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Influence of diazepam on clinically designed FMRI
Linköping University, Department of Medical and Health Sciences, Radiology. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences.
Linköping University, Department of Neuroscience and Locomotion. Linköping University, Faculty of Health Sciences.
National Board of Forensic Sciences, Linköping.
Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Department of Medical and Health Sciences, Radiation Physics. Linköping University, Department of Medical and Health Sciences, Radiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Radiation Physics. Östergötlands Läns Landsting, Centre for Medical Imaging, Department of Radiology in Linköping.ORCID iD: 0000-0001-8661-2232
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2007 (English)In: The Journal of Neuropsychiatry and Clinical Neurosciences, ISSN 0895-0172, E-ISSN 1545-7222, Vol. 19, no 2, 164-172 p.Article in journal (Refereed) Published
Abstract [en]

The authors investigated the effect of diazepam on clinically relevant measures from functional magnetic resonance imaging (fMRI) examinations. Twenty volunteers were scanned twice. Using a double-blind randomized study design, the volunteers received placebo on one occasion, and on the other, 5 mg of diazepam. Three functional tests were used: motor, word generation, and working memory. Images were analyzed individually for each subject and the number of activated voxels and the laterality index were calculated. No significant effects related to the drug were detected. In contrast, the motor and working memory tasks showed a significant decrease in the number of activated voxels between Sessions 1 and 2, independently of diazepam administration. These results indicate that diazepam may be administered for premedication prior to fMRI investigations.

Place, publisher, year, edition, pages
2007. Vol. 19, no 2, 164-172 p.
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:liu:diva-17989DOI: 10.1176/appi.neuropsych.19.2.164ISI: 000245666300009PubMedID: 17431063OAI: oai:DiVA.org:liu-17989DiVA: diva2:213948
Available from: 2009-04-30 Created: 2009-04-30 Last updated: 2017-12-13Bibliographically approved
In thesis
1. Functional Magnetic Resonance Imaging for Clinical Diagnosis: Exploring and Improving the Examination Chain
Open this publication in new window or tab >>Functional Magnetic Resonance Imaging for Clinical Diagnosis: Exploring and Improving the Examination Chain
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Functional Magnetic Resonance Imaging (fMRI) is a relatively new imaging technique, first reported in 1992, which enables mapping of brain functions with high spatial resolution. Functionally active areas are distinguished by a small signal increase mediated by changes in local blood oxygenation in response to neural activity. The ability to non-invasively map brain function and the large number of MRI scanners quickly made the method very popular, and fMRI have had a huge impact on the study of brain function, both in healthy and diseased subjects.

The most common clinical application of fMRI is pre-surgical mapping of brain functions in order to optimise surgical interventions. The clinical fMRI examination procedure can be divided into four integrated parts: (1) patient preparation, (2) image acquisition, (3) image analysis and (4) clinical decision. In this thesis, important aspects of all parts of the fMRI examination procedure are explored with the aim to provide recommendations and methods for prosperous clinical usage of the technique.

The most important results of the thesis were: (I) administration of low doses of diazepam to reduce anxiety did not invalidate fMRI mapping results of primary motor and language areas, (II) the choice of visual stimuli equipment can have severe impact on the mapping of visual areas, (III) three-dimensional fMRI imaging sequences did not perform better than two-dimensional imaging sequences, (IV) adaptive spatial filtering can improve the fMRI data analysis, (V) clinical decisions should not be based on activation results from a single statistical threshold.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2009. 73 p.
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1121
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-18095 (URN)978-91-7393-645-3 (ISBN)
Public defence
2009-06-02, Majoren, Brigaden Restaurang & Konferens, Brigadgatan 17, 587 58 Linköping, Linköping, 09:15 (Swedish)
Opponent
Supervisors
Available from: 2009-05-06 Created: 2009-05-06 Last updated: 2014-10-02Bibliographically approved
2. Application of fMRI in clinical situations
Open this publication in new window or tab >>Application of fMRI in clinical situations
2006 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Since its discovery in the early 1990's functional MRI (fMRI) has become the most widely used technique for mapping of brain functions. Its non-invasiveness and the large number of MR-scanners have contributed to the popularity of fMRI. In recent years the interest in using fMRI as a clinical instrument has increased, primarily for pre-operative planning. The purpose of this work is to improve the applicability of fMRI to clinical situations.

In order to attain the objectives the capacity of analysis methods for fMRI was evaluated, design of paradigms to suit patients was looked into and the effects of an anxiolytic was investigated.

Especially when fMRI is used in the clinic it is crucial that the analysis method employed is sensitive and reliable. It was confirmed that the method developed by Friman et al. is a worthy competitor to other analysis methods. In general the abilities of patients are reduced compared with healthy volunteer subjects. Therefore one has to design the tasks and task instructions to be readily comprehensible. In addition it is not uncommon that patients are anxious before the examinations and the unfamiliar environment in the MR department. Some need a small dose of an anxiolytic to be able to undergo the examination. The effect of an anxiolytic on healthy volunteers was evaluated. No effects on the fMRI results was identified but the results were confounded by a large session effect.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2006. 83 p.
Series
Linköping Studies in Health Sciences. Thesis, ISSN 1100-6013 ; 76
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-36015 (URN)29386 (Local ID)91-85497-79-7 (ISBN)29386 (Archive number)29386 (OAI)
Presentation
2006-05-02, Wranne-salen, Hälsouniversitet, Linköping, 08:30 (Swedish)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2013-09-20

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Ragnehed, MattiasLundberg, PeterEngström, Maria

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Ragnehed, MattiasLundberg, PeterEngström, Maria
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RadiologyCenter for Medical Image Science and Visualization (CMIV)Faculty of Health SciencesDepartment of Neuroscience and LocomotionRadiation PhysicsDepartment of Radiation PhysicsDepartment of Radiology in LinköpingCenter for Medical Image Science and Visualization
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The Journal of Neuropsychiatry and Clinical Neurosciences
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