175 research outputs found

    Total-body contrast-enhanced MRA on a short, wide-bore 1.5-T system: intra-individual comparison of Gd-BOPTA and Gd-DOTA

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    Total-body contrast-enhanced MRA (CE-MRA) provides information of the entire vascular system according to a one-stop-shop approach. Short, wide-bore scanners have not yet been used for total-body CE-MRA, probably due to their restricted field of view in the z-direction. The purpose of this feasibility study is to introduce an image protocol for total-body MRA on a short, wide-bore system. The protocol includes five to six table-moving steps and two injection runs. Two pharmacologically different contrast materials (CM) were applied in ten healthy volunteers in view of possible CM-dependent influences on the protocol outcome (Gd-Bopta, Gd-Dota). Differences consisted of significantly higher CNR with Gd-Bopta with a mean of 73.8 ± 38.7 versus 69.1 ± 34.3 (p = 0.008), significantly better arterial visualization values with Gd-Dota with a mean of 1.26 ± 0.44 versus 1.53 ± 0.73 (p = 0.003) and a tendency to less venous overlay with Gd-Dota, mean 1.19 ± 0.44 and 1.34 ± 0.72, respectively (p = 0.065) (two-tailed Wilcoxon matched-pairs test). Overall 94% of the steps were valued as qualitatively excellent or good. The good results with both CM suggest a transfer to further patient evaluatio

    Optimization of imaging before pulmonary vein isolation by radiofrequency ablation: breath-held ungated versus ECG/breath-gated MRA

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    Isolation of the pulmonary veins has emerged as a new therapy for atrial fibrillation. Pre-procedural magnetic resonance (MR) imaging enhances safety and efficacy; moreover, it reduces radiation exposure of the patients and interventional team. The purpose of this study was to optimize the MR protocol with respect to image quality and acquisition time. In 31 patients (23-73years), the anatomy of the pulmonary veins, left atrium and oesophagus was assessed on a 1.5-Tesla scanner with four different sequences: (1) ungated two-dimensional true fast imaging with steady precession (2D-TrueFISP), (2) ECG/breath-gated 3D-TrueFISP, (3) ungated breath-held contrast-enhanced three-dimensional turbo fast low-angle shot (CE-3D-tFLASH), and (4) ECG/breath-gated CE-3D-TrueFISP. Image quality was scored from 1 (structure not visible) to 5 (excellent visibility), and the acquisition time was monitored. The pulmonary veins and left atrium were best visualized with CE-3D-tFLASH (scores 4.50 ± 0.52 and 4.59 ± 0.43) and ECG/breath-gated CE-3D-TrueFISP (4.47 ± 0.49 and 4.63 ± 0.39). Conspicuity of the oesophagus was optimal with CE-3D-TrueFISP and 2D-TrueFISP (4.59 ± 0.35 and 4.19 ± 0.46) but poor with CE-3D-tFLASH (1.03 ± 0.13) (p < 0.05). Acquisition times were shorter for 2D-TrueFISP (44 ± 1s) and CE-3D-tFLASH (345 ± 113s) compared with ECG/breath-gated 3D-TrueFISP (634 ± 197s) and ECG/breath-gated CE-3D-TrueFISP (636 ± 230s) (p < 0.05). In conclusion, an MR imaging protocol comprising CE-3D-tFLASH and 2D-TrueFISP allows assessment of the pulmonary veins, left atrium and oesophagus in less than 7 min and can be recommended for pre-procedural imaging before electric isolation of pulmonary vein

    Keine gewöhnliche perianale Fistel

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    Zusammenfassung: Wir präsentieren den Fall eines 63-jährigen Schweizer Staatsbürgers mit chronischer Diarrhö, Schleimabgang ab ano, analer Fistel und chronischem Analulkus bei anamnestisch bekannter Lungentuberkulose vor 56Jahren. Nach Bildgebung wurde klinisch und endoskopisch initial der Verdacht auf eine chronisch entzündliche Darmerkrankung geäußert. Erst eine gezielte Probenentnahme und Untersuchung mittels PCR konnte die Diagnose einer abdominalen Tuberkulose mit perianaler Manifestation sichern. Die differenzialdiagnostische Berücksichtigung der extrapulmonalen Tuberkulose ist wichtig bei der Abklärung chronisch abdomineller Symptome. Eine immunsuppressive Therapie bei ursprünglich vermuteter chronisch entzündlicher Darmerkrankung hätte zu einer Progression mit Gefahr der miliaren Tuberkulose führen könne

    Cardiovascular magnetic resonance imaging for diagnosis and clinical management of suspected cardiac masses and tumours

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    Aims To evaluate the diagnostic accuracy of cardiovascular magnetic resonance (CMR) imaging from a risk-stratification and therapeutic-management perspective in patients with suspected cardiac tumours. Methods and results Cardiovascular magnetic resonance exams of 41 consecutive patients (aged 61 ± 14 years, 21 men) referred for evaluation of a suspected cardiac mass were reviewed for tumour morphology and signal characteristics in various unenhanced and contrast-enhanced sequences. Cardiovascular magnetic resonance-derived diagnosis and treatment were compared with clinical outcome and histology in patients undergoing surgery or autopsy (n = 20). In 18 of 41 patients, CMR excluded masses or reclassified them as normal variants; all were treated conservatively. In 23 of 41 patients, CMR diagnosed a neoplasm (14 ‘benign', 8 ‘malignant', and 1 'equivocal'); 18 of these patients were operated on, 2 managed conservatively, and 3 by palliation. During follow-up of 705 (inter-quartile range 303-1472) days, 13 patients died. No tumour-related deaths occurred in conservatively managed patients. Patients with a CMR-based diagnosis and treatment of benign tumour had a similar survival as patients without detectable tumour. Compared with histology, CMR correctly classified masses as ‘benign or malignant' in 95% of the cases. Tumour perfusion, invasiveness, localization, and pericardial fluid were valuable to distinguish between malignant and benign tumours. Soft tissue contrast and signal intensity patterns in various sequences were valuable for excluding neoplastic lesions and helped to obtain tissue characterization at the histological level in selected tumour cases, respectively. Conclusion Comprehensive CMR provides a confident risk-stratification and clinical-management tool in patients with suspected tumours. Patients where CMR excludes tumours can be managed conservativel

    Freshwater megafauna diversity: Patterns, status and threats

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    Aim: Freshwater megafauna remain underrepresented in research and conservation, despite a disproportionately high risk of extinction due to multiple human threats. Therefore, our aims are threefold; (i) identify global patterns of freshwater megafauna richness and endemism, (ii) assess the conservation status of freshwater megafauna and (iii) demonstrate spatial and temporal patterns of human pressure throughout their distribution ranges. Location: Global. Methods: We identified 207 extant freshwater megafauna species, based on a 30 kg weight threshold, and mapped their distributions using HydroBASINS subcatchments (level 8). Information on conservation status and population trends for each species was extracted from the IUCN Red List website. We investigated human impacts on freshwater megafauna in space and time by examining spatial congruence between their distributions and human pressures, described by the Incident Biodiversity Threat Index and Temporal Human Pressure Index. Results: Freshwater megafauna occur in 76% of the world s main river basins (level 3 HydroBASINS), with species richness peaking in the Amazon, Congo, Orinoco, Mekong and Ganges-Brahmaputra basins. Freshwater megafauna are more threatened than their smaller counterparts within the specific taxonomic groups (i.e., fishes, mammals, reptiles and amphibians). Out of the 93 freshwater megafauna species with known population trends, 71% are in decline. Meanwhile, IUCN Red List assessments reported insufficient or outdated data for 43% of all freshwater megafauna species. Since the early 1990s, human pressure has increased throughout 63% of their distribution ranges, with particularly intense impacts occurring in the Mekong and Ganges-Brahmaputra basins. Main conclusions: Freshwater megafauna species are threatened globally, with intense and increasing human pressures occurring in many of their biodiversity hotspots. We call for research and conservation actions for freshwater megafauna, as they are highly sensitive to present and future pressures including a massive boom in hydropower dam construction in their biodiversity hotspots. © 2018 John Wiley & Sons LtdBundesministerium für Bildung und Forschung, Grant/Award Number: “GLANCE” project (01 LN1320A); European Union’s Horizon 2020 Programme for Research, Technological ?evelopment and demonstration, Grant/Award Number: AQUACROSS (642317); Villum Fonden, Grant/Award Number: VKR023371; Education, Audiovisual and Culture Executive Agency (Erasmus Mundus Joint ?octorate programme “SMART”); EU Marie Sklodowska-Curie programme, Grant/Award Number: H2020-MSCA-IF-2015-706784, H2020-MSCA-IF-2016-748625; Ministerium für Wissenschaft, Forschung und Kunst Baden-Württemberg (Junior Professorship Program

    Thermography and thermoregulation of the face

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    BACKGROUND: Although clinical diagnosis of thermoregulation is gaining in importance there is no consistent evidence on the value of thermography of the facial region. In particular there are no reference values established with standardised methods. METHODS: Skin temperatures were measured in the facial area at 32 fixed measuring sites in 26 health subjects (7–72 years) with the aid of a contact thermograph (Eidatherm). A total of 6 measurements were performed separately for the two sides of the face at intervals of equal lengths (4 hours) over a period of 24 hours. Thermoregulation was triggered by application of a cold stimulus in the region of the ipsilateral ear lobe. RESULTS: Comparison of the sides revealed significant asymmetry of face temperature. The left side of the face showed a temperature that was on the average 0.1°C lower than on the right. No increase in temperature was found following application of the cold stimulus. However, a significant circadian rhythm with mean temperature differences of 0.7°C was observed. CONCLUSION: The results obtained should be seen as an initial basis for compiling an exact thermoprofile of the surface temperature of the facial region that takes into account the circadian rhythm, thus closing gaps in studies on physiological changes in the temperature of the skin of the face

    Standardized image interpretation and post-processing in cardiovascular magnetic resonance - 2020 update : Society for Cardiovascular Magnetic Resonance (SCMR): Board of Trustees Task Force on Standardized Post-Processing

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    With mounting data on its accuracy and prognostic value, cardiovascular magnetic resonance (CMR) is becoming an increasingly important diagnostic tool with growing utility in clinical routine. Given its versatility and wide range of quantitative parameters, however, agreement on specific standards for the interpretation and post-processing of CMR studies is required to ensure consistent quality and reproducibility of CMR reports. This document addresses this need by providing consensus recommendations developed by the Task Force for Post-Processing of the Society for Cardiovascular Magnetic Resonance (SCMR). The aim of the Task Force is to recommend requirements and standards for image interpretation and post-processing enabling qualitative and quantitative evaluation of CMR images. Furthermore, pitfalls of CMR image analysis are discussed where appropriate. It is an update of the original recommendations published 2013

    In-vivo assessment of normal T1 values of the right-ventricular myocardium by cardiac MRI

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    To test feasibility of myocardial T1 mapping of the right ventricle (RV) at systole when myocardium is more compact and to determine the most appropriate imaging plane. 20 healthy volunteers (11 men; 33±8years) were imaged on a 1.5T scanner (MAGNETOM Avanto, Siemens AG, Erlangen, Germany). A modified look-locker inversion-recovery sequence was acquired at mid-ventricular short axis (SAX), as horizontal long-axis view and as transversal view at systole (mean trigger time 363±37ms). Myocardial T1 time of the left-ventricular and RV myocardium was measured within a region of interest (ROI) on generated T1-maps. The most appropriate imaging plane for the RV was determined by the ability to draw a ROI including the largest amount of myocardium without including adjacent tissue or blood. At systole, when myocardium is thicker, measurements of the RV myocardium were feasible in 18/20 subjects. Average size of the ROI was 0.42±0.28cm2. In 10/18 subjects, short axis was the most appropriate imaging plane to obtain measurements (p=0.034). Average T1 time of the RV myocardium was 1,016±61ms, and average T1 of the left-ventricular (LV) was 956±25ms (p<0.001). T1 mapping of the RV myocardium is feasible during systole in the majority of healthy subjects but with a small ROI only. SAX plane was the optimal imaging plane in the majority of subjects. Native myocardial T1 time of the RV is significantly longer compared to the LV, which might be explained by the naturally higher collagen content of the RV
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