High-Resolution Diffusivity Imaging at 3.0 T for the Detection of Degenerative Changes

Berg, Andreas; Singer, Thomas; Moser, Ewald

doi:10.1097/01.rli.0000078762.72335.57

Cited by 22 publications

(13 citation statements)

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“…An alternative model of osteoarthritis is the use of trypsin to induce the degeneration of proteoglycan (66)(67)(68). Trypsin is a 24 kDa endopeptidase commonly produced in the pancreas for the digestion of dietary amino acids (69).…”

Section: Models Of Osteoarthritis In Articular Cartilagementioning

confidence: 99%

Sodium and T_1ρ MRI for molecular and diagnostic imaging of articular cartilage

et al. 2006

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In this article, both sodium magnetic resonance (MR) and T 1r relaxation mapping aimed at measuring molecular changes in cartilage for the diagnostic imaging of osteoarthritis are reviewed. First, an introduction to structure of cartilage, its degeneration in osteoarthritis (OA) and an outline of diagnostic imaging methods in quantifying molecular changes and early diagnostic aspects of cartilage degeneration are described. The sodium MRI section begins with a brief overview of the theory of sodium NMR of biological tissues and is followed by a section on multiple quantum filters that can be used to quantify both bi-exponential relaxation and residual quadrupolar interaction. Specifically, (i) the rationale behind the use of sodium MRI in quantifying proteoglycan (PG) changes, (ii) validation studies using biochemical assays, (iii) studies on human OA specimens, (iv) results on animal models and (v) clinical imaging protocols are reviewed. Results demonstrating the feasibility of quantifying PG in OA patients and comparison with that in healthy subjects are also presented. The section concludes with the discussion of advantages and potential issues with sodium MRI and the impact of new technological advancements (e.g. ultra-high field scanners and parallel imaging methods). In the theory section on T 1r , a brief description of (i) principles of measuring T 1r relaxation, (ii) pulse sequences for computing T 1r relaxation maps, (iii) issues regarding radio frequency power deposition, (iv) mechanisms that contribute to T 1r in biological tissues and (v) effects of exchange and dipolar interaction on T 1r dispersion are discussed. Correlation of T 1r relaxation rate with macromolecular content and biomechanical properties in cartilage specimens subjected to trypsin and cytokineinduced glycosaminoglycan depletion and validation against biochemical assay and histopathology are presented. Experimental T 1r data from osteoarthritic specimens, animal models, healthy human subjects and as well from osteoarthritic patients are provided. The current status of T 1r relaxation mapping of cartilage and future directions is also discussed. Copyright # 2006 John Wiley & Sons, Ltd. KEYWORDS: cartilage; arthritis; spin-lock; T1rho; sodium; MRI OSTEOARTHRITIS Osteoarthritis (OA) affects more than half of the population above the age of 65 (1,2) and has a significant negative impact on the quality of life of elderly individuals (3). The economic costs in the USA from OA have been estimated to be more than 1% of the gross domestic product (4). OA is now increasingly viewed as a metabolically active joint disorder of diverse etiologies. The biochemistry of the disease is characterized by the following changes in cartilage: reduced proteoglycan (PG) concentration, possible changes in the size of collagen fibril and aggregation of PG, increased water content and increased rate of synthesis and degradation of matrix macromolecules. The earliest changes in the cartilage due to OA result in a partial breakdown in the proteoglyc...

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Section: Models Of Osteoarthritis In Articular Cartilagementioning

confidence: 99%

Sodium and T_1ρ MRI for molecular and diagnostic imaging of articular cartilage

et al. 2006

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“…For the trypsin group, 5 mg of trypsin (Sigma Chemical Co., St. Louis) in 40 ml Tris buffer was injected into the nucleus pulposus. Trypsin catalyzes the hydrolysis of peptide bonds and has been used previously to dissolve denatured collagen leaving the remaining collagen intact (Berg et al, 2003).…”

Section: Experimental Groupsmentioning

confidence: 99%

Assessment of compressive modulus, hydraulic permeability and matrix content of trypsin-treated nucleus pulposus using quantitative MRI

Périé

Iatridis

Demers

et al. 2006

Journal of Biomechanics

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“…The now available high-field MR systems offer high intrinsic signal thus allowing a further increase in spatial resolution. For neurological applications it has been demonstrated that the higher spatial resolution improves detail delineation and thus diagnostic accuracy [1][2][3][4][5]. Wholebody applications are now being evaluated at 3 T [6][7][8][9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

MRI of the pelvis at 3 T: very high spatial resolution with sensitivity encoding and flip-angle sweep technique in clinically acceptable scan time

et al. 2005

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High-Resolution Diffusivity Imaging at 3.0 T for the Detection of Degenerative Changes

Abstract: In a trypsin-based arthritis model, the spatial localization and quantification of damaged areas have been shown to be possible on a whole body 3.0 T MR system. Measurement times achieved for these high spatial resolution studies make in vivo investigations feasible.

Cited by 22 publications

References 15 publications

Sodium and T_1ρ MRI for molecular and diagnostic imaging of articular cartilage

Sodium and T_1ρ MRI for molecular and diagnostic imaging of articular cartilage

Assessment of compressive modulus, hydraulic permeability and matrix content of trypsin-treated nucleus pulposus using quantitative MRI

MRI of the pelvis at 3 T: very high spatial resolution with sensitivity encoding and flip-angle sweep technique in clinically acceptable scan time

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High-Resolution Diffusivity Imaging at 3.0 T for the Detection of Degenerative Changes

Abstract: In a trypsin-based arthritis model, the spatial localization and quantification of damaged areas have been shown to be possible on a whole body 3.0 T MR system. Measurement times achieved for these high spatial resolution studies make in vivo investigations feasible.

Cited by 22 publications

References 15 publications

Sodium and T1ρ MRI for molecular and diagnostic imaging of articular cartilage

Sodium and T1ρ MRI for molecular and diagnostic imaging of articular cartilage

Assessment of compressive modulus, hydraulic permeability and matrix content of trypsin-treated nucleus pulposus using quantitative MRI

MRI of the pelvis at 3 T: very high spatial resolution with sensitivity encoding and flip-angle sweep technique in clinically acceptable scan time

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Sodium and T_1ρ MRI for molecular and diagnostic imaging of articular cartilage

Sodium and T_1ρ MRI for molecular and diagnostic imaging of articular cartilage