dGEMRIC was validated in vitro by comparing the GAG calculated from the MR
measurements of Gd(DTPA)2- concentration to that derived from biochemical
measures of GAG. The correlation was high for both bovine and human samples
(e.g. Figure 1). Furthermore, variations in GAG across a sample were
evident in both the dGEMRIC images and histologic sections in both bovine
tissue degraded with interleukin-1 (Figure 2) and GAG lesions present in
human samples obtained from patients undergoing total knee replacement
surgeries (Figure 3).
GAG by dGEMRIC vs GAG by DMB
3D MRI of a 2 mm cultured cartilage plug with 25 micron isotropic
resolution shows morphologically intact cartilage (proton density image,
upper left), with heavy T1 (dGEMRIC) variations (upper right). A 2D section
of the 3D dataset matches the distribution of GAG by H&E staining.
: Proton density image shows morphologically intact cartilage.
: T1 weighted image shows large defect in GAG concentration.
: The defect in GAG is seen on toluidine blue staining.
For more information, see these references:
Bashir A, Gray ML, Burstein D. Gd-DTPA2- as a measure of cartilage
degradation. Magn Reson Med 1996; 36:665-673.
Bashir A, Gray ML, Hartke J, Burstein D. Nondestructive Imaging of
Human Cartilage Glycosaminoglycan Concentration by MRI. Magn Reson Med 1999; 41:857-865.