Suitability of T1Gd as the “dGEMRIC index” at 1.5T and 3.0T

✍ Scribed by Ashley Williams; Brandon Mikulis; Nitya Krishnan; Martha Gray; Charlie McKenzie; Deborah Burstein

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 306 KB
• Volume: 58
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.21376

✦ Synopsis

Abstract

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. Magn Reson Med 58:830–834, 2007. © 2007 Wiley‐Liss, Inc.