A pyramid approach to subpixel registration based on intensity

Thévenaz, P.; Ruttimann, Urs E.; Unser, Michaël

doi:10.1109/83.650848

Cited by 2,784 publications

(2,077 citation statements)

References 48 publications

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“…Geometric distortion due to B0 field inhomogeneity was corrected for during reconstruction using a multi-echo reference scan [45]. Next, data were first co-registered and motion corrected using a pyramid iterative algorithm [46]. Finally, affne spatial transformation was used with the brain rotated into AC-PC coordinate frame and then linearly scaled into the Talairach reference frame prior to statistical analysis [47].…”

Section: Functional Mrimentioning

confidence: 99%

Comprehensive presurgical functional MRI language evaluation in adult patients with epilepsy

Szaflarski

Holland

Jacola

et al. 2008

Epilepsy & Behavior

113

137

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Functional magnetic resonance imaging (fMRI) has the potential to replace the intracarotid amobarbital procedure (IAP) in presurgical evaluation of patients with epilepsy patients. In this study, we compared fMRI verb generation (VG) and semantic decision/tone decision (SDTD) tasks and the IAP in their ability to localize language functions in patients with epilepsy undergoing presurgical evaluation. We enrolled 50 healthy controls to establish normal language activation patterns for VG and SDTD tasks at 3 or 4 T, and to design language regions of interest (ROIs) that were later applied to 38 patients with epilepsy (28 of 38 also underwent the IAP). We calculated laterality indices (LIs) for each task for each subject based on the ROIs, and we used general linear modeling to analyze the fMRI data. All healthy and epileptic subjects activated language areas with both fMRI tasks. We found significant correlations in language lateralization between the fMRI tasks (r = 0.495, P ≤ 0.001) and between VG and IAP (r = 0.652, P < 0.001) and SDTD and IAP (r = 0.735, P < 0.001). The differences in LIs between SDTD and VG tasks were small and not affected by age, gender, epilepsy status, handedness, or performance. SDTD and VG tasks combined explained approximately 58.4% in the variability of the IAP/language. In the general linear modeling, only the SDTD task significantly contributed to the determination of language lateralization in patients with epilepsy undergoing presurgical evaluation. Results indicate a moderate convergent validity between both fMRI language tasks and between IAP and fMRI tasks. The results of this study indicate that either of these fMRI tasks can be used for language lateralization in patients with epilepsy undergoing presurgical evaluation, but that the SDTD task is likely to provide more information regarding language lateralization than the VG task.

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Section: Functional Mrimentioning

confidence: 99%

Comprehensive presurgical functional MRI language evaluation in adult patients with epilepsy

Szaflarski

Holland

Jacola

et al. 2008

Epilepsy & Behavior

113

137

View full text Add to dashboard Cite

show abstract

“…The EPI images were corrected for geometrical distortion and Nyquist ghost artifacts using the multi-echo reference method (Schmithorst et al, 2001). The reconstructed EPI data were corrected for drift using quadratic baseline correction on a pixel-by-pixel basis (Hu et al, 1995;Le & Hu, 1996), co-registered to further reduce the effects of motion artifacts (Thevenaz & Unser, 1998), and transformed into Talairach coordinates (Talairach & Tournoux, 1988) using a linear affine transformation shown previously to be valid for individuals 5 to 18 years of age (Muzik & Chugani, 2000;Wilke et al, 2002).…”

Section: Fmri Data Acquisition and Analysesmentioning

confidence: 99%

Long-term neural processing of attention following early childhood traumatic brain injury: fMRI and neurobehavioral outcomes

Kramer

Chiu

Walz

et al. 2008

J Inter Neuropsych Soc

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Attentional deficits are common and significant sequelae of pediatric traumatic brain injury (TBI). However, little is known about how the underlying neural processes that support different components of attention are affected. The present study examined brain activation patterns using f MRI in a group of young children who sustained a TBI in early childhood (n 5 5; mean age 5 9.4), and a group of age-matched control children with orthopedic injuries (OI) (n 5 8) during a continuous performance task (CPT). Four children in the TBI group had moderate injuries, and one had a severe injury. Performance on the CPT task did not differ between groups. Both TBI and OI children activated similar networks of brain regions relevant to sustained attention processing, but the TBI group demonstrated several areas of significantly greater activation relative to controls, including frontal and parietal regions. These findings of over-activation of the relevant attention network in the TBI group contrast with those obtained in imaging studies of Attention-Deficit0Hyperactivity Disorder where under-activation of the attention network has been documented. This study provides evidence that young children's brains function differently following a traumatic brain injury, and that these differences persist for years after the injury. (JINS, 2008, 14, 424-435.)

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“…Subjects' head movements were minimized by instructing them to remain still and by packing foam padding around their heads. Images were corrected for motion using a pyramid coregistration technique without landmarks that measures mean square differences in intensity between a reference image and succeeding time point images (Thévenaz and Unser, 1998). After realignment, all data sets were reviewed as a cine loop for uncorrected movement and were to be removed from the study if motion was detected.…”

Section: Image Acquisitionmentioning

confidence: 99%

A Preliminary fMRI Study of Sustained Attention in Euthymic, Unmedicated Bipolar Disorder

Strakowski

Adler

Holland

et al. 2004

Neuropsychopharmacol

225

180

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The symptoms of bipolar disorder suggest dysfunction of anterior limbic networks that modulate emotional behavior and that reciprocally interact with dorsal attentional systems. Bipolar patients maintain a constant vulnerability to mood episodes even during euthymia, when symptoms are minimal. Consequently, we predicted that, compared with healthy subjects, bipolar patients would exhibit abnormal activation of regions of the anterior limbic network with corresponding abnormal activation of other cortical areas involved in attentional processing. In all, 10 unmedicated euthymic bipolar patients and 10 group-matched healthy subjects were studied with fMRI while performing the Continuous Performance Task-Identical Pairs version (CPT-IP). fMRI scans were obtained on a 3.0 T Bruker system using an echo planar imaging (EPI) pulse sequence, while subjects performed the CPT-IP and a control condition to contrast group differences in regional brain activation. The euthymic bipolar and healthy subjects performed similarly on the CPT-IP, yet showed significantly different patterns of brain activation. Specifically, bipolar patients exhibited increased activation of limbic, paralimbic, and ventrolateral prefrontal areas, as well as visual associational cortices. Healthy subjects exhibited relatively increased activation in fusiform gyrus and medial prefrontal cortex. In conclusion, these differences suggest that bipolar patients exhibit overactivation of anterior limbic areas with corresponding abnormal activation in visual associational cortical areas, permitting successful performance of an attentional task. Since the differences occurred in euthymia, they may represent trait, rather than state, abnormalities of brain function in bipolar disorder.

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A pyramid approach to subpixel registration based on intensity

Cited by 2,784 publications

References 48 publications

Comprehensive presurgical functional MRI language evaluation in adult patients with epilepsy

Comprehensive presurgical functional MRI language evaluation in adult patients with epilepsy

Long-term neural processing of attention following early childhood traumatic brain injury: fMRI and neurobehavioral outcomes

A Preliminary fMRI Study of Sustained Attention in Euthymic, Unmedicated Bipolar Disorder

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