• Journal of the Korean Society of Radiology
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• v.11 no.4
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• pp.227-234
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• 2017

This study evaluated the usefulness of the elasticity score and strain ratio in the differential diagnosis of benign and malignant nodules in thyroid elastography. We performed a retrospective analysis based on the results of fine needle aspiration cytology. The Chi-square test and the Mann-Whitney U test were used to analyze the difference between the five degrees of elasticity score and strain ratio according to the benign and malignant thyroid nodules. ROC curve analysis was used to determine the elasticity score and the best cut-off value of the strain ratio for the prediction of malignant nodules. There was a statistically significant difference (p=0.000) between the homogeneity of the elasticity score and the difference of the strain ratio between the benign and malignant nodule groups. On the ROC curve analysis, the elasticity score and the srain ratio for predicting benign and malignant nodules were determined as AUC 0.842, 0.700, cut-off value 3, 2.49 (p=0.001). Therefore, the elasticity score and strain ratio may be useful in the differential diagnosis of thyroid nodules.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.475-481
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• 2017

As the research about supplementary education of radiological technologist who works in Gyoungsangnam province, this study was conducted to draw the improvements by analyzing the satisfaction level and problems of the supplementary education. During November 01, 2016 to December 15, 2016, after we sent out a total of 250 questionnaires for the survey to radiological technologists working at medical institution located in Gyoungsangnam province, 200 questionnaires suitable for research were analysis by using SPSS 18.0 statistical analysis software. As the satisfaction factors, 21 items such as system, subject, help, appropriateness of lecturer selection, professionalism were used. And as the problem factors, 18 items such as place, transportation, diversity, administrative treatment, education promotion, proceed method were used. Consequentially, the satisfaction level(3.12 point) and problems(3.01 point) of the supplementary education were confirmed as normal level. The supplementary education is an essential education that any health and medical service personnel must complete. In order to improve the effectiveness and efficaciousness of the education, the diverse opinions and efforts to improve the education levels must be supported. Futhermore, through the realistic educational program, the continuous education for radiological technologist with excellent qualities and competence should be done.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.547-556
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• 1996

The purpose of this study was to evaluate the skeletal, dental and soft tissue profile changes following the face mask therapy in growing skeletal class III malocclusion patients. The fifteen patients with the good results were selected among the patients who visited the Department of Orthodontics in Seoul National University Hospital. The mean age was 10.63(range 7.25-13.25) years and the mean treatment duration was 9.84(range 2.00-27.00) months. Lateral cephalograms were taken just before and after face mask application. After tracing the cephalograms, thirty five items(twety angular and fifteen linear) were measured. The differences before and after the face mask therapy were compared statistically by the paired t-test(p<0.05). The results were as follows : SNA and Co-A(effective maxillary length) increased significantly after using the face mask(p<0.001), which reflects the orthopedic changes of maxilla. SNB and Co-Gn(effective mandibular length) also showed an increase(p<0.01), which may be a result of the strong growth trends of the samples. FMA, SN-GoGn and Y-axis angle increased significantly(p<0.01), which means the backward and downward rotation of the mandible. This positional change seemed to have compensated an increase of effective mandibular length. There was no statistically significant difference in angulation of upper and lower incisors between pre-treatment and post-treatment(p>0.05). In soft tissue profile, the upper lip was positioned anteriorly(p<0.01) after treatment and approximated to the normal standards.

• Parasites, Hosts and Diseases
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• v.34 no.1
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• pp.21-26
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• 1996

An experimental study was carried out to observe the effects of radiation on the infectivity of metacercariae of Gymnophalloines seoi to C3H mice. Oysters, the second intermediate host, were collected from an endemic area, and non-irradiated control, metacercaria-irradiation, and oyster-irradiation groups were prepared . One hundred metacercariae were infected orally to each mouse, and worm recovery rate was compared by groups at 7th day post-infection. In the metacercaria-irradiation group, the worm recovery rate was significantly reduced at radiation doses higher than 200 Gy, and the number of intrauterine eggs significantly reduced at doses over 50 Gy. In the oyster- irradiation group, 50 Gy significantly reduced both the worm recovery rate and number of uterine eggs. In the two groups, no worm was recovered at 1,000 Gy irradiation. Conclusively, irradiation of oysters with 200-1,000 Gy was effective to control infectivity of metacercariae to C3H mice, and could be adopted as a control measure for gymno-phalloidiasis.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.399-408
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• 1998

Purpose : This study was designed to demonstrate the potential therapeutic advantage of 3-dimensional (3-D) treatment planning over the conventional 2-dimensional (2-D) approach in patients with carcinoma of the nasopharynx. Materials and Methods : The two techniques were compared both qualitatively and quantitatively for the boost portion of the treatment (19.8 Gy of a total 70.2 Gy treatment schedule) in patient with T4. The comparisons between 2-D and 3-D plans were made using dose statistics, dose-volume histogram, tumor control probabilities, and normal tissue complication probabilities. Results : The 3-D treatment planning improved the dose homogeneity in the planning target volume. In addition, it caused the mean dose of the planning target volume to increase by 15.2$\%$ over 2-D planning. The mean dose to normal structures such as the temporal lobe, brain stem, parotid gland, and temporomandibular joint was reduced with the 3-D plan. The probability of tumor control was increased by 6$\%$ with 3-D treatment planning compared to the 2-D planning, while the probability of normal tissue complication was reduced. Conclusion : This study demonstrated the potential advantage of increasing the tumor control by using 3-D planning. but prospective studies are required to define the true clinical benefit.

• Journal of the Korean Society of Radiology
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• v.8 no.4
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• pp.163-170
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• 2014

This study is to investigate neuro-anatomical correlation between neuropsychological results and cerebral cortex thickness of cognitive ability in the brain MRI targeting the patients with mild cognitive impairment. It was that 78 people who were diagnosed as first Parkinson's disease followed by neuropsychological screening battery(Parkinson's disease with mild cognitive impairment: 39 people; Parkinson's disease with normal cognition: 39 people) and 32 people of normal group were selected. Correlation between mild cognitive impairment and normal cognitive impairment and correlation between neuropsychological screening battery and cerebral cortex thickness in the brain MRI were performed by independent sample t-test or Pearson correlation coefficient and then level of significance of collected data was verified in p<0.05. As a result, cerebral cortex thickness of the Parkinson's disease with mild cognitive impairment in both side precuneas and right inferiortemporal lobe had statistically significant decrease. In addition, function of visuospatial ability, verbal and visual memory was reduced in neuropsychological screening battery for cognitive assessment. Especially, there was correlation between neuropsychological screening battery of verbal and visual memory anatomical left precuneus.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.3
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• pp.156-162
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• 2021

The number of smart farms has increased to save labor in agricultural production as the subsidy become available from central and local governments. The number of illegal greenhouses has also increased, which causes serious issues for the local governments. In the present study, we developed Mask-RCNN model to detect greenhouses based on satellite images. Greenhouses in the satellite images were labeled for training and validation of the model. The Mask-RC NN model had the average precision (AP) of 75.6%. The average precision values for 50% and 75% of overlapping area were 91.1% and 81.8%, respectively. This results indicated that the Mask-RC NN model would be useful to detect the greenhouses recently built without proper permission using a periodical screening procedure based on satellite images. Furthermore, the model can be connected with GIS to establish unified management system for greenhouses. It can also be applied to the statistical analysis of the number and total area of greenhouses.

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.555-564
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• 2021

Thalamus is known to play an important role in the regulation of nerve function. Thalamus, located in the center of the brain, is involved in sleep, arousal, and emotional regulation, and has been reported to be associated with multiple sclerosis, essential tremors, and neurodegenerative diseases such as Parkinson's disease. In addition, it has been reported that iron deposits in the thalamus can cause depressive symptoms with age. Although there are discrepancies between studies, it can be deduced that the thalamus region has a clear effect on neurological disorders due to a strong relationship between the thalamus and neurological functions such as emotional control and processing. Through tractography analysis, the connectivity between the detailed areas of each subcortical region was investigated in the form of a matrix, showing strong connectivity and weak interhemispheric connectivity. In the 59> group, the WM connectivity of thalamus was found to be weaker than those of the two groups. Comparisons between the two groups showed that the young groups (10-39 and 40-59) had higher connection intensity than the 59> group and that statistically significant differences in 3 connection pathways were found in each hemisphere. A decrease in thalamus-related connection strength in aging has shown that it can affect emotional and neurological disorders such as anxiety and depression, and network measurements can help assess cognitive impairment across clinical conditions.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.402-413
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• 2022

The aim of this study was to identify factors that affect the treatment duration and to predict the duration of forced eruption in impacted maxillary canines using panoramic radiographs and cone-beam computed tomography. This retrospective study was performed by reviewing medical records and radiographs of 73 patients (93 impacted maxillary canines) from the age of 8 to 18 years who were treated with surgical and orthodontic interventions on impacted maxillary canines from January 2012 to December 2020 in Ajou University Dental Hospital. Stepwise multiple regression analysis showed that the distance between the canine cusp tip and the occlusal plane, mesio-distal location, bucco-palatal location, patient's age, and use of rapid palatal expansion are significant factors with regard to the duration of forced eruption. There was a statistically significant correlation of the treatment duration with the angulation between the axis of the canine and the occlusal plane and unilateral or bilateral impaction. It can be concluded that the duration of forced eruption in impacted maxillary canines could be shorter when the impacted canine is closer to the occlusal plane and located in the lateral incisor or canine area, buccal or middle, the patient is younger and uses rapid palatal expansion.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.961-968
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• 2022

Rotator cuff tears are a leading cause of shoulder pain in adults. Due to the increase in social activities, the number of patients complaining of shoulder pain is increasing, and interest in shoulder diseases is also increasing. With the development of ultrasound equipment, the sensitivity and specificity of diagnosis are high, and it is used to diagnose rotator cuff tears in musculoskeletal disease. Ultrasound is recognized as a complementary method to MRI examination in rotator cuff tears. Therefore, this study aimed to find out the diagnostic usefulness of ultrasound and MRI examinations in the diagnosis of shoulder rotator cuff tears.A retrospective analysis was performed on 262 patients who were diagnosed with final rotator cuff damage by arthroscopy after completing ultrasound and MRI examinations. Sensitivity, feature, positive predictive value, image predictive value, and touch were disassembled for the test results. In addition, the degree of clavicular tear was scored and recorded in 5 stages. Ultrasound examination was similar to MRI examination results for both full-thickness and partial tears, and there was no statistically significant difference. Partial tear test results showed higher positive predictive value and accuracy than MRI test. In conclusion, ultrasound can be fully utilized as a screening test for rotator cuff disease, and it is thought that it will be selected and used clinically according to the patient's constitution and situation.