T2 values of femoral cartilage of the knee joint: comparison between pre-contrast and post-contrast images.
OBJECTIVE
To retrospectively evaluate the relationship between T2 values of pre- and post-contrast magnetic resonance (MR) images of femoral cartilage in patients with varying degrees of osteoarthritis.


METHODS
A total of 19 patients underwent delayed gadolinium-enhanced MRI of cartilage. Six regions of interest for T2 value measurement were obtained from pre- and post-contrast T2-weighted, sagittal, multi-slice, multi-echo, source images in each subject. Regions with modified Noyes classification grade 2B and 3 were excluded. Comparison of T2 values between pre- and post-contrast images and T2 values among regions with the grade 0, 1 and 2A groups were statistically analyzed.


RESULTS
Of a total of 114 regions, 79 regions showing grade 0 (n = 46), 1 (n = 18), or 2A (n = 15) were analyzed. The overall and individual T2 values of post-contrast images were significantly lower than those of pre-contrast images (overall, 35.3 ± 9.2 [mean ± SD] vs. 29.9 ± 8.2, p < 0.01; range of individual, 28.9-37.6 vs. 27.1-36.4, p < 0.01). Pearson correlation coefficients showed a strong positive correlation between pre- and post-contrast images (rho-Pearson = 0.712-0.905). T2 values of pre- and post-contrast images of the grade 0 group were significantly lower than those of the grade 1/2A group (pre T2, p = 0.003; post T2, p = 0.006).


CONCLUSIONS
T2 values of the femoral cartilage of the knee joint are significantly lower on post-contrast images than on pre-contrast images. Furthermore, these T2 values have a strong positive correlation between pre- and post-contrast images.
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Korea.
Hyun Jung
HJ
Yoon
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Korea.
Young Cheol
YC
Yoon
Department of Preventive Medicine, Kyung Hee University School of Medicine, Seoul 130-872, Korea.
Bong-Keun
BK
Choe
D000328:Adult; D000368:Aged; D002358:Cartilage, Articular / Q000473:pathology; D003287:Contrast Media; D005260:Female; D005269:Femur; D019786:Gadolinium DTPA; D006801:Humans; D007719:Knee Joint; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies
D003287:Contrast Media; D019786:Gadolinium DTPA
Cartilage, articular; Magnetic resonance; Osteoarthritis; T2 mapping; dGEMRIC