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Cartilage imaging at 3.0T with gradient refocused acquisition in the steady‐state (GRASS) and IDEAL fat‐water separation
Author(s) -
Kijowski Richard,
Tuite Michael,
Passov Leo,
Shimakawa Ann,
Hu Huanzhou,
Reeder Scott B.
Publication year - 2008
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21414
Subject(s) - cartilage , ideal (ethics) , synovial fluid , synovial joint , magnetic resonance imaging , biomedical engineering , knee cartilage , knee joint , materials science , nuclear medicine , medicine , anatomy , articular cartilage , radiology , osteoarthritis , pathology , surgery , philosophy , alternative medicine , epistemology
Purpose To demonstrate the feasibility of evaluating the articular cartilage of the knee joint at 3.0T using gradient refocused acquisition in the steady‐state (GRASS) and iterative decomposition of water and fat with echo asymmetry and least‐squares estimation (IDEAL) fat‐water separation. Materials and Methods Bloch equation simulations and a clinical pilot study ( n = 10 knees) were performed to determine the influence of flip angle of the IDEAL‐GRASS sequence on the signal‐to‐noise ratio (SNR) of cartilage and synovial fluid and the contrast‐to‐noise ratio (CNR) between cartilage and synovial fluid at 3.0T. The optimized IDEAL‐GRASS sequence was then performed on 30 symptomatic patients as part of the routine 3.0T knee MRI examination at our institution. Results The optimal flip angle was 50° for IDEAL‐GRASS cartilage imaging, which maximized contrast between cartilage and synovial fluid. The IDEAL‐GRASS sequence consistently produced high‐quality fat‐ and water‐separated images of the knee with bright synovial fluid and 0.39 × 0.67 × 1.0 mm resolution in 5 minutes. IDEAL‐GRASS images had high cartilage SNR and high contrast between cartilage and adjacent joint structures. The IDEAL‐GRASS sequence provided excellent visualization of cartilage lesions in all patients. Conclusion The IDEAL‐GRASS sequence shows promise for use as a morphologic cartilage imaging sequence at 3.0T. J. Magn. Reson. Imaging 2008;28:167–174. © 2008 Wiley‐Liss, Inc.