TY - JOUR A1 - Lohr, David A1 - Terekhov, Maxim A1 - Weng, Andreas Max A1 - Schroeder, Anja A1 - Walles, Heike A1 - Schreiber, Laura Maria T1 - Spin echo based cardiac diffusion imaging at 7T: An ex vivo study of the porcine heart at 7T and 3T JF - PLoS ONE N2 - Purpose of this work was to assess feasibility of cardiac diffusion tensor imaging (cDTI) at 7 T in a set of healthy, unfixed, porcine hearts using various parallel imaging acceleration factors and to compare SNR and derived cDTI metrics to a reference measured at 3 T. Magnetic resonance imaging was performed on 7T and 3T whole body systems using a spin echo diffusion encoding sequence with echo planar imaging readout. Five reference (b = 0 s/mm\(^2\)) images and 30 diffusion directions (b = 700 s/mm\(^2\)) were acquired at both 7 T and 3 T using a GRAPPA acceleration factor R = 1. Scans at 7 T were repeated using R = 2, R = 3, and R = 4. SNR evaluation was based on 30 reference (b = 0 s/mm\(^2\)) images of 30 slices of the left ventricle and cardiac DTI metrics were compared within AHA segmentation. The number of hearts scanned at 7 T and 3 T was n = 11. No statistically significant differences were found for evaluated helix angle, secondary eigenvector angle, fractional anisotropy and apparent diffusion coefficient at the different field strengths, given sufficiently high SNR and geometrically undistorted images. R≥3 was needed to reduce susceptibility induced geometric distortions to an acceptable amount. On average SNR in myocardium of the left ventricle was increased from 29±3 to 44±6 in the reference image (b = 0 s/mm\(^2\)) when switching from 3 T to 7 T. Our study demonstrates that high resolution, ex vivo cDTI is feasible at 7 T using commercial hardware. KW - Heart KW - Diffusion tensor imaging KW - Eigenvectors KW - Cardiac ventricles KW - Tractography KW - Magnetic resonance imaging KW - Data acquisition KW - Swine Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201376 VL - 14 IS - 3 ER - TY - JOUR A1 - Schuster, Frank A1 - Johannsen, Stephan A1 - Moegele, Susanne A1 - Metterlein, Thomas A1 - Roewer, Norbert A1 - Anetseder, Martin T1 - The effect of succinylcholine on malignant hyperthermia events in susceptible swine N2 - Background While the impact of volatile anaesthetics to induce malignant hyperthermia (MH) is abundantly clear, the role of succinylcholine still remains controversial. To evaluate the influence of succinylcholine on porcine MH events, the authors investigated the hemodynamic and metabolic responses in MH susceptible (MHS) and non-susceptible (MHN) swine following either succinylcholine or halothane application alone or a combination of both substances. Methods With approval of the local animal care committee 27 MHS and 30 MHN pigs were anaesthetized and mechanically ventilated. Fiberoptic probes for continuous PCO2 measurement were inserted into the femoral vein and the triceps muscle. Group A received succinylcholine 4 mg/kg, group B incremental doses of halothane (0.5, 1.0 vol%) and group C succinylcholine and halothane simultaneously. Vital signs were recorded continuously. Results Prior to drug application measured values did not differ between MHS and MHN. While MHN pigs did not show relevant alterations, succinylcholine, halothane and the combination of both lead to significant hemodynamic and metabolic changes in MHS swine. Conclusions Hemodynamic and metabolic alterations following succinylcholine were similar to halothane in MHS pigs. The combination of both pharmacological agents potentiated the observed effects. According to these results succinylcholine acted as an independent and supportive factor during onset of an MH episode. KW - Malignant hyperthermia KW - Succinylcholine KW - Halothane KW - Swine Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110302 ER -