Comparison of 1.5 and 3.0 T for Contrast-Enhanced Pulmonary Magnetic Resonance Angiography

• Type of Material: Article
• Authors: Frank Joseph Londy, University of Michigan; Suzan Lowe, University of Michigan; Paul D. Stein, Michigan State University; John G. Weg, University of Michigan; Robert Eisner, Emory University; Kenneth V. Leeper, Emory University; Pamela K. Woodard, Washington University; H. Dirk Sostman, Weill Cornell Medical College; Kathleen A. Jablonski, George Washington University; Sarah E. Fowler, George Washington University; Charles A. Hales, Harvard University; Russell D. Hull, University of Calgary; Alexander Gottschalk, Michigan State University; David P. Naidich, New York University; Thomas L. Chenevert, University of Michigan
• Language: English
• Date: 2012-03-01
• Publisher: SAGE Publications (UK and US): Open Access Titles
• Publication Version: Final Published Version
• Copyright Statement: © SAGE Publications 2012.
• Final Published Version (URL): http://dx.doi.org/10.1177/1076029611419840
• Title of Journal or Parent Work: Clinical and Applied Thrombosis/Hemostasis
• ISSN: 1076-0296
• Volume: 18
• Issue: 2
• Start Page: 134
• End Page: 139
• Grant/Funding Information: The authors received no financial support for the research, authorship, and/or publication of this article.
• Keywords: PERFUSION; Peripheral Vascular Disease; Hematology; CIRCULATION; Life Sciences & Biomedicine; INITIAL-EXPERIENCE; MR-ANGIOGRAPHY; MRI; Science & Technology; EMBOLISM; Cardiovascular System & Cardiology; image quality; DIAGNOSIS; field strength; pulmonary embolism
• Research Categories: Health Sciences, Radiology; Health Sciences, Medicine and Surgery

Abstract

Objective: In a recent multi-center trial of gadolinium contrast-enhanced magnetic resonance angiography (Gd-MRA) for diagnosis of acute pulmonary embolism (PE), two centers utilized a common MRI platform though at different field strengths (1.5T and 3T) and realized a signal-to-noise gain with the 3T platform. This retrospective analysis investigates this gain in signal-to-noise of pulmonary vascular targets. Methods: Thirty consecutive pulmonary MRA examinations acquired on a 1.5T system at one institution were compared to 30 consecutive pulmonary MRA examinations acquired on a 3T system at a different institution. Both systems were from the same MRI manufacturer and both used the same Gd-MRA pulse sequence, although there were some protocol adjustments made due to field strength differences. Region-of-interests were manually defined on the main pulmonary artery, 4 pulmonary veins, thoracic aorta, and background lung for objective measurement of signal-to-noise, contrast-to-noise, and bolus timing bias between centers. Results: The 3T pulmonary MRA protocol achieved higher spatial resolution yet maintained significantly higher signal-to-noise ratio (≥13%, p = 0.03) in the main pulmonary vessels relative to 1.5T. There was no evidence of operator bias in bolus timing or patient hemodynamic differences between groups. Conclusion: Relative to 1.5T, higher spatial resolution Gd-MRA can be achieved at 3T with a sustained or greater signal-to-noise ratio of enhanced vasculature.