Towards whole-cortex enhancement with a ultrahigh dielectric constant helmet at 3T
| Autor: | Navid P. Gandji, Sebastian Rupprecht, Matthew T. Lanagan, Qing X. Yang, Christopher T. Sica, Michael T. Lanagan, Ryan J. Hou |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Radio Waves Neuroimaging Dielectric Signal-To-Noise Ratio Article Patient Positioning 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Histogram Homogeneity (physics) Image Processing Computer-Assisted Humans Radiology Nuclear Medicine and imaging Computer Simulation High-κ dielectric Cerebral Cortex Brain Mapping Human head Phantoms Imaging Power deposition Electromagnetic Radiation Specific absorption rate Brain Reproducibility of Results equipment and supplies Magnetic Resonance Imaging Healthy Volunteers Electromagnetic coil Female 030217 neurology & neurosurgery Algorithms Biomedical engineering |
| Zdroj: | Magn Reson Med |
| Popis: | Purpose To present a 3T brain imaging study using a conformal prototype helmet constructed with an ultra-high dielectric constant (uHDC; er ~ 1000) materials that can be inserted into standard receive head-coils. Methods A helmet conformal to a standard human head constructed with uHDC materials was characterized through electromagnetic simulations and experimental work. The signal-to-noise ratio (SNR), transmit efficiency, and power deposition with the uHDC helmet inserted within a 20-channel head coil were measured in vivo and compared with a 64-channel head coil and the 20-channel coil without the helmet. Seven healthy volunteers were analyzed. Results Simulation and in vivo experimental results showed that transmit efficiency was improved by nearly 3 times within localized regions for a quadrature excitation, with a measured global increase of 58.21 ± 6.54% over 7 volunteers. The use of a parallel transmit spokes pulse compensated for severe degradation of B 1 + homogeneity, at the expense of higher global and local specific absorption rate levels. A SNR histogram analysis with statistical testing demonstrated that the uHDC helmet enhanced a 20-channel head coil to the level of the 64-channel head coil, with the improvements mainly within the cortical brain regions. Conclusion A prototype uHDC helmet enhanced the SNR of a standard head coil to the level of a high density 64-channel coil, although transmit homogeneity was compromised. Further improvements in SNR may be achievable with optimization of this technology, and could be a low-cost approach for future radiofrequency engineering work in the brain at 3T. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|