@article{beaffb4590db472e996d04f32bd39ba5,
title = "In vivo measurement of T1 and T2 relaxation times in awake pigeon and rat brains at 7T",
abstract = "Purpose: Establishment of regional longitudinal (T1) and transverse (T2) relaxation times in awake pigeons and rats at 7T field strength. Regional differences in relaxation times between species and between two different pigeon breeds (homing pigeons and Figurita pigeons) were investigated. Methods: T1 and T2 relaxation times were determined for nine functionally equivalent brain regions in awake pigeons and rats using a multiple spin-echo saturation recovery method with variable repetition time and a multi-slice/multi-echo sequence, respectively. Optimized head fixation and habituation protocols were applied to accustom animals to the scanning conditions and to minimize movement. Results: The habituation protocol successfully limited movement of the awake animals to a negligible minimum, allowing reliable measurement of T1 and T2 values within all regions of interest. Significant differences in relaxation times were found between rats and pigeons but not between different pigeon breeds. Conclusion: The obtained T1 and T2 values for awake pigeons and rats and the optimized habituation protocol will augment future MRI studies with awake animals. The differences in relaxation times observed between species underline the importance of the acquisition of T1/T2 values as reference points for specific experiments. Magn Reson Med 79:1090–1100, 2018.",
keywords = "MRI, avian, longitudinal relaxation time, transverse relaxation time",
author = "Mehdi Behroozi and Caroline Chwiesko and Felix Str{\"o}ckens and Magdalena Sauvage and Xavier Helluy and Jutta Peterburs and Onur G{\"u}nt{\"u}rk{\"u}n",
note = "Funding Information: 1Department of Psychology, Institute of Cognitive Neuroscience, Biopsychology, Ruhr-University Bochum, Bochum, Germany. 2Department of Neurophysiology, Faculty of Medicine, Ruhr-University Bochum, Bochum, Germany. 3Mercator Research Group, Ruhr-University Bochum, Bochum, Germany. 4Leibniz Institute for Neurobiology, Functional Architecture of Memory Department, Magdeburg, Germany. 5Faculty of Medicine, Otto von Guericke University Magdeburg, Magdeburg, Germany. 6Division of Cognitive Neuroscience, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA. 7Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Research Centre at Stellenbosch University, Stellenbosch, South Africa. Grant sponsor: O.G. was funded by the German Research Society (Deutsche Forschungsgemeinschaft, DFG) through SFB 874. *Correspondence to: Mehdi Behroozi, Faculty of Psychology, Institute of Cognitive Neuroscience, Biopsychology, Ruhr-University Bochum, Universita€tsstra{\ss}e 150, 44780, Bochum, Germany. E-mail: mehdi.behroozi@ruhr-uni-bochum.de. Twitter: @BehrooziMehdi Funding Information: Animal imaging was conducted at the Ruhr-University Bochum Imaging Centre, Bochum, Germany with support from the Mercator Foundation. m.s. would like to thank the Mercator Stiftung and the International Graduate School of Neurosciences of the Ruhr-University Bochum. All of the authors would like to thank Dr. Erhan Gen? for helpful discussions and Dr. Zachery Beer for proofreading. Publisher Copyright: {\textcopyright} 2017 International Society for Magnetic Resonance in Medicine",
year = "2018",
month = feb,
day = "1",
doi = "10.1002/mrm.26722",
language = "English (US)",
volume = "79",
pages = "1090--1100",
journal = "Magnetic resonance in medicine",
issn = "0740-3194",
publisher = "John Wiley and Sons Inc.",
number = "2",
}