An order parameter without magic angle effect (OPTIMA) derived from R 1 ρ
Magn Reson Med
; 83(5): 1783-1795, 2020 05.
Article
en En
| MEDLINE
| ID: mdl-31691348
PURPOSE: MR R2 imaging of ordered tissue exhibits the magic angle effect, potentially masking subtle pathological changes in cartilage. This work aimed to develop an orientation-independent order parameter (S) exclusively sensitive to collagen degeneration. METHODS: A theory was developed based on R1ρ dispersion coupled with a simplified molecular motion model in which anisotropic R2a(θ) became directly proportional to correlation time τbθ and S could be derived. This new parameter was validated with ex vivo R1ρ dispersion reported on orientated (n = 4), enzymatically depleted bovine cartilage (n = 6), and osteoarthritic human knee specimens (n = 14) at 9.4 Tesla, which was further demonstrated on 1 healthy human knee in vivo at 3 Tesla. RESULTS: τbθ from orientation-dependent R1ρ dispersion revealed a significantly high average correlation (r = 0.89 ± 0.05, P < 0.05) with R2a (θ) on cartilage samples and a moderate correlation (r = 0.48, P < 0.001) for the human knee in vivo. The derived S (10-3 ) significantly decreased in advanced osteoarthritis (1.64 ± 0.03 vs. 2.30 ± 0.11, P < 0.001) and collagen-depleted samples (1.30 ± 0.11 vs. 2.12 ± 0.12, P < 0.001) when compared with early osteoarthritis and the control, respectively. CONCLUSION: The proposed order parameter could be a potentially useful orientation-independent MR biomarker for collagen alterations in cartilage and other highly structured tissues.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Cartílago Articular
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Magn Reson Med
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
Año:
2020
Tipo del documento:
Article
Pais de publicación:
Estados Unidos