Suitability of T(1Gd) as the dGEMRIC index at 1.5T and 3.0T.
Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) is based on the theory that Gd-DTPA(2-) will distribute in inverse relation to cartilage glycosaminoglycan (GAG). T(1Gd) (T(1) after penetration of a 0.2 mmol/kg dose of Gd-DTPA(2-)) has been used as the dGEMRIC index, although (1/T(1Gd)-1/T(1o)) should be more representative of Gd-DTPA(2-) concentration (where T(1o) = T(1) before contrast). T(1o) and T(1Gd) were measured in 20 volunteers at both 1.5T and 3T and the correlation between the metrics of T(1Gd) and (1/T(1Gd)-1/T(1o)) was calculated. There was a high correlation coefficient between the two metrics at both field strengths, with R = 0.94, 0.93, and 0.90 for central medial femur, posterior medial femur, and medial tibia, respectively, at 1.5T and 0.87, 0.94, 0.96 at 3T. In all cases P < 0.0001. Therefore, these data suggest that, for native cartilage, the current practice of measuring T(1Gd) (but not also T(1o)) is adequate at both 1.5T and 3T.
Williams
Ashley
A
Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA.
Mikulis
Brandon
B
Krishnan
Nitya
N
Gray
Martha
M
McKenzie
Charlie
C
Burstein
Deborah
D
D002356:Cartilage / Q000737:chemistry*; D005682:Gadolinium; D006025:Glycosaminoglycans / Q000032:analysis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*
D006025:Glycosaminoglycans; D005682:Gadolinium