practice.

Cardiac fluorine-18 fluorodeoxyglucose imaging using a dual-head gamma camera with coincidence detection: a clinical pilot study.

Abstract.Dual-headed gamma cameras with coincidence detection (MCD) are increasingly used for imaging of positron-emitting tracers, such as fluorine-18 fluorodeoxyglucose (FDG). In this study, we examined differences between FDG MCD and FDG positron emission tomography (PET) as the gold standard to determine whether FDG MCD could be used for assessment of myocardial viability in daily practice. Nineteen patients with a previous myocardial infarction (17 men; mean left ventricular ejection fraction 44%±13%) underwent FDG MCD, FDG PET, resting echocardiography and technetium-99m tetrofosmin gated single-photon emission tomography (SPET). At the 50% threshold value for FDG PET, the area under the receiver operating characteristic curve for FDG MCD was 0.77±0.03. In 107 dyssynergic segments on echocardiography and 151 segments with hypoperfusion on 99mTc-tetrofosmin SPET, the specificity of FDG MCD for the detection of myocardial viability was 72% and 76% respectively, with a sensitivity of 69% and 72% respectively. Regional analysis showed a significantly lower agreement of FDG MCD and FDG PET in the inferior and septal regions (58% for dyssynergic segments and 65% for segments with hypoperfusion), as compared with the other regions (85% for dyssynergic regions, P<0.05, and 86% for segments with hypoperfusion, P<0.05). Five patients (26%), who all had a body mass index ≥25% kg/m2, showed more than 25% disagreement between FDG MCD and FDG PET. Because of the moderate overall agreement with FDG PET, the low sensitivity in akinetic or dyskinetic regions and the low agreement in the inferior and septal regions, further studies and implementations of technical developments are needed before FDG MCD can be introduced into clinical practice for the assessment of myocardial viability.

The current and future status of nuclear cardiology: a consensus report

Cardiac imaging now provides a range of anatomical and functional information with some overlap in the ability of individual techniques to guide diagnosis and management. This report summarizes the conclusions of a panel of cardiac imagers who assembled to discuss the current state of the field. It focuses principally on options for nuclear cardiology, the choice between individual techniques, and areas where further advances would benefit patient management.

Accuracy of commercially available processing algorithms for planar radionuclide ventriculography using data for a dynamic left ventricular phantom

BackgroundAutomatic and semi-automatic algorithms to calculate ejection fraction (EF) from planar radionuclide ventriculography (PRV) have been used for many years in nuclear medicine. Validation of these algorithms is scarce and often performed on outdated versions of the software. Nevertheless, clinical trials where PRV is being used as the ‘gold standard’ for EF are numerous. Because of the importance attributed to the EF calculated by these programs, the accuracy of the resulting EF was assessed with a dynamic left ventricular physical phantom. MethodsA dynamic left ventricular phantom was used to simulate 21 combinations of various ejection fractions (7–66%) and end diastolic volumes (27–290 ml). For each combination, a planar radionuclide ventriculograph was acquired, converted to an interfile format and transferred into processing stations with 10 different contemporaneously available commercial algorithms. The gold standard was the ‘real’ EF of the phantom, derived from the exact volume of the ventricle in end diastolic and end systolic position. Correlation and Bland–Altman analysis was performed between the real EF and the calculated EF. ResultsThe correlation for all data was excellent (r=0.98), the mean difference was very acceptable (0.98%). Nevertheless, Bland–Altman analysis showed a significant trend in the difference between real and calculated EF, with a growing underestimation for higher ranges of EF, due to an overestimation of background in larger volumes compared to smaller ones. ConclusionThe determination of EF from PRV, calculated with commercially available algorithms, correlates closely to the real EF of a dynamic left ventricular phantom. This phantom can be used in the development and validation of algorithms for PRV studies, in software audits and in quality assurance procedures.

The contribution of bone scintigraphy in occupational health or medical insurance claims: a retrospective study

Abstract. Patients with a suspicion of bone damage following an industrial or traffic accident are often referred for bone scintigraphy as part of an occupational health or medical insurance investigation. The aim of this study was to assess the contribution and the potential role of bone scintigraphy compared with X-ray investigations in the aforementioned situation. To this end we evaluated 70 consecutive patients referred for bone scintigraphy during 1996 and 1997 by occupational health or medical insurance physicians. The most common reasons for referral were the exclusion of occult fractures of hands and feet, whiplash injuries, reflex sympathetic dystrophy or avascular necrosis, or the differentiation between an old and a recent vertebral fracture. X-rays were only available for comparative review of 53 patients, so only those were analysed. The results of bone scintigraphy were compared with X-rays, and their contribution and potential role in occupational health or medical insurance investigations assessed. In 31 out of the 53 patients investigated, bone scintigraphy findings concurred with X-rays as to the number and location of abnormalities. For 19 of the 53 patients, bone scintigraphy showed clinically relevant additional foci when compared with X-rays, predominantly involving lesions to hands/wrists and feet/ankles. Among these 19 patients, scintigraphic diagnoses were subsequently confirmed in ten cases by means of X-ray or computed tomography. In four patients, supplementary radiological investigations revealed no abnormalities, and in five patients no further investigations were undertaken. Finally, in three of the 53 patients, X-rays revealed bone damage (burst fractures) whilst the corresponding bone scintigraphy was negative, thus excluding recent injury. In conclusion, in 22 patients, representing 42% of the cases analysed, bone scintigraphy was conclusive compared with X-ray imaging in the final diagnosis and in this way in detecting occult or excluding active bone damage after a traffic or industrial accident. This makes bone scintigraphy a useful investigation in situations where a full or partial disablement claim has to be confirmed, extended or terminated.