The Survey of Magnetic Resonance Imaging Quality according to Magnetic Field Strength in Korea

BackgroundThe development and clinical adoption of quantitative imaging biomarkers (radiomics) has established the need for the identification of parameters altering radiomics reproducibility. The aim of this study was to assess the impact of magnetic field strength on magnetic resonance imaging (MRI) radiomics features in neuroradiology clinical practice.MethodsT1 3D SPGR sequence was acquired on two phantoms and 10 healthy volunteers with two clinical MR devices from the same manufacturer using two different magnetic fields (1.5 and 3T). Phantoms varied in terms of gadolinium concentrations and textural heterogeneity. 27 regions of interest were segmented (phantom: 21, volunteers: 6) using the LIFEX software. 34 features were analyzed.ResultsIn the phantom dataset, 10 (67%) out of 15 radiomics features were significantly different when measured at 1.5T or 3T (student’s t-test, p < 0.05). Gray levels resampling, and pixel size also influence part of texture features. These findings were validated in healthy volunteers.ConclusionsAccording to daily used protocols for clinical examinations, radiomic features extracted on 1.5T should not be used interchangeably with 3T when evaluating texture features. Such confounding factor should be adjusted when adapting the results of a study to a different platform, or when designing a multicentric trial.

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Using electromagnetic field calculations to understand the complexity of magnetic resonance imaging (MRI) at high magnetic field strength

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) ◽

10.1109/aps.2001.958872 ◽

2002 ◽

Author(s):

M.B. Smith ◽

C. Collins ◽

Qing Yang ◽

Jinghua Wang ◽

Wanzhan Liu

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Field ◽

Electromagnetic Field ◽

Magnetic Resonance ◽

Field Strength ◽

Magnetic Field Strength ◽

High Magnetic Field ◽

Resonance Imaging ◽

High Magnetic Field Strength ◽

Magnetic Resonance Imaging Mri

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Operating magnetic field strength for nuclear magnetic resonance imaging

Radiographics ◽

10.1148/radiographics.4.1.44 ◽

1984 ◽

Vol 4 (1) ◽

pp. 44-47

Author(s):

Seong Ki Mun

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Field ◽

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Field Strength ◽

Magnetic Field Strength ◽

Nuclear Magnetic Resonance Imaging ◽

Resonance Imaging ◽

Nuclear Magnetic

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Magnetic resonance imaging at ultra-high magnetic field strength: An in vivo assessment of number, size and distribution of pelvic lymph nodes

PLoS ONE ◽

10.1371/journal.pone.0236884 ◽

2020 ◽

Vol 15 (7) ◽

pp. e0236884 ◽

Cited By ~ 1

Author(s):

Ansje S. Fortuin ◽

Bart W. J. Philips ◽

Marloes M. G. van der Leest ◽

Mark E. Ladd ◽

Stephan Orzada ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Field ◽

Magnetic Resonance ◽

Field Strength ◽

Lymph Nodes ◽

Magnetic Field Strength ◽

Resonance Imaging ◽

High Magnetic Field Strength ◽

In Vivo Assessment

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Theoretical signal-to-noise ratio and spatial resolution dependence on the magnetic field strength for hyperpolarized noble gas magnetic resonance imaging of human lungs

Medical Physics ◽

10.1118/1.1833593 ◽

2005 ◽

Vol 32 (1) ◽

pp. 221-229 ◽

Cited By ~ 43

Author(s):

Juan Parra-Robles ◽

Albert R. Cross ◽

Giles E. Santyr

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Field ◽

Magnetic Resonance ◽

Field Strength ◽

Signal To Noise Ratio ◽

Noble Gas ◽

Resonance Imaging ◽

Signal To Noise ◽

Human Lungs ◽

The Magnetic Field

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Erratum: “Theoretical signal-to-noise ratio and spatial resolution dependence on the magnetic field strength for hyperpolarized noble gas magnetic resonance imaging of human lungs” [Med. Phys. 32, 221-229 (2005)]

Medical Physics ◽

10.1118/1.2189711 ◽

2006 ◽

Vol 33 (5) ◽

pp. 1525-1526 ◽

Cited By ~ 1

Author(s):

Juan Parra-Robles ◽

Albert R. Cross ◽

Giles E. Santyr

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Field ◽

Magnetic Resonance ◽

Field Strength ◽

Signal To Noise Ratio ◽

Noble Gas ◽

Resonance Imaging ◽

Signal To Noise ◽

Human Lungs ◽

The Magnetic Field

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Intraoperative Magnetic Resonance Imaging-guided neurosurgery at 3-T

Operative Neurosurgery ◽

10.1227/01.neu.0000205284.04252.87 ◽

2006 ◽

Vol 58 (suppl_4) ◽

pp. ONS-338-ONS-346 ◽

Cited By ~ 11

Author(s):

Charles L. Truwit ◽

Walter A. Hall

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Field ◽

Magnetic Resonance ◽

Field Strength ◽

Intraoperative Imaging ◽

Surgical Techniques ◽

Main Magnetic Field ◽

Neurosurgical Procedures ◽

Resonance Imaging ◽

Intraoperative Magnetic Resonance Imaging

Abstract Objective: Between 1997 and 2004, more than 700 neurosurgical procedures were performed in a 1.5-T magnetic resonance-guided therapy suite. During this period, the concept of high-field intraoperative magnetic resonance imaging (MRI) was validated, as was a new surgical guidance tool, the Navigus (Image-guided Neurologics, Melbourne, FL), and its methodology, prospective stereotaxy. Clinical protocols were refined to optimize surgical techniques. That implementation, the “Minnesota suite, ” has recently been revised, and a new suite with a 3-T MRI scanner has been developed. Methods: On the basis of experience at the initial 1.5-T suite, a new suite was designed to house a 3-T MRI scanner with wide surgical access at the rear of the scanner (opposite the patient couch). Use of electrocautery, a fiberoptic headlamp, a power drill, and MRI-compatible neurosurgical cutlery was anticipated by inclusion of waveguides and radiofrequency filter panels that penetrate the MRI suite's radiofrequency shield. An MRI-compatible head holder was adapted for use on the scanner table. A few items exhibiting limited ferromagnetism were used within the magnetic field, taking strict precautions. Results: During the initial procedures (all magnetic resonance-guided neurobiopsies), the new suite functioned as anticipated. Although metallic artifact related to titanium needles is more challenging at 3 T than at 1.5 T, it can be contained even at 3 T. Similar to 1.5 T, such artifact is best contained when the device is oriented along B0, the main magnetic field. Surgical needles, disposable scalpels, and disposable razors, despite being minimally ferromagnetic, were easily controlled by the surgeon. Conclusion: An intraoperative magnetic resonance-guided neurosurgical theater has been developed with a 3-T MRI scanner. Intraoperative imaging is feasible at this field strength, and concerns regarding specific absorption rate can be allayed. Infection control procedures can be designed to permit neurosurgery within this environment. Despite the increase in magnetic field strength, safety can be maintained.

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Intraoperative Neurophysiological Monitoring in an Open Low-field Magnetic Resonance Imaging System: Clinical Experience and Technical Considerations

Operative Neurosurgery ◽

10.1227/01.neu.0000310705.72487.f9 ◽

2008 ◽

Vol 63 (suppl_4) ◽

pp. ONS268-ONS276 ◽

Cited By ~ 8

Author(s):

Andrea Szelényi ◽

Thomas Gasser ◽

Volker Seifert

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Field ◽

Magnetic Resonance ◽

Evoked Potentials ◽

Intraoperative Mri ◽

Neurophysiological Monitoring ◽

Resonance Imaging ◽

Stainless Steel Needle ◽

Imaging Quality ◽

Low Field

Abstract Objective: The intraoperative combination of an open magnetic resonance imaging (MRI) system with neurophysiological localization and continuous monitoring techniques allows for the best available anatomic and physiological orientation as well as real-time functional monitoring. Methodological aspects and technical adaptations for this combination of methods and the experience in 29 patients with tumors in the central region are reported. Methods: MRI-compatible platinum/iridium electrodes for intraoperative neuromonitoring were attached to the patient’s head. All other electrodes located outside the magnet were stainless steel needle-electrodes for recording of motor evoked potentials and for stimulating somatosensory evoked potentials. Intraoperative MRI was performed using a 0.15-T intraoperative magnetic resonance scanner (PoleStar N20; Medtronic Surgical Navigation Technologies, Louisville, KY). Results: The calculated and measured values of the maximum induced magnetic field (2 × 10−6T), induced voltage (0.1 V), and force (0.01 N) by the static or changing magnetic field within all attached electrodes were negligible and proved the method’s safety. In 29 patients, platinum/iridium electrodes with low susceptibility showed no interference with the imaging quality. Furthermore, neurophysiological monitoring could be performed with unaffected recording quality. Side effects (e.g., thermal induction) were not observed. Conclusion: Neurophysiological monitoring for evoked potentials and direct cortical stimulation can be performed with standard quality within a low-field intraoperative MRI system. Electrodes fixed to the head should be of low magnetic susceptibility to guarantee optimal imaging quality. The combined use of an open ultra low-field MRI system and intraoperative monitoring allows for resection control and continuous functional monitoring.

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