This MRI """"""""technology development"""""""" grant (R01 RR15396) was funded by the NCRR as a Bioengineering Research grant, a role now shifted to NIBIB. The initial grant advanced the then new technologies of multi- channel high-speed MRI, including the first clinical 32-channel parallel MRI;local gradients with ~10-fold increases in strength and speed;optimized signal-to-noise ratio (SNR) detectors;the invention of strip detectors;and thermometry, achieving order-of-magnitude gains in speed and performance at 1.5 Tesla (1.5T). Meanwhile, clinical 3T MRI scanners have arrived, and this more-focused renewal request, extends thermometry and detector optimization to address core safety issues of RF heating and dosimetry, and the safety and potential performance gains of internal detectors at 3T. These are developed for applications to high-resolution imaging in atherosclerosis. In particular, we provide new preliminary in vivo and in vitro experimental and theoretical data suggesting a nearly quadrupling of signal-to-noise ratio (SNR), a ~10-fold gain in field-of-view (FOV) area at 3T, and 80-1505m resolution of vessel walls. While 3T delivers higher SNR, the RF power deposited during MRI, the specific absorption rate (SAR, W/kg), quadruples from 1.5T to 3T, all else being the same, raising genuine safety concerns that fundamentally limit 3T scanner operation. Yet, there are currently no independent means of measuring SAR during MRI for ensuring compliance with FDA and/or IRB guidelines when evaluating new MRI techniques, investigating RF burns caused by MRI, establishing reliable SAR levels for assessing device safety, or for routine MRI quality assessment by Medical Physicists. The central safety issue is addressed in Aim 1 which develops the first SAR dosimeter for clinical head and body MRI and applies it to assessing scanner SAR following burn reports, and to device testing.
Aim 2 develops new high-SNR internal detectors, solving the increased heating and decoupling problems at 3T, and applying the technology to an animal model of atherosclerosis.
Aim 3 extends this to a new MRI method that is inherently locked to the internal detector, creating a true MRI endoscope. The endoscope provides micro- imaging directly from the view-point of the probe as it is advanced, avoiding the inefficiencies of interrogating probe location with the scanner. It is also tested on the atherosclerosis model.
Aim 4 returns to dosimetry, extending our thermometry work to the much higher potential for RF heating of internal metallic detectors at 3T, using the detector itself as an independent RF radiometer. These bio-engineering advances will broadly benefit the multiple NIH institutes that utilize MRI, and contribute importantly to the safety of this key modality.

Public Health Relevance

This grant provides novel technology for independently assessing RF power deposition in MRI for monitoring its safe operation, and for evaluating the safety of implanted devices. It will provide new internal MRI probes that promise large sensitivity and resolution gains for local high-resolution imaging and MRI endoscopy, with potential applications to the assessment and treatment of vascular disease and vulnerable plaque.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB007829-09
Application #
8101079
Study Section
Biomedical Imaging Technology Study Section (BMIT)
Program Officer
Liu, Guoying
Project Start
2008-09-30
Project End
2014-06-30
Budget Start
2011-07-01
Budget End
2014-06-30
Support Year
9
Fiscal Year
2011
Total Cost
$528,343
Indirect Cost
Name
Johns Hopkins University
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Liu, Xiaoyang; Ellens, Nicholas; Williams, Emery et al. (2017) A Combined Intravascular MRI Endoscope and Intravascular Ultrasound (IVUS) Transducer for High-Resolution Image-Guided Ablation. Proc Int Soc Magn Reson Med Sci Meet Exhib Int Soc Magn Reson M 25:1178
Wang, Guan; Zhang, Yi; Hegde, Shashank Sathyanarayana et al. (2017) High-resolution and accelerated multi-parametric mapping with automated characterization of vessel disease using intravascular MRI. J Cardiovasc Magn Reson 19:89
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Zhang, Yi; Heo, Hye-Young; Jiang, Shanshan et al. (2017) Fast, Reliable 3D Amide Proton Transfer Imaging of Brain Tumors at 3T with Variably-accelerated Sensitivity Encoding (vSENSE). Proc Int Soc Magn Reson Med Sci Meet Exhib Int Soc Magn Reson M 25:
Zhang, Yi; Liu, Xiaoyang; Zhou, Jinyuan et al. (2017) Ultrafast compartmental relaxation time mapping with linear algebraic modeling. Proc Int Soc Magn Reson Med Sci Meet Exhib Int Soc Magn Reson M 25:0071
Zhang, Yi; Heo, Hye-Young; Jiang, Shanshan et al. (2016) Highly accelerated chemical exchange saturation transfer (CEST) measurements with linear algebraic modeling. Magn Reson Med 76:136-44
Zhang, Yi; Heo, Hye-Young; Lee, Dong-Hoon et al. (2016) Fast Chemical Exchange Saturation Transfer (CEST) Imaging with Variably-accelerated Sensitivity Encoding (vSENSE). Proc Int Soc Magn Reson Med Sci Meet Exhib Int Soc Magn Reson M 24:1522
Wang, Guan; Zhang, Yi; Hegde, Shashank Sathyanarayana et al. (2016) Highly Accelerated, Intravascular T1, T2, and Proton Density Mapping with Linear Algebraic Modeling and Sensitivity Profile Correction at 3T. Proc Int Soc Magn Reson Med Sci Meet Exhib Int Soc Magn Reson M 24:2829
Ertürk, M Arcan; Sathyanarayana Hegde, Shashank; Bottomley, Paul A (2016) Radiofrequency Ablation, MR Thermometry, and High-Spatial-Resolution MR Parametric Imaging with a Single, Minimally Invasive Device. Radiology 281:927-932
Zhang, Yi; Heo, Hye-Young; Lee, Dong-Hoon et al. (2016) Highly-accelerated CEST Measurements in Three Dimensions with Linear Algebraic Modeling. Proc Int Soc Magn Reson Med Sci Meet Exhib Int Soc Magn Reson M 24:1524

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