科研之友
微信
新浪微博
Facebook
分享链接
摘要
This work describes the design and construction of a radio-frequency (RF) coil optimized for imaging the optic nerve on a Siemens 3T TIM Trio MRI scanner. The specific goals were to optimize signal sensitivity from the orbit to the optic chiasm and improve SNR over previous designs. The optic nerve (ON) coil was constructed using two fiberglass formers that fit together in a clamshell arrangement to maintain a high filling factor for any head size. This design maintains close coil-to-sample coupling near the eyes and around the entire head to eliminate the air void regions that occur between coil and sample when heads are imaged in one-piece rigid head coils. The anterior mask former holds 26 overlapping coil elements in a soccer ball layout. The posterior former supports the neck and head and houses two additional overlapped coil elements, totaling to 28 elements. Signal-to-noise-ratio (SNR) measurements on a custom-made homogeneous head phantom using the optic nerve coil showed a 310% increase in SNR near the orbits and 60% increase at the optic chiasm compared to the 12-channel Siemens head coil. Inverse g-factor maps show that the ON coil performs well for parallel imaging over the region of the optic nerve, providing a possible reduction of eyeball motion artifacts. Images from volunteer studies demonstrate that high-resolution imaging of the optic nerve can be achieved using 3T MRI with advanced imaging coils, leading to improved patient care for optic neuritis patients.
- 出版日期2012-8
