• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.1
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• pp.63-71
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• 1983

A dye-edge tracking algorithm was used to determine the corresponding points in the two images(anterior-posterior and lateral) of the digital subtraction biplane angiography. This correspondence was used to reconstruct three dimensional images of cerebral artery in a dog experiment. The method was tested by comparing the measured image of oblique view with the computed reconstructed image. For the present study, we have developed three new algorithms. The first algorithm is to determine the corresponding dye-edge points using the fact the dye density at the moving edge avows the same changing pattern in the two projection views. This moving pattern of dye-edge density is computed using a matching method of cross-correlation for the two sequential frames' dye density. The second algorithm is for simplified perspective transformation, and the third one is to identify the specific corresponding points on the small vessels. The present method can be applied to compute the blood velocity using the dye-edge displacement and the three- dimensional distance data.

• Journal of Korean Foot and Ankle Society
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• v.15 no.4
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• pp.217-222
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• 2011

Purpose: The aim of this study was to evaluate the result of combined Weil and dorsal closing wedge osteotomy for Freiberg's disease. Materials and Methods: We performed combined Weil and dorsal closing wedge osteotomy of the second metatarsal under the diagnosis of Freiberg's disease in 7 patients, 7 feet (2 male and 5 female). The mean age at the time of operation was 29 years and the mean follow-up period was 31 months. Patients had no trauma history and no combined deformity of the foot. The surgical results were evaluated by VAS and weight bearing radiographs in antero-posterior and oblique projection. Results: According to Smillie staging system, there were 1 of stage II, 2 of stage III and 4 of stage IV patients. The osteotomy site was united at 8 weeks and the second metatarsal was shortened in length of average 2.8 mm. Remodeling of the metatarsal head was observed at 24 months. The mean VAS was decreased from 8.2 points preoperatively to 2.7 points at follow-up. And average range of motion of second metatarso-phalangeal joint was increased from 30o preoperatively to 45o at follow-up. There was no transfer metatarsalgia or arthritis of the metatarsal head during follow-up. Conclusion: Combined Weil and dorsal closing wedge osteotomy of the metatarsal appears to be an effective procedure for the treatment of Freiberg's disease with a view to shortening of metatarsal length and elevation of metatarsal head.