@article{AndelovicWinterJakobetal.2021, author = {Andelovic, Kristina and Winter, Patrick and Jakob, Peter Michael and Bauer, Wolfgang Rudolf and Herold, Volker and Zernecke, Alma}, title = {Evaluation of plaque characteristics and inflammation using magnetic resonance imaging}, series = {Biomedicines}, volume = {9}, journal = {Biomedicines}, number = {2}, issn = {2227-9059}, doi = {10.3390/biomedicines9020185}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228839}, year = {2021}, abstract = {Atherosclerosis is an inflammatory disease of large and medium-sized arteries, characterized by the growth of atherosclerotic lesions (plaques). These plaques often develop at inner curvatures of arteries, branchpoints, and bifurcations, where the endothelial wall shear stress is low and oscillatory. In conjunction with other processes such as lipid deposition, biomechanical factors lead to local vascular inflammation and plaque growth. There is also evidence that low and oscillatory shear stress contribute to arterial remodeling, entailing a loss in arterial elasticity and, therefore, an increased pulse-wave velocity. Although altered shear stress profiles, elasticity and inflammation are closely intertwined and critical for plaque growth, preclinical and clinical investigations for atherosclerosis mostly focus on the investigation of one of these parameters only due to the experimental limitations. However, cardiovascular magnetic resonance imaging (MRI) has been demonstrated to be a potent tool which can be used to provide insights into a large range of biological parameters in one experimental session. It enables the evaluation of the dynamic process of atherosclerotic lesion formation without the need for harmful radiation. Flow-sensitive MRI provides the assessment of hemodynamic parameters such as wall shear stress and pulse wave velocity which may replace invasive and radiation-based techniques for imaging of the vascular function and the characterization of early plaque development. In combination with inflammation imaging, the analyses and correlations of these parameters could not only significantly advance basic preclinical investigations of atherosclerotic lesion formation and progression, but also the diagnostic clinical evaluation for early identification of high-risk plaques, which are prone to rupture. In this review, we summarize the key applications of magnetic resonance imaging for the evaluation of plaque characteristics through flow sensitive and morphological measurements. The simultaneous measurements of functional and structural parameters will further preclinical research on atherosclerosis and has the potential to fundamentally improve the detection of inflammation and vulnerable plaques in patients.}, language = {en} } @article{HuflageKarstenKunzetal.2021, author = {Huflage, Henner and Karsten, Sebastian and Kunz, Andreas Steven and Conrads, Nora and Jakubietz, Rafael Gregor and Jakubietz, Michael Georg and Pennig, Lenhard and Goertz, Lukas and Bley, Thorsten Alexander and Schmitt, Rainer and Grunz, Jan-Peter}, title = {Improved diagnostic accuracy for ulnar-sided TFCC lesions with radial reformation of 3D sequences in wrist MR arthrography}, series = {European Radiology}, volume = {31}, journal = {European Radiology}, number = {12}, issn = {1432-1084}, doi = {10.1007/s00330-021-08024-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266512}, pages = {9399-9407}, year = {2021}, abstract = {Objectives Triangular fibrocartilage complex (TFCC) injuries frequently cause ulnar-sided wrist pain and can induce distal radioulnar joint instability. With its complex three-dimensional structure, diagnosis of TFCC lesions remains a challenging task even in MR arthrograms. The aim of this study was to assess the added diagnostic value of radial reformatting of isotropic 3D MRI datasets compared to standard planes after direct arthrography of the wrist. Methods Ninety-three patients underwent wrist MRI after fluoroscopy-guided multi-compartment arthrography. Two radiologists collectively analyzed two datasets of each MR arthrogram for TFCC injuries, with one set containing standard reconstructions of a 3D thin-slice sequence in axial, coronal and sagittal orientation, while the other set comprised an additional radial plane view with the rotating center positioned at the ulnar styloid. Surgical reports (whenever available) or radiological reports combined with clinical follow-up served as a standard of reference. In addition, diagnostic confidence and assessability of the central disc and ulnar-sided insertions were subjectively evaluated. Results Injuries of the articular disc, styloid and foveal ulnar attachment were present in 20 (23.7\%), 10 (10.8\%) and 9 (9.7\%) patients. Additional radial planes increased diagnostic accuracy for lesions of the styloid (0.83 vs. 0.90; p = 0.016) and foveal (0.86 vs. 0.94; p = 0.039) insertion, whereas no improvement was identified for alterations of the central cartilage disc. Readers' confidence (p < 0.001) and assessability of the ulnar-sided insertions (p < 0.001) were superior with ancillary radial reformatting. Conclusions Access to the radial plane view of isotropic 3D sequences in MR arthrography improves diagnostic accuracy and confidence for ulnar-sided TFCC lesions.}, language = {en} } @article{SchnabelCamenKnebeletal.2021, author = {Schnabel, Renate B. and Camen, Stephan and Knebel, Fabian and Hagendorff, Andreas and Bavendiek, Udo and B{\"o}hm, Michael and Doehner, Wolfram and Endres, Matthias and Gr{\"o}schel, Klaus and Goette, Andreas and Huttner, Hagen B. and Jensen, Christoph and Kirchhof, Paulus and Korosoglou, Grigorius and Laufs, Ulrich and Liman, Jan and Morbach, Caroline and Navabi, Darius G{\"u}nther and Neumann-Haefelin, Tobias and Pfeilschifter, Waltraut and Poli, Sven and Rizos, Timolaos and Rolf, Andreas and R{\"o}ther, Joachim and Sch{\"a}bitz, Wolf R{\"u}diger and Steiner, Thorsten and Thomalla, G{\"o}tz and Wachter, Rolf and Haeusler, Karl Georg}, title = {Expert opinion paper on cardiac imaging after ischemic stroke}, series = {Clinical Research in Cardiology}, volume = {110}, journal = {Clinical Research in Cardiology}, number = {7}, issn = {1861-0692}, doi = {10.1007/s00392-021-01834-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266662}, pages = {938-958}, year = {2021}, abstract = {This expert opinion paper on cardiac imaging after acute ischemic stroke or transient ischemic attack (TIA) includes a statement of the "Heart and Brain" consortium of the German Cardiac Society and the German Stroke Society. The Stroke Unit-Commission of the German Stroke Society and the German Atrial Fibrillation NETwork (AFNET) endorsed this paper. Cardiac imaging is a key component of etiological work-up after stroke. Enhanced echocardiographic tools, constantly improving cardiac computer tomography (CT) as well as cardiac magnetic resonance imaging (MRI) offer comprehensive non- or less-invasive cardiac evaluation at the expense of increased costs and/or radiation exposure. Certain imaging findings usually lead to a change in medical secondary stroke prevention or may influence medical treatment. However, there is no proof from a randomized controlled trial (RCT) that the choice of the imaging method influences the prognosis of stroke patients. Summarizing present knowledge, the German Heart and Brain consortium proposes an interdisciplinary, staged standard diagnostic scheme for the detection of risk factors of cardio-embolic stroke. This expert opinion paper aims to give practical advice to physicians who are involved in stroke care. In line with the nature of an expert opinion paper, labeling of classes of recommendations is not provided, since many statements are based on expert opinion, reported case series, and clinical experience.}, language = {en} } @article{TerekhovElabyadSchreiber2021, author = {Terekhov, Maxim and Elabyad, Ibrahim A. and Schreiber, Laura M.}, title = {Global optimization of default phases for parallel transmit coils for ultra-high-field cardiac MRI}, series = {PLoS One}, volume = {16}, journal = {PLoS One}, number = {8}, doi = {10.1371/journal.pone.0255341}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265737}, year = {2021}, abstract = {The development of novel multiple-element transmit-receive arrays is an essential factor for improving B\(_1\)\(^+\) field homogeneity in cardiac MRI at ultra-high magnetic field strength (B\(_0\) > = 7.0T). One of the key steps in the design and fine-tuning of such arrays during the development process is finding the default driving phases for individual coil elements providing the best possible homogeneity of the combined B\(_1\)\(^+\)-field that is achievable without (or before) subject-specific B\(_1\)\(^+\)-adjustment in the scanner. This task is often solved by time-consuming (brute-force) or by limited efficiency optimization methods. In this work, we propose a robust technique to find phase vectors providing optimization of the B-1-homogeneity in the default setup of multiple-element transceiver arrays. The key point of the described method is the pre-selection of starting vectors for the iterative solver-based search to maximize the probability of finding a global extremum for a cost function optimizing the homogeneity of a shaped B\(_1\)\(^+\)-field. This strategy allows for (i) drastic reduction of the computation time in comparison to a brute-force method and (ii) finding phase vectors providing a combined B\(_1\)\(^+\)-field with homogeneity characteristics superior to the one provided by the random-multi-start optimization approach. The method was efficiently used for optimizing the default phase settings in the in-house-built 8Tx/16Rx arrays designed for cMRI in pigs at 7T.}, language = {en} }