T1 Delta r MRI quantification of arthroscopically confirmed cartilage degeneration

Nine asymptomatic subjects and six patients underwent T1 Delta *r MRI to determine whether Outerbridge grade 1 or 2 cartilage degeneration observed during arthroscopy could be detected noninvasively. MRI was performed 2-3 months postarthroscopy, using sagittal T1-weighted and axial and coronal T1 Delta *r MRI, from which spatial T1 Delta *r relaxation maps were calculated from segmented T1-weighted images. Median T1 Delta *r relaxation times of patients with arthroscopically documented cartilage degeneration and asymptomatic subjects were significantly different (P < 0.001), and median T1 Delta *r exceeded asymptomatic articular cartilage median T1 Delta *r by 2.5 to 9.2 ms. In eight observations of mild cartilage degeneration at arthroscopy (Outerbridge grades 1 and 2), mean compartment T1 Delta *r was elevated in five, but in all observations, large foci of increased T1 Delta *r were observed. It was determined that T1 Delta *r could detect some, but not all, Outerbridge grade 1 and 2 cartilage degeneration but that a larger patient population is needed to determine the sensitivity to these changes. Magn Reson Med 63:1376-1382, 2010. [copy 2010 Wiley-Liss, Inc.