• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.117-123
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• 2021

This paper is to establish a basis for a dose reduction strategy by confirming correlations with the factors that may affect the radiation dose based on the dose records in low-dose chest CT and abdominal non-contrast CT. In order to find out the causes of unnecessary exposure, the correlation between seven factors (age, gender, height, weight, BMI, patient status [inpatient and outpatient], and use of dose modulation) and CT dose were identified. Logistic regression was used as the statistical analysis for correlation verification. In the low dose chest CT, as the higher values of height and BMI and dose modulation off were associated with lowering the risk exceeding Diagnostic Reference Levels(DRL) (odds ration<1, p<0.05). However, as woman compared to man and the higher values of weight were associated with highering the risk exceeding DRL (odds ration>1, p<0.05). In the abdomen CT, as dose modulation off were associated with lowering the risk exceeding DRL (odds ration<1, p<0.05). Therefore It is necessary to conduct research on the relationship between various factors affecting radiation exposure and patient radiation dose for reducing the dose.

• Journal of Trauma and Injury
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• v.30 no.2
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• pp.25-32
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• 2017

Purpose: The use of computed tomography (CT) to evaluate acute abdominal complaints has increased over the past two decades. We investigated how the clinical practice of patients with intestinal perforation has changed with the increasing use of abdominal CT in the emergency department (ED). Methods: We compared ED arrival to CT time, ED arrival to surgical consultation time, and ED arrival to operation time according to the method of diagnosis from 2003-2004 and 2013-2014. Results: In patients with gastrointestinal perforation, time from ED arrival to CT was shorter ($111.4{\pm}66.2min$ vs. $199.0{\pm}97.5min$, p=0.001) but time to surgical consultation was longer ($135.1{\pm}78.8$ vs. $77.9{\pm}123.7$, p=0.006) in 2013-2014 than in 2003-2004. There was no statistically significant difference in time to operation for perforation confirmed either by plain film or CT between the two time periods. There was no statistically significant difference in length of hospital or ICU stay or mortality between the two groups. Conclusion: With the increasing use of abdominal CT in ED, ED arrival to CT time has decreased and ED arrival to surgical consultation time has increased in gastrointestinal perforation. These changes of clinical performance do not delay ED arrival to operation time or adversely influence patient outcome.

• Journal of Trauma and Injury
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• v.22 no.1
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• pp.57-64
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• 2009

Purpose: Computed tomography (CT) is an accurate test for evaluating hemodynamically stable patients with blunt abdominal trauma. Until now, there have been few studies concentrating on the diagnostic and prognostic significance of the intravenous contrast extravasation (CE) site. We investigated the site of CE on abdominopelvic CT (APCT) and its effect on treating trauma patients and predicting the clinical outcome. Methods: The 50 patients admitted to our emergency department with blunt abdominal trauma showing CE on APCT from January 2004 to September 2006 were included in this study. Patients were prospectively collected, and medical records were reviewed and analyzed. The patients'clinical and lab findings, Focused Assessment with Sonography for Trauma (FAST) findings, CT findings were analyzed. CE sites were classified as intraperitoneal, retroperitoneal, and pelvic cavity and were correlated with post-treatment complications, mortality, and morbidity. Results: Of the 50 patients (mean age : $45{\pm}18years$, 29 males, 21 females) included in our study, 33 patients died (66%). There was no correlation between CE site and ICU or total hospitalization duration (p=0.553, p=0.523). During the first 24 hours of resuscitation, the pelvic cavity group required a mean of 20 units more of packed red blood cell (pRBC) transfusion compared to other groups (p=0.003). In the intraperitoneal group, more patients received operative invasive intervention - either laparotomy or embolization (p=0.025). The intraperitoneal group had the highest mortality, with 13 deaths (11/33, 39%), and the highest early mortality rate (10/13, 76%) in the first 24 hours (p=0.001). Conclusion: Intraperitoneal CE on the CT scan in cases of blunt abdominal trauma is regarded as an indication of a need for invasive intervention (either angiography or laparotomy) and of a higher mortality rate in the first 24 hours. A pelvic cavity CE rquires more aggressive transfusion with pRBC. However, the CT findings themselves showed no significant correlation with overall mortality, morbidity, or hospitalization.

• Journal of radiological science and technology
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• v.28 no.4
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• pp.279-286
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• 2005

Purpose : There are two modalities, those are small bowel series(SBS) and abdominal pelvic computed tomography(CT), for diagnosis of small bowel disease. The aim of this study is to lend radiological technologists who are doing the two modalities assistance in the understanding characteristic of disease by comparing the two results. Meterials and method : 284 patients were examined the two SBS and abdominal pelvic CT together from 1999 to 2003. 250 ml $BaSO_4$ suspension 40 w/v% and 600ml carboxy methyl cellulose 0.5 w/v% were used for SBS. Abdominal Pelvic CT was examined in one hour before taking 450 ml $BaSO_4$ suspension 1.5 w/v%. The CT scan was done in 72 sec after 150 ml contrast media injection. the used protocol was helical mode 5:5 mm pitch 1.375:1, speed 27.50, exposure 120 kv, 240 mA, tube rotation time 0.5 sec. the statistic analysis was conducted with statistical program SPSS 10 version with frequency and crossing analysis. P-value less than 0.05 were considered significant. Results : In the results of SBS, normal findings were 131 patients(46.1%), inflammatory bowel disease(IBD) 64(22.9%), ischemia+ileocolitis+vasculitis 22(7.7%), Obstruction+stricture 21(7.7%) and Others 45(15.9%). In the results of abdominal pelvic CT, normal findings were 103 patients(36.3%), inflammatory bowel disease 65(22.9%), wall thickening+lymphadenopathy 42(14.8%), Fluid collection 17(6%), and Others 57case(20%). The same results of the two were 130patients(45.8%). 30patients(10.6%) of normal finding in SBS were diagnosed as wall thickening+lymphadenopathy and IBD in CT, and 15patients(5.3%) of normal finding in CT were diagnosed as ischemia+ileocolitis+vasculitis, mass and IBD in SBS(p<0.05). Transit time delay was diagnosed in 10patients(3.5%) on only SBS, wall thickening+lymphadenopathy was diagnosed in 20patients(7%) in only CT(p<0.05). Conclusion : We think that proper examination method will be selected in the small bowel disease, if we understand the characteristics of the disease and method.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.231-234
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• 2017

Extrahepatic bile duct injury is commonly associated with hepatic, duodenal, or pancreatic injuries, and isolated extrahepatic bile duct injury is rare. We report a patient who presented with an isolated extrahepatic bile duct injury after blunt trauma. A 50-year-old man was referred to our hospital after having suffered a fall down injury. His laboratory findings showed hyperbiliribinemia with elevated aspartate aminotransferase and alanine aminotransferase level. Initial abdominal computed tomography (CT) showed a mild degree of hemoperitoneum without evidence of abdominal solid organ injury. On the 3rd day of hospitalization, the patient complained of dyspnea and severe abdominal discomfort. Follow-up abdominal CT showed no significant interval change. Owing to the patient's condition, Emergency laparotomy revealed a large amount of bile-containing fluid collection and about 1 cm in size laceration on the left lateral side of the common hepatic duct. Primary repair of the injured bile duct with T-tube insertion was performed On postoperative day (POD) 30, endoscopic retrograde cholangiopancreatography showed minimal bile leakage and endoscopic sphincteroplasty and endoscopic retrograde biliary drainage were performed. On POD 61, the T-tube was removed and the patient was discharged.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.6
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• pp.679-686
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• 2018

Objective: The aim of this study was to identify the clinical characteristics and risk factors associated with the admission of patients in the emergency department (ED) within 30 days after discharge. Methods: A retrospective, observational study was conducted on adult patients presenting with abdominal pain to the ED of a single, urban, university hospital, between January 2014 and December 2015, who revisited the ED within 30 days after discharge. Data was collected on the emergency severity index level, time to contact doctors, physical examination, laboratory tests, use of computed tomography (CT), and patient disposition on revisitation. The primary outcome was hospital admission following an ED revisit in the 30-day period after the first visit. Results: During the study period, 19,480 patients visited the ED with the chief complaint of abdominal pain, and 13,577 were discharged. A total of 251 patients (1.29%) revisited the ED within 30 days, of which 89 were eligible for the study. The primary outcome was associated with not performing a CT scan on the initial visit and an increased C-reactive protein (CRP) value. Receiver operating characteristic curve analysis showed that a cut-off baseline CRP value of >0.35 mg/dL can predict the primary outcome with a sensitivity and specificity of 75% and 62.1%, respectively (area under the curve, 0.701; 95% confidence interval, 0.569-0.833; P=0.007). Conclusion: An increased CRP value and not performing abdominal CT were associated with a higher rate of admission following ED revisits of patients with abdominal pain. Future prospective studies on the role of abdominal CT imaging in patients presenting to the ED with abdominal pain will be needed.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.299-312
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• 1993

Anthropometry, computed tomography(CT) at the umbilical level, nutrient intake, blood pressure, serum levels of lipids and lipoproteins and response of glucose, c-peptide, insulin, and free fatty acid(FFA) during oral glucose tolerance test(OGTT) were estimated on 11 normal-weight controls and 35 overweight and obese middle-agd men. The areas of total abdominal, subcutaneous and visceral were determined by CT scanning technique. Total abdominal fat area correlated the most significantly with the levels of serum lipids, lipoproteins and insulin among several obese indices. Compared with normal-weight controls, overweight and obese men with abdominal fat lower than 29000$\textrm{mm}^2$ showed an increase in waist-hip ratio, areas of total abdominal(35%), visceral and subcutaneous fat and C-peptide response area during OGTT, though age, percent ideal body weight, body mass index, % body fat, and all biochemical indices except C-peptide response area were not different between two groups. Overweight and obese men with abdominal fat greater than 29000$\textrm{mm}^2$ showed a higher values in total abdominal fat(85%), serum levels of triglyceride, total-and LDL-cholesterol, the ratio of LDL-to HDL-cholesterol, and response areas of FFA, insulin and C-peptide during OGTT than normal-weight controls. Overweight and obese men with great abdominal fat showed an increase in alcohol ingestion and percent calorie intake per total energy expenditure, compared with normal-weight controls. Our results indicate that obesity and a certain level of total abdominal fat accumulation is required to observe abnormal levels of serum lipids, lipoproteins and insulin in Korean middle-aged men. In addition, increased alcohol and calorie intake and decreased physical activity could partly explain total abdominal fat accumulation in men.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.93-100
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• 2021

The purpose of this study is to find out the factors that affect the patient's exposure dose during the abdominal CT scan using the bolus tracking technique, and reducing the radiation exposure to the patient during the abdominal CT scan using the bolus tracking technique by adjusting the delay time according to the corresponding factor. The experiment was divided into two parts, and the first experiment was conducted with 300 patients There were 188 males and 112 females, and their average age was 58±12.18(19~85). In the second experiment, 150 subjects (100 males and 50 females) who were undergoing their follow-up examination among the first experiment subjects, and the difference in dose before and after was compared by applying the delay time according to the influencing factor. As a result of the first experiment, there was a relationship between the arrival time of the contrast media and the heart rate, and it was found that the arrival time decreased as the heart rate increased for both men and women. As a result of the second experiment, the average dose of CTDIvol and DLP before/after applying the delay time according to the heart rate decreased 4.98 mGy and 5.33 mGy·cm in the male group, and 3.54 mGy and 3.88 mGy·cm in the female group. By applying proper delay time according to the patient's heart rate during abdominal CT scan with the bolus tracking technique, the radiation exposure dose of the patient can be reduced.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.1065-1072
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• 2021

In Computed Tomography, abdominal examination showed the highest proportion of use, and effort of reducing the radiation dose is required. Recently introduced Iterative Reconstruction(IR) is repetitive reconstruction technique of Computed Tomography. SIEMENS' IR, ADMIRE and GE's IR, ASIR-V, were used in this examination. Noise, % Contrast, and High contrast resolution were measured by using ACR phantom for image quality evaluation. In addition, CTDI_vol and DLP displayed in the CT device were used for dose evaluation. When FBP and IR were compared, stage 2 to stage 5 of ADMIRE and 10, 30, 50, 70, and 90% of ASIR-V were applied, noise could be reduced from a minimum of 0.46 to a maximum of 2.38 in ADMIRE compared to FBP, and noise from a minimum of 0.51 to a maximum of 2.5 in ASIR-V compared to FBP. Also, % Contrast and High contrast resolution of FBP and IR were no statistical difference. When IR was used for abdominal CT examination, the radiation dose of ADMIRE is reduced by 25.39% compared to the radiation dose of FBP. Also, the radiation dose of ASIR-V is reduced by 16.61% compared to the radiation dose of FBP. In conclusion, it is believed that if IR is applied during abdominal CT examination, the radiation dose can be reduced without deteriorating the image quality.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.266-274
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• 2009

An abdominal aortic aneurysm occurs most commonly in older individuals (between 65 and 75), and more in men and smokers. The most important complication of an abdominal aortic aneurysm is rupture, which is most often a fatal event. An abdominal aortic aneurysm weakens the walls of the blood vessel, leaving it vulnerable to bursting open, or rupturing, and spilling large amounts of blood into the abdominal cavity. surface modeling is very useful to surgery for quantitative analysis of abdominal aortic aneurysm. the 3D representation and surface modeling an abdominal aortic aneurysm structure taken from Multi Detector Computed Tomography. The construction of the 3D model is generally carried out by staking the contours obtained from 2D segmentation of each CT slice, so the quality of the 3D model strongly defends on the precision of segmentation process. In this work we present deformable model algorithm. deformable model is an energy-minimizing spline guided by external constraint force. External force which we call Gradient Vector Flow, is computed as a diffusion of a gradient vectors of gray level or binary edge map derived from the image. Finally, we have used snakes successfully for abdominal aortic aneurysm segmentation the performance of snake was visually and quantitatively validated by experts.