• 대한방사선치료학회지
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• 제29권2호
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• pp.33-41
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• 2017

목 적: 종양에는 최대한의 선량을 부여하고 주변의 정상조직에는 최소한의 선량이 조사되도록 부작용을 줄이는 목적으로 방사선 치료기술이 발전함에 따라 다양한 치료계획 및 치료 방법이 개발되고 있다. 방사선 치료 시 CT(Computed tomography)와 MRI(Magnetic resonance imaging)영상의 융합은 종양에 선량을 전달하는데 커다란 역할을 한다. 본 연구의 목적은 치료계획 시 자체 제작한 팬톰을 이용하여 CT와 MRI영상들의 융합을 통해 영상의 재현성 및 유용성을 평가하고 획득한 영상에서 타겟 선량을 비교, 분석해보고자 한다. 대상 및 방법: 자체 제작한 팬톰을 이용하여 CT 촬영을 하고, 자장의 세기가 다른 1.5T 와 3.0T의 MRI 촬영을 하여 영상을 획득한다. CT 촬영을 한 팬톰의 영상과 각기 다른 자장의 세기로 촬영한 팬톰의 MRI영상에서 팬톰 내에 존재하는 작은 홀의 크기 및 용적의 재현성을 비교하고, 임의의 타겟에서 선량 변화를 비교, 분석한다. 결 과: 13개의 작은 홀 직경은 CT 촬영에서 최대 31 mm, 최소 27.54 mm를 나타냈으며, 실제 제작한 것과 비교하여 평균 29.28 mm 1 % 이내로 측정되었다. 1.5T MRI 퓨전 영상에서는 최대 31.65 mm, 최소 24.3 mm를 나타냈으며, 평균 28.8 mm 1 % 이내로 측정되었다. 3.0T MRI 퓨전 영상에서는 최대 30.2 mm, 최소 27.92 mm를 나타냈으며, 평균 29.41 mm 1.3 % 이내로 측정되었다. 타겟의 조사된 선량변화는 CT에서 95.9-102.1 %, CT-1.5T MRI 퓨전영상에서 93.1-101.4 %, CT-3.0T MRI 퓨전영상에서는 96-102 %의 선량변화를 보였다. 결 론: CT 및 MRI는 영상획득 시 다른 알고리즘이 적용된다. 또한 인체의 장기는 각기 다른 밀도를 가지고 있으므로 영상 획득 시 이미지 왜곡이 발생할 수 있다. 이러한 부정확한 영상의 묘사는 타겟의 용적범위 및 선량에 영향을 주기 때문에 정확한 타겟의 용적과 위치는 불필요한 선량이 조사되는 것을 방지하며, 치료계획 시 오차를 방지할 수 있다. 즉 CT와 MRI 영상이 가지고 있는 영상 표출 알고리즘의 장점을 이용하여 치료계획에 적용해야 할 것이다.

• Journal of Chest Surgery
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• 제36권2호
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• pp.79-85
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• 2003

배경: 흉부 전산화 단층촬영(CT)의 폐암 진단율의 한계로 인하여 최근 폐암에 대한 진단과 병기결정에 양전자단층촬영(PET)이 유정한 것으로 알려져 있다. 이에 우리나라 폐암 환자에서 진단 및 병기 결정에 전산화 단층촬영과 양전자단층촬영의 진단율의 차이점과 유용성을 비교하고자 하였다. 대상 및 방법: 1998년 6월부터 1999년 12월까지 흥부 X-선 촬영과 CT에서 폐암이 의심퇴거나 진단된 55명에서, 차 장기에서 폐로 전이된 9명과 폐암수술후 재발된 5명을 제외한 41명을 대상으로 수술전 CT와 PET 소견과 종격동경이나 개흉술로 확진된 조직병리 소견을 비교하였다. 결과: 41명 대상환자 중 폐종양의 조직학적 진단은 악성병변이 35례 (편평세포암 19례, 선암 14례, 선편평세포암 2례)있고, 양성병변은 6례였다. 폐종양의 악성여부에 대한 CT와 PET 두가지 검사의 민감도, 특이도, 정확도는 같았으며 각각 100%, 50%, 92.7%였다. 최종적인 병리적 림프 절군 병기는 N0-Nl 31례, N2 8례, N3 2례 였다. 림프절군 병기가 일치하는 경우는 CT가 31례, PET가 28례였고, CT와 PET의 각간 6례에서 병리학적 림프절 병기보나 낮게 평가되었고, CT의 4례, PET의 7례에서 병기보다 높게 평가되었다. 조직검사가 가능했던 108개비 종격동 림프절군 중 18개 림프절군에서 악성으고 나왔고, 종격동 림프절군 침범여부에 대한 CT와 PET의 민감도, 특이도, 정확도는 각각 39.8%, 93.3%. 84.3%와 61.1%, 90.0%, 85.2% 였다. 종격동 림프절군 대한 CT와 PET 검사를 종합하여 같이 분석하였을 때 민감도 77.8%, 특이도 93.3%, 정확도 90.7%이었다. 결론: 폐종양과 림프절군의 병기 설정에 있어 PET검사는 CT와 비교하여 비슷한 유용성이 있는 건사로 사료되며, CT와 PET두 검사를 같이 시행하여 검토할 때 정착도를 높일 수 있다고 여겨진다.

• Advances in pediatric surgery
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• 제19권2호
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• pp.57-65
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• 2013

The entity of negative appendectomies still poses a dilemma in chlidren. Focused computed tomography (CT) scanning has become the diagnostic test of choice in many hospitals. However, the impact of CT scans on the diagnosis in children is unknown exactly. The purpose of this study was to critically evaluate CT scans for the evaluation of acute appendicitis in children, to review utilization of this diagnostic test in our appendicitis population and to determine if diagnostic accuracy has improved. A retrospective analysis of efficacy of CT scan for diagnosis of appendicitis in children was conducted. Children undergoing appendectomy for acute appendicitis were reviewed from 2007 to 2012. Perforation and negative appendectomy (removal of a normal appendix) rates were determined by the final pathologic report. Statistical comparison were made using the $x^2$ test and significance was assigned at p < 0.05. Five hundred four appendectomies were performed. Mean age was $10.1{\pm}3.21$ years, and 62.7% were boys. Overall, 308 children (61.1%) underwent CT scanning, 100 (19.8%) had US performed, and 97 (19.2%) had no radiographic study. A pathologically normal appendix was removed in 8.7% (27 of 308) of CT patients, 9.0% (9 of 100) of US patients, and 11.3% (11 of 97) of patients without a study. The frequency of CT scanning increased from 29.7% (27 of 91) of all children in 2007 to 75.6% (59 of 78) in 2012, whereas utilization of US decreased from 30.8% (28 of 91) to 11.5% (9 of 78). During this time period the difference in the negative appendectomy rate did change significantly from 14% to 6%. Liberal use of CT scans in diagnosing appendicitis in children has resulted in a decreased negative appendectomy rate.

• Investigative Magnetic Resonance Imaging
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• 제20권4호
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• pp.241-249
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• 2016

Purpose: To evaluate the added value of diffusion weighted imaging (DWI) to computed tomography (CT) for detecting pancreatic abnormality in patients with clinically suspected acute pancreatitis (AP). Materials and Methods: 203 patients who underwent abdomen CT and subsequent DWI to do a workup for epigastric pain were analyzed. Two blinded radiologists independently performed an interval reading based on CT image sets first, then based on combined CT and DWI image sets. The diagnostic criterion on DWI was the increased signal intensity in the pancreas to that of the spleen. For quantitative analysis, the third radiologist measured ADC value of the pancreas in each patient. Results: For AP (n = 43), the sensitivity for detecting pancreatic abnormality increased, from 42% to 70% for reader 1 (P < 0.05) and from 44% to 72% for reader 2 (P < 0.05). For borderline pancreatitis (n = 42), the sensitivity also increased, from 10% to 26% for reader 1 (P < 0.05) and from 7% to 29% for reader 2 (P < 0.05). The mean ADC values (unit, ${\times}10^{-3}mm^2/s$) were significantly different among the three groups (for AP, $1.09{\pm}0.16$; for borderline pancreatitis, $1.28{\pm}0.2$; for control, $1.46{\pm}0.15$, P < 0.05). Conclusion: Sensitivity for detecting pancreatic abnormality increased significantly after adding DWI to CT in patients with clinically suspected AP.

• 한국임상수의학회지
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• 제25권1호
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• pp.9-14
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• 2008

This purpose of this study was to describe and compare the radiographic and computed tomographic(CT) appearance of the experimentally induced Legg-Calve-Perthes Disease(LCPD) in dogs. LCPD was experimentally induced at the left femoral head in 7 litters of a dog. The lesions were evaluated with radiography, CT, and contrast CT every week from day 7 to day 70 after operation. Histopathologic examination was performed on 92th day after operation. Every images were evaluated according to the staging system of the osteonecrosis published by Association Research of Circulation Osseous in 1997 and the scoring(0-4). On CT scan, diffuse porotic lesion and focal sclerotic lesion were detected on day 14 and on day 21 after operation, respectively. Subchondral fracture, articular collapse and crescent sign with decreased attenuation were shown on day 28 after operation for the first time and no change of the sign were detected from operation day 9 to day 70 after operation. Focal porotic lesion and irregular radiopacity of femoral head were detected on day $41{\pm}7.48$ and on day $51{\pm}5.29$ after operation respectively on radiographs. In scoring evaluation, 2.00 was scored on day 14 after operation on CT scan, on day 56 after operation on radiographs, respectively This study has shown that CT is more suitable for early diagnosis of LCPB and has superior sensitivity than radiography. Also, CT has been expected to be important for staging and treatment of LCPD.

• Journal of Trauma and Injury
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• 제29권4호
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• pp.161-166
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• 2016

Purpose: Bleeding is the primary cause of death after severe pelvic fracture. Transcatheter arterial embolization (TAE) is the mainstay of treatment for arterial bleeding. This study aimed to determine the frequency of bleeding by angiography of blush-positive pelvic fractures on computed tomography (CT) images. The bleeding arteries that were involved were investigated by pelvic angiography. Methods: This retrospective cohort study evaluated 83 pelvic fracture patients who were treated in the intensive care unit of the author's trauma center between January 01, 2013 and April 30, 2015. Results: Overall mortality was 9 of 83 patients (10.8%). Blush was observed in 37 patients; blush-positive patients had significantly higher mortality (24.3%) than blush-negative patients (0%). Twenty-four of the 83 patients (28.9%) underwent pelvic angiography. Bleeding was showed in 22 of 24 patients in pelvic angiography. TAE was successfully performed in 21 (95.5%) of the bleeding 22 patients. Angiography was performed in 23 of 37 blush-positive patients, and arterial bleeding was identified in 21 (91.3%). A total 33 bleeding arteries were identified in 22 angiography-positive patients. The most frequent origin of bleeding was internal iliac artery (69.7%) followed by the external iliac artery (18.2%) and lumbar arteries (12.1%). Conclusion: The vascular blush observed in CT scans indicates sites of ongoing bleeding in pelvic angiography. TAE is an excellent therapeutic option for arterial bleeding and has a high success rate with few complications.

• 대한방사선기술학회지:방사선기술과학
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• 제19권2호
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• pp.51-57
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• 1996

Radiography should be used judiciously and should not delay patients resuscitation. In the patient with emergency multiple trauma, three radiography should be obtained-cervical spine, anteroposterior(AP) chest, and AP pelvis. These examinations can be done in the resuscitation area, usually with a portable X-ray unit, but should not interrupt the resuscitation process. A retrospective study was carried on 157 emergency multiple trauma patients who were admitted to Yong Dong Severance Hospital from January, to December in 1995. I analyzed the types of X-ray examinations in emergency multiple trauma patients, and classified the patients by disoriented group of mentality. The results were as follows: 1. The subjects were 7.1%(157patients) of 2,208 trauma patients(7.3%) in total 30,085 emergency patients. 2. Male to female ratio was 2.57 : 1. The age distribution was highest from 31 years to 40 years(28.0% ). 3. The peak time of patient's entrance in emergency center was between 8 : 00 pm and 2 : 00 am(36.9%), and second peak time was between 2 : 00 pm and 8 : 00 pm (29.3%). 4. According to the injury type, traffic accident, motorcycle accident and falling down were 71.3%, 8.3% and 20.4% respectively. 5. According to the exposure rate of Computed Tomography, chest CT, cervical CT pelvis CT and brain CT were 39.5%, 24.2%, 69.4% and 51.6% respectively.

• Journal of Korean Neurosurgical Society
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• 제38권3호
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• pp.202-205
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• 2005

Objective : The purpose of this study is to measure the dimensions of foramen ovale and to localize the zygomatic point using computed tomography[CT] in Korean adults with idiopathic trigeminal neuralgia. Methods : Facial axial CT scans using the orbitomeatal plane were performed in 67patients [39males and 28females; mean age 58.8years] with idiopathic classic trigeminal neuralgia. We measured the size of the foramen ovale and localized the zygomatic point which was a skin marker over the ipsilateral zygoma that approximates the lateral projection of a straight line joining the centers of the two foramen ovale. Results : The axial dimensions of the foramen ovale on the orbitomeatal plane were of average length : $8.18{\pm}0.82mm$ [range $6.9{\sim}11.5mm$]. width : $4.06{\pm}0.86mm$ [$2.5{\sim}5.7mm$]. The average distance between the external acoustic meatus and the zygomatic point was $21.64{\pm}1.99mm$ [$16.3{\sim}25.0mm$] and the average distance of anterior margin of condylar process of mandible to zygomatic point was $4.29{\pm}1.19mm$ [$1.0{\sim}7.0mm$]. Conclusion : The anatomical understandings including the size of the foramen ovale and localization of the zygomatic point could be helpful in determining a plan of percutaneous approaches to foramen ovale.

• Radiation Oncology Journal
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• 제31권4호
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• pp.228-233
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• 2013

Purpose: The aim of this study was to evaluate changes in breast tumor bed volume during whole breast irradiation (WBI). Materials and Methods: From September 2011 to November 2012, thirty patients who underwent breast-conserving surgery (BCS) followed by WBI using computed tomography (CT) simulation were enrolled. Simulation CT scans were performed before WBI (CT1) and five weeks after the breast irradiation (CT2). The tumor bed was contoured based on surgical clips, seroma, and postoperative change. We retrospectively analyzed the factors associated with tumor bed volumetric change. Results: The median tumor bed volume on CT1 and CT2 was 29.72 and 28.6 mL, respectively. The tumor bed volume increased in 9 of 30 patients (30%) and decreased in 21 of 30 patients (70%). The median percent change in tumor bed volume between initial and boost CT was -5%. Seroma status (p = 0.010) was a significant factor in tumor bed volume reduction of 5% or greater. However, patient age, body mass index, palpability, T stage, axillary lymph node dissection, and tumor location were not significant factors for tumor bed volumetric change. Conclusion: In this study, volumetric change of tumor bed cavity was frequent. Patients with seroma after BCS had a significant volume reduction of 5% or greater in tumor bed during breast irradiation. Thus, resimulation using CT is indicated for exquisite boost treatment in breast cancer patients with seroma after surgery.

• Radiation Oncology Journal
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• 제28권4호
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• pp.224-230
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• 2010

목적: 본 연구에서는 콘빔 CT에서 산란선 제거를 위한 aft-multple-slit (AMS) 시스템을 설계하였다. 예비 연구로서 본 시스템의 효용성을 검증하기 위해 MC 시뮬레이션을 수행하였다. 대상 및 방법: 가상 시뮬레이션은 산란선과 산란선+일차선을 계산할 수 있는 MCNPX의 radiography tally 5를 이용하였다. AMS는 빔의 발산성을 고려한 각이 동일한 아크 형태이고, 길이 방향에서의 산란선을 막는다. AMS의 효용성을 위한 평가는 AMS를 사용하지 않았을 때의 일차선과 산란선을 비교함으로써 수행되었다. 2D projection 영상을 얻기 위해 전체의 AMS는 한번의 캔트리 회전 후 AMS에 의해 가려진 부분의 영상 획득을 위해 다시 한 번 회전하는 구조이다. 결과: 일차선의 2D projection 영상은 모든 AMS의 폭에서 그리고 AMS를 사용하지 않았을 때에도 동일하였으나 일차선+산란선의 2D projection 영상은 slit의 폭에 따라 결과가 변했다. Slit의 폭을 5 mm, 10 mm, 15 mm, 20 mm로 하였을 때 평균 산란성 제거율은 29%, 15%, 9%, 8%였다. 결론: 본 연구에서는 AMS를 이용한 콘빔 CT의 산란선 제거 효과를 평가하였다. MC 시뮬레이션을 이용한 본 시스템의 사전 연구에서는 상당한 산란선 제거 효과를 보여주었다.