Switched array coils

Abstract

Switched array coils (SACs) are a useful tool in local coil imaging since they allow in a user-friendly manner one to make the best choice in the trade-off between field of view and signal-to-noise ratio. This is done by selecting the current path within a conductor array equipped with suitable switches. Since the switching can be controlled by the system, this allows changing of the coil dimensions within multislice sequences. Thus image quality can be improved due to smaller coil dimensions for a given slice and a larger area can be covered by electronically shifting this sensitive area. The principle can be applied to surface--as well as volume--coil designs.

The Cardiovascular Magnetic Resonance Machine: Hardware and Software Requirements

“…Surface coils should also fit differing anterior thorax contours closely. Flexible coils may contain a range of coil conductors for different volume coverage which are enabled as needed [72,101]. Ideally they include automatic re-tuning of inevitable changes when they are flexed [42,75].…”

Optimization of the number of selectable channels for spine phased array coils for transverse imaging

“…1,5 In addition, if the detection coils can be selected in the MRI system, it is possible to perform imaging over a wide area while maintaining a good SNR or to vary the imaging area. 6 One anatomical region in which these characteristics of phased array coils can be put to particularly good use is the spine. This system, comprising a linear arrangement of coil elements of the same size and shape with selectable channels, allows simple control of input signals suitable to each target region and vertebral level.…”

“…This system, comprising a linear arrangement of coil elements of the same size and shape with selectable channels, allows simple control of input signals suitable to each target region and vertebral level. 6 When imaging for disorders that can affect the spinal cord, such as multiple sclerosis, it is advantageous to be able to evaluate the spinal cord over a wide area.…”

Simple partial volume transceive coils for in vivo 1H MR studies at high magnetic fields

“…A common approach today is the construction of a transmit-only coil and a receive-only coil combination, which typically requires timed active and/or passive decoupling. The landmark development of phased-array receiver coils boosted the sensitivity of MR dramatically (5,6). However, phased arrays require the availability of multiple receiver channels and software support within an MR system.…”