Frahm, Jens

[["dc.bibliographiccitation.firstpage","1066"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Clinical Radiology"],["dc.bibliographiccitation.lastpage","1071"],["dc.bibliographiccitation.volume","69"],["dc.contributor.author","Fasshauer, Martin"],["dc.contributor.author","Joseph, Arun A."],["dc.contributor.author","Kowallick, Johannes Tammo"],["dc.contributor.author","Unterberg-Buchwald, Christine"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Voit, Dirk"],["dc.contributor.author","Steinmetz, M."],["dc.contributor.author","Staab, Wieland"],["dc.contributor.author","Schaetz, S."],["dc.contributor.author","Zhang, S."],["dc.contributor.author","Frahm, Jens"],["dc.contributor.author","Lotz, Joachim"],["dc.contributor.author","Sohns, J. M."],["dc.date.accessioned","2018-11-07T09:34:30Z"],["dc.date.available","2018-11-07T09:34:30Z"],["dc.date.issued","2014"],["dc.description.abstract","AIM: To evaluate the potential of real-time phase-contrast flow magnetic resonance imaging (MRI) at 40 ms resolution for the simultaneous determination of blood flow in the ascending aorta (AA) and superior vena cava (SVC) in response to reduced intrathoracic pressure (Mueller manoeuvre). MATERIALS AND METHODS: Through-plane flow was assessed in 20 healthy young subjects using real-time phase-contrast MRI based on highly undersampled radial fast low-angle shot (FLASH) with image reconstruction by regularized non-linear inversion. Haemodynamic alterations (three repetitions per subject = 60 events) were evaluated during normal breathing (10 s), inhalation with nearly closed epiglottis (10 s), and recovery (20 s). RESULTS: Relative to normal breathing and despite interindividual differences, reduced intrathoracic pressure by at least 30 mmHg significantly decreased the initial peak mean velocity (averaged across the lumen) in the AA by -24 +/- 9% and increased the velocity in the SVC by +28 +/- 25% (p < 0.0001, n = 23 successful events). Respective changes in flow volume per heartbeat were -25 +/- 9% in the AA and +49 +/- 44% in the SVC (p < 0.0001, n = 23). Flow parameters returned to baseline during sustained pressure reduction, while the heart rate was elevated by 10% (p < 0.0001) after the start (n = 24) and end (n = 17) of the manoeuvre. CONCLUSIONS: Real-time flow MRI during low intrathoracic pressure non-invasively revealed quantitative haemodynamic adjustments in both the AA and SVC. (C) 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved."],["dc.description.sponsorship","DFG [LO 1773/1]"],["dc.identifier.doi","10.1016/j.crad.2014.06.004"],["dc.identifier.isi","000342881800013"],["dc.identifier.pmid","25060931"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32184"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","W B Saunders Co Ltd"],["dc.relation.issn","1365-229X"],["dc.relation.issn","0009-9260"],["dc.title","Real-time phase-contrast flow MRI of haemodynamic changes in the ascending aorta and superior vena cava during Mueller manoeuvre"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","206"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Journal of Prosthetic Dentistry"],["dc.bibliographiccitation.lastpage","209"],["dc.bibliographiccitation.volume","119"],["dc.contributor.author","Krohn, Sebastian"],["dc.contributor.author","Frahm, Jens"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Wassmann, Torsten"],["dc.contributor.author","Joseph, Arun A."],["dc.contributor.author","Bürgers, Ralf"],["dc.date.accessioned","2021-06-01T10:49:53Z"],["dc.date.available","2021-06-01T10:49:53Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.1016/j.prosdent.2017.03.022"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/86447"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-425"],["dc.relation.issn","0022-3913"],["dc.title","Diagnosis of disk displacement using real-time MRI: Clinical report of two patients"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","82"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of Cerebral Blood Flow & Metabolism"],["dc.bibliographiccitation.lastpage","89"],["dc.bibliographiccitation.volume","31"],["dc.contributor.author","Dechent, Peter"],["dc.contributor.author","Schuetze, Gunther"],["dc.contributor.author","Helms, Gunther"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Frahm, Jens"],["dc.date.accessioned","2018-11-07T09:01:32Z"],["dc.date.available","2018-11-07T09:01:32Z"],["dc.date.issued","2011"],["dc.description.abstract","One of the characteristics of the blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) response to functional challenges of the brain is the poststimulation undershoot, which has been suggested to originate from a delayed recovery of either cerebral blood volume (CBV) or cerebral metabolic rate of oxygen to baseline. Using bolus-tracking MRI in humans, we recently showed that relative CBV rapidly normalizes after the end of stimulation. As this observation contradicts at least part of the blood-pool contrast agent studies performed in animals, we reinvestigated the CBV contribution by dynamic T1-weighted three-dimensional MRI (8 seconds temporal resolution) and Vasovist at 3T (12 subjects). Initially, we determined the time constants of individual BOLD responses. After injection of Vasovist, CBV-related T1-weighted signal changes revealed a signal increase during visual stimulation (1.7% +/- 0.4%), but no change relative to baseline in the poststimulation phase (0.2% +/- 0.3%). This finding renders the specific nature of the contrast agent unlikely to be responsible for the discrepancy between human and animal studies. With the assumption of normalized cerebral blood flow after stimulus cessation, a normalized CBV lends support to the idea that the BOLD MRI undershoot reflects a prolonged elevation of oxidative metabolism. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 82-89; doi:10.1038/jcbfm.2010.133; published online 25 August 2010"],["dc.identifier.doi","10.1038/jcbfm.2010.133"],["dc.identifier.isi","000285870700011"],["dc.identifier.pmid","20736964"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24451"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0271-678X"],["dc.title","Basal cerebral blood volume during the poststimulation undershoot in BOLD MRI of the human brain"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2225"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","European Journal of Radiology"],["dc.bibliographiccitation.lastpage","2230"],["dc.bibliographiccitation.volume","85"],["dc.contributor.author","Krohn, Sebastian"],["dc.contributor.author","Gersdorff, Nikolaus"],["dc.contributor.author","Wassmann, Torsten"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Joseph, Arun A."],["dc.contributor.author","Buergers, Ralf"],["dc.contributor.author","Frahm, Jens"],["dc.date.accessioned","2018-11-07T10:05:09Z"],["dc.date.available","2018-11-07T10:05:09Z"],["dc.date.issued","2016"],["dc.description.abstract","The purpose of this study was to develop and evaluate a novel method for real-time MRI of TMJ function at high temporal resolution and with two different contrasts. Real-time MRI was based on undersampled radial fast low angle shot (FLASH) acquisitions with iterative image reconstruction by regularized nonlinear inversion. Real-time MRI movies with T1 contrast were obtained with use of a radiofrequency-spoiled FLASH sequence, while movies with T2/T1 contrast employed a gradient-refocused FLASH version. TMJ function was characterized in 40 randomly selected volunteers by sequential 20 s acquisitions of both the right and left joint during voluntary opening and closing of the mouth (in a medial, central and lateral oblique sagittal section perpendicular to the long axis of the condylar head). All studies were performed on a commercial MRI system at 3 T using the standard head coil, while online reconstruction was achieved with a bypass computer fully integrated into the MRI system. As a first result, real-time MRI studies of the right and left TMJ were successfully performed in all 40 subjects (80 joints) within a total examination time per subject of only 15 min. Secondly, at an in-plane resolution of 0.75 mm and 5 mm section thickness, the achieved temporal resolution was 66.7 ms per image or 15 frames per second. Thirdly, both T1-weighted and T2/T1-weighted real-time MRI movies provided information about TMJ function such as disc position, condyle mobility and disc-condyle relationship. While T1 contrast offers a better delineation of structures during rapid jaw movements, T2/T1 contrast was rated superior for characterizing the articular disc. In conclusion, the proposed real-time MRI method may become a robust and efficient tool for the clinical assessment of TMJ function. (C) 2016 Elsevier Ireland Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.ejrad.2016.10.020"],["dc.identifier.isi","000389511400011"],["dc.identifier.pmid","27842671"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38846"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Ireland Ltd"],["dc.relation.issn","1872-7727"],["dc.relation.issn","0720-048X"],["dc.title","Real-time MRI of the temporomandibular joint at 15 frames per second-A feasibility study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1721"],["dc.bibliographiccitation.issue","14"],["dc.bibliographiccitation.journal","NeuroReport"],["dc.bibliographiccitation.lastpage","1725"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Baudewig, Jürgen"],["dc.contributor.author","Treue, Stefan"],["dc.contributor.author","Frahm, Jens"],["dc.date.accessioned","2022-10-06T13:35:26Z"],["dc.date.available","2022-10-06T13:35:26Z"],["dc.date.issued","2002"],["dc.identifier.doi","10.1097/00001756-200210070-00006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/116095"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-602"],["dc.relation.issn","0959-4965"],["dc.relation.orgunit","Deutsches Primatenzentrum"],["dc.title","Functional MRI of self-controlled stereoscopic depth perception"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","10"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Fluids and Barriers of the CNS"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Aktas, Gökmen"],["dc.contributor.author","Kollmeier, Jost M."],["dc.contributor.author","Joseph, Arun A."],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Ludwig, Hans-Christoph"],["dc.contributor.author","Gärtner, Jutta"],["dc.contributor.author","Frahm, Jens"],["dc.contributor.author","Dreha-Kulaczewski, Steffi"],["dc.date.accessioned","2019-07-09T11:50:48Z"],["dc.date.available","2019-07-09T11:50:48Z"],["dc.date.issued","2019"],["dc.description.abstract","Background Respiration-induced pressure changes represent a powerful driving force of CSF dynamics as previously demonstrated using flow-sensitive real-time magnetic resonance imaging (MRI). The purpose of the present study was to elucidate the sensitivity of CSF flow along the spinal canal to forced thoracic versus abdominal respiration. Methods Eighteen subjects without known illness were studied using real-time phase-contrast flow MRI at 3 T in the aqueduct and along the spinal canal at levels C3, Th1, Th8 and L3. Subjects performed a protocol of forced breathing comprising four cycles of 2.5 s inspiration and 2.5 s expiration. Results The quantitative results for spinal CSF flow rates and volumes confirm previous findings of an upward movement during forced inspiration and reversed downward flow during subsequent exhalation—for both breathing types. However, the effects were more pronounced for abdominal than for thoracic breathing, in particular at spinal levels Th8 and L3. In general, CSF net flow volumes were very similar for both breathing conditions pointing upwards in all locations. Conclusions Spinal CSF dynamics are sensitive to varying respiratory performances. The different CSF flow volumes in response to deep thoracic versus abdominal breathing reflect instantaneous adjustments of intrathoracic and intraabdominal pressure, respectively. Real-time MRI access to CSF flow in response to defined respiration patterns will be of clinical importance for patients with disturbed CSF circulation like hydrocephalus, pseudotumor cerebri and others."],["dc.identifier.doi","10.1186/s12987-019-0130-0"],["dc.identifier.pmid","30947716"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59832"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Spinal CSF flow in response to forced thoracic and abdominal respiration"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","461"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Imaging in Medicine"],["dc.bibliographiccitation.lastpage","476"],["dc.bibliographiccitation.volume","4"],["dc.contributor.author","Uecker, Martin"],["dc.contributor.author","Zhang, Shuo"],["dc.contributor.author","Voit, Dirk"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Frahm, Jens"],["dc.date.accessioned","2017-09-07T11:54:24Z"],["dc.date.available","2017-09-07T11:54:24Z"],["dc.date.issued","2012"],["dc.identifier.doi","10.2217/iim.12.32"],["dc.identifier.gro","3145161"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2866"],["dc.notes.intern","Crossref Import"],["dc.notes.status","public"],["dc.publisher","Future Medicine Ltd"],["dc.relation.issn","1755-5191"],["dc.relation.issn","1755-5205"],["dc.title","Real-time MRI: recent advances using radial FLASH"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Open Medical Imaging Journal"],["dc.bibliographiccitation.lastpage","5"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","Frahm, Jens"],["dc.contributor.author","Schätz, Sebastian"],["dc.contributor.author","Untenberger, Markus"],["dc.contributor.author","Zhang, Shuo"],["dc.contributor.author","Voit, Dirk"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Sohns, Jan Martin"],["dc.contributor.author","Lotz, Joachim"],["dc.contributor.author","Uecker, Martin"],["dc.date.accessioned","2017-09-07T11:54:24Z"],["dc.date.available","2017-09-07T11:54:24Z"],["dc.date.issued","2014"],["dc.identifier.doi","10.2174/1874347101408010001"],["dc.identifier.gro","3145160"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2865"],["dc.notes.intern","Crossref Import"],["dc.notes.status","public"],["dc.publisher","Bentham Science Publishers Ltd."],["dc.relation.issn","1874-3471"],["dc.title","On the Temporal Fidelity of Nonlinear Inverse Reconstructions for Real- Time MRI – The Motion Challenge"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","189"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Restorative Neurology and Neuroscience"],["dc.bibliographiccitation.lastpage","197"],["dc.bibliographiccitation.volume","27"],["dc.contributor.author","von Lewinski, Friederike"],["dc.contributor.author","Hofer, Sabine"],["dc.contributor.author","Kaus, Juergen"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Rothkegel, Holger"],["dc.contributor.author","Schweizer, Renate"],["dc.contributor.author","Liebetanz, David"],["dc.contributor.author","Frahm, Jens"],["dc.contributor.author","Paulus, Walter J."],["dc.date.accessioned","2018-11-07T08:35:28Z"],["dc.date.available","2018-11-07T08:35:28Z"],["dc.date.issued","2009"],["dc.description.abstract","Purpose: EMG-triggered electrostimulation (EMG-ES) may improve the motor performance of affected limbs of hemiparetic stroke patients even in the chronic stage. This study was designed to characterize cortical activation changes following intensified EMG-ES in chronic stroke patients and to identify predictors for successful rehabilitation depending on disease severity. Methods: We studied 9 patients with severe residual hemiparesis, who underwent 8 weeks of daily task-orientated multi-channel EMG-ES of the paretic arm. Before and after treatment, arm function was evaluated clinically and cortical activation patterns were assessed with functional MRI (fMRI) and/or transcranial magnetic stimulation (TMS). Results: As response to therapy, arm function improved in a subset of patients with more capacity in less affected subjects, but there was no significant gain for those with Box & Block test values below 4 at inception. The clinical improvement, if any, was accompanied by an ipsilesional increase in the sensorimotor cortex (SMC) activation area in fMRI and enhanced intracortical facilitation (ICF) as revealed by paired TMS. The SMC activation change in fMRI was predicted by the presence or absence of motor-evoked potentials (MEPs) on the affected side. Conclusions: The present findings support the notion that intensified EMG-ES may improve the arm function in individual chronic hemiparetic stroke patients but not in more severely impaired individuals. Functional improvements are paralleled by increased ipsilesional SMC activation and enhanced ICF supporting neuroplasticity as contributor to rehabilitation. The clinical score at inception and the presence of MEPs have the best predictive potential."],["dc.identifier.doi","10.3233/RNN-2009-0469"],["dc.identifier.isi","000267763500004"],["dc.identifier.pmid","19531874"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/18074"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Ios Press"],["dc.relation.issn","0922-6028"],["dc.title","Efficacy of EMG-triggered electrical arm stimulation in chronic hemiparetic stroke patients"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","398"],["dc.bibliographiccitation.journal","Neuromuscular Disorders"],["dc.bibliographiccitation.lastpage","407"],["dc.contributor.author","Bartels, Claudia"],["dc.contributor.author","Mertens, Nina"],["dc.contributor.author","Hofer, Sabine"],["dc.contributor.author","Merboldt, Klaus-Dietmar"],["dc.contributor.author","Dietrich, Jeannine"],["dc.contributor.author","Frahm, Jens"],["dc.contributor.author","Ehrenreich, Hannelore"],["dc.date.accessioned","2017-09-07T11:46:20Z"],["dc.date.available","2017-09-07T11:46:20Z"],["dc.date.issued","2008"],["dc.description.abstract","We investigated the frequency and functional relevance of corpus callosum degeneration in amyotrophic lateral sclerosis (ALS). A total of 22 ALS patients and 29 healthy controls performed the newly developed Contralateral Co-Movement Test as indicator of callosal dysfunction. Diffusion tensor imaging was applied to determine fractional anisotropy values in the callosal area containing the crossing motor fibers and in the pyramidal tracts in 13 subjects of each group.ALS patients had more than twice the amount of co-movements as compared to healthy subjects. Contralateral co-movements correlated with fractional anisotropy values of the corpus callosum motor region as did ALS Functional Rating Scale as measure of disease progression. In both groups, contralateral co-movements correlated with the central motor index (ratio of the mean of fractional anisotropy values of both pyramidal tracts and corpus callosum motor region). Neuropsychological test results failed to show correlations with functional or morphological parameters.Combining Contralateral Co-Movement Test and diffusion tensor imaging in ALS revealed the close relation between functional and morphological impairment in the degenerating central motor-neuronal network. The Contralateral Co-Movement Test delivers simple means of symptom quantification, independent of ALS Functional Rating Scale, for future neuroprotective trials."],["dc.identifier.doi","10.1016/j.nmd.2008.02.005"],["dc.identifier.gro","3150478"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7247"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.title","Callosal dysfunction in amyotrophic lateral sclerosis correlates with diffusion tensor imaging of the central motor system"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]