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Volume 40, Issue 2, February 2013
The purpose of the authors study was to investigate a functional MRI (fMRI) technique with an ultrashort echo-time (UTE) sequence.Methods:
An UTE-based fMRI technique was applied to 17 young healthy volunteers during visual stimulations on a 3T MRI system. In addition, a blood oxygen level-dependent (BOLD) fMRI image was also obtained to compare functional changes in the brain. The one-samplet-test was performed to investigate increased or decreased signals during baseline and stimulation conditions for all subjects. Furthermore, regions-of-interest were placed by selecting one of the peak activated voxels from the UTE-based and BOLD data to investigate the level of signal changes on the time-course.Results:
During the visual activation period, the decreased signals were shown in the visual cortex for the UTE-based method, while both increased and decreased signals were found in the cortex for the BOLD method. The averaged signal changes for the UTE-based data were −0.48 ± 0.37% in the left lingual gyrus, while the changes on the BOLD data were 1.71 ± 0.87% in the right lingual gyrus.Conclusions:
The UTE-based fMRI technique can detect the neuronal activity corresponding to neuronal function. The UTE-based method should be able to improve spatial localization and has much lower sensitivity to field inhomogeneities. Therefore, UTE-based fMRI can be useful to the neurosciences and clinical populations.
DASSIM-RT is likely to become the method of choice over conventional IMRT and VMAT for delivery of highly conformal radiotherapy40(2013); http://dx.doi.org/10.1118/1.4773025View Description Hide Description