Abstract
Purpose: To characterize peripheral nerve stimulation (PNS) of an asymmetric head-only gradient coil that is compatible with a commercial high–channel-count receive-only array. Methods: Two prototypes of an asymmetric head-only gradient coil set with a 42-cm inner diameter were constructed for brain imaging at 3T with maximum performance specifications of up to 85 mT/m and 708 T/m/s. Tests were performed in 24 volunteers to measure PNS thresholds with the transverse (x = left–right; y = anterior–posterior [A/P]) gradient coils of both prototypes. Fourteen of these 24 volunteers were also tested for the z-gradient PNS in the second prototype and were scanned with high–slew-rate echo planar imaging (EPI) immediately after the PNS tests. Results: For both prototypes, the y-gradient PNS threshold was markedly higher than the x-gradient threshold. The z-gradient threshold was intermediate between those for the x- and y-coils. Of the 24 volunteers, only two experienced y-gradient PNS at 80 mT/m and 500 T/m/s. All volunteers underwent the EPI scan without PNS when the readout direction was set to A/P. Conclusion: Measured PNS characteristics of asymmetric head-only gradient coil prototypes indicate that such coils, especially in the A/P direction, can be used for fast EPI readout in high-performance neuroimaging scans with substantially reduced PNS concerns compared with conventional whole body gradient coils. Magn Reson Med 76:1939–1950, 2016.
Original language | English (US) |
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Pages (from-to) | 1939-1950 |
Number of pages | 12 |
Journal | Magnetic Resonance in Medicine |
Volume | 76 |
Issue number | 6 |
DOIs | |
State | Published - Dec 1 2016 |
Externally published | Yes |
Keywords
- EPI
- head-only gradient coil
- neuroimaging
- peripheral nerve stimulation
- PNS
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging