@article{GodelPhamKeleetal.2019,
  author    = {Godel, Tim and Pham, Mirko and Kele, Henrich and Kronlage, Moritz and Schwarz, Daniel and Brun{\´e}e, Merle and Heiland, Sabine and Bendszus, Martin and B{\"a}umer, Philipp},
  title     = {Diffusion tensor imaging in anterior interosseous nerve syndrome - functional MR Neurography on a fascicular level},
  series = {NeuroImage: Clinical},
  volume    = {21},
  journal   = {NeuroImage: Clinical},
  doi       = {10.1016/j.nicl.2019.101659},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233061},
  year      = {2019},
  abstract  = {Purpose By applying diffusor tensor imaging (DTI) in patients with anterior interosseous nerve syndrome (AINS), this proof of principle study aims to quantify the extent of structural damage of a peripheral nerve at the anatomical level of individual fascicles. Methods In this institutional review board approved prospective study 13 patients with spontaneous AINS were examined at 3 Tesla including a transversal T2-weighted turbo-spin-echo and a spin-echo echo-planar-imaging pulse sequence of the upper arm level. Calculations of quantitative DTI parameters including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) for median nerve lesion and non-lesion fascicles as well as ulnar and radial nerve were obtained. DTI values were compared to each other and to a previously published dataset of 58 healthy controls using one-way Analysis of Variance with Bonferroni correction and p-values <.05 were considered significant. Receiver operating characteristic (ROC) curves were performed to assess diagnostic accuracy. Results FA of median nerve lesion fascicles was decreased compared to median nerve non-lesion fascicles, ulnar nerve and radial nerve while MD, RD, and AD was increased (p < .001 for all parameters). Compared to median nerve values of healthy controls, lesion fascicles showed a significant decrease in FA while MD, RD, and AD was increased (p < .001 for all parameters). FA of median nerve non-lesion fascicles showed a weak significant decrease compared to healthy controls (p < .01) while there was no difference in MD, RD, and AD. ROC analyses revealed an excellent diagnostic accuracy of FA, MD and RD in the discrimination of median nerve lesion and non-lesion fascicles in AINS patients as well as in the discrimination of lesion fascicles and normative median nerve values of healthy controls. Conclusion By applying this functional MR Neurography technique in patients with AINS, this proof of principle study demonstrates that diffusion tensor imaging is feasible to quantify structural nerve injury at the anatomical level of individual fascicles.},
  language  = {en}
}
@article{BeyhoffLohrThieleetal.2020,
  author    = {Beyhoff, Niklas and Lohr, David and Thiele, Arne and Foryst-Ludwig, Anna and Klopfleisch, Robert and Schreiber, Laura M. and Kintscher, Ulrich},
  title     = {Myocardial Infarction After High-Dose Catecholamine Application—A Case Report From an Experimental Imaging Study},
  series = {Frontiers in Cardiovascular Medicine},
  volume    = {7},
  journal   = {Frontiers in Cardiovascular Medicine},
  doi       = {10.3389/fcvm.2020.580296},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217959},
  year      = {2020},
  abstract  = {Although heart failure following myocardial infarction (MI) represents a major health burden, underlying microstructural and functional changes remain incompletely understood. Here, we report on a case of unexpected MI after treatment with the catecholamine isoproterenol in an experimental imaging study in mice using different state-of-the-art imaging modalities. The decline in cardiac function was documented by ultrahigh-frequency echocardiography and speckle-tracking analyses. Myocardial microstructure was studied ex vivo at a spatial resolution of 100 × 100 × 100 μm\(^{3}\) using diffusion tensor magnetic resonance imaging (DT-MRI) and histopathologic analyses. Two weeks after ISO treatment, the animal showed an apical aneurysm accompanied by reduced radial strain in corresponding segments and impaired global systolic function. DT-MRI revealed a loss of contractile fiber tracts together with a disarray of remaining fibers as corresponding microstructural correlates. This preclinical case report provides valuable insights into pathophysiology and morphologic-functional relations of heart failure following MI using emerging imaging technologies.},
  language  = {en}
}
@article{LohrTerekhovVeitetal.2020,
  author    = {Lohr, David and Terekhov, Maxim and Veit, Franziska and Schreiber, Laura Maria},
  title     = {Longitudinal assessment of tissue properties and cardiac diffusion metrics of the ex vivo porcine heart at 7 T: Impact of continuous tissue fixation using formalin},
  series = {NMR in Biomedicine},
  volume    = {33},
  journal   = {NMR in Biomedicine},
  number    = {7},
  doi       = {10.1002/nbm.4298},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-215536},
  year      = {2020},
  abstract  = {In this study we aimed to assess the effects of continuous formalin fixation on diffusion and relaxation metrics of the ex vivo porcine heart at 7 T. Magnetic resonance imaging was performed on eight piglet hearts using a 7 T whole body system. Hearts were measured fresh within 3 hours of cardiac arrest followed by immersion in 10\% neutral buffered formalin. T\(_{2}\)* and T\(_{2}\) were assessed using a gradient multi-echo and multi-echo spin echo sequence, respectively. A spin echo and a custom stimulated echo sequence were employed to assess diffusion time-dependent changes in metrics of cardiac diffusion tensor imaging. SNR was determined for b = 0 images. Scans were performed for 5 mm thick apical, midcavity and basal slices (in-plane resolution: 1 mm) and repeated 7, 15, 50, 100 and 200 days postfixation. Eigenvalues of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) decreased significantly (P < 0.05) following fixation. Relative to fresh hearts, FA values 7 and 200 days postfixation were 90\% and 80\%, while respective relative ADC values at those fixation stages were 78\% and 92\%. Statistical helix and sheetlet angle distributions as well as respective mean and median values showed no systematic influence of continuous formalin fixation. Similar to changes in the ADC, values for T\(_{2}\), T\(_{2}\)* and SNR dropped initially postfixation. Respective relative values compared with fresh hearts at day 7 were 64\%, 79\% and 68\%, whereas continuous fixation restored T\(_{2}\), T\(_{2}\)* and SNR leading to relative values of 74\%, 100\%, and 81\% at day 200, respectively. Relaxation parameters and diffusion metrics are significantly altered by continuous formalin fixation. The preservation of microstructure metrics following prolonged fixation is a key finding that may enable future studies of ventricular remodeling in cardiac pathologies.},
  language  = {en}
}