So Dug Lim

Publications (2)4.32 Total impact

• Article: Chronologic change in the growth plate after radiofrequency-induced thermal injury: MRI-histologic correlation.

  Sung Gyu Moon, Heung Sik Kang, Sung-Hwan Hong, Na Ra Kim, Joon Woo Lee, So Dug Lim
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  ABSTRACT: The purposes of this study were to assess chronologic changes in normal growth plate after radiofrequency-induced thermal injury and to evaluate the feasibility of MRI for revealing alteration of the growth plate. Radiofrequency ablation was performed on the right proximal tibia of 13 8-week-old New Zealand White rabbits. An 18-gauge cooled-tip electrode with a 5-mm active tip was placed distal to the physis under fluoroscopic guidance. MRI, including T1- and T2-weighted images, gradient-recalled echo images, and contrast-enhanced T1-weighted images, was performed 2, 4, and 12 weeks after ablation. Rabbits were sacrificed 2 (n = 4), 4 (n = 4), and 12 weeks (n = 5) after ablation. The sequential changes in the ablated zone, the injured physis, and the nonablated portion of the physis were correlated between MRI features and histologic results. Diameter of the nonenhancing lesion on MR images strongly correlated with the size of the region of coagulation necrosis at gross examination. The intraclass correlation coefficients were 0.98 and 0.94 for the long and short axes (p < 0.001). On gradient-recalled echo images, physial conspicuity was less in the injured physis than in the nonablated portion and less in the ablated than the control tibia. Physial conspicuity was graded for comparison with physial thickness at microscopic examination. The thickness of the physis was less in the ablated than in the control tibia 4 and 12 weeks after treatment (p < 0.05, paired Student t test). The cartilage column of the injured physis was delaminated 2 weeks after treatment, and a bone bridge through the injured physis was detected at 4 weeks. Radiofrequency-induced thermal injury causes early closure of the physis. MRI can depict the extent of radiofrequency-induced thermal injury and alterations in the physis that lead to early closure.
  American Journal of Roentgenology 02/2012; 198(2):W163-72. · 2.78 Impact Factor
• Article: Effects of epidural TNF-α inhibitor injection: analysis of the pathological changes in a rat model of chronic compression of the dorsal root ganglion.

  Na Ra Kim, Joon Woo Lee, Su Ryoung Jun, In Joon Lee, So Dug Lim, Jin Sup Yeom, Kyung-Hoi Koo, Wook Jin, Heung Sik Kang
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  ABSTRACT: To evaluate the efficacy of a single direct epidural injection of tumor necrosis factor (TNF)-α inhibitor to reduce the pathological changes in nerve fiber injuries in a rat model of chronic compression of the dorsal root ganglion (CCD). A surgical procedure for CCD was performed in 17 adult male F-344 rats. The effects of the epidural TNF-α inhibitors on CCD-induced pathological changes were investigated. Three groups of rats (n = 17) were used: (1) CCD + saline (n = 4), (2) CCD + triamcinolone (n = 5), and (3) CCD + TNF-α inhibitors (n = 8). Their dorsal root ganglia and nerve roots were removed on postoperative day 14. The intraneural edema, demyelination, and Wallerian degeneration of all 17 rats were scored pathologically. The pathology scores of the rats in the TNF-α inhibitor treatment group (1.38 ± 0.74) indicated a mild degree of intraneural edema compared to the saline treatment group (2.25 ± 0.50, p = 0.041). In addition, rats in the TNF-α inhibitor treatment group (2.13 ± 0.35) had a mild degree of demyelination compared to the saline treatment group (2.75 ± 0.50, p = 0.038) and the triamcinolone treatment group (2.80 ± 0.45, p = 0.019). The differences in the pathology scores for Wallerian degeneration were not statistically significant in all three study groups (p = 0.658). The epidural injection of a TNF-α inhibitor was more effective than a placebo and comparable to triamcinolone in reducing pathological nerve injury progression.
  Skeletal Radiology 06/2011; 41(5):539-45. · 1.54 Impact Factor