• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.539-546
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• 2019

Liver biopsy is invasive and it is a risk of complications. Nevertheless, liver biopsy is gold standard for predicting liver fibrosis. To compensate for these shortcomings, in this study, the liver fibrosis stage was divided using Fibroscan(R) in 200 chronic hepatitis C patients. And, the usefulness and cut-off values of fibrosis index based on four factors(FIB-4), AST to platelet ratio index(APRI) and AST/ALT ratio(AAR) calculated as serum tests were investigated by analyzing ROC curve. As a result, using FIB-4 and APRI rather than AAR is appropriate for evaluation of liver fibrosis. And using APRI to predict significant Fibrosis(F2) and FIB-4 is considered useful for predicting cirrhosis(F4). By applying the advantages of the serum based liver fibrosis marker, which are convenient and repeatable, liver fibrosis follow-up term can be reduced, and furthermore, the prevalence of liver cirrhosis and hepatocellular carcinoma(HCC) can be reduced.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.627-634
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• 2020

Instead of lead, we intend to develop shielding materials for morphological implementation by mixing barium sulfate, an eco-friendly substance, and PLA filament, a 3D printer material. The environmental substance, barium sulfate powder and PLA filament, a 3D printer material, were used, and the shielding was made with a 3D printer after being fused into an extruder to mix the powder powder of barium sulfate with PLA. To check the mixing ratio of barium sulfate powder and PLA filament, the mixing input was analyzed, and the absorption dose by thickness according to barium sulfate content was obtained to check the shielding function of the mixed shielding. In the evaluation of the mixture of sulfate barium powder particles and PLA filaments, it was mixed in the most appropriate proportion when the content was 30% in the apparent and electron microscopic observation photographs. In the absorption dose results by thickness according to barium sulfate content, the difference between the content of 0% and the content of each % was greatest at 0.5 cm in thickness and the lowest dose value at 3 cm in thickness when the barium content was 30%. In addition, as the barium content began to increase at 30%, the absorbed dose value increased again. Instead of conventional lead, barium sulfate, an eco-friendly substance, could be mixed with PLA, a filament material, to create morphological shielding. Based on this study, it is expected that the mixing ratio of barium to the mixture is the most appropriate 30%, and will be used as the basis for the implementation of morphological shielding using 3D printers in the diagnosis and treatment section.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.112-123
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• 2007

Purpose: Evaluate the clinical results of humerus neck nonunion treated with Polarus intramedullary nail. Materials and Methods: 8 patients who underwent surgery for nonunion of humerus surgical neck fracture were included. All patients were female, the average age was 65 years. 5 out the total 8 cases initially received surgery, open reduction and internal fixation with metal plate in 1 case, Ender nail insertion in 2 cases, external fixator in 1 case and closed reduction and percutaneous pinning in 1 case. The other 3 non union cases initial received conservative managemnent. The average period of nonunion was 9 months in the operated group and 6.2 months in the conservative group. All 8 cases received closed reduction with intrameedullary Polarus nail and auto iliac bone graft. Union was confirmed radiologically, and functional evaluation was done with the UCLA functional criteria. Results: All 8 cases showed union on radiologic evaluation. Average time to union was 3.5 months, average follow up period was 27 months. Average UCLA shoulder evaluation score was 7.6 points preoperatively which improved to 26.3 points after surgery. Active shoulder flexion was 40.7 degrees preoperatiely which increased to 104 degrees after surgery. Shoulder abduction improved from 32.9 degrees preoperatively to 96.3 degrees after surgery. UCLA functional criteria was good in 5 cases and fair in 3 cases, which no poor cases. Conclusion: Polarus IM nailing and AIBG is a useful method for treating nonunion of humerus neck fracture with improvement in union and function.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.801-809
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• 2019

Existing Gamma Knife Radiosurgery(GKRS) for large lesions is often conducted in stages with volume or dose partitions. Often in case of volume division the target used to be divided into sub-volumes which are irradiated under the determined prescription dose in multi-sessions separated by a day or two, 3~6 months. For the entire course of treatment, treatment informations of the previous stages needs to be reflected to subsequent sessions on the newly mounted stereotactic frame through coordinate transformation between sessions. However, it is practically difficult to implement the previous dose distributions with existing Gamma Knife system except in the same stereotactic space. The treatment area is expanding because it is possible to perform the multistage treatment using the latest Gamma Knife Platform(GKP). The purpose of this study is to introduce the image-coregistration based on the stereotactic spaces and the strategy of multistage GKRS such as the determination of prescription dose at each stage using new GKP. Usually in image-coregistration either surgically-embedded fiducials or internal anatomical landmarks are used to determine the transformation relationship. Author compared the accuracy of coordinate transformation between multi-sessions using four or six anatomical landmarks as an example using internal anatomical landmarks. Transformation matrix between two stereotactic spaces was determined using PseudoInverse or Singular Value Decomposition to minimize the discrepancy between measured and calculated coordinates. To evaluate the transformation accuracy, the difference between measured and transformed coordinates, i.e., ${\Delta}r$, was calculated using 10 landmarks. Four or six points among 10 landmarks were used to determine the coordinate transformation, and the rest were used to evaluate the approaching method. Each of the values of ${\Delta}r$ in two approaching methods ranged from 0.6 mm to 2.4 mm, from 0.17 mm to 0.57 mm. In addition, a method of determining the prescription dose to give the same effect as the treatment of the total lesion once in case of lesion splitting was suggested. The strategy of multistage treatment in the same stereotactic space is to design the treatment for the whole lesion first, and the whole treatment design shots are divided into shots of each stage treatment to construct shots of each stage and determine the appropriate prescription dose at each stage. In conclusion, author confirmed the accuracy of prescribing dose determination as a multistage treatment strategy and found that using as many internal landmarks as possible than using small landmarks to determine coordinate transformation between multi-sessions yielded better results. In the future, the proposed multistage treatment strategy will be a great contributor to the frameless fractionated treatment of several Gamma Knife Centers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1750-1756
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• 2011

This study evaluated the effect of antioxidants treatment; (Vit. C and E) on the physicochemical and sensory properties of Tarakjuk treated with gamma-irradiation under two different temperature conditions, e.g. room and frozen temperatures. In samples of Tarakjuk irradiated at room temperature, Vit. C gradually decreased the pH level as the concentration increased (p<0.05), whereas Vit. E did not. Addition of both Vit. C and E to Tarakjuk decreased TBA (2-thiobarbituric acid) value while also increasing viscosity. However, these antioxidants did not cause any change in Hunter's color values. Sensory properties showed that Vit. C and E significantly improved the overall acceptability of Tarakjuk, and the addition of 0.1% each Vit. C and E was best treatment. In samples of Tarakjuk subjected to combined treatment with antioxidants and irradiation under frozen temperature conditions, Vit. C and E were effective in decreasing TBA value, improving viscosity, and maintaining sensory quality. Especially, co-treatment with 0.1% Vit. C and E augmented the observed effect (p<0.05). Therefore, combined treatment with antioxidants and irradiation under frozen temperature conditions could improve the final sensory quality of gamma-irradiated Tarakjuk.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.369-375
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• 2011

In dental radiography, panoramic views cause distortion and thus may bring about inaccurate results in the process of quantitative analysis. In this connection, there has recently been an increasing use of cone beam computed tomography (CBCT) that is known to provide high-resolution images and positional information. In this study, a dental computed tomography unit, 'DCT-90-P IMPLAGRAPHY (Vatech, Korea)', was applied to 20 patients for 24 seconds respectively, with a tube voltage of 85kVp and a tube current of 7mA. The data of CBCT were three-dimensionally reconstructed by use of a computer program, and were histomorphometrically analyzed. The results showed that the diameter of mandibular canal is less distorted at a certain inclination of the mandibular body. The image tends to seem more distended in proportion to the distance between the subject and film. Also, the image tends to be affected according as it is out of focus. In conclusion, it requires that the image should be reconstructed in light of anatomic position and structure.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.45-51
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• 2020

The purpose of this study was to analyze the educational effect of self-directed learning method using 3D printed anatomy on radiological science students. The subjects were 32 students (20 males and 12 females) in the second year of radiological science at university. They were divided two groups as a non-active student group and an active student group. A learning method was self-directed learning using 3D printed anatomical structures, and the effects of quantitative learning improvement were evaluated before and after the learning. The qualitative evaluation of the students was analyzed on the Likert's 5-point scale for the interest, satisfaction, and learning effects (memorization convenience of anatomy name, radiography Interpret ability, understanding on bones structure, and X-ray projection technique). As a result, the enhancement of learning improved 65.4% on average, and all students got scored high on all variables. Especially non-active student groups showed higher correlation coefficients in all variables except interest and radiography interpret than active student groups. These results might suggest that self-directed learning using 3D printed anatomical structures could have a positive educational effect on radiological science students.

• Journal of Radiation Protection and Research
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• v.22 no.3
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• pp.195-205
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• 1997

This paper is to assess the effect of Adaptagen as a radioprotector in which main component is alkaloid fraction of ginseng. Evaluation was made in vitro and in vivo study with NIGP(S) mouse by the measurement of regeneration of jejunal crypt cell and micronucleus assay to analyze radioprotective effect of ginseng alkaloid fraction in comparison with that of water fraction after whole body irradiation. The results were as follows, 1. The degree of radiation damage of mouse jejunal crypt cell was diminished in both of alkaloid and water fraction groups compared to control group but more in alkaloid fraction group than water fraction group. Regeneration of mouse jejunal crypt cell was higher both in alkaloid and water fraction groups than control group. 3. In vitro study, frequency of micronucleus was diminished in tendency for the treated groups than control group but statistically insignificant. 4. In vitro study, frequency of micronucleus was diminished in both alkaloid and water fraction groups compared to control group but more in alkaloid fraction group than water fraction group.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.155-159
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• 2013

Late effects of chronic exposure to gamma radiation are potential hazards to worker in radiation facilities as well as to the general public. Recently, chronic gamma radiation exposure effects have become a serious concern. Using a total of 60 mice, we studied the biological effects of medium-dose chronic exposure to gamma radiation. Sixty female 6-week-old specific pathogen free Balb/c mice were randomly divided into six groups (five groups irradiated and one non-irradiated control group). Irradiation was carried out for 7 days using gamma rays at dose rates of 119.65, 238.10, 357.14, 476.19 and $595.24mGy\;h^{-1}$ with total doses 20, 40, 60, 80 and 100 Gy. After irradiation, we determined survival rate of gamma radiation exposed mice during 1 week and 476.19 and $595.24mGy\;h^{-1}$ exposed group mice showed less 10% of survival rate. Otherwise, 119.65, 238.10 and $357.14mGy\;h^{-1}$ exposed group mice were survived each 100%, 80% and 70%. Half of survived mice after 1 week are immediately sacrifice and counted body and spleen weights. Compared with control non-irradiated group, total body weights and spleen weights isolated from 119.65, 238.10 and 357.14 irradiated group mice showed significant decreased. However, no significant alteration was observed between 119.65, 238.10 and $357.14mGy\;h^{-1}$ irradiated group. Overall, our results show for the first time that medium-dose chronic gamma radiation has the potential to stimulation of biological effects.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.252-260
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• 2004

The purpose of study is to evaluate the clinical implication of malignant Pleural Lavage Cytology (PLC) in primary lung cancer. 315 patients were examined with pleural lavage cytology in Asan Medical Center between November 1998 and August 2002. The patients were chosen from primary lung cancer patients with no pleural effusion according to preoperative radiologic examination; no tumor invasion into the chest wall and no diffuse pleural adhesion in intraoperative findings, The pleural cavity and lung were washed with 100 $m\ell$ of warm normal saline. The 315 patients consisted of 237 men and 78 women. The incidence of malignant PLC was found in 28 patients (8.9%). For patients in early stages (I & II), survival rate was 93.9% in positive malignant PLC and 85.7% in negative malignant PLC. 31 patients (13.6%) had local or distant recurrences; 2-year recurrence-free rate was 90.1% in negative PLC and 87.5% in positive PLC. The survival and recurrence-free rate in each stage were not statistically associated with the result of PLC. Median follow-up was 16.4 months from the surgery. To access implication of malignant PLC in primary lung cancer, a long-term follow-up and further study are required.