The Effect of Hypercarbia and Hyperoxia on the Total Blood Flow to the Retina as Assessed by Magnetic Resonance Imaging

2011 ◽  
Vol 52 (9) ◽  
pp. 6867 ◽  
Author(s):  
Nasim Maleki ◽  
David C. Alsop ◽  
Weiying Dai ◽  
Christopher Hudson ◽  
Jay S. Han ◽  
...  
1998 ◽  
Vol 41 (3) ◽  
pp. 538-548 ◽  
Author(s):  
Sean C. Huckins ◽  
Christopher W. Turner ◽  
Karen A. Doherty ◽  
Michael M. Fonte ◽  
Nikolaus M. Szeverenyi

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.


Author(s):  
A.I. Zamiatina, M.V. Medvedev

A case of prenatal diagnosis of the corpus callosum lipoma at 32–33 weeks of gestation is presented. In a consultative examination, a hyperechoic formation with clear contours was found in the projection of the septum pellucidum, occupying the rostrum, genu, and truncus of corpus callosum, without signs of intratumorally blood flow in the color Doppler mapping mode. The prenatal diagnosis of "callosum lipoma" was established, confirmed after the birth of a child during magnetic resonance imaging.


Author(s):  
Bashair A. Alhummiany ◽  
David Shelley ◽  
Margaret Saysell ◽  
Maria‐Alexandra Olaru ◽  
Bernd Kühn ◽  
...  

2011 ◽  
Vol 6 (03) ◽  
pp. 203-206
Author(s):  
Toshio Honda ◽  
Mareomi Hamada ◽  
Yuji Matsumoto ◽  
Hiroshi Matsuoka ◽  
Kunio Hiwada

Sign in / Sign up

Export Citation Format

Share Document