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Multiparametric MRI of Epiphyseal Cartilage Necrosis (Osteochondrosis) with Histological Validation in a Goat Model.

Wang L, Nissi MJ, Tóth F, Shaver J, Johnson CP, Zhang J, Garwood M, Carlson CS, Ellermann JM - PLoS ONE (2015)

Bottom Line: All relaxation time constants differentiated normal epiphyseal cartilage from lesions of ischemic cartilage necrosis, and the histological staining results confirmed the proteoglycan (PG) loss in the areas of ischemia.In the scanned specimens, all of the measured relaxation time constants were higher in the articular than in the normal epiphyseal cartilage, consistently allowing differentiation between these two tissues.Multiparametric MRI provided a sensitive approach to discriminate between necrotic and viable epiphyseal cartilage and between articular and epiphyseal cartilage, which may be useful for diagnosing and monitoring OC lesions and, potentially, for assessing effectiveness of treatment interventions.

View Article: PubMed Central - PubMed

Affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States of America; Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, United States of America.

ABSTRACT

Purpose: To evaluate multiple MRI parameters in a surgical model of osteochondrosis (OC) in goats.

Methods: Focal ischemic lesions of two different sizes were induced in the epiphyseal cartilage of the medial femoral condyles of goats at 4 days of age by surgical transection of cartilage canal blood vessels. Goats were euthanized and specimens harvested 3, 4, 5, 6, 9 and 10 weeks post-op. Ex vivo MRI scans were conducted at 9.4 Tesla for mapping the T1, T2, T1ρ, adiabatic T1ρ and TRAFF relaxation times of articular cartilage, unaffected epiphyseal cartilage, and epiphyseal cartilage within the area of the induced lesion. After MRI scans, safranin O staining was conducted to validate areas of ischemic necrosis induced in the medial femoral condyles of six goats, and to allow comparison of MRI findings with the semi-quantitative proteoglycan assessment in corresponding safranin O-stained histological sections.

Results: All relaxation time constants differentiated normal epiphyseal cartilage from lesions of ischemic cartilage necrosis, and the histological staining results confirmed the proteoglycan (PG) loss in the areas of ischemia. In the scanned specimens, all of the measured relaxation time constants were higher in the articular than in the normal epiphyseal cartilage, consistently allowing differentiation between these two tissues.

Conclusions: Multiparametric MRI provided a sensitive approach to discriminate between necrotic and viable epiphyseal cartilage and between articular and epiphyseal cartilage, which may be useful for diagnosing and monitoring OC lesions and, potentially, for assessing effectiveness of treatment interventions.

No MeSH data available.


Related in: MedlinePlus

Regression analysis of the percent differences of all parametric MRI relaxation constants and of the light absorption between the viable and necrotic epiphyseal cartilage.The solid line shows the linear fitting (R2 = 0.39) between the percent differences of all MR relaxation constants (Table 4) and the percent difference of the light absorption (Table 2, column 4), resulting in the slope equal to 0.21.
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pone.0140400.g005: Regression analysis of the percent differences of all parametric MRI relaxation constants and of the light absorption between the viable and necrotic epiphyseal cartilage.The solid line shows the linear fitting (R2 = 0.39) between the percent differences of all MR relaxation constants (Table 4) and the percent difference of the light absorption (Table 2, column 4), resulting in the slope equal to 0.21.

Mentions: The regression analysis in Fig 5 compares the percent difference of the light absorption (fourth column in Table 2) vs. the percent difference of the measured relaxation constants (Table 4) between the viable and necrotic epiphyseal cartilage. The measured percent difference of relaxation constants did not change proportionally with that of the light absorption, which is proportional to the PG loss. The slope of the fitted line (solid, R2 = 0.39) is about 0.21, indicating that the relaxation time constants generally had less percent change than the corresponding light absorption. When the difference in light absorption is less than 60%, T2, T1ρ, adiabatic T1ρ, and TRAFF generally appear above the dashed line (slope = 1), meaning these relaxation constants were more sensitive than the optical density experiment at the early stage of the disease. However, when PG was dramatically lost (the percent difference of the light absorption >140%), it can be seen that the relaxation constants reached a plateau and did not increase further.


Multiparametric MRI of Epiphyseal Cartilage Necrosis (Osteochondrosis) with Histological Validation in a Goat Model.

Wang L, Nissi MJ, Tóth F, Shaver J, Johnson CP, Zhang J, Garwood M, Carlson CS, Ellermann JM - PLoS ONE (2015)

Regression analysis of the percent differences of all parametric MRI relaxation constants and of the light absorption between the viable and necrotic epiphyseal cartilage.The solid line shows the linear fitting (R2 = 0.39) between the percent differences of all MR relaxation constants (Table 4) and the percent difference of the light absorption (Table 2, column 4), resulting in the slope equal to 0.21.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608749&req=5

pone.0140400.g005: Regression analysis of the percent differences of all parametric MRI relaxation constants and of the light absorption between the viable and necrotic epiphyseal cartilage.The solid line shows the linear fitting (R2 = 0.39) between the percent differences of all MR relaxation constants (Table 4) and the percent difference of the light absorption (Table 2, column 4), resulting in the slope equal to 0.21.
Mentions: The regression analysis in Fig 5 compares the percent difference of the light absorption (fourth column in Table 2) vs. the percent difference of the measured relaxation constants (Table 4) between the viable and necrotic epiphyseal cartilage. The measured percent difference of relaxation constants did not change proportionally with that of the light absorption, which is proportional to the PG loss. The slope of the fitted line (solid, R2 = 0.39) is about 0.21, indicating that the relaxation time constants generally had less percent change than the corresponding light absorption. When the difference in light absorption is less than 60%, T2, T1ρ, adiabatic T1ρ, and TRAFF generally appear above the dashed line (slope = 1), meaning these relaxation constants were more sensitive than the optical density experiment at the early stage of the disease. However, when PG was dramatically lost (the percent difference of the light absorption >140%), it can be seen that the relaxation constants reached a plateau and did not increase further.

Bottom Line: All relaxation time constants differentiated normal epiphyseal cartilage from lesions of ischemic cartilage necrosis, and the histological staining results confirmed the proteoglycan (PG) loss in the areas of ischemia.In the scanned specimens, all of the measured relaxation time constants were higher in the articular than in the normal epiphyseal cartilage, consistently allowing differentiation between these two tissues.Multiparametric MRI provided a sensitive approach to discriminate between necrotic and viable epiphyseal cartilage and between articular and epiphyseal cartilage, which may be useful for diagnosing and monitoring OC lesions and, potentially, for assessing effectiveness of treatment interventions.

View Article: PubMed Central - PubMed

Affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States of America; Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, United States of America.

ABSTRACT

Purpose: To evaluate multiple MRI parameters in a surgical model of osteochondrosis (OC) in goats.

Methods: Focal ischemic lesions of two different sizes were induced in the epiphyseal cartilage of the medial femoral condyles of goats at 4 days of age by surgical transection of cartilage canal blood vessels. Goats were euthanized and specimens harvested 3, 4, 5, 6, 9 and 10 weeks post-op. Ex vivo MRI scans were conducted at 9.4 Tesla for mapping the T1, T2, T1ρ, adiabatic T1ρ and TRAFF relaxation times of articular cartilage, unaffected epiphyseal cartilage, and epiphyseal cartilage within the area of the induced lesion. After MRI scans, safranin O staining was conducted to validate areas of ischemic necrosis induced in the medial femoral condyles of six goats, and to allow comparison of MRI findings with the semi-quantitative proteoglycan assessment in corresponding safranin O-stained histological sections.

Results: All relaxation time constants differentiated normal epiphyseal cartilage from lesions of ischemic cartilage necrosis, and the histological staining results confirmed the proteoglycan (PG) loss in the areas of ischemia. In the scanned specimens, all of the measured relaxation time constants were higher in the articular than in the normal epiphyseal cartilage, consistently allowing differentiation between these two tissues.

Conclusions: Multiparametric MRI provided a sensitive approach to discriminate between necrotic and viable epiphyseal cartilage and between articular and epiphyseal cartilage, which may be useful for diagnosing and monitoring OC lesions and, potentially, for assessing effectiveness of treatment interventions.

No MeSH data available.


Related in: MedlinePlus