Cone-beam Reconstruction using Limited EPID Projections for Seeds Localization / 의학물리

In this study, we describe the preliminary application for the delineation of a metal object using cone-beam reconstruction (CBR) based on limited electronic portal imaging device (EPID) projections. A typical Feldkamp, Davis and Kress (FDK) reconstruction algorithm accompanying the edge preserving smoothing filter was used as only a few projections are acquired for reconstruction. In a correlation study of the projection numbers, we found that the size of the seeds and their location depicted by these CBR images were almost identical. Limited views were used for CBR, and our method is inexpensive and competitive for use in clinical applications.

Development of QA Phantom Prototype for Imaged Based Radiation Treatment System / 의학물리

In this study, we developed the protopype of QA phantom for image QA including an additional component for image based radiation treatment system. The new phantom considered two main parts: Image quality and fusion accuracy. Image quality part included for daily CT number linearity and spatial resolution, and fusion accuracy part designed to simulate a simple translation-rotation setting. The CT scans of the phantom obtained from conventional CT, MVCT of Tomotherapy unit, and both image sets were satisfied the recommendation of spatial resolution. This phantom was simple and efficient for daily imaging QA, and it is important to provide a new concept of verification of image registration.

The Effect of Doxorubicin and Allopurinol in Chemomyectomy

This study was designed to identify doxorubicin as a permanent chemomyectomy agent that overcomes reversible effect of botulinum toxin A. Doxorubicin was assessed for its ability to bring about a permanent chemomyectomy and the effects of pretreatment were observed to assess its ability to prevent any complications brought about by doxorubicin. A total of thirteen rabbits were assigned to the control group(n=3) and two experimental groups(n=5 for each group). To investigate the myopathic changes following the injections of the agent, both orbicularis oculi muscles of the lower eyelids of each rabbit in the control group were directly injected with single dose of 0.2ml normal saline. Group I were injected with 0.5mg/0.2ml of doxorubicin into the right eyelid and 1.0 mg/0.2 ml of doxorubicin into the left. Group II were given an intravenous injection of 35mg/kg of allopurinol as the pretreatment, then 30minutes later injected with 0.5mg/0.2ml of doxorubicin into the right and 1.0mg/ 0.2ml of doxorubicin into the left. The rabbits were examined daily to monitor the onset, duration and size of skin necrosis and histologically examined two and four months after initial injections. The myopathic change after doxorubicin injection was persistent and irreversible. The dose related effects of doxorubicin chemomyectomy were confirmed by the histologic finding. Skin necrosis occurred in all cases of doxorubicin injection(both 0.5mg and 1.0mg), however the allopurinol pretreatment decreased the size of the skin necrosis in case of the high dose(1.0mg) of doxorubicin. The combined use of allopurinol and doxorubicin reduced the myopathic change more effectively than doxorubicin use alone. Further study is needed to determine optimal dose and administration method, which we feel will contribute to safer and permanent chemomyectomy.

Clinical analysis of composite graft replacement of amputated digital tips

Composite grafting remains a technique which is used reluctantly and without great hope of success. In the recent two years, unexpectedly good result of composite graft was gained from 30 cases. The purpose of our study is to identify factors influencing success and to overlook long-term problems from a cosmetic and a functional view point. A retrospective review and a questionnaire about 30 fingers of 29 patients which were operated for composite graft at Kyongju hospital of Dongguk university from March 1997 to February 1999 were carried out. In all cases of composite grafting, tie-over dressing and heat lamp were applied and left for five days. And following result and conclusion were obtained. 1. 24(80%) of 30 finger tips replaced as composite graft were survived completely or partially. 2. At children with an age range 1 to 14, the survival rate (100%) of composite grafted tips was higher than that (75%) at adults. So, patient's age was important factor for success. 3. The type of injury was more important factor than the level of amputation. The survival rate(100%) of tips to cutting injury was higher than that(75%) of tips to crushing injury. 4. The delay in time from amputation and replacement did not significantly correlate with the survival rate. But, all tips replaced within 3 hours were survived completely or partially. 5. Even if partial necrosis on grafted tips was present, a result of long-time conservative treatment with minimal debridrement was excellent. Especially in children, the tips with conservative treatment showed normal appearance, several months later. 6. Cosmetic and functional results were better in child group and in groups with higher survival rate. Most common problem in cosmetic aspect was a short digit and that in functional aspect was a tender tip. 7. As a heat lamp increased blood supply, we could obtain better outcome.

Full-thickness skin grafts for vaginal reconstruction in mayer-fokitansky-hauser syndrom

Mayer-Rokitansky-Kuster-Hauser Syndrom is characterized by the absence of the vagina and the uterus, the presence of apparently normal tubes and ovaries, feminine appearance, normal female secondary sexual characteristics, a normal 46, XX karyotypes, and a feminine psychosexual orientation. Absence of the vagina results from an embryological arrest in the development of the lower portion of the Mullerian system. Various methods of surgical treatment for the vaginal absence in this syndrom have been introduced but the ideal method to restore the original dimension and function of the normal vagina was not found. The two cases reviewed in this paper were all treated with modified McIndoe operation using full thickness skin grafts. Postoperatively both women were satisfied without complications, i,e. lack of skin graft, bleeding, urethrovaginal fistula, perforation of the rectum, rectovaginal fistula and significant vaginal stricture. This paper reveals the satisfactory results that were uniformly good.