Comparison study of intraarticular and intravenous gadolinium-enhanced magnetic resonance imaging of cartilage in a canine model.
BACKGROUND
Magnetic resonance (MR) imaging and measurement of glycosaminoglycan (GAG) have potential for characterization of hyaline articular cartilage. Recently, some reports have demonstrated the potential of direct administration of contrast media for MR imaging of cartilage.


OBJECTIVE
To prove the feasibility of intraarticular gadolinium-enhanced MR imaging of cartilage (iGEMRIC) and T1 relaxation mapping of the articular cartilage in vivo with intraarticular injection of Gd-DTPA2-.


METHODS
Five healthy beagle dogs underwent MR imaging and T1 relaxation mapping of the knee joints of both hind legs. The delayed gadolinium-enhanced MR imaging of cartilage (dGEMRIC) and iGEMRIC techniques were interchanged with MR imaging. For dGEMRIC, a double routine dose of Gd-DTPA2- (0.2 mM/kg) was administered intravenously. For iGEMRIC, 2.5 and 1.25 mmol/l saline-diluted Gd-DTPA2- solutions were separately injected into the right and left knee joints, respectively, prior to MR imaging. Color-coded T1 maps of 20 femoral condyles were obtained from the dGEMRIC and iGEMRIC images. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and glycosaminoglycan (GAG) delineation of articular cartilage were compared between the dGEMRIC and iGEMRIC techniques.


RESULTS
The mean SNR was higher with dGEMRIC than with iGEMRIC, but the difference was not statistically significant (P=0.174). The mean (+/-SD) CNR was higher with iGEMRIC (-11.6+/-3.4) than with dGEMRIC (-16.7+/-4.0; P=0.000), although the absolute value of the CNR was higher with dGEMRIC. The layering and gradient distribution of GAG were more clearly visualized on the iGEMRIC images. The mean scores of GAG delineation with dGEMRIC and iGEMRIC were 0.7+/-0.6 and 2.2+/-1.7, respectively. The iGEMRIC method better visualized GAG distribution (P=0.001).


CONCLUSIONS
Although the SNR did not differ significantly between the iGEMRIC and dGEMRIC techniques, the color-coded T1 map produced with iGEMRIC allowed better cartilage evaluation. Thus, iGEMRIC exhibits the useful features of both MR arthrography and dGEMRIC, and provides a color-coded T1 map that is useful for diagnosing early articular cartilage damage.
Kwack
Kyu-Sung
KS
Department of Radiology, Ajou University Medical Center, Suwon, South Korea.
Cho
Jae Hyun
JH
Kim M
Myung Soon
MS
Yoon
Choon-Sik
CS
Yoon
Yeo Seung
YS
Choi
Jae Won
JW
Kwon
Jong Won
JW
Min
Byoung-Hyun
BH
Sun
Joo Sung
JS
Kim
Sun Yong
SY
D000818:Animals; D002358:Cartilage, Articular / Q000033:anatomy & histology*; D003287:Contrast Media / Q000008:administration & dosage*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005240:Feasibility Studies; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006025:Glycosaminoglycans / Q000032:analysis; D006614:Hindlimb / Q000033:anatomy & histology*; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D007270:Injections, Intra-Articular; D007275:Injections, Intravenous; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D012680:Sensitivity and Specificity
D003287:Contrast Media; D006025:Glycosaminoglycans; D019786:Gadolinium DTPA