{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Sica CT"],"funding":["NIBIB NIH HHS","National Institutes of Health"],"pagination":["1123-1134"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC6879784"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["83(3)"],"pubmed_abstract":["<h4>Purpose</h4>To present a 3T brain imaging study using a conformal prototype helmet constructed with an ultra-high dielectric constant (uHDC; ε<sub>r</sub> ~ 1000) materials that can be inserted into standard receive head-coils.<h4>Methods</h4>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.<h4>Results</h4>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 B1+ 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.<h4>Conclusion</h4>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."],"journal":["Magnetic resonance in medicine"],"pubmed_title":["Toward whole-cortex enhancement with an ultrahigh dielectric constant helmet at 3T."],"pmcid":["PMC6879784"],"funding_grant_id":["U01 EB026978","R01 EB021277","U01 EB026978‐01"],"pubmed_authors":["Hou RJ","Rupprecht S","Gandji NP","Yang QX","Sica CT","Lanagan MT"],"additional_accession":[]},"is_claimable":false,"name":"Toward whole-cortex enhancement with an ultrahigh dielectric constant helmet at 3T.","description":"<h4>Purpose</h4>To present a 3T brain imaging study using a conformal prototype helmet constructed with an ultra-high dielectric constant (uHDC; ε<sub>r</sub> ~ 1000) materials that can be inserted into standard receive head-coils.<h4>Methods</h4>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.<h4>Results</h4>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 B1+ 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.<h4>Conclusion</h4>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.","dates":{"release":"2020-01-01T00:00:00Z","publication":"2020 Mar","modification":"2024-02-14T20:02:25.249Z","creation":"2021-03-03T08:15:57Z"},"accession":"S-EPMC6879784","cross_references":{"pubmed":["31502708"],"doi":["10.1002/mrm.27962"]}}