Brain activation measured using functional magnetic resonance imaging during the Tower of London task

2006 ◽  
Vol 18 (5) ◽  
pp. 216-225 ◽  
Author(s):  
Inge-Andre Rasmussen ◽  
Ida Kristin Antonsen ◽  
Erik Magnus Berntsen ◽  
Jian Xu ◽  
Jim Lagopoulos ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Brain Activation ◽  
Healthy Control Group ◽  
Control Group ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Tower Of London ◽  
Healthy Control

Background:Individuals with traumatic brain injury (TBI) often suffer from a number of enduring cognitive impairments such as in attention, memory, speed of processing information and dual-task performance.Objective:The aim of this study was to assess the patterns of regional brain activation in response to the Tower of London (ToL) task in a group of patients suffering from chronic TBI using functional magnetic resonance imaging (fMRI).Methods:fMRI was performed during performance of the ToL planning task in 10 patients suffering from severe TBI and in 10 age- and sex-matched controls using a 3 T magnetic resonance scanner.Results:Performance data showed no difference in response accuracy between the TBI group and the healthy control group. Statistical parametric brain maps showed that the TBI group activates larger and additional areas of the cerebral cortex than the healthy control group both for tasks and for a subtraction contrast between the tasks.Conclusions:The results of this study are interpreted as a cortical reorganization inside the executive system of vigilance and working memory in patients with TBI. Both parietal and frontal areas are recruited to compensate for damaged brain tissue.

Subanesthetic Isoflurane Affects Task-induced Brain Activation in a Highly Specific Manner

2001 ◽  
Vol 94 (6) ◽  
pp. 973-981 ◽  
Author(s):  
Wolfgang Heinke ◽  
Christian Schwarzbauer
Keyword(s):  
Magnetic Resonance Imaging ◽  
Neural Networks ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Brain Activation ◽  
Control Group ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Experimental Conditions ◽  
Isoflurane Group

Background Functional magnetic resonance imaging of blood oxygenation level-dependent signal changes offers a very promising approach to investigate activated neural networks during anesthesia. Methods Sixteen healthy male volunteers, assigned into two groups of eight subjects (isoflurane group, control group), were investigated by functional magnetic resonance imaging during different experimental conditions. The isoflurane group successively breathed air (baseline condition), isoflurane in air (0.42 vol% inspiratory; isoflurane condition) and air again (recovery condition) while performing a visual search task, whereas the control group breathed air during all experimental conditions. Functional magnetic resonance images were acquired during the entire experimental session. In addition, reaction times and error rates were recorded. Results A significant isoflurane-related decrease (z > 3.1 corresponding to P < 0.001) in task-induced brain activation was found in three distinct cortical regions: the right anterio-superior insula (Talairach coordinates: x = 32, y = 22, z = 8) and the banks of the left and right intraparietal sulcus (Talairach coordinates: x = -34, y = -36, z = 32; x = 22, y = -60, z = 41, respectively). Subcortical structures (lateral geniculate nucleus) and the primary cortices (motor cortex, visual cortex) were not affected. All measured parameters indicated a nearly complete recovery of the affected networks within 5 min. Conclusions Our findings indicate that subanesthetic isoflurane affected task-induced activation in specific neural networks rather than causing a global decrease in functional activation.

Heartburn Perception and Brain Activation in Non-Erosive Reflux Disease Patients Evaluated by Functional Magnetic Resonance Imaging

2011 ◽  
Vol 140 (5) ◽  
pp. S-154-S-155
Author(s):  
Cassiano M. Forcelini ◽  
José Carlos Tomiozzo ◽  
Ricard Farré ◽  
Sidia M. Callegari-Jacques ◽  
Marcelo Ribeiro ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Reflux Disease ◽  
Brain Activation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

scholarly journals A Functional Magnetic Resonance Imaging Technique Based on Nulling Extravascular Gray Matter Signal

2008 ◽  
Vol 29 (1) ◽  
pp. 144-156 ◽  
Author(s):  
Yuji Shen ◽  
Risto A Kauppinen ◽  
Rishma Vidyasagar ◽  
Xavier Golay
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Gray Matter ◽  
Visual Stimulation ◽  
Brain Activation ◽  
Blood Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Fmri Signal

A new functional magnetic resonance imaging (fMRI) technique is proposed based on nulling the extravascular gray matter (GM) signal, using a spatially nonselective inversion pulse. The remaining MR signal provides cerebral blood volume (CBV) information from brain activation. A theoretical framework is provided to characterize the sources of GM-nulled (GMN) fMRI signal, effects of partial voluming of cerebrospinal fluid (CSF) and white matter, and behaviors of GMN fMRI signal during brain activation. Visual stimulation paradigm was used to explore the GMN fMRI signal behavior in the human brain at 3T. It is shown that the GMN fMRI signal increases by 7.2% ± 1.5%, which is two to three times more than that obtained with vascular space occupancy (VASO)-dependent fMRI (−3.2% ± 0.2%) or blood oxygenation level-dependent (BOLD) fMRI (2.9% ± 0.7%), using a TR of 3,000 ms and a resolution of 2 × 2 × 5 mm3. Under these conditions the fMRI signal-to-noise ratio (SNRfMRI) for BOLD, GMN, and VASO images was 4.97 ± 0.76, 4.56 ± 0.86, and 2.43 ± 1.06, respectively. Our study shows that both signal intensity and activation volume in GMN fMRI depend on spatial resolution because of partial voluming from CSF. It is shown that GMN fMRI is a convenient tool to assess CBV changes associated with brain activation.

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