Comparison of Analog and Digital Transceiver Systems for MR Imaging

Abstract

We critically evaluated analog and digital transceivers for magnetic resonance (MR) imaging systems under identical experimental conditions to identify and compare their advantages and disadvantages. MR imaging experiments were performed using a 4.74-tesla vertical-bore superconducting magnet and a high sensitivity gradient coil probe. We acquired 3-dimensional spin echo images of a kumquat with and without using a gain-stepping scan technique to extend the dynamic range of the receiver systems. The acquired MR images clearly demonstrated nearly identical image quality for both transceiver systems, but DC and ghosting artifacts were obtained for the analog transceiver system. We therefore concluded that digital transceivers have several advantages over the analog transceivers.

Magnetic Resonance Microscopy of Chemically Fixed Human Embryos Performed in University of Tsukuba Since 1999 to 2015

“…B and MRTechnology, Tsukuba, Japan for Fig. C) were used in Figure B,C, and digital RF transceivers (MRTechnology) were used for Figure A,D (Hashimoto et al, ).…”

“…1B and MRTechnology, Tsukuba, Japan for Fig. 1C) were used in Figure 1B,C, and digital RF transceivers (MRTechnology) were used for Figure 1A,D (Hashimoto et al, 2012(Hashimoto et al, , 2014. Figure 2A,B show four-and eight-channel super-parallel gradient coil probes used for the super-parallel MR microscope shown in Figure 1B.…”

Echo-Planar Imaging for a 9.4 Tesla Vertical-Bore Superconducting Magnet Using an Unshielded Gradient Coil

“…A digital MRI transceiver (DTRX6, MRTechnology, Tsukuba, Ibaraki) controlled by a personal computer (PC) controller 7,8 was used for generation of pulse sequences and NMR signal acquisition timing control, which was actually controlled by a flexible data acquisition software program (Sampler 7D, MRTechnology) running under Windows 7 operating system (Microsoft, Redmond, WA, USA). The PC controller has great capability in gradient wave generation because every pulse sequence event [e.g., RF amplitudes (16-bit in quadrature), gradient amplitudes (16-bit for each channel), and data acquisition control] can be controlled by a 128-bit word issued every 1 μs.…”

Perspectives in Wireless Radio Frequency Coil Development for Magnetic Resonance Imaging

“…The choice of suitable digitization components is a critical task, as there is always a trade-off between achievable conversion rates, bit resolution, power dissipation, cost, and scalability to multichannel systems. In general, on-coil digitization is advantageous, as it improves signal and phase stability, yielding better image quality, and offers easier scalability to multi-channel systems [18,19,31]. For component selection, the main challenges are related to the MR signal properties.…”

“…This significantly lowers the ADC sampling rate requirement. Analog down-conversion is often used in traditional systems [31,35] but can also be advantageous for easier system reconfiguration to other B 0 fields and higher power efficiency (<240 mW/channel [21]). This was shown with broadband on-coil receivers for optical fiber transmission of digital signals from two [21] or four [24] wrist coil channels at 1.5-10.5 T. Direct undersampling corresponds to sampling at lower than twice the maximum frequency and digital demodulation at the same time.…”