An independent multichannel imaging research system for ultrashort echo time imaging on clinical MR systems

Abstract

Most clinical magnetic resonance systems do not have access to ultrashort echo time (UTE) imaging. The aim of this project was to develop a fully independent imaging insert for clinical MR systems to provide this new research application without disturbing routine operation. The initial clinical target for the system was improved orthopedic upper limb imaging using ultrashort repeat and echo time acquisitions. Echo times as short as TE ¼ 80 ls were attained for standard 2DFT gradient echo sequences and TE ¼ 25 ls for asymmetrically sampled radial acquisitions using the 160 mm inside diameter symmetrical cylindrical insert gradient set. The spectrometer was able to acquire 32 channels simultaneously with 14 bit resolution at up to 2.5 MS/s and had broadband operation from 250 kHz up to 200 MHz. Only eight active RF channels were constructed and used for this study. Acoustic noise with the insert coil was up to 30 dbA quieter than a whole body gradient system operating at the same gradient strength. The insert provides a useful method of performing UTE imaging using a standard clinical MRI system with no disturbance to normal operation.

The Agfa Mayneord lecture: MRI of short and ultrashortT2andT2* components of tissues, fluids and materials using clinical systems

“…A variety of solutions have been proposed in the past, but these have had relatively little clinical impact. The recent development of multi-acquisition variable-resonance image combination (MAVRIC) [59] and slice encoding for metal artefact correction (SEMAC) [60] has resulted in a remarkable degree of restoration of images that are grossly degraded by metallic artefact when imaged using [31,[159][160][161] 2D two half pulses Radial from centre out BLAST [162] 3D hard pulse FID acquisition PETRA [163] No gradient applied during radiofrequency ZTE [164] BLAST PETRA ZTE WASPI [32] 3D hard pulse with gradient on. Preparation pulses with water and fat signal suppression…”

A home‐built digital optical MRI console using high‐speed serial links

“…Commercial MRI instruments are generally associated with a high cost and technological opaqueness. Over the past few decades, researchers have worked to counteract these problems by developing affordable, home‐built MRI systems or their major components, along with detailed technical information that is open to the public .…”