Brain functional BOLD perturbation modelling for forward fMRI and inverse mapping

نویسندگان

  • Zikuan Chen
  • Jennifer Robinson
  • Vince Calhoun
چکیده

PURPOSE To computationally separate dynamic brain functional BOLD responses from static background in a brain functional activity for forward fMRI signal analysis and inverse mapping. METHODS A brain functional activity is represented in terms of magnetic source by a perturbation model: χ = χ0 +δχ, with δχ for BOLD magnetic perturbations and χ0 for background. A brain fMRI experiment produces a timeseries of complex-valued images (T2* images), whereby we extract the BOLD phase signals (denoted by δP) by a complex division. By solving an inverse problem, we reconstruct the BOLD δχ dataset from the δP dataset, and the brain χ distribution from a (unwrapped) T2* phase image. Given a 4D dataset of task BOLD fMRI, we implement brain functional mapping by temporal correlation analysis. RESULTS Through a high-field (7T) and high-resolution (0.5mm in plane) task fMRI experiment, we demonstrated in detail the BOLD perturbation model for fMRI phase signal separation (P + δP) and reconstructing intrinsic brain magnetic source (χ and δχ). We also provided to a low-field (3T) and low-resolution (2mm) task fMRI experiment in support of single-subject fMRI study. Our experiments show that the δχ-depicted functional map reveals bidirectional BOLD χ perturbations during the task performance. CONCLUSIONS The BOLD perturbation model allows us to separate fMRI phase signal (by complex division) and to perform inverse mapping for pure BOLD δχ reconstruction for intrinsic functional χ mapping. The full brain χ reconstruction (from unwrapped fMRI phase) provides a new brain tissue image that allows to scrutinize the brain tissue idiosyncrasy for the pure BOLD δχ response through an automatic function/structure co-localization.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Using functional magnetic resonance imaging (fMRI) to explore brain function: cortical representations of language critical areas

Pre-operative determination of the dominant hemisphere for speech and speech associated sensory and motor regions has been of great interest for the neurological surgeons. This dilemma has been of at most importance, but difficult to achieve, requiring either invasive (Wada test) or non-invasive methods (Brain Mapping). In the present study we have employed functional Magnetic Resonance Imaging...

متن کامل

Inverse Mapping of BOLD fMRI: 4D Magnetic Susceptibility (χ) Tomography

Background: A brain magnetic state (in terms of magnetic susceptibility distribution χ) can be detected by T2*-weighted MRI (T2*MRI) undergoing a cascade of data transformations. The MRI transformations cause distortions (or spatial morphing), which may be undone by solving the inverse imaging or mapping problem. Upon having a dataset acquired from Blood Oxygenation Level-Dependent (BOLD) funct...

متن کامل

BRAIN MAPPING IN NEUROSURGERY

Background and Aim: Brain mapping is a study of the anatomy and function of the CNS (central nervous system). Brain mapping has many techniques and these techniques are permanently changing and updating. From the beginning, brain mapping was invasive and for brain mapping, electrical stimulation of the exposed brain was needed. However, nowadays brain mapping does not require electrical stimula...

متن کامل

Evaluation of Sensory Pathways in Spinal Cord by Comparison of fMRI Methodologies

Introduction: Today, clinicians and neuroscientists need to have a comprehensive survey of neurological pathologies and injuries. For the First-time, SEEP contrast and Spin-Echo pulse sequences was used for functional imaging of the Lumbar spinal cord. This method used by several research groups for Spinal cord mapping, but other researchers tried to improve BOLD fMRI to Spina...

متن کامل

Using functional magnetic resonance imaging (fMRI) to explore brain function: cortical representations of language critical areas

Pre-operative determination of the dominant hemisphere for speech and speech associated sensory and motor regions has been of great interest for the neurological surgeons. This dilemma has been of at most importance, but difficult to achieve, requiring either invasive (Wada test) or non-invasive methods (Brain Mapping). In the present study we have employed functional Magnetic Resonance Imaging...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 13  شماره 

صفحات  -

تاریخ انتشار 2018