The Significance of Echo Time in fMRI BOLD Contrast: A Clinical Study during Motor and Visual Activation Tasks at 1.5 T
| Autor: | Despina Antypa, T. Boursianis, G Gourzoulidis, Apostolos H. Karantanas, Thomas G. Maris, Panagiotis G. Simos, Emmanouela Kosteletou, Efrosini Papadaki, G. Kalaitzakis, Katerina Nikiforaki, Kostas Marias |
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| Rok vydání: | 2021 |
| Předmět: |
fMRI/motor activation
media_common.quotation_subject Computer applications to medicine. Medical informatics R858-859.7 Hemodynamics computer.software_genre Somatosensory system echo time Article 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Nuclear magnetic resonance Voxel medicine Contrast (vision) Humans T2* measurement Radiology Nuclear Medicine and imaging media_common Visual Cortex Physics Blood-oxygen-level dependent Echo time Motor Cortex Neurochemistry Mr imaging Magnetic Resonance Imaging medicine.anatomical_structure fMRI/visual activation computer 030217 neurology & neurosurgery Motor cortex MR imaging BOLD |
| Zdroj: | Tomography Volume 7 Issue 3 Pages 30-343 Tomography, Vol 7, Iss 30, Pp 333-343 (2021) |
| ISSN: | 2379-139X |
| Popis: | Blood Oxygen Level Dependent (BOLD) is a commonly-used MR imaging technique in studying brain function. The BOLD signal can be strongly affected by specific sequence parameters, especially in small field strengths. Previous small-scale studies have investigated the effect of TE on BOLD contrast. This study evaluates the dependence of fMRI results on echo time (TE) during concurrent activation of the visual and motor cortex at 1.5 T in a larger sample of 21 healthy volunteers. The experiment was repeated using two different TE values (50 and 70 ms) in counterbalanced order. Furthermore, T2* measurements of the gray matter were performed. Results indicated that both peak beta value and number of voxels were significantly higher using TE = 70 than TE = 50 ms in primary motor, primary somatosensory and supplementary motor cortices (p < 0.007). In addition, the amplitude of activation in visual cortices and the dorsal premotor area was also higher using TE = 70 ms (p < 0.001). Gray matter T2* of the corresponding areas did not vary significantly. In conclusion, the optimal TE value (among the two studied) for visual and motor activity is 70 ms affecting both the amplitude and extent of regional hemodynamic activation. |
| Databáze: | OpenAIRE |
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