Position-history and spin-history artifacts in fMRI time-series

L Muresan*, R Renken, JBTM Roerdink, H Duifhuis

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

    9 Citations (Scopus)

    Abstract

    What is the impact of the spin history and position history on signal intensity after the alignment of acquired volumes? This question arises in many fMRI studies. We will focus on spin-history artefacts generated by the position-history of the scanned object. In fMRI an object is driven to steady state by applying a few dummy scans at the start of each measurement. A change in object position will disrupt the tissue's steady state magnetization. The disruption will propagate to the next few acquired volumes until a steady state is reached again. The variables which are involved in changing the longitudinal magnetization are: the shape and the position of the slice profiles, the times at which RF pulses occurred, the equilibrium magnetization map and the T, map. Knowledge of these variables enables the prediction of those situations and the locations where the spin-history may compromise the fMRI analysis. In this paper we present a simulation of spin-history artefacts. The simulation shows that these effects, following a displacement, are similar to the transient period at the beginning of the measurement. Introducing gaps between the acquired slices increases these artefacts.

    Original languageEnglish
    Title of host publicationMEDICAL IMAGING 2002: PHYSIOLOGY AND FUNCTION FROM MULTIDIMENSIONAL IMAGES
    EditorsAN Clough, CT Chen
    Place of PublicationBELLINGHAM
    PublisherSPIE - INT SOC OPTICAL ENGINEERING
    Pages444-451
    Number of pages8
    ISBN (Print)0-8194-4428-6
    Publication statusPublished - 2002
    EventMedical Imaging 2002 Conference - , Canada
    Duration: 24-Feb-200228-Feb-2002

    Publication series

    NamePROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE)
    PublisherSPIE-INT SOC OPTICAL ENGINEERING
    Volume4683
    ISSN (Print)0277-786X

    Other

    OtherMedical Imaging 2002 Conference
    CountryCanada
    Period24/02/200228/02/2002

    Keywords

    • artefacts
    • fMRI
    • position-history
    • spin-history
    • steady state
    • EMPIRICAL ANALYSES
    • MOTION CORRECTION
    • NULL-HYPOTHESIS
    • FUNCTIONAL MRI
    • REALIGNMENT
    • STATISTICS

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