Quantitative assessment of blood flow, blood volume and blood oxygenation effects in functional magnetic resonance imaging

1998 ◽  
Vol 4 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Peter C.M. van Zijl ◽  
Scott M. Eleff ◽  
John A. Ulatowski ◽  
Joni M.E. Oja ◽  
Aziz M. Uluǧ ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Blood Volume ◽  
Quantitative Assessment ◽  
Blood Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

Functional Magnetic Resonance Imaging Measures of Blood Flow Patterns in the Human Auditory Cortex in Response to Sound

1998 ◽  
Vol 41 (3) ◽  
pp. 538-548 ◽  
Author(s):  
Sean C. Huckins ◽  
Christopher W. Turner ◽  
Karen A. Doherty ◽  
Michael M. Fonte ◽  
Nikolaus M. Szeverenyi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Speech Stimuli ◽  
Complex Stimuli ◽  
Scanning Session ◽  
Auditory Research

Functional Magnetic Resonance Imaging (fMRI) holds exciting potential as a research and clinical tool for exploring the human auditory system. This noninvasive technique allows the measurement of discrete changes in cerebral cortical blood flow in response to sensory stimuli, allowing determination of precise neuroanatomical locations of the underlying brain parenchymal activity. Application of fMRI in auditory research, however, has been limited. One problem is that fMRI utilizing echo-planar imaging technology (EPI) generates intense noise that could potentially affect the results of auditory experiments. Also, issues relating to the reliability of fMRI for listeners with normal hearing need to be resolved before this technique can be used to study listeners with hearing loss. This preliminary study examines the feasibility of using fMRI in auditory research by performing a simple set of experiments to test the reliability of scanning parameters that use a high resolution and high signal-to-noise ratio unlike that presently reported in the literature. We used consonant-vowel (CV) speech stimuli to investigate whether or not we could observe reproducible and consistent changes in cortical blood flow in listeners during a single scanning session, across more than one scanning session, and in more than one listener. In addition, we wanted to determine if there were differences between CV speech and nonspeech complex stimuli across listeners. Our study shows reproducibility within and across listeners for CV speech stimuli. Results were reproducible for CV speech stimuli within fMRI scanning sessions for 5 out of 9 listeners and were reproducible for 6 out of 8 listeners across fMRI scanning sessions. Results of nonspeech complex stimuli across listeners showed activity in 4 out of 9 individuals tested.

A Quantitative Physiologic Model of Blood Oxygenation for Functional Magnetic Resonance Imaging

1995 ◽  
Vol 30 (11) ◽  
pp. 669-682 ◽  
Author(s):  
GASSER M. HATHOUT ◽  
SANJIV S. GAMBHIR ◽  
RAMESH K. GOPI ◽  
KONRAD A.T. KIRLEW ◽  
YONG CHOI ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Blood Oxygenation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Physiologic Model

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.

Distinctive Cortical Articulatory Representation in Cleft Lip and Palate: A Preliminary Functional Magnetic Resonance Imaging Study

2006 ◽  
Vol 43 (5) ◽  
pp. 620-624 ◽  
Author(s):  
Hideo Shinagawa ◽  
Takashi Ono ◽  
Ei-ichi Honda ◽  
Tohru Kurabayashi ◽  
Atsushi Iriki ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Sensorimotor Cortex ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Blood Oxygenation ◽  
Cortical Representation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging

Objective: To investigate cortical representation of articulation of the bilabial plosive in patients with cleft lip and palate. Design: We examined cortical representation for /pa/-articulation in cleft lip and palate patients using blood oxygenation level–dependent functional magnetic resonance imaging. Subjects: Data from four postsurgical adult cleft lip and palate patients were compared with those from six healthy volunteers. Results: Activation foci were found in the bilateral primary sensorimotor cortex in all cleft lip and palate patients, as in the controls. The sensorimotor cortex ipsilateral to the side of cleft lip and palate showed greater activation in unilateral cleft lip and palate patients, whereas the sensorimotor cortex contralateral to the side on which cheiloplasty had been performed earlier showed greater activation in a bilateral cleft lip and palate patient. Conclusions: The results suggest that there may be an ipsilateral dominance in cortical representation during bilabial articulation to the side of the cleft in the upper lip.

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