A solution to the dynamic range problem in MRI using a parallel image acquisition

Abstract

ABSTRACT:A parallel image acquisition system has been developed to solve the dynamic range problem in MRI. The parallel receiver system was tested using 3D large matrix spin echo and gradient echo images. The dynamic range of the receiver system was extended to about 80 dB, which was sufficient for a large-matrix (256 ϫ 256 ϫ 512) 3D gradient echo image acquisition at a voxel resolution of 60 m 3 . Our method can be a simple and efficient technique for solving the dynamic range problem in MRI.

Magnetic Resonance Microscopy of Chemically Fixed Human Embryos at High Spatial Resolution

“…This SNR degradation is caused by elongation of the T 1 that is roughly proportional to 1/3rd power of the resonance frequency (about 1.6 times loss at 9.4T compared with that at 2.35T) and the insufficient receiver dynamic range pointed out in the previous study. 9 Image contrast of the liver As shown in Fig. 2b and 2c, image contrast of the liver is quite different between the 2 magnetic field strengths.…”

A digital receiver with fast frequency- and gain-switching capabilities for MRI systems

“…Because the gain control range of the AD8331 is about 42 dB in our design, according to Ref. [15], the dynamic range of the receiver may be expected to extend to above 125 dB with the aid of the GS technique.…”

“…However, with this technique the scan time is increased. Another solution uses multiple receivers with different gains to acquire MR signals in parallel [15]. Obviously, this greatly complicates the hardware structure.…”

Comparison of Analog and Digital Transceiver Systems for MR Imaging

“…4[b], [d]). Figure 5 shows the relative average signal power in the k-space plotted against the wave number of the MR signal of the kumquat, which we call the "k-power plot," [22][23][24] obtained with and without the gain-stepping scan for the analog and digital transceivers.…”

“…20,24 Therefore, although a correct gain setting is indispensable, a 16-bit digital resolution is sufficient for most MR imaging.…”