Article

Quantitative MRI of cartilage and bone: Degenerative changes in osteoarthritis

Institute of Anatomy and Musculoskeletal Research, Paracelsus Private Medical University (PMU), A-5020 Salzburg, Austria.
NMR in Biomedicine (Impact Factor: 3.56). 11/2006; 19(7):822-54. DOI: 10.1002/nbm.1063
Source: PubMed

ABSTRACT Magnetic resonance imaging (MRI) and quantitative image analysis technology has recently started to generate a great wealth of quantitative information on articular cartilage and bone physiology, pathophysiology and degenerative changes in osteoarthritis. This paper reviews semiquantitative scoring of changes of articular tissues (e.g. WORMS = whole-organ MRI scoring or KOSS = knee osteoarthritis scoring system), quantification of cartilage morphology (e.g. volume and thickness), quantitative measurements of cartilage composition (e.g. T2, T1rho, T1Gd = dGEMRIC index) and quantitative measurement of bone structure (e.g. app. BV/TV, app. TbTh, app. Tb.N, app. Tb.Sp) in osteoarthritis. For each of these fields we describe the hardware and MRI sequences available, the image analysis systems and techniques used to derive semiquantitative and quantitative parameters, the technical accuracy and precision of the measurements reported to date and current results from cross-sectional and longitudinal studies in osteoarthritis. Moreover, the paper summarizes studies that have compared MRI-based measurements with radiography and discusses future perspectives of quantitative MRI in osteoarthritis. In summary, the above methodologies show great promise for elucidating the pathophysiology of various tissues and identifying risk factors of osteoarthritis, for developing structure modifying drugs (DMOADs) and for combating osteoarthritis with new and better therapy.

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    • "Magnetic resonance (MR) imaging allows direct visualization of knee cartilage and quantitative measurement on cartilage to monitor osteoarthritis (OA) progression [1]. The advancement of MR imaging contributes greatly to the search for effective OA imaging biomarker [2]. Imaging biomarker is defined as " any anatomic, physiologic, biochemical, or molecular parameter detectable with one or more imaging methods used to diagnose the presence and/or severity of disease [3]. "
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    The Scientific World Journal 05/2014; 2014. DOI:10.1155/2014/294104 · 1.73 Impact Factor
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    • "There is considerable interest in methodologies which could give a reliable indication of cartilage degradation or preservation over short timescales in order to evaluate new interventions and pharmaceutical therapies. Disappointingly, average cartilage volume change as detected by structural MRI was only 4-6% per year [2], with no consensus on measurement or analysis methodology. MRI measures of cartilage integrity have focused on T2 [3], T1rho [4], and the delayed gadolinium enhancement MRI of cartilage (dGEMRIC) [5]. "
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    ABSTRACT: Structural magnetic resonance imaging (MRI) has shown great utility in diagnosing soft tissue burden in osteoarthritis (OA), though MRI measures of cartilage integrity have proven more elusive. Sodium MRI can reflect the proteoglycan content of cartilage; however, it requires specialized hardware, acquisition sequences, and long imaging times. This study was designed to assess the potential of a clinically feasible sodium MRI acquisition to detect differences in the knee cartilage of subjects with OA versus healthy controls (HC), and to determine whether longitudinal changes in sodium content are observed at 3 and 6 months. 28 subjects with primary knee OA and 19 HC subjects age and gender matched were enrolled in this ethically-approved study. At baseline, 3 and 6 months subjects underwent structural MRI and a 0.4ms echo time 3D T1-weighted sodium scan as well as the knee injury and osteoarthritis outcome score (KOOS) and knee pain by visual analogue score (VAS). A standing radiograph of the knee was taken for Kellgren-Lawrence (K-L) scoring. A blinded reader outlined the cartilage on the structural images which was used to determine median T1-weighted sodium concentrations in each region of interest on the co-registered sodium scans. VAS, K-L, and KOOS all significantly separated the OA and HC groups. OA subjects had higher T1-weighted sodium concentrations, most strongly observed in the lateral tibial, lateral femoral and medial patella ROIs. There were no significant changes in cartilage volume or sodium concentration over 6 months. This study has shown that a clinically-feasible sodium MRI at a moderate 3T field strength and imaging time with fluid attenuation by T1 weighting significantly separated HCs from OA subjects.
    PLoS ONE 08/2013; 8(8):e73067. DOI:10.1371/journal.pone.0073067 · 3.23 Impact Factor
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    • "modalities. So far, Magnetic Resonance Imaging (MRI) has been evidenced as the most promising imaging modality as it provides morphological and physiological assessment of AC degeneration by means of images and quantitative information [4]. MRI is non-invasive, non-ionizing and invivo modality. "
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    ABSTRACT: The onset of osteoarthritis (OA), a most common knee joint disease, can be characterized by the degeneration of articular cartilage (AC). Degenerative changes in AC have been assessed by the morphological and physiological measurements using non-invasive modality such as Magnetic Resonance Imaging (MRI) to obtain MRI images of the knee. However, visualization and quantification of AC from MR images is difficult due to the low visibility contrast of AC compared to surrounding tissues, low and varying signal intensities in cartilage region and variable intensities in different slices of single dataset. In this work, we present a method to fuse multinuclear ((23)Na and (1)H) MR images acquired in the same plane without changing the position of the human knee as well as the Radio Frequency (RF) coil. This work is performed towards our hypothesis that fusion of sodium and proton images will provide an enhanced image that can be used for an accurate assessment of cartilage morphology. Our result shows that merging of sodium knee MR image with proton knee MR image resulting in enhanced contrast information in the cartilage region and resolves low visibility and varying intensities issue with 2D/3D proton MR. We conclude that the proposed method can further be utilized for the accurate assessment of cartilage morphology.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 07/2013; 2013:6466-6469. DOI:10.1109/EMBC.2013.6611035
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