• Progress in Medical Physics
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• v.24 no.1
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• pp.76-83
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• 2013

Previous studies about effect of respiratory motion on diagnostic imaging and radiation therapy have been performed by monitoring external motions but these can not reflect internal organ motion well. The aim of this study was to develope the artificial pulmonary nodule able to perform non-invasive implantation to dogs in the thorax and to evaluate applicability of the model to respiratory motion studies on PET image acquisition and radiation delivery by phantom studies. Artificial pulmonary nodule was developed on the basis of 8 Fr disposable gastric feeding tube. Four anesthetized dogs underwent implantation of the models via trachea and implanted locations of the models were confirmed by fluoroscopic images. Artificial pulmonary nodule models for PET injected $^{18}F$-FDG and mounted on the respiratory motion phantom. PET images of those acquired under static, 10-rpm- and 15-rpm-longitudinal round motion status. Artificial pulmonary nodule models for radiation delivery inserted glass dosemeter and mounted on the respiratory motion phantom. Radiation delivery was performed at 1 Gy under static, 10-rpm- and 15-rpm-longitudinal round motion status. Fluoroscpic images showed that all models implanted in the proximal caudal bronchiole and location of models changed as respiratory cycle. Artificial pulmonary nodule model showed motion artifact as respiratory motion on PET images. SNR of respiratory gated images was 7.21. which was decreased when compared with that of reference images 10.15. However, counts of respiratory images on profiles showed similar pattern with those of reference images when compared with those of static images, and it is assured that reconstruction of images using by respiratory gating improved image quality. Delivery dose to glass dosemeter inserted in the models were same under static and 10-rpm-longitudinal motion status with 0.91 Gy, but dose delivered under 15-rpm-longitudinal motion status was decreased with 0.90 Gy. Mild decrease of delivered radiation dose confirmed by electrometer. The model implanted in the proximal caudal bronchiole with high feasibility and reflected pulmonary internal motion on fluoroscopic images. Motion artifact could show on PET images and respiratory motion resulted in mild blurring during radiation delivery. So, the artificial pulmonary nodule model will be useful tools for study about evaluation of motion on diagnostic imaging and radiation therapy using laboratory animals.

• Radiation Oncology Journal
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• v.18 no.1
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• pp.11-16
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• 2000

Purpose :We peformed the retrospective analysis to find the outcome of external beam radiotherapy alone in advanced esophageal cancer patients. Methods and Materials : One hundred and six Patients treated with external beam radiotherapy alone between July 1990 and December 1996 were analyzed retrospectively. We limited the site of the lesions to the thoracic esophagus and cell type to the squamous cell carcinoma. Follow-up was completed in 100 patients (94$\%$) and ranged from 1 month to 92 months (median; 6 months). Results :The median age was 62 years old and male to female ratio was 104 2. Fifty-three percent was the middle thorax lesion and curative radiotherapy was peformed in 83$\%$. Mean tumor dose delivered with curative aim was 58.6 Gy (55$\~$70.8 Gy) and median duration of the radiation therapy was 53 days. The median survival of all patients was 6 months and )-year and 2-year overall survival rate was 27$\%$ and 12$\%$, respectively, Improvement of dysphagia was obtained in most patients except for 7 patients who underwent feeding gastrostomy. The complete response rate immediately after radiation therapy was 32$\%$ (34/106). The median survival and 2-year survival rate of the complete responder was 14 months and 30$\%$ respectively, while those of the nonresponder was 4 months and 0$\%$ respectively (p=0.000). The median survival and 2-year survival rate of the patients who could tolerate regular diet was 9 months and 16$\%$ while those of the patients who could not tolerate regular diet was 3 months and 0$\%$, respectively (p=0.004). The survival difference between the patients with S cm or less tumor length and those with more than 5 cm tumor length was marginally statistically significant (u=0,06). However, the survival difference according to the periesophageal invasion or mediastinal tyrnphadenopathy in the chest CT imaging study was not statistically significant in this study. In a multivariate analysis, the statistically significant covariates to the survival were complete response to radiotherapy, tumor length, and initial degree of dysphagia in a decreasing order. The complication was observed in 10 patients (9$\%$). Conclusion :The survival outcome for advanced esophageal cancer patients treated by external beam radiotherapy alone was very poor. In the treatment of these patients, the brachytherapy and chemotherapy should be added to improve the treatment outcome.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.299-306
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• 2009

Purpose : To compare radiation dose for coronary CT angiography (CTA) obtained with 6 examination protocols such as a retrospectively ECG gated helical scan, a prospectively ECG gated sequential scan, low kVp technique, and cardiac dose modulation technique. Materials and Methods : Coronary CTA was performed by using 6 current clinical protocols to evaluate effective dose and organ dose in primary beam area with anthropomorphic female phantom and glass dosimetric system in 64 channel multi-detector CT. After acquiring topograms of frontal and lateral projection with 80 kVp and 10 mA, main coronary scan was done with 0.35 sec tube rotation time, 40 mm collimation ($0.625\;mm{\times}64\;ea$), small scan field of view (32 cm diameter), 105 mm scan length. Heart beat rate of phantom was maintained 60 bpm in ECG gating. In constant mAs technique 120 kVp, 600 mA was used, and 100 kVp for low kVp technique. In a retrospectively ECG gated helical CT technique 0.22 pitch was used, peak mA (600 mA) was adopted in range of $40{\sim}80%$ of R-R interval and 120mA(80% reduction) in others with cardiac dose modulation. And 210 mAs was used without cardiac dose modulation. In a prospectively ECG gated sequential CT technique data were acquired at 75% R-R interval (middle diastolic phase in cardiac cycle), and 120 msec additional padding of the tube-on time was used. For effective dose calculation region specific conversion factor of dose length product in thorax was used, which was recommended by EUR 16262. Results : The mean effective dose for conventional coronary CTA without cardiac dose modulation in a retrospectively ECG gated helical scan was 17.8 mSv, and mean organ dose of heart was 103.8 mGy. With low kVp and cardiac dose modulation the mean effective dose showed 54.5% reduction, and heart dose showed 52.3% reduction, compared with that of conventional coronary CTA. And at the sequential scan(SnapShot pulse mode) under prospective ECG gating the mean effective dose was 4.9 mSv, this represents an 72.5% reduction compared with that of conventional coronary CTA. And heart dose was 33.8 mGy, this represents 67.4% reduction. In the sequential scan technique under prospective ECG gating with low kVp the mean effective dose was 3.0 mSv, this represents an 83.2% reduction compared with that of conventional coronary CTA. And heart dose was 17.7 mGy, this represents an 82.9% reduction. Conclusion : In coronary CTA at retrospectively ECG gated helical scan, cardiac dose modulation technique using low kVp reduced dose to 50% above compared with the conventional helical scan. And the prospectively ECG gated sequential scan offers substantially reduced dose compared with the traditional retrospectively ECG gated helical scan.

• Journal of Chest Surgery
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• v.39 no.2 s.259
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• pp.127-133
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• 2006

Background: In the studies of the distribution of time to death in trauma patients, the early deaths within several hours after injury were a large component of total trauma deaths. Due to the development of trauma system, overall mortality of trauma was decreased, but trauma is still the major cause of deaths. Material and Method: From January 1994 to December 2003, trauma patients who had been admitted and had expired at tertiary hospital were enrolled. There was a total of 400 cases, a retrospective study was done to determine the distribution of trauma mortality according to the part of the body that were severely injured part and compared the difference between early deaths within 6 hours and late deaths after 6 hours. We also analysed the risk factors of early deaths due to trauma. Result: In severe injury to the head and abdomen, the distribution of mortality was bimodal. But, in severe chest injuries, the distribution was log-shape and most early deaths were almost of trauma related. The average of GCS were 5.86$\pm$4.15 for the early deaths and 8.24$\pm$5.02 for the late deaths (p < 0.05). The AIS of thorax were 2.66$\pm$1.87 for the early deaths and 1.55$\pm$1.76 for late deaths. The risk factors for early mortality were non-EMS transportation (odds ratio 3.474), high AIS (odds ratio 1.491) and GCS (odds ratio 0.859). Conclusion: In trauma patients, the causes of early mortality were severe brain injury and massive hemorrhage. Also severe chest injuries were the major cause of the early deaths in truama. Early diagnosis of chest injury can frequently be missed in the acute trauma setting. Therefore, high index of suspicion, a careful examination, and aggressive surgical treatment are important in multiple trauma patients.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.214-221
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• 2008

Purpose: We make a qualitative analysis of whether Fusion SPECT/CT can find lesion's anatomical sites better than existing SPECT or not, and we want to show the usefulness of SPECT/CT through finding out effects of CT attenuation correction on SPECT images. Materials and Method: 1. The evaluation of fusion images: This study comprised patients who was tested $^{131}I$-MIBG, Bone, $^{111}In$-Octreotide, Meckel's diverticulum, Parathyroid MIBI with Precedence 16 or Symbia T2 from 2008 Jan to Aug. We compared SPECT/CT image with non fusion image and make a qualitative analysis. 2. The evaluation of attenuation correction: We classified 38 patients who was tested 201Tl myocardial exam with Symbia T2 into 5 sections by using Cedars Sinai' QPS program - Ant, Inf, Lat, Septum, Apex. And we showed each section's perfusion states by percentage. We compared the each section's perfusion-states differences between CT AC and Non AC by average${\pm}$standard deviation. Results: 1. The evaluation of fusion images : In high energy $^{131}I$ cases, it was hard to grasp exact anatomical lesions due to difference between regions and surrounding lesions' uptake level. After combining with CT, we could grabs anatomical lesion more exactly. And in meckel's diverticulum case or to find lesions around bowels or organs with $^{111}In$ cases, it demonstrates its superiority. Bone SPECT/CT images help to distinguish between disk spaces certainly and give correct results. 2. The evaluation of attenuation correction: There is no significant difference statistically in Ant and Lat (p>0.05), but there is a meaningful difference in Inferior, Apex and Septum (p<0.05). AC perfusion at inferior wall in the 5 sections of myocardium: The perfusion difference between Non AC perfusion image ($68.58{\pm}7.55$) and CT corrected perfusion image ($76.84{\pm}6.52$) was the largest by $8.26{\pm}4.95$ (p<0.01, t=10.29). Conclusion: Nuclear medicine physicians can identify not only molecular image which shows functional activity of lesions but also anatomical location information of lesions with more accuracy using the combination of SPECT and CT systems. Of course this combination helps nuclear medicine physician find out the abnormal parts. Moreover combined data sets help separate between normal group and abnormal group in complicated body part. So clinicians can carry out diagnosis and treatment planning at the same time with a single test image. In addition, when we examine a myocardium in thorax where attenuation can occur easily, we can trust perfusion more in a certain region in SPECT test because CT provides the capability for accurate attenuation correction. In these reasons, we think we can prove the justice after treatment fusion image.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.201-212
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• 2007

This study was conducted to investigate the biology of three species, Tipula latemarginata Alexander, T. nova Walker and T. aino Alexander, of the Genus Tipula in Korea. Field surveys for the biology of the species were carried out at the three sites of Neaseong Stream area in Bongwha County from January 2001 to December 2005. Also many individuals of the species were reared in laboratory to investigate the biology. The larval habitats of the species were streams, rivers, paddy fields, damp earth or leaky revetments. The Tipula larvae were herbivorous. Newly-hatched first instar larvae fed on soft algae, and the larvae gradually fed on leaves, stems and roots of a variety of plants or hard leaf litters, as they grew. During the molting of the larvae their body kept moving from left to right and up and down. Molting usually took not more than 2 hours, and about four hours after molting, the larvae started to eat heavily. The Tipula larvae in aquatic places moved to drier land for pupation and went through short prepupal stage lasting 1-2 days for pupation at fourth instar larval stage. When emerging, the Tipula pupae placed their head and thorax on the earth, but the other parts in the earth. Emergence from the pupal case required about 20 min. to one hour. Mating of Tipula adults took place within 5-7min. after emergence and the duration of mating was about 40 min. The female adults of the species laid eggs by walking with 3 pairs of legs over the damp earth or algal beds. Their body was positioned vertically on the ground with their wings spread $120^{\circ}$ and legs landed on the surface. The oviposition usually took place from one day to 4 days after emergence and the number of eggs carried by female adults were an average of 501-760 per individual. Tipula adults didn't normally feed, and drank water only occasionally. For a few days after emergence, the adults reared in the laboratory rarely drank water. As they neared to death, however, they frequently drank water. The longevity of adults reared in the laboratory with only water during the summer was ca. 4-9 days and males usually survived a little longer than females. The longevity of T. nova was increased 3 times or more as much by feeding them 3% sugar water. Male adults of T. latemarginata outnumbered female adults by 2.6 : 1 in the fields.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.502-512
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• 1995

Background: One quarter to one third of patients with NSCLC present with primary tumors that although confined to the thorax are too extensive for surgical resection. Until resently standard treatment for these patients had been thoracic radiation, which produces tumor regression in most patients but few cures and dismal 5-year survival rate. The fact that death for most patients with stage III tumors is caused by distant metastases has promped a reevaluation of combined modality treatment approaches that include systemic chemotherapy. Therefore, we report the results observed in a study to evaluate the effect of multimodality treatment in locally advanced non-small cell lung cancer from 1/91 to 8/93 in CNUH. Method: We grouped the patients according to the treatment modalities and evaluated response rate, median survival and the effect of prognostic variables. Among 67 patients evaluated, twenty seven patients classified with group A, received cisplatin and etoposide containing combination chemotherapy alone, eighteen patients, classified with group B, received chemotherapy and radiotherapy, fifteen patients, group C, received neoadjuvant or adjuvant chemotherapy and surgery with/without radiation therapy, seven patients, group D, received only supportive care. Result: The major response rate for group A and B was 37% and 61% respectively. There was no statistically significant difference in response rate between A and B groups(p=0.97). The analysis of prognostic factors showed that differences of age, sex, pathology, blood type, smoking year, stage and ECOG performance did not related to improvement in survival. Median survival time was 8.6 months for group A, 13.4 months for group B, 19.2 months for group C, and 5.4 months for group D, respectively and there was statistically significant difference(p=0.003), suggesting that multimodality therapy was associated with signigicant improvement in survival. Subset survival analysis showed a significant therapeutic effect for earlier stage and good performance state(p=0.007, 0.009, respectively). A possible survival advantages were observed for major response groups. Conclusion: It was suggested that multimodality therapy for the management of patients who had stage III disease, has yielded good median survival and long survival for seleted patients. But, it is necessory to validate above result with further investigation in large scale and in prospective randomized trials.

• Tuberculosis and Respiratory Diseases
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• v.48 no.1
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• pp.45-53
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• 2000

Background: The literature on variations of rib is limited. Very little has been written in the radiological journal of this country on the subject. It seemed of interest to investigate the nature and incidence of congenital variations in a series of routine chest roentgenograms. The topic of rib variations has not been covered extensively in the radiological journals in Korea. This has presented an opportunity to investigate the nature, type, shape and incidences of congenital rib variations in normal Korean adults from a series of routine roentgenograms. Methods: Chest radiographs of 5,000 adults, who visited our hospital for a routine check-up or for employment physical examinations from January 1996 to September 1998, were consecutively reviewed. The sex distribution consisted of 2,827 male males and 2,173 female females(ratio of 1.3:1) with the age range aged between 19 and 65 years(mean age: 34.6 years) were included. The chest PAs were analyzed for the presence, type, location, and shape of the rib variations. From this data the incidence of each type of variations was calculated. Results: Seventy-six of the 5,000 adults(1.52%), 63 male(2.23%) and 13 female(0.6%), showed 88 cases of rib variation(Table 1). The most common variation was the bifid rib(n=35), followed by hypoplasia of the rib(n=22), flaring of the rib(n=18), bridging of the ribs(n=7), cervical ribs(n=3), and fusion of between ribs(n=3)(Table 2). The bifid rib(Table 1) was found most frequent in the right fourth rib(12/35, 34.3%), followed by the left fifth rib(6/35, 17.1%) and right third rib(6/35, 17.1%). Hypoplasia of the rib was common in first rib(20/22, 90.9%). Flaring of the rib was common at fourth rib(8/18, 44.4%, right and left combined), and bridging between ribs was common between first and second rib(3/7, 42.9%). Conclusion : The percentage of incidence of rib variations in adults was 1.52%. Bifid rib was the most common variation, followed by hypoplasia, flaring, bridging, cervical rib, and fusion of ribs, in decreasing order.

• The Korean Nurse
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• v.36 no.5
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• pp.45-62
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• 1998

The study was conducted from November 1995 to May 1996 at the one general hospital in Seoul. The total subjects of this study were 412 patients who have the experience of fall accident, among them 31 was who have fallen during hospitalization and 381 was who visited emergency room and out patient clinic. The purposes of this study were to determine the characteristics, risk factors and results of fall accident and to suggest the nursing strategies for prevention of fall. Data were collected by reviewing the medical records and interviewing with the fallers and their family members. For data analysis, spss/pc+ program was utilized for descriptive statistics, adjusted standardized $X^2$-test. The results of this study were as follows: 1) Total subjects were 412 fallers, of which 245(59.5%) were men and 167(40.5%) were women. Age were 0-14 years 79(19.2%), 15-44 years 125(30.4%), 45-64 years 104(25.2%), over 65 years 104(25.2%). 2) There was significant association between age and the sexes ($X^2$=39.17, P=0.00). 3) There was significant association between age and history of falls ($X^2$=44.41. P= .00). And history of falls in the elderly was significantly associated with falls. 4) There was significant association with age and medical diagnosis ($X^2$=140.66, P= .00), chief medical diagnosis were hypertension(34), diabetis mellitus(22), arthritis(11), stroke(8), fracture(7), pulmonary tuberculosis(6), dementia(5) and cataract(5), 5) There was significant association between age and intrinsic factors: cognitive impairment, mobility impairment, insomnia, emotional problems, urinary difficulty, visual impairments, hearing impairments, use of drugs (sedatives , antihypertensive drugs, diuretics, antidepressants) (P < 0.05). But there was no significant association between age and dizziness ($X^2$=2.87, P=.41). 6) 15.3% of total fallers were drunken state when they were fallen. 7) Environmental factors of fall accident were unusual posture (50.9%), slips(35.2%), trips (9.5%) and collision(4.4%). 8) Most of falls occurred during the day time, peak frequencies of falls occurred from 1pm to 6pm and 7am to 12am. 9) The places of fall accident were roads(22.6%), house-stairs 06.7%), rooms, floors, kitchen (11.2%), the roof-top, veranda, windows(10.9%), hospital(7.5%), ice or snowy ways(5.8%), bathroom(4.9%), playground, park(4.9%), subway-stairs(4.4%) and public-bathrooms (2.2%). 10) Activities at the time of fall accident were walking(37.6%), turning around or reaching for something(20.9%), going up or down stairs09.2%), exereise, working07.4%), up or down from a bed(2.7%), using wheelchair or walking aids, standing up or down from a chair(2.2%) and standing still(2.2%). 11) Anatomical locations of injuries by falls were head, face, neck(31.3%), lower extremities (29.9%). upper extremities(20.6%), spine, thorax, abdomen or pelvic contents(l1.4%) and unspecified(2.9%). 12) Types of injures were fracture(47.6%), bruises03.8%), laceration (13.3%), sprains(9.0%), headache(6.6%), abrasions(2.9%), intracranial hemorrage(2.4%) and burns(0.5%). 13) 41.5% of the fallers were hospitalized and average of hospitalization was 22.3 days. 14) The six fallers(1.46%) died from fall injuries. The two fallers died from intracranial hemorrage and the four fallers died of secondary infection; pneumonia(2), sepsis(1) and cell lulitis(1). It is suggested that 1) Further study is needed with larger sample size to identify the fall risk factors. 2) After the fall accident, comprehensive nursing care and regular physical exercise should be emphasized for the elderly person. 3) Safety education and safety facilities of the public place and home is necessary for fall prevention.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.881-887
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• 2023

This study aims to analyze the development and current trends of AI-based medical imaging devices commercialized in South Korea. As of September 30, 2023, there were a total of 186 AI-based medical devices licensed, certified, and reported to the Korean Ministry of Food and Drug Safety, of which 138 were related to imaging. The study comprehensively examined the yearly approval trends, equipment types, application areas, and key functions from 2018 to 2023. The study found that the number of AI medical devices started from four products in 2018 and grew steadily until 2023, with a sharp increase after 2020. This can be attributed to the interaction between the advancement of AI technology and the increasing demand in the medical field. By equipment, AI medical devices were developed in the order of CT, X-ray, and MR, which reflects the characteristics and clinical importance of the images of each equipment. This study found that the development of AI medical devices for specific areas such as the thorax, cranial nerves, and musculoskeletal system is active, and the main functions are medical image analysis, detection and diagnosis assistance, and image transmission. These results suggest that AI's pattern recognition and data analysis capabilities are playing an important role in the medical imaging field. In addition, this study examined the number of Korean products that have received international certifications, particularly the US FDA and European CE. The results show that many products have been certified by both organizations, indicating that Korean AI medical devices are in line with international standards and are competitive in the global market. By analyzing the impact of AI technology on medical imaging and its potential for development, this study provides important implications for future research and development directions. However, challenges such as regulatory aspects, data quality and accessibility, and clinical validity are also pointed out, requiring continued research and improvement on these issues.