International Journal on Magnetic Particle Imaging IJMPI
Vol. 10 No. 1 Suppl 1 (2024): Int J Mag Part Imag
Preliminary Results: Large Bore Clinical MPI System Imaging Human Head-sized FOVs
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Copyright (c) 2024 Erica E Mason, Elliott Barcikowski, John Carl, Mike Chandeeing, Bryanna Davison, Benjamin Fellows, Walter Fetsch, Kyle Fields, Joan Greve, Justin J Konkle, Eli Mattingly, Toby Sanders, Olivia Sehl, David Trease, Ashley Truxal, Marcela Weyhmiller, Patrick W Goodwill
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Abstract
Clinical-scale MPI development has, so far, typically been optimized toward specific body parts and/or clinical applications, including functional brain imaging[1], perfusion[2], interventional[3], and cardiac imaging[4]. These systems have magnet free bore sizes in the range of 20-45 cm[1]–[3], [5], [6]. To date, the largest field of view MPI images published are 10 x 14 cm2[2] and 11 x 12 cm2[3]. Also, previous assessments of magnetostimulation have focused on the transmit field[7]–[9].
In this work, we present progress in our development of a general-purpose, human-scale MPI system capable of imaging large fields of view used clinically in MRI and CT. We show the overall hardware design, phantom imaging results, and human magnetostimulation results for all magnetic fields (i.e., gradient, drive, and slow shift) experienced during imaging.
The main magnet has a 60 cm magnet free bore and is designed to fit the shoulders. The magnet produces a field-free point with a measured performance of 0.6 T/m at 40 kW of power dissipation. A water-cooled head/extremity coil produces a transmit field of up to 7 mTp continuous, requiring a reactive power of 0.5 MW. As a general-purpose system, the imaging FOV is limited by coil size, and we set it to 23 x 23 x 6 cm3 to match FOVs seen in MRI head imaging. We present imaging results of phantoms filled with VivoTrax (Magnetic Insight, Inc.) tracer, including spiral phantoms, sensitivity, resolution, and dynamic range phantoms. We conclude by demonstrating safe, magnetostimulation-free imaging sequences in the feet of three healthy volunteers.
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References
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