A high-dynamic-range digital RF-over-fiber link for MRI receive coils using delta-sigma modulation.

Coaxial cables commonly used to connect radio-frequency (RF) coil arrays with the control console of an MRI scanner are susceptible to electromagnetic coupling. As the number of RF channels increases, such coupling could result in severe heating and pose a safety concern. Non-conductive transmission solutions based on fiber-optic cables are considered to be one of the alternatives but are limited by the high dynamic range (>80 dB) of typical MRI signals.

SU-E-J-55: Development of a Novel Cableless Radiolucent RF Coil for MR-Guided Radiation Therapy (MRgRT™).

Purpose: To demonstrate the feasibility of a novel radiotherapy-compatible cableless radiofrequency (RF) coil for an MR-guided radiation therapy(MRgRT™) system that employs a movable MRI system. This coil technology will expedite clinical workflow by eliminating need for coil connections and cables, allowing RF coils to remain in place for treatment.

Methods: We quantified radiation transmission factors and surface dose changes for aluminum (Al), copper (Cu) and FR4 substrate typical of RF coils using a Varian Trilogy linear accelerator.

Decompression sickness risk model: development and validation by 150 prospective hypobaric exposures.

Introduction: High altitude exposure has an inherent risk of altitude decompression sickness (DCS). A predictive DCS model was needed to reduce operational risk. To be operationally acceptable, such a theoretical model would need to be validated in the laboratory using human subjects.

Application of the SUSHI method to the design of gradient coils.

An approach to potential improvements in magnetic field shielding for a gradient coil system with cylindrical geometry is presented, utilizing "supershielding" conditions for the currents on both the primary and the secondary coils. It is demonstrated that the field can be strongly suppressed everywhere outside a cylindrical shield coil radius, even though the finite-length active shield only partially surrounds a primary coil. The supershielding method, which is aimed at controlling eddy currents, still has sufficient freedom to maintain the desired magnetic field behavior inside the imaging volume.