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Longitudinal In Vivo Evaluation of Articular Cartilage Injuries in Rabbit Using Quantitative MR Imaging : 

Longitudinal In Vivo Evaluation of Articular Cartilage Injuries in Rabbit Using Quantitative MR Imaging Ryan Doan, B.S. Carmen Taylor, Ph.D. Alexis Dang, M.D. C. Benjamin Ma, M.D. Sharmila Majumdar, Ph.D.

Disclosure: 

Disclosure My disclosure along with my co-authors is listed in the disclosure index on the DVD of the Transactions of the 55th Annual Meeting I have no potential conflicts with this presentation

Introduction/Motivation: 

Introduction/Motivation Osteoarthritis affects over 20 million people annually in the US NIAMS 2007 Quantitative MR has been used to evaluate biochemical changes associated with early osteoarthritis Leigh 1997 ACL-transected rabbits develop articular cartilage degeneration in vivo Hacker 1996

Specific Aims: 

Specific Aims Our primary goal is to characterize the rabbit ACL-transection model longitudinally using T1? and T2 mapping in cartilage Our secondary goal is to evaluate doxycycline in the ACL-transection rabbit model

T1? and T2 imaging: 

T1? and T2 imaging images adapted from Dunn et al 2004

Hypothesis: 

Hypothesis ACL-transection would be associated with an increase in T1? and T2 values Treatment with doxycycline would prevent an increase in T1? and T2 values

Methods: Injury and Treatment: 

Methods: Injury and Treatment In each rabbit, one knee received ACL transection while contralateral knee received sham surgery Rabbits randomized to receive doxycycline (n=6) or no treatment (n=6) Pill images adapted from epocrates.com

Methods: Image Acquisition: 

Methods: Image Acquisition SPGR matrix: 512x256 FOV: 12 cm TR/TE: 15/6.7ms slice thickness: 1 mm T1?/T2 matrix = 256x128 FOV = 12 cm slice thickness = 1 mm T1? : TR/TE = 9.3/3.7ms TSL= 0,10,40,80ms FSL= 500 Hz T2: TE = 4.1, 14.5, 25, 45.9 ms

T1? Maps – 3 week timepoint: 

T1? Maps – 3 week timepoint

T2 Maps – 3 week timepoint: 

T2 Maps – 3 week timepoint

T1? Results: 

T1? Results

T2 Results: 

T2 Results

Discussion: 

Discussion T1? and T2 values were elevated at early time points, following ACL-transection injury, suggesting early matrix destruction Effects of doxycycline treatment not found to be significant, based upon T1? and T2 measurements

Conclusions: 

Conclusions Quantitative MR can be used to make longitudinal measurements and compare disease states over time in the rabbit ACL-transection model

Acknowledgments: 

Acknowledgments Carmen Taylor Jenny Folkesson Ahi Issever Janet Blumenfeld Gabby Blumenkrantz Karl Saldanha Mike Sode Andrew Burghardt Ryan Doan Ehsan Saadat Ben Hyun Bryan Hermannsson Kiran Sekhon Bora Shin Musculoskeletal and Quantitative Imaging Research Group Sharmila Majumdar Thomas Link Benjamin Ma Xiaojuan Li Galateia Kazakia Radu Bolbos Julio Carballido-Gamio Roland Krug Richard Souza Jin Zuo Chongsoo Shin Alexis Dang