Premium
Lightweight, compact, and high‐performance 3 T MR system for imaging the brain and extremities
Author(s) -
Foo Thomas K. F.,
Laskaris Evangelos,
Vermilyea Mark,
Xu Minfeng,
Thompson Paul,
Conte Gene,
Epps Christopher,
Immer Christopher,
Lee SeungKyun,
Tan Ek T.,
Graziani Dominic,
Mathieu JeanBaptise,
Hardy Christopher J.,
Schenck John F.,
Fiveland Eric,
Stautner Wolfgang,
Ricci Justin,
Piel Joseph,
Park Keith,
Hua Yihe,
Bai Ye,
Kagan Alex,
Stanley David,
Weavers Paul T.,
Gray Erin,
Shu Yunhong,
Frick Matthew A.,
Campeau Norbert G.,
Trzasko Joshua,
Huston John,
Bernstein Matt A.
Publication year - 2018
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27175
Subject(s) - fluid attenuated inversion recovery , image quality , flip angle , scanner , slew rate , electromagnetic coil , nuclear medicine , magnet , specific absorption rate , magnetic resonance imaging , amplitude , biomedical engineering , physics , computer science , nuclear magnetic resonance , materials science , medicine , optics , radiology , image (mathematics) , artificial intelligence , voltage , telecommunications , quantum mechanics , antenna (radio)
Purpose To build and evaluate a small‐footprint, lightweight, high‐performance 3T MRI scanner for advanced brain imaging with image quality that is equal to or better than conventional whole‐body clinical 3T MRI scanners, while achieving substantial reductions in installation costs. Methods A conduction‐cooled magnet was developed that uses less than 12 liters of liquid helium in a gas‐charged sealed system, and standard NbTi wire, and weighs approximately 2000 kg. A 42‐cm inner‐diameter gradient coil with asymmetric transverse axes was developed to provide patient access for head and extremity exams, while minimizing magnet‐gradient interactions that adversely affect image quality. The gradient coil was designed to achieve simultaneous operation of 80‐mT/m peak gradient amplitude at a slew rate of 700 T/m/s on each gradient axis using readily available 1‐MVA gradient drivers. Results In a comparison of anatomical imaging in 16 patients using T 2 ‐weighted 3D fluid‐attenuated inversion recovery (FLAIR) between the compact 3T and whole‐body 3T, image quality was assessed as equivalent to or better across several metrics. The ability to fully use a high slew rate of 700 T/m/s simultaneously with 80‐mT/m maximum gradient amplitude resulted in improvements in image quality across EPI, DWI, and anatomical imaging of the brain. Conclusions The compact 3T MRI system has been in continuous operation at the Mayo Clinic since March 2016. To date, over 200 patient studies have been completed, including 96 comparison studies with a clinical 3T whole‐body MRI. The increased gradient performance has reliably resulted in consistently improved image quality.