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A standard system phantom for magnetic resonance imaging
Author(s) -
Stupic Karl F.,
Ainslie Maureen,
Boss Michael A.,
Charles Cecil,
Dienstfrey Andrew M.,
Evelhoch Jeffrey L.,
Finn Paul,
Gimbutas Zydrunas,
Gunter Jeffrey L.,
Hill Derek L. G.,
Jack Clifford R.,
Jackson Edward F.,
Karaulanov Todor,
Keenan Kathryn E.,
Liu Guoying,
Martin Michele N.,
Prasad Pottumarthi V.,
Rentz Nikki S.,
Yuan Chun,
Russek Stephen E.
Publication year - 2021
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.28779
Subject(s) - imaging phantom , scanner , calibration , fiducial marker , image resolution , image quality , computer science , quality assurance , distortion (music) , medical imaging , medical physics , nuclear magnetic resonance , optics , physics , artificial intelligence , image (mathematics) , medicine , amplifier , computer network , external quality assessment , bandwidth (computing) , pathology , quantum mechanics
Purpose A standard MRI system phantom has been designed and fabricated to assess scanner performance, stability, comparability and assess the accuracy of quantitative relaxation time imaging. The phantom is unique in having traceability to the International System of Units, a high level of precision, and monitoring by a national metrology institute. Here, we describe the phantom design, construction, imaging protocols, and measurement of geometric distortion, resolution, slice profile, signal‐to‐noise ratio (SNR), proton‐spin relaxation times, image uniformity and proton density. Methods The system phantom, designed by the International Society of Magnetic Resonance in Medicine ad hoc committee on Standards for Quantitative MR, is a 200 mm spherical structure that contains a 57‐element fiducial array; two relaxation time arrays; a proton density/SNR array; resolution and slice‐profile insets. Standard imaging protocols are presented, which provide rapid assessment of geometric distortion, image uniformity, T 1 and T 2 mapping, image resolution, slice profile, and SNR. Results Fiducial array analysis gives assessment of intrinsic geometric distortions, which can vary considerably between scanners and correction techniques. This analysis also measures scanner/coil image uniformity, spatial calibration accuracy, and local volume distortion. An advanced resolution analysis gives both scanner and protocol contributions. SNR analysis gives both temporal and spatial contributions. Conclusions A standard system phantom is useful for characterization of scanner performance, monitoring a scanner over time, and to compare different scanners. This type of calibration structure is useful for quality assurance, benchmarking quantitative MRI protocols, and to transition MRI from a qualitative imaging technique to a precise metrology with documented accuracy and uncertainty.