• 제목/요약/키워드: CT (computerized tomography)

검색결과 180건 처리시간 0.024초

Chest-wall Surface Dose During Post-mastectomy Radiation Therapy, with and without Nonmagnetic Bolus: A Phantom Study

  • Choi, Cheon Woong;Hong, Joo Wan;Park, Cheol Soo;Ahn, Jae Ouk
    • Journal of Magnetics
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    • 제21권2호
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    • pp.293-297
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    • 2016
  • For mastectomy patients, sufficient doses of radiation should be delivered to the surface of the chest wall to prevent recurrence. A bolus is used to increase the surface dose on the chest wall, whereby the surface dose is confirmed with the use of a virtual bolus during the computerized treatment-planning process. The purpose of this study is an examination of the difference between the dose of the computerized treatment plan and the dose that is measured on the bolus. Part of the left breast of an Anderson Rando phantom was removed, followed by the attainment of computed tomography (CT) images that were used as the basis for computerized treatment plans that were established with no bolus, a 3 mm-thick bolus, a 5 mm-thick bolus, and a 10 mm-thick bolus. For the computerized treatment plan, a prescribed dose regimen was dispensed daily and planning target volume (PTV) coverage was applied according to the RTOG 1304 guidelines. Using each of the established computerized treatment plans, chest-wall doses of 5 points were measured; this chest-wall dose was used as the standard for the analysis of this study, while the level of significance was set at P < 0.05. The measurement of the chest-wall dose with no bolus is 1.6 % to 10.3 % higher, and the differences of the minimum average and the maximum average of the five measurement points are -13.8 and -1.9, respectively (P < 0.05); however, when the bolus was used, the dosage was measured as 3.7 % to 9.2 % lower, and the differences of the minimum average and the maximum average are 7.4 and 9.0, -1.2 and 17.4, and 8.1 and 19.8 for 3 mm, 5 mm, and 10 mm, respectively (P < 0.05). As the thickness of the bolus is increased, the differences of the average surface dose are further increased. There are a variety of factors that affect the surface dose on the chest wall during post-mastectomy radiation therapy, for which verification is required; in particular, a consideration of the appropriate thickness and the number of uses when a bolus is used, and which has the greatest effect on the surface dose on the chest wall, is considered necessary.

컴퓨터 영상을 이용한 임플란트 식립부위의 골밀도와 조직학적 연구 (BONE DENSITY AND HISTOMORPHOMETRY ASSESSMENT OF DENTAL IMPLANT USING COMPUTERIZED TOMOGRAPHY)

  • 손장호;최병환;박수원;조영철;성일용;이지호;변기정
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제31권2호
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    • pp.136-142
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    • 2009
  • Bone density in the recipient implant site seems to be an important factor for long term success of endosseous implants. Preoperative evaluation of bone density is very helpful to assist the clinician with the treatment planning of implant therapy. Accurate information on bone density will help the surgeon identify suitable implant sites, thereby improving the success rate of the procedure. Purpose; The aim of this study was to evaluate a correlation between bone density measured preoperatively with computerized tomography and histologically measured bone density by bone biopsy. Patients and methods; Twenty seven patients were selected. All the patients were in good health, with no systemic disorder and additional bone graft. Preoperatively the patients underwent CT scanning to evaluate Houmsfield Unit(HU). Each patients wore a surgical template for implant placement. During surgery 2mm in diameter and 6mm in length specimens were taken. Histomorphometric analysis was performed using digitalized image analysis software Axiovision 4.3. Also, the Resonance frequency analysis(RFA) and insertion torque values were recorded. Results; The highest histomorphometric values was found in the posterior mandible $32.3{\pm}3.8$, followed by $29.9{\pm}2.6$ for the posterior maxilla, $29.4{\pm}2.6$ for the anterior maxilla, $28.6{\pm}2.3$ for the anterior mandible(p=0.214). The hounsfield unit was $989.2{\pm}258.1$ in the posterior mandible, $845.0{\pm}241.5$ in the anterior maxilla, $744.5{\pm}92.6$ in the anterior mandible, $697.3{\pm}136.9$ in the posterior maxilla(p=0.045). This results may suggest that there are strong correlation between the histomorphometric values and hounsfield unit(r=0.760, p<0.05). The RF measurements were $81.9{\pm}2.4$ ISQ in the posterior mandible, $79.0{\pm}1.4$ ISQ in the anterior mandible, $78.3{\pm}4.6$ ISQ in the posterior maxilla, $76.5{\pm}5.0$ ISQ in the anterior maxilla(p=0.048). The insertion torque values was $43.2{\pm}4.2\;Ncm$ in the posterior mandible, $42.0{\pm}0.0\;Ncm$ in the anterior mandible, $41.3{\pm}4.1\;Ncm$ in the posterior maxilla, $40.8{\pm}3.8\;Ncm$ in the anterior maxilla(p=0.612). This results may suggest that there are statistical significance between the hounsfield unit and the insertion torque values(r=0.494, p<0.05), the histomorphometric values and the insertion torque values(r=0.689, p<0.05). But there was no correlation between histomorphometric values and ISQ. There was no statistical significance in age and gender effect on parameters. Conclusions; There was significant correlations between bone density and implant stability parameters. The bone density measurements using preoperative CT may help clinicians to predict primary stability before implant insertion, which is associated with implant survival rates.

Nasal Anthropometry on Facial Computed Tomography Scans for Rhinoplasty in Koreans

  • Moon, Kyung Min;Cho, Geon;Sung, Ha Min;Jung, Min Su;Tak, Kyoung Seok;Jung, Sung-Won;Lee, Hoon-Bum;Suh, In Suck
    • Archives of Plastic Surgery
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    • 제40권5호
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    • pp.610-615
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    • 2013
  • Background Cephalometric analysis is essential for planning treatment in maxillofacial and aesthetic facial surgery. Although photometric analysis of the Korean nose has been attempted in the past, anthropometry of the deeper nasal structures in the same population based on computerized tomography (CT) has not been published. We therefore measured three anthropometric parameters of the nose on CT scans in our clinical series of patients. Methods We conducted the current retrospective study of a total of 100 patients (n=100) who underwent a CT-guided radiological measurement at our institution during a period ranging from January of 2008 to August of 2010. In these patients, we took three anthropometric measurements: the nasofrontal angle, the pyramidal angle, and the linear distance between the nasion and the tip of the nasal bone. Results The mean nasofrontal angle was $131.14^{\circ}$ in the male patients and $140.70^{\circ}$ in the female patients. The mean linear distance between the nasion and the tip of the nasal bone was 21.28 mm and 18.02 mm, respectively. The mean nasal pyramidal angle was $112.89^{\circ}$ and $103.25^{\circ}$ at the level of the nasal root, $117.49^{\circ}$ and $115.60^{\circ}$ at the middle level of the nasal bone, and $127.99^{\circ}$ and $125.04^{\circ}$ at the level of the tip of the nasal bone, respectively. Conclusions In conclusion, our data will be helpful in the preparation of silicone implants for augmentation and/or corrective rhinoplasty in ethnic Korean people.

중풍 환자의 배뇨장애에 대한 구료법의 효과 (Clinical Study on the Effects of Moxibustion for Post-stroke Voiding Dysfunction)

  • 강경숙;정은정;문상관;고창남;조기호;김영석;배형섭;이경섭
    • 대한한의학회지
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    • 제21권4호
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    • pp.236-241
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    • 2000
  • Background and Purpose : Cerebrovascular accident is a serious neurologic event. It can have temporary or permanent effects on survivors, including memory, cognition and volitional control of voiding. The purpose of this study is to evaluate the clinical effect of moxibustion in patients with voiding dysfunction after a cerebrovascular accident. Methods : Twenty patients with post-stroke voiding dysfunction were studied. All patients had computerized tomography(CT) and magnetic resonance imaging(MRI) to localize the lesion in the central nervous system. They were randomly divided into two groups : the control and moxibustion group. Ten of twenty patients underwent moxibustion treatment by randomization. The moxibustion group receieved moxibustion at three points : Chung-guk (Conception Vessel CV3), Kuanwon (CV4) Kihae (CV6). Residual urine volume evaluation was undertaken in all patients. Results : 1. IIn the balanced bladder time, the moxibustion group had the shorter time than non moxibustion group. But there was no significiant difference between the moxibustion group and non-moxibustion group. 2. In the residual urine volume, the moxibustion group and non-moxibustion group showed a tendency to decrease. But there was no significiant difference between the moxibustion group and non-moxibustion group. Conclusions : Though further study is needed, our findings suggested that the time of achieving balanced voiding was shorter with moxibustion than in the control group.

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Linezolid Treatment for Osteomyelitis due to Staphylococcus Epidermidis with Reduced Vancomycin Susceptibility

  • Nam, Joon-Rok;Kim, Myoung-Soo;Lee, Chae-Heuck;Whang, Dong-Hee
    • Journal of Korean Neurosurgical Society
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    • 제43권6호
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    • pp.307-310
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    • 2008
  • Limited therapeutic options are available for vancomycin intermediate-resistant Staphylococcus epidermidis (VISE) infections and no optimum therapy has been established. We report a case of VISE skull osteomyelitis that was successfully treated with linezolid. The patient was a 53-year-old man who presented with headache, nausea and dysphasia. Brain computerized tomography (CT) demonstrated a subdural hematoma in the left hemisphere. Craniotomy and hematoma evacuation was performed and he showed good recovery despite a scalp wound infection caused by methicillin-resistant Staphylococcus aureus (MRSA). The organism isolated from the scalp wound was sensitive to vancomycin. The patient was treated with intravenous vancomycin for 44 days. However, he showed a high fever, persistent positive methicillin-resistant Staphylococcus epidermidis (MRSE) blood cultures, and a deteriorating clinical status. He underwent infected skull bone flap removal and linezolid treatment for 35 days. During one year of follow up, he has not had any further episodes of osteomyelitis or fever. Linezolid has shown to be effective agent to eradiate osteomyelitis caused by VISE.

한국인 성인남자의 개별 이도내 음향응답에 대한 경계요소 해석 (Boundary Element Analysis for Individual Acoustic Responses in Ear Canal of Korean Adults)

  • 이두호;안태수;손영석;신지영
    • 한국소음진동공학회논문집
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    • 제23권3호
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    • pp.226-233
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    • 2013
  • Individual differences in head-related transfer functions(HRTFs) were calculated using boundary element(BE) models for three Korean adults. The BE models for the individuals were developed from the computerized tomography(CT) images of the individuals. The BE models were composed of the head, pinna, and ear canal. The frequency-dependent impedance boundary conditions were imposed on the skin, hair, and tympanic membrane. The HRTFs calculated from the individual BE models showed large difference above 2 kHz in magnitude and in the locations of peaks and valleys of the frequency spectrums, which should be considered in virtual auditory sound field. The identified individual differences in the HRTFs demonstrate that the developed BE models can be utilized successfully in order to obtain the HRTFs information of individuals.

복부대동맥 동맥류의 유동특성에 관한 in vitro 실험적 연구 (In vitro experimental study on flow characteristics of abdominal aorta aneurysm)

  • 이진평;김두상;이상준
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.10-12
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    • 2008
  • Hemodynamic features of blood flow in the abdominal aorta aneurysm (AAA) are very important, because they are closely related with the rupture of aneurysm to death. It has been considered that the wall shear stress of blood flows influences the formation, growth, and rupture of AAA. On this account, it is important to understand the flow structure of blood in the aneurysm. In this study, the whole velocity field information inside a typical AAA was measured using an in vitro AAA model under the pulsatile flow condition. The vessel geometry was reconstructed based on the computerized tomography (CT) data of a patient. The AAA model was made by using a rapid prototyping (RP) method, based on the reconstructed vessel geometry. Velocity fields in the AAA model were measured at different pulsatile phases using a PIV (particle image velocimetry) system. As experimental results, a large-scale vortex is formed inside the AAA model and the vortices located near the AAA wall are supposed to increase the local pressure and wall shear stress. In this study, the AAA wall stress found to be was one of the most important governing parameters giving rise to the ruptured aneurysm.

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주조 구조물 수축공의 형상단순화 기법을 통한 정적하중에 대한 영향도 분석 (Contribution Analysis Using Shape Simplification Method for Casting Structure Shrinkage)

  • 곽시영;임채호;백재욱
    • 대한기계학회논문집A
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    • 제33권8호
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    • pp.807-812
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    • 2009
  • Most structure engineers give the casting components over-estimated factor of safety without any reasonable foundation due to the worries about the unavoidable defects such as shrinkages and porosity in castings; the engineers have little knowledge on the relation between the defect and structural behavior. And the workers in casting field also do not know how to control the defects by manufacturing; they do not know to where the defects move or until how size they reduce the defects. In this study, shrinkage defect was scanned by industrial computerized tomography instrument (CT), and subsequently was modeled to a spheroid primitive for structural analysis. Using these simplified models of shrinkage, we observed the effects of the defect on the results of the structural analysis. A commercial structural analysis code was used to do the analysis works. Considering the conclusions, it is possible to manage the shrinkages effectively in casting process and to design the products with more reliable

Acute Ischemic Stroke: Current Management and Role of the Nurse Practitioner

  • Kang, Ji-Yeon;Coleman, Patricia;Kim, Keum-Soon;Yi, Young-Hee;Choi, Eun-Jung
    • 중환자간호학회지
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    • 제2권1호
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    • pp.26-35
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    • 2009
  • Purpose: This paper reviews current diagnostic evaluation, treatment, nursing considerations, and the nurse practitioner’s (NP) role in acute ischemic stroke care. Methods: National guidelines and extensive literature on acute stroke care were reviewed and a relevant clinical case was introduced. Results: Computerized tomography (CT) of the head without contrast is the initial brain imaging procedure for patients with an acute stroke. Magnetic resonance imaging (MRI) can be an alternative test. Restoration of cerebral perfusion to the affected area is a key therapeutic strategy for ischemic stroke. A number of treatment strategies such as thrombolysis, anticoagulation, antiplatelet, and surgical treatment can be selected to improve blood flow to the ischemic region. The NP on the stroke team is involved with immediate stroke management including neurological assessment, ensuring adequate oxygenation, blood pressure management, activity, and diet. Discharge planning with the patient, family teaching and coordination of follow up care should also be implemented early in the hospitalization. Conclusion: The nurse practitioner is one of the cardinal members on the stroke team, and must be updated with current treatment and management guidelines.

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미만성 축삭 손상으로 유발된 속발성 치매 환자 1례에 대한 증례 보고 (A Case Report of Secondary Dementia Patient Caused by Diffuse Axonal Injury)

  • 송창훈;정종진;오성원;김수연;이상민;정명숙;백태현;이슬희
    • 대한한방내과학회지
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    • 제28권3호
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    • pp.645-654
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    • 2007
  • The purpose of this study is to present a case of secondary dementia caused by diffuse axonal injury. We diagnosed this patient with diffuse axonal injury by using brain computerized tomography(CT) and magnetic resonance imaging(MRI), and also diagnosed secondary dementia based on DSM-IV. To evaluate prognosis of the patient, we used K-DRS(Korean-Dementia Rating Scale) and gave him a written test. As a result of treating this patient with oriental medicine, the K-DRS score increased and the overall clinical symptoms improved. In oriental medicine, case studies of diffuse axonal injury are yet insufficient, hence more clinical studies and researches will be needed.

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