A quantitative comparison of BOLD fMRI responses to noxious and innocuous stimuli in the human spinal cord

A combination of functional magnetic resonance imaging and diffusion tensor image to explore structure–function relationship in healthy and myelopathic spinal cord

“…The result showed that BOLD signal change in response to bilateral sensory stimulation was significantly higher than unilateral stimulation in healthy and myelopathic cord. The BOLD signal change in healthy cord (5.1%-5.5%) was consistent with the earlier reports, 18,20 whereas the signal change in myelopathic cord (6.5%-7.9%) was significantly higher than that in healthy cord. Earlier studies have reported that there was enhanced activation in diseased 35 or injured cord 36 in comparison with healthy cord.…”

“…32 The time series were band-pass filtered (0.05-0.5 Hz), and no spatial smoothing was performed due to the limited dimensions of the spinal cord and the expected extent. 20 Active voxels were identified as those having P<0.0025 (uncorrected), which were consistent with the earlier fMRI in the cervical spinal cord. 33 The mean MRI signal change at each time point of active voxels was obtained to generate the whole time course of the hemodynamic response to the neuronal activity in the spinal cord.…”

“…Compared with brain, the threshold used for spinal fMRI analysis was relatively lower, where Z value ranged from 1.6 to 3.1. 12,15,17,20,32,33 In consideration of 256 volumes acquired in each run, the threshold for identifying the active voxels in our study is much stricter than those thresholds used in earlier spinal BOLD fMRI studies. In this study, the stimulation block applied to the left hand, right hand, and bilateral hand was designed to be given in a pseudorandom order.…”

“…[9][10][11] Functional MRI (fMRI) with blood oxygen level dependent (BOLD) is playing a primary role in neuroscience study. A number of studies with spinal cord BOLD fMRI have explored neuronal activation induced by motor tasks [12][13][14][15][16] or sensory stimuli [17][18][19][20] in healthy as well as injured spinal cord. 21 Some studies combining BOLD fMRI and diffusion tensor MRI were conducted in the brain to detect the relationship between functional activation and structural integrity.…”

Robust preprocessing for stimulus-based functional MRI of the moving fetus

“…There exist some automatic tools of evaluating volume outliers, including AFNI (3dTqual) and FSL (fsl_motion_outliers). [39][40][41] However, these tools do not adequately address small subject motion as well as the temporal variation of BOLD signals since volume outliers are detected based on spatial correlation between a motion-corrected volume and the template. In this section, we propose a method for VOR, using a probabilistic approach based on the temporal outliers of BOLD time series, which is optimized to be robust for temporal variation of signals.…”