TY - JOUR
T1 - Opportunities in interventional and diagnostic imaging by using high-performance low-field-strength MRI
AU - Campbell-Washburn, Adrienne E.
AU - Ramasawmy, Rajiv
AU - Restivo, Matthew C.
AU - Bhattacharya, Ipshita
AU - Basar, Burcu
AU - Herzka, Daniel A.
AU - Hansen, Michael S.
AU - Rogers, Toby
AU - Patricia Bandettini, W.
AU - McGuirt, Delaney R.
AU - Mancini, Christine
AU - Grodzki, David
AU - Schneider, Rainer
AU - Majeed, Waqas
AU - Bhat, Himanshu
AU - Xue, Hui
AU - Moss, Joel
AU - Malayeri, Ashkan A.
AU - Jones, Elizabeth C.
AU - Koretsky, Alan P.
AU - Kellman, Peter
AU - Chen, Marcus Y.
AU - Lederman, Robert J.
AU - Balaban, Robert S.
N1 - Funding Information:
Study supported by the Division of Intramural Research, National Heart, Lung and Blood Institute, National Institutes of Health (ZO1-HL006213, ZO1-HL006214, ZO1-HL005062, ZO1-HL006039).
Funding Information:
From the Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md (A.E.C.W., R.R., M.C.R., I.B., B.B., D.A.H., M.S.H., T.R., W.P.B., D.R.M., C.M., M.Y.C., R.J.L.); Siemens Healthcare GmbH, Erlangen, Germany (D.G., R.S.); Siemens Medical Solutions Inc, Malvern Pa (W.M., H.B.); Systems Biology Center, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, 10 Center Dr, Building 10, Room 4C-1581, Bethesda, MD 20892-1458 (H.X., P.K., R.S.B.); Pulmonary Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (J.M.); Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Md (A.A.M., E.C.J.); and Laboratory of Functional and Molecular Imaging, Division of Intramural Research, National Institute of Neurologic Disorders and Stroke, National Institutes of Health, Bethesda, Md (A.P.K.). Received February 26, 2019; revision requested April 15; revision received August 6; accepted August 15. Address correspondence to R.S.B. (e-mail: [email protected]).
Publisher Copyright:
© RSNA, 2019
PY - 2019
Y1 - 2019
N2 - Background: Commercial low-field-strength MRI systems are generally not equipped with state-of-the-art MRI hardware, and are not suitable for demanding imaging techniques. An MRI system was developed that combines low field strength (0.55 T) with high-performance imaging technology. Purpose: To evaluate applications of a high-performance low-field-strength MRI system, specifically MRI-guided cardiovascular catheterizations with metallic devices, diagnostic imaging in high-susceptibility regions, and efficient image acquisition strategies. Materials and Methods: A commercial 1.5-T MRI system was modified to operate at 0.55 T while maintaining high-performance hardware, shielded gradients (45 mT/m; 200 T/m/sec), and advanced imaging methods. MRI was performed between January 2018 and April 2019. T1, T2, and T2* were measured at 0.55 T; relaxivity of exogenous contrast agents was measured; and clinical applications advantageous at low field were evaluated. Results: There were 83 0.55-T MRI examinations performed in study participants (45 women; mean age, 34 years 6 13). On average, T1 was 32% shorter, T2 was 26% longer, and T2* was 40% longer at 0.55 T compared with 1.5 T. Nine metallic interventional devices were found to be intrinsically safe at 0.55 T (,1°C heating) and MRI-guided right heart catheterization was performed in seven study participants with commercial metallic guidewires. Compared with 1.5 T, reduced image distortion was shown in lungs, upper airway, cranial sinuses, and intestines because of improved field homogeneity. Oxygen inhalation generated lung signal enhancement of 19% 6 11 (standard deviation) at 0.55 T compared with 7.6% 6 6.3 at 1.5 T (P = .02; five participants) because of the increased T1 relaxivity of oxygen (4.7e24 mmHg21sec21). Efficient spiral image acquisitions were amenable to low field strength and generated increased signal-to-noise ratio compared with Cartesian acquisitions (P , .02). Representative imaging of the brain, spine, abdomen, and heart generated good image quality with this system. Conclusion: This initial study suggests that high-performance low-field-strength MRI offers advantages for MRI-guided catheterizations with metal devices, MRI in high-susceptibility regions, and efficient imaging.
AB - Background: Commercial low-field-strength MRI systems are generally not equipped with state-of-the-art MRI hardware, and are not suitable for demanding imaging techniques. An MRI system was developed that combines low field strength (0.55 T) with high-performance imaging technology. Purpose: To evaluate applications of a high-performance low-field-strength MRI system, specifically MRI-guided cardiovascular catheterizations with metallic devices, diagnostic imaging in high-susceptibility regions, and efficient image acquisition strategies. Materials and Methods: A commercial 1.5-T MRI system was modified to operate at 0.55 T while maintaining high-performance hardware, shielded gradients (45 mT/m; 200 T/m/sec), and advanced imaging methods. MRI was performed between January 2018 and April 2019. T1, T2, and T2* were measured at 0.55 T; relaxivity of exogenous contrast agents was measured; and clinical applications advantageous at low field were evaluated. Results: There were 83 0.55-T MRI examinations performed in study participants (45 women; mean age, 34 years 6 13). On average, T1 was 32% shorter, T2 was 26% longer, and T2* was 40% longer at 0.55 T compared with 1.5 T. Nine metallic interventional devices were found to be intrinsically safe at 0.55 T (,1°C heating) and MRI-guided right heart catheterization was performed in seven study participants with commercial metallic guidewires. Compared with 1.5 T, reduced image distortion was shown in lungs, upper airway, cranial sinuses, and intestines because of improved field homogeneity. Oxygen inhalation generated lung signal enhancement of 19% 6 11 (standard deviation) at 0.55 T compared with 7.6% 6 6.3 at 1.5 T (P = .02; five participants) because of the increased T1 relaxivity of oxygen (4.7e24 mmHg21sec21). Efficient spiral image acquisitions were amenable to low field strength and generated increased signal-to-noise ratio compared with Cartesian acquisitions (P , .02). Representative imaging of the brain, spine, abdomen, and heart generated good image quality with this system. Conclusion: This initial study suggests that high-performance low-field-strength MRI offers advantages for MRI-guided catheterizations with metal devices, MRI in high-susceptibility regions, and efficient imaging.
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U2 - 10.1148/radiol.2019190452
DO - 10.1148/radiol.2019190452
M3 - Article
C2 - 31573398
AN - SCOPUS:85073581726
SN - 0033-8419
VL - 293
SP - 384
EP - 393
JO - RADIOLOGY
JF - RADIOLOGY
IS - 2
ER -