Balanced SSFP imaging of the musculoskeletal system
ABSTRACT Magnetic resonance imaging (MRI), with its unique ability to image and characterize soft tissue noninvasively, has emerged as one of the most accurate imaging methods available to diagnose bone and joint pathology. Currently, most evaluation of musculoskeletal pathology is done with two-dimensional acquisition techniques such as fast spin echo (FSE) imaging. The development of three-dimensional fast imaging methods based on balanced steady-state free precession (SSFP) shows great promise to improve MRI of the musculoskeletal system. These methods may allow acquisition of fluid sensitive isotropic data that can be reformatted into arbitrary planes for improved detection and visualization of pathology. Sensitivity to fluid and fat suppression are important issues in these techniques to improve delineation of cartilage contours, for detection of marrow edema and derangement of other joint structures. J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc.
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- "Three-dimensional FFE with selective frequency and a spatially selective excitation radiofrequency pulse with binominal amplitude ratios serve water-selective excitation and fat suppression that enables relatively better imaging of the internal joint structure compared with 3D SPGR sequences (32, 33). In balanced FFE imaging, banding artifacts due to off-resonance are challenging as repetition time increases or at high field (34). Thus, in this study we compared 3D isotropic TSE intermediate-weighted MR imaging with 3D isotropic FFE with WATS-f in terms of the image quality of the ankle joint, which has a more complex joint and ligament structure compared with the knee joint. "
ABSTRACT: To compare the image quality of volume isotropic turbo spin echo acquisition (VISTA) imaging method with that of the three-dimensional (3D) isotropic fast field echo (FFE) imaging method applied for ankle joint imaging. MR imaging of the ankles of 10 healthy volunteers was performed with VISTA and 3D FFE sequences by using a 3.0 T machine. Two radiologists retrospectively assessed the tissue contrast between fluid and cartilage (F-C), and fluid and the Achilles tendon (F-T) with use of a 4-point scale. For a quantitative analysis, signal-to-noise ratio (SNR) was obtained by imaging phantom, and the contrast ratios (CRs) were calculated between F-T and F-C. Statistical analyses for differences in grades of tissue contrast and CRs were performed. VISTA had significantly superior grades in tissue contrast of F-T (p = 0.001). Results of 3D FFE had superior grades in tissue contrast of F-C, but these result were not statistically significant (p = 0.157). VISTA had significantly superior CRs in F-T (p = 0.002), and 3D FFE had superior CRs in F-C (p = 0.003). The SNR of VISTA was higher than that of 3D FFE (49.24 vs. 15.94). VISTA demonstrates superior tissue contrast between fluid and the Achiles tendon in terms of quantitative and qualitative analysis, while 3D FFE shows superior tissue contrast between fluid and cartilage in terms of quantitative analysis.Korean journal of radiology: official journal of the Korean Radiological Society 07/2012; 13(4):443-9. DOI:10.3348/kjr.2012.13.4.443 · 1.57 Impact Factor
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ABSTRACT: Osteoarthritis (OA) is the most common musculoskeletal degenerative disease, affecting millions of people. Although OA has been considered primarily a cartilage disorder associated with focal cartilage degeneration, it is accompanied by well-known changes in subchondral and trabecular bone, including sclerosis and osteophyte formation. The exact cause of OA initiation and progression remains under debate, but OA typically first affects weightbearing joints such as the knee. Magnetic resonance imaging (MRI) has been recognized as a potential tool for quantitative assessment of cartilage abnormalities due to its excellent soft tissue contrast. Over the last two decades, several new MR biochemical imaging methods have been developed to characterize the disease process and possibly predict the progression of knee OA. These new MR biochemical methods play an important role not only for diagnosis of disease at an early stage, but also for their potential use in monitoring outcome of various drug therapies (success or failure). Recent advances in multicoil radiofrequency technology and high field systems (3 T and above) significantly improve the sensitivity and specificity of imaging studies for the diagnosis of musculoskeletal disorders. The current state-of-the-art MR imaging methods are briefly reviewed for the quantitative biochemical and functional imaging assessment of musculoskeletal systems.Seminars in musculoskeletal radiology 10/2008; 12(3):266-80. DOI:10.1055/s-0028-1083109 · 1.09 Impact Factor
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ABSTRACT: High field magnetic resonance imaging at 3.0 T is rapidly gaining clinical acceptance as the preferred platform for magnetic resonance (MR) imaging. This is spurred in part because advances in the manufacture of magnet technology have brought the cost of 3.0-T magnets into the range of previous 1.5-T machines, as well as ongoing research demonstrating numerous advantages of 3.0 T over 1.5 T in neurological imaging. Many factors are responsible for improved imaging at higher field strength, including increased signal-to-noise and contrast-to-noise ratios. The impact of 3.0-T imaging of the musculoskeletal system has been less dramatic because its optimization is more complicated in the musculoskeletal system than in the brain. Many issues must be considered beyond what might be expected from simply doubling the field strength, including hardware design, protocol modifications because of changes in tissue characteristics at higher fields, artifact reduction, and safety. This article addresses many of these concerns, focusing on techniques to optimize high field MR imaging of the musculoskeletal system.Seminars in musculoskeletal radiology 10/2008; 12(3):185-95. DOI:10.1055/s-0028-1083103 · 1.09 Impact Factor