R Deichmann

Summary

Affiliation: University College London
Country: UK

Publications

  1. ncbi request reprint Echo time dependence of BOLD contrast and susceptibility artifacts
    Maria Luisa Gorno-Tempini
    Wellcome Department of Cognitive Neurology, Institute of Neurology, 12 Queen Square, London WC1N 3BG, United Kingdom
    Neuroimage 15:136-42. 2002
  2. ncbi request reprint Optimal EPI parameters for reduction of susceptibility-induced BOLD sensitivity losses: a whole-brain analysis at 3 T and 1.5 T
    Nikolaus Weiskopf
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK
    Neuroimage 33:493-504. 2006
  3. ncbi request reprint Optimisation of the 3D MDEFT sequence for anatomical brain imaging: technical implications at 1.5 and 3 T
    R Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK
    Neuroimage 21:757-67. 2004
  4. ncbi request reprint Fast high-resolution T1 mapping of the human brain
    Ralf Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, UK
    Magn Reson Med 54:20-7. 2005
  5. ncbi request reprint RF inhomogeneity compensation in structural brain imaging
    R Deichmann
    Wellcome Department of Cognitive Neurology, Institute of Neurology, London, UK
    Magn Reson Med 47:398-402. 2002
  6. ncbi request reprint Optimized RF excitation for anatomical brain imaging of the occipital lobe using the 3D MDEFT sequence and a surface transmit coil
    Ralf Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, UK
    Magn Reson Med 53:1212-6. 2005
  7. ncbi request reprint Fast structural brain imaging using an MDEFT sequence with a FLASH-EPI hybrid readout
    R Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, 12 Queen Square, London WC1N 3BG, UK
    Neuroimage 33:1066-71. 2006
  8. ncbi request reprint Optimized EPI for fMRI studies of the orbitofrontal cortex
    R Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London WC1N 3BG, UK
    Neuroimage 19:430-41. 2003
  9. ncbi request reprint Compensation of susceptibility-induced BOLD sensitivity losses in echo-planar fMRI imaging
    R Deichmann
    Institute of Neurology, Wellcome Department of Cognitive Neurology, London WC1N 3BG, United Kingdom
    Neuroimage 15:120-35. 2002
  10. ncbi request reprint Removing the effects of CSF partial voluming on fitted CBF and arterial transit times using FAIR, a pulsed arterial spin labelling technique
    J Wiersma
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, UK
    MAGMA 19:115-23. 2006

Detail Information

Publications33

  1. ncbi request reprint Echo time dependence of BOLD contrast and susceptibility artifacts
    Maria Luisa Gorno-Tempini
    Wellcome Department of Cognitive Neurology, Institute of Neurology, 12 Queen Square, London WC1N 3BG, United Kingdom
    Neuroimage 15:136-42. 2002
    ..However, although the amount of signal loss is reduced at the lower TE, this does not appear to be sufficient to recover the BOLD signal in regions affected by susceptibility artifacts (i.e., anterior temporal lobes)...
  2. ncbi request reprint Optimal EPI parameters for reduction of susceptibility-induced BOLD sensitivity losses: a whole-brain analysis at 3 T and 1.5 T
    Nikolaus Weiskopf
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK
    Neuroimage 33:493-504. 2006
    ..g., encompassing the medial OFC, can be increased by more than 15%. The maps of optimal parameters allow for assessing the feasibility and improving fMRI of brain regions affected by susceptibility-induced BS losses...
  3. ncbi request reprint Optimisation of the 3D MDEFT sequence for anatomical brain imaging: technical implications at 1.5 and 3 T
    R Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK
    Neuroimage 21:757-67. 2004
    ..It is shown both theoretically and experimentally that these problems can be avoided by using spin tagging and fat saturation...
  4. ncbi request reprint Fast high-resolution T1 mapping of the human brain
    Ralf Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, UK
    Magn Reson Med 54:20-7. 2005
    ..In addition, an improved fitting algorithm based on smoothed flip angle maps is presented and tested successfully...
  5. ncbi request reprint RF inhomogeneity compensation in structural brain imaging
    R Deichmann
    Wellcome Department of Cognitive Neurology, Institute of Neurology, London, UK
    Magn Reson Med 47:398-402. 2002
    ..It is shown experimentally that images acquired with the compensation pulse may be segmented without using intensity correction algorithms during data postprocessing...
  6. ncbi request reprint Optimized RF excitation for anatomical brain imaging of the occipital lobe using the 3D MDEFT sequence and a surface transmit coil
    Ralf Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, UK
    Magn Reson Med 53:1212-6. 2005
    ..The method is particularly useful for certain applications in neuroimaging that require technical equipment that is too large for standard coils or should not be exposed to RF fields...
  7. ncbi request reprint Fast structural brain imaging using an MDEFT sequence with a FLASH-EPI hybrid readout
    R Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, 12 Queen Square, London WC1N 3BG, UK
    Neuroimage 33:1066-71. 2006
    ....
  8. ncbi request reprint Optimized EPI for fMRI studies of the orbitofrontal cortex
    R Deichmann
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London WC1N 3BG, UK
    Neuroimage 19:430-41. 2003
    ..In contrast to several other techniques proposed in the literature for reducing susceptibility effects, this method does not compromise the temporal resolution and is therefore applicable to event-related studies...
  9. ncbi request reprint Compensation of susceptibility-induced BOLD sensitivity losses in echo-planar fMRI imaging
    R Deichmann
    Institute of Neurology, Wellcome Department of Cognitive Neurology, London WC1N 3BG, United Kingdom
    Neuroimage 15:120-35. 2002
    ..The results suggest that the compensation method allows for the detection of activation in brain areas which are usually unavailable for BOLD studies...
  10. ncbi request reprint Removing the effects of CSF partial voluming on fitted CBF and arterial transit times using FAIR, a pulsed arterial spin labelling technique
    J Wiersma
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, UK
    MAGMA 19:115-23. 2006
    ..The fit remained robust for high CSF fractions. Our analysis and simulations demonstrate that using magnitude FAIR data minimises the detrimental effects of CSF partial voluming. Data from a healthy volunteer illustrate these results...
  11. ncbi request reprint Real-time functional magnetic resonance imaging: methods and applications
    Nikolaus Weiskopf
    Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, WC1N 3BG London, UK
    Magn Reson Imaging 25:989-1003. 2007
    ....
  12. pmc Voxel-based cortical thickness measurements in MRI
    Chloe Hutton
    Wellcome Trust Centre for Neuroimaging, Institute of Neurology, UCL, London, UK
    Neuroimage 40:1701-10. 2008
    ..We propose that the analysis of VBCT maps can provide results that are complementary to other anatomical analyses such as voxel-based morphometry...
  13. ncbi request reprint Concurrent TMS-fMRI and psychophysics reveal frontal influences on human retinotopic visual cortex
    Christian C Ruff
    UCL Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AR, United Kingdom
    Curr Biol 16:1479-88. 2006
    ....
  14. pmc A method for improving the performance of gradient systems for diffusion-weighted MRI
    Zoltan Nagy
    Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, UK
    Magn Reson Med 58:763-8. 2007
    ..The scaling factor is the square root of the ratio of the expected and observed diffusion constants. In addition, fiber tracking results in the human brain were noticeably affected by improving the gradient system calibration...
  15. ncbi request reprint Mapping of the cerebral vascular response to hypoxia and hypercapnia using quantitative perfusion MRI at 3 T
    Ulrike Nöth
    Wellcome Trust Centre for Neuroimaging, Institute of Neurology, UCL, 12 Queen Square, London, UK
    NMR Biomed 21:464-72. 2008
    ..As the brain is particularly vulnerable to hypoxia, a condition associated with cardiorespiratory diseases, CVR maps may help in the clinic to identify the areas most prone to damage because of a reduced CVR...
  16. pmc Optimized EPI for fMRI studies of the orbitofrontal cortex: compensation of susceptibility-induced gradients in the readout direction
    Nikolaus Weiskopf
    Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, WC1N 3BG, UK
    MAGMA 20:39-49. 2007
    ..Here, BOLD sensitivity losses due to susceptibility- induced gradients in the readout (RO) direction are characterized and a compensation approach is developed...
  17. pmc Distinct causal influences of parietal versus frontal areas on human visual cortex: evidence from concurrent TMS-fMRI
    Christian C Ruff
    UCL Institute of Cognitive Neuroscience, 17 Queen Square, London WC1N 3AR, UK
    Cereb Cortex 18:817-27. 2008
    ..Our results show directly that parietal and frontal regions can indeed have distinct patterns of causal influence upon functional activity in human visual cortex...
  18. pmc Non-invasive mapping of corticofugal fibres from multiple motor areas--relevance to stroke recovery
    Jennifer M Newton
    Wellcome Department of Imaging Neuroscience, University College London London, UK
    Brain 129:1844-58. 2006
    ..These results confirm that selective disruption of motor corticofugal fibres influences functional reorganization and outcome in individual patients...
  19. pmc The cutaneous rabbit illusion affects human primary sensory cortex somatotopically
    Felix Blankenburg
    UCL Institute of Cognitive Neuroscience, Department of Psychology, University College London, London, United Kingdom
    PLoS Biol 4:e69. 2006
    ..These results provide direct evidence that illusory somatosensory percepts can affect primary somatosensory cortex in a manner that corresponds somatotopically to the illusory percept...
  20. pmc Eye-specific effects of binocular rivalry in the human lateral geniculate nucleus
    John Dylan Haynes
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK
    Nature 438:496-9. 2005
    ..The human LGN is thus the earliest stage of visual processing that reflects eye-specific dominance and suppression...
  21. ncbi request reprint Neural responses during anticipation of a primary taste reward
    JOHN P O'DOHERTY
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, 12 Queen Square, WC1 3BG, London, United Kingdom
    Neuron 33:815-26. 2002
    ..Apart from OFC, these regions were not activated by reward receipt. The findings indicate that when rewards are predictable, brain regions recruited during expectation are, in part, dissociable from areas responding to reward receipt...
  22. ncbi request reprint Image distortion correction in fMRI: A quantitative evaluation
    Chloe Hutton
    Wellcome Department of Cognitive Neurology, Institute of Neurology, London WCIN 3BG, United Kingdom
    Neuroimage 16:217-40. 2002
    ..However, we suggest that the variance between successively measured field maps introduces additional unwanted variance in the voxel time-series and is therefore not adequate to correct for time-varying distortions...
  23. ncbi request reprint Functional heterogeneity in human olfactory cortex: an event-related functional magnetic resonance imaging study
    Jay A Gottfried
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London, WC1N 3BG, United Kingdom
    J Neurosci 22:10819-28. 2002
    ..They also show that brain regions mediating emotional processing are differentially activated by odor valence, providing evidence for a close anatomical coupling between olfactory and emotional processes...
  24. ncbi request reprint Dissociating valence of outcome from behavioral control in human orbital and ventral prefrontal cortices
    John O'Doherty
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, London WC1N 3BG, United Kingdom
    J Neurosci 23:7931-9. 2003
    ..These results suggest functional heterogeneity within the OFC, with a role for this region in representing stimulus-reward values, signaling changes in reinforcement contingencies and in behavioral control...
  25. ncbi request reprint 3D DT-MRI using a reduced-FOV approach and saturation pulses
    Jiun Jie Wang
    School of Medical Technology, ChangGung University, Taoyuan County, Taiwan
    Magn Reson Med 51:853-7. 2004
    ..This method enables DT measurements to be obtained with high isotropic spatial resolution and whole-brain coverage. To avoid ghosting artifacts, the data are combined in image space rather than in k-space...
  26. doi request reprint Evidence for segregated and integrative connectivity patterns in the human Basal Ganglia
    Bogdan Draganski
    Wellcome Trust Centre for Neuroimaging, Institute of Neurology, UCL, London WC1N 3BG, United Kingdom
    J Neurosci 28:7143-52. 2008
    ..We believe that this method can be used to examine pathophysiological concepts in a number of basal ganglia-related disorders...
  27. ncbi request reprint Dissociable roles of ventral and dorsal striatum in instrumental conditioning
    John O'Doherty
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK
    Science 304:452-4. 2004
    ..Our results suggest partly dissociable contributions of the ventral and dorsal striatum, with the former corresponding to the critic and the latter corresponding to the actor...
  28. pmc 3D MDEFT imaging of the human brain at 4.7 T with reduced sensitivity to radiofrequency inhomogeneity
    David L Thomas
    Wellcome Trust High Field MR Research Laboratory, Department of Medical Physics and Bioengineering, University College London, London WC1N 3AR, UK
    Magn Reson Med 53:1452-8. 2005
    ..7 T, resulting in high-quality T(1)-weighted images of the whole human brain at high field strength with uniform signal intensity and contrast, despite the presence of significant RF inhomogeneity...
  29. ncbi request reprint Selective averaging for the diffusion tensor measurement
    Jiun Jie Wang
    Department of Medical Imaging and Radiological Sciences, ChangGung University, Taoyuan County 333, Taiwan
    Magn Reson Imaging 23:585-90. 2005
    ..Differences were noticed between modulus and complex averaging in DTI quantification, but both showed reduced artifact and improved signal-to-noise ratio...
  30. ncbi request reprint Improvement of the image quality of T1-weighted anatomical brain scans
    Clare Howarth
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, 12 Queen Square, London WC1N 3BG, Great Britain, UK
    Neuroimage 29:930-7. 2006
    ..Furthermore, the presented methods for improving the image quality can be combined with other artefact reduction techniques...
  31. ncbi request reprint Cerebral vascular response to hypercapnia: determination with perfusion MRI at 1.5 and 3.0 Tesla using a pulsed arterial spin labeling technique
    Ulrike Nöth
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, London, UK
    J Magn Reson Imaging 24:1229-35. 2006
    ..Additionally, to improve GM CBF quantification a high-resolution GM-mask was applied...
  32. ncbi request reprint Representation of interaural time delay in the human auditory midbrain
    Sarah K Thompson
    Department of Physiology and UCL Ear Institute, University College London, 332 Gray s Inn Road, London WC1X 8EE, UK
    Nat Neurosci 9:1096-8. 2006
    ..The data require a new model for human ITD processing...
  33. pmc Vagus nerve stimulation for treatment-resistant depression: behavioral and neural effects on encoding negative material
    Hugo D Critchley
    Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, Queen Square, London, UK
    Psychosom Med 69:17-22. 2007
    ..We hypothesized that the antidepressant action of VNS may emerge through corrective influences on 'negativity bias' in memory. We therefore examined the impact of VNS on emotional memory and its underlying brain activity...