• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.8
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• pp.160-171
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• 1994

The wide dynamic range and severely attenuated contrast in mediastinal area appearing in typical chest radiographs have often caused difficulties in effective visualization and diagnosis of lung diseases. This paper proposes a new adaptive image enhancement technique which potentially solves this problem and there by improves observer performance through image processing. In the proposed method image processing is applied to the chest radiograph with different processing parameters for the lung field and mediastinum adaptively since there are much differences in anatomical and imaging properties between these two regions. To achieve this the chest radiograph is divided into the lung and mediastinum by gray level thresholding using the cumulative histogram and the dynamic range compression and local contrast enhancement are carried out selectively in the mediastinal region. Thereafter a gray scale transformation is performed considering the JND(just noticeable difference) characteristic for effective image displa. The processed images showed apparenty improved contrast in mediastinum and maintained moderate brightness in the lung field. No artifact could be observed. In the visibility evaluation experiment with 5 radiologists the processed images with better visibility was observed for the 5 important anatomical structures in the thorax.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.16 no.1
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• pp.19-24
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• 1986

The author performed radiographical analysis of the third molar dentition and characteristic relation to anatomical oral structure. For this purpose 506 orthopantomagraph film, male 283cases and female 223 cases, aged from 15 to 30 years were evaluated by means of Winter's classification in conjunction with some other methods. Through the study following results were obtained; 1. The eruption of(equation omitted) were found in 229 cases followed by 61 cases of(equation omitted) and 45 cases showed no evidence of eruption. 2. The classification based on the relation of ramus to distal portion of the 2nd molar revealed class Ⅱ, 460 cases (61.8%) and 182 cases (24.5%) were class Ⅲ. 3. Parallelism between long axis of mandibular third molar and the second molar were found in 302 cases (40.8%) and mesial inclination of the third molar were 280 cases (37.6%). 4. Average inclination degree among these cases showed 138.62±12.56°.

• Korean Journal of Head & Neck Oncology
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• v.5 no.1
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• pp.15-20
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• 1989

There is a difficulty in complete removal of tumor developing at the parapharyngeal space or infratemporal space where they are just under the skull base. We have experienced 3 cases of malignant tumors and 5 cases of benign tumors arising from the parapharyngeal spaces and/or infratemporal space since 1976. We hereby present 8 cases of primary tumors arising in these spaces with a review of anatomical relationship between above spaces, the characteristic symptoms, diagnostic technics, and surgical approaches which should be considered in their management.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.680-686
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• 1989

Supravalvular aortic stenosis may be defined as an obstructive congenital deformity of the ascending aorta which originates just distal to the level of the origin of the coronary arteries. It may occur in several different anatomical form. Three type have been described; the hourglass, the hypoplastic and the membranous type, each term identifying the gross characteristic of the lesion causing by the aortic obstruction. Non cardiovascular condition commonly associated with supravalvular aortic stenosis are mental retardation, facial anomalies, hypercalcemia, etc. The diagnosis can be established preoperatively by left heart catheterization and selective angiography. Recently, we experienced a case of multiple localized supravalvular aortic stenosis involving, just above the sinus Valsalva and just proximal of the innominate artery. The surgical correction which was performed by a vertical incision across the each narrowing of aorta with replacement of diamond shaped double velour Woven Dacron patch under the CPB. He was discharged without any event.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.1
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• pp.141-148
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• 1993

The author analyzed the clinical and radiographic findings of 109 malignant tumors of epithelial origin occured in the jaws of the patients visited the infirmaries of Dentistry, Chosun University and several university in Korea during 1978 to 1988. The observed results were as follows: 1. It appeared that 93 % of the total 397 cases diagnosed as oral malignant tumors were squamous cell carcinomas. 2. The incidence ratios between nodular type and ulcer type were 4 to 1 in maxilla and 3 to 1 in mandible. 3. In nearly 50% of all patients complained of pain due to impingement of tumor mass or ulcer. 4. Most of carcinomas of maxilla eventually invaded into maxillary sinus and palate. 5. Characteristic features on the radiographs were the lesion with ill-defined border, the direct destruction of the alveolar bone and anatomical landmark without displacement of the involved teeth and the gray shadow of the tumor mass in the lesion.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.155-156
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• 2009

In this paper we present 3D image analysis of liver and blood vessels using MDCT. The purpose is to enhance the performance of clinician in assessing anatomical information of liver and blood vessels. The system consists of two parts: 3D image reconstruction and analysis of the 3D liver and blood vessel image. The central vein of the liver is the most important blood vessel for the liver transplantation. We will find the central vein's location and characteristic, and will scheme out a computer assistant liver transplantation planning. It will be an effective tool for interventional radiology, surgical planning, and quantitative diagnosis.

• ALGAE
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• v.19 no.3
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• pp.161-174
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• 2004

Phonological, morphological and molecular characteristics of Spatoglossum pacificum Yendo are examined. S. pacificum has an annual life cycle composed of saprophytes with apparent absence of male and female gametophytes in Korea. The seasonal growth of this species explains that the annual growth is closely related to the monthly variation of water temperature. S. pacificum has protruding reproductive structures above the outmost cortical layer. Although this observation is restricted to several species, reproductive structures on the thallus can make S. pacificurn distinguishable from S. crassum and S. lacturn. The morphogenesis of a midrib at the base of S. pacificum in this study is the same as those of Dictyopteris but different from those of S. crassum and S. lacturn, suggesting that S. pacificum is closely related to Dictyopteris. In the comparison of plastid gene sequences among species of Spatoglossum and Dictyopteris, S. pacificum is more similar to D. divaricata and D. undulate than those of S. crassum in rbcL, rbcS, psbA and psaA. This result is congruent with the anatomical characteristic of a midrib at the base of the thallus and the protrusion of reproductive organs on the thallus. The phylogenetic relationship based on these plastid genes also shows that S. pacifism is included in Dictyotpteris Glade and separated from S. crassum. We propose the new combination of Dictyopteris pacifica (Yendo) I.K. Hwang, H.S. Kim et W.J. Lee, comb. nov. based on the differences of anatomical characteristics of the midrib, the existence of reproductive organs on thallus and the molecular analyses.

• Korean Journal of Pharmacognosy
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• v.44 no.4
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• pp.320-325
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• 2013

"SaCheolNaMu" has been used as a Korean folk medicine for the jaundice, lumbago and uterine diseases. Although a crude drug related to this folk medicine is sold in traditional herbal market, the botanical origin of this drug has not been pharmacognostically confirmed yet. In this study, the morphological and anatomical characteristics of the stem of Euonymus species growing in Korea, i.e. Euonymus japonica and E. fortunei var. radicans were studied to clarify the botanical origin of "SaCheolNaMu". As a result, it was found that these two species could be discriminated by the morphological criteria such as the thickness of cuticles, the number of collenchyma cell layers, and the frequency of druse and resinous substance. According to these criteria, it was elucidated that the commercial folk medicine "SaCheolNaMu" was the stem of E. japonica. Meanwhile, HPLC-DAD analysis on the 70% ethanolic extracts of two species showed significantly different HPLC profiles each other. The molecular ions of three characteristic peaks shown in the chromatogram of two species were identified by ESI-MS, and their structures were estimated to be flavonol glycosides.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2441-2445
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• 2015

Background: Several risk factors leading to malignant transformation of hydatidiform moles have been described previously. Many studies showed that prophylactic chemotherapy for high risk hydatidiform moles could significantly decrease the incidence of malignancy. Thus, it is essential to discover a breakthrough to determine patients with high risk malignancy so that prophylactic chemotherapy can be started as soon as possible. Objectives: Development of a scoring system of risk factors as a predictor of hydatidiform mole malignant transformation. Materials and Methods: This research is a case control study with hydatidiform mole and choriocarcinoma patients as subjects. Multiple logistic regression was used to analyze the data. Odds ratios (OR), attributable at risk (AR : OR-1) and risk index ($ARx{\beta}$) were calculated for develoipment of a scoring system of malignancy risk. The optimal cut-off point was determined using receiver operating characteristic (ROC) curve. Results: This study analyzed 34 choriocarcinoma cases and 68 benign hydatidiform mole cases. Four factors significantly increased the risk of malignancy, namely age ${\geq}35$ years old (OR:4.41, 95%CI:1.07-16.09, risk index 5); gestational age ${\geq}$ 12weeks (OR:11.7, 95%CI:1.8-72.4, risk index 26); uterine size greater than the gestational age (OR:10.2, 95%CI:2.8-36.6, risk index 21); and histopathological grade II-III (OR:3.4, 95%CI:1.1-10.6, risk index 3). The lowest and the highest scores for the risk factors were zero and 55, respectively. The best cut-off point to decide high risk malignancy patients was ${\geq}31$. Conclusions: Malignant transformation of hydatidiform moles can be predicted using the risk scoring by analyzing the above four parameters. Score ${\geq}31$ implies high risk patients so that prophylactic chemotherapy can be promptly administered for prevention.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.3
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• pp.139-144
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• 2011

The purpose of this report is recommending a standard indicator which reflects the radiation exposure that is incident on a detector after every exposure event and that reflects the noise levels present in the image data. The experiment was performed with mobile digital X-ray unit and used a acrylic phantom for exposure index measurement. Exposure modality was kVp, mAs, SID. After every exposure, make a data sheet for characteristic curve of detector response. The equipment performed Mobile digital X-ray unit provide the user with values ralated to the incident exposure(air kerma)to the digital detector. They are showed as a logarithmic function shaped. As a result, DEI means a relative measure of exposure to the detector, as compared to the expected exposure for a particular anatomical view. Radiographic technique is the combination of factors used to exposure an anatomical part to produce a high quality radiography and technique charts used most commonly by radiographers to produce consistently exposure level which patient dose can be kept acceptably low.