Research Topics
| R DeichmannSummaryAffiliation: University College London Country: UK Publications
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Detail Information
Publications
Echo time dependence of BOLD contrast and susceptibility artifactsMaria 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)...- Optimal EPI parameters for reduction of susceptibility-induced BOLD sensitivity losses: a whole-brain analysis at 3 T and 1.5 TNikolaus 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... - Optimisation of the 3D MDEFT sequence for anatomical brain imaging: technical implications at 1.5 and 3 TR 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... - Fast high-resolution T1 mapping of the human brainRalf 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... - RF inhomogeneity compensation in structural brain imagingR 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... - Optimized RF excitation for anatomical brain imaging of the occipital lobe using the 3D MDEFT sequence and a surface transmit coilRalf 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... - Fast structural brain imaging using an MDEFT sequence with a FLASH-EPI hybrid readoutR Deichmann
Wellcome Department of Imaging Neuroscience, Institute of Neurology, 12 Queen Square, London WC1N 3BG, UK
Neuroimage 33:1066-71. 2006.... - Optimized EPI for fMRI studies of the orbitofrontal cortexR 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... - Compensation of susceptibility-induced BOLD sensitivity losses in echo-planar fMRI imagingR 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... - Removing the effects of CSF partial voluming on fitted CBF and arterial transit times using FAIR, a pulsed arterial spin labelling techniqueJ 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... - Real-time functional magnetic resonance imaging: methods and applicationsNikolaus Weiskopf
Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, WC1N 3BG London, UK
Magn Reson Imaging 25:989-1003. 2007.... 
Voxel-based cortical thickness measurements in MRIChloe 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...- Concurrent TMS-fMRI and psychophysics reveal frontal influences on human retinotopic visual cortexChristian C Ruff
UCL Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AR, United Kingdom
Curr Biol 16:1479-88. 2006.... - A method for improving the performance of gradient systems for diffusion-weighted MRIZoltan 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... - Mapping of the cerebral vascular response to hypoxia and hypercapnia using quantitative perfusion MRI at 3 TUlrike 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... - Optimized EPI for fMRI studies of the orbitofrontal cortex: compensation of susceptibility-induced gradients in the readout directionNikolaus 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... - Distinct causal influences of parietal versus frontal areas on human visual cortex: evidence from concurrent TMS-fMRIChristian 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... - Non-invasive mapping of corticofugal fibres from multiple motor areas--relevance to stroke recoveryJennifer 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... - The cutaneous rabbit illusion affects human primary sensory cortex somatotopicallyFelix 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... - Eye-specific effects of binocular rivalry in the human lateral geniculate nucleusJohn 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... - Neural responses during anticipation of a primary taste rewardJOHN 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... - Image distortion correction in fMRI: A quantitative evaluationChloe 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... - Functional heterogeneity in human olfactory cortex: an event-related functional magnetic resonance imaging studyJay 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... - Dissociating valence of outcome from behavioral control in human orbital and ventral prefrontal corticesJohn 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... - 3D DT-MRI using a reduced-FOV approach and saturation pulsesJiun 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... 
Evidence for segregated and integrative connectivity patterns in the human Basal GangliaBogdan 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...- Dissociable roles of ventral and dorsal striatum in instrumental conditioningJohn 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... - 3D MDEFT imaging of the human brain at 4.7 T with reduced sensitivity to radiofrequency inhomogeneityDavid 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... - Selective averaging for the diffusion tensor measurementJiun 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... - Improvement of the image quality of T1-weighted anatomical brain scansClare 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... - Cerebral vascular response to hypercapnia: determination with perfusion MRI at 1.5 and 3.0 Tesla using a pulsed arterial spin labeling techniqueUlrike 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... - Representation of interaural time delay in the human auditory midbrainSarah 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... - Vagus nerve stimulation for treatment-resistant depression: behavioral and neural effects on encoding negative materialHugo 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...