Deutsch
 
Hilfe Datenschutzhinweis Impressum
  DetailsucheBrowse

Datensatz

 
 
DownloadE-Mail
  Single-shot compensation of image distortions and BOLD contrast optimization using multi-echo EPI for real-time fMRI

Weiskopf, N., Klose, U., Birbaumer, N., & Mathiak, K. (2005). Single-shot compensation of image distortions and BOLD contrast optimization using multi-echo EPI for real-time fMRI. NeuroImage, 24(4), 1068-1079. doi:10.1016/j.neuroimage.2004.10.012.

Item is

Basisdaten

einblenden: ausblenden:
Genre: Zeitschriftenartikel

Externe Referenzen

einblenden:

Urheber

einblenden:
ausblenden:
 Urheber:
Weiskopf, Nikolaus1, 2, 3, Autor           
Klose, Uwe2, Autor
Birbaumer, Niels1, 4, Autor
Mathiak, Klaus5, Autor
Affiliations:
1Institute of Medical Psychology and Behavioral Neurobiology, Eberhard Karls University Tübingen, Germany, ou_persistent22              
2Section of Experimental MR of the CNS, Department of Radiology, Eberhard Karls University Tübingen, Germany, ou_persistent22              
3Wellcome Trust Centre for Neuroimaging, University College London, United Kingdom, ou_persistent22              
4Center for Mind/Brain Sciences, University of Trento, Italy, ou_persistent22              
5Department of Neurology and Stroke, Hertie-Institute for Clinical Brain Research, Eberhard Karls University Tübingen, Germany, ou_persistent22              

Inhalt

einblenden:
ausblenden:
Schlagwörter: Distortion correction; Echo-planar imaging; EPI; Functional magnetic resonance imaging; fMRI; Real-time; Single-shot; BOLD; Sensitivity; Multi-echo; Multi-image
 Zusammenfassung: Functional magnetic resonance imaging (fMRI) is most commonly based on echo-planar imaging (EPI). With higher field strengths, gradient performance, and computational power, real-time fMRI has become feasible; that is, brain activation can be monitored during the ongoing scan. However, EPI suffers from geometric distortions due to inhomogeneities of the magnetic field, especially close to air-tissue interfaces. Thus, functional activations might be mislocalized and assigned to the wrong anatomical structures. Several techniques have been reported which reduce geometric distortions, for example, mapping of the static magnetic field B(0) or the point spread function for all voxels. Yet these techniques require additional reference scans and in some cases extensive computational time. Moreover, only static field inhomogeneities can be corrected, because the correction is based on a static reference scan. We present an approach which allows for simultaneous acquisition and distortion correction of a functional image without a reference scan. The technique is based on a modified multi-echo EPI data acquisition scheme using a phase-encoding (PE) gradient with alternating polarity. The images exhibit opposite distortions due to the inverted PE gradient. After adjusting the contrast of the images acquired at different echo times, this information is used for the distortion correction. We present the theory, implementation, and applications of this single-shot distortion correction. Significant reduction in geometric distortion is shown both for phantom images and human fMRI data. Moreover, sensitivity to the blood oxygen level-dependent (BOLD) effect is increased by weighted summation of the undistorted images.

Details

einblenden:
ausblenden:
Sprache(n): eng - English
 Datum: 2004-08-172004-04-242004-10-082004-12-082005-02-15
 Publikationsstatus: Erschienen
 Seiten: -
 Ort, Verlag, Ausgabe: -
 Inhaltsverzeichnis: -
 Art der Begutachtung: Expertenbegutachtung
 Identifikatoren: DOI: 10.1016/j.neuroimage.2004.10.012
 Art des Abschluß: -

Veranstaltung

einblenden:

Entscheidung

einblenden:

Projektinformation

einblenden:

Quelle 1

einblenden:
ausblenden:
Titel: NeuroImage
Genre der Quelle: Zeitschrift
 Urheber:
Affiliations:
Ort, Verlag, Ausgabe: -
Seiten: - Band / Heft: 24 (4) Artikelnummer: - Start- / Endseite: 1068 - 1079 Identifikator: ISSN: 1053-8119
CoNE: https://pure.mpg.de/cone/journals/resource/954922650166