• Journal of Periodontal and Implant Science
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• 제44권1호
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• pp.13-19
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• 2014

Purpose: The purpose of this study was to retrospectively evaluate the survival of periodontally hopeless teeth that were intentionally extracted and replanted after a delay and to compare the radiographic characteristics of the survival group with those of the failure group. Methods: The clinical and radiographic data from patients who underwent delayed intentional replantation between March 2000 and July 2010 were reviewed. Twenty-seven periodontally hopeless teeth were extracted and preserved in medium supplemented with antibiotics for 10-14 days. The teeth were then repositioned in the partially healed extraction socket and followed for 3 to 21 months. The radiographic parameters were analyzed using a paired t test and the cumulative survival rate was analyzed using Kaplan-Meier analysis. Results: Seven replanted teeth failed and the overall cumulative survival rate was 66.4%. In the survival group, the amount of bone loss was reduced from 68.45% to 34.66% three months after replantation. There was radiologic and clinical evidence of ankylosis with 5 teeth. However, no root resorption was found throughout the follow-up period. In the failure group, bone formation occurred from the bottom of the socket. However, a remarkable radiolucent line along the root of a replanted tooth existed. The line lengthened and thickened as time passed. Finally, in each case of failure, the tooth was extracted due to signs of inflammation and increased mobility. Conclusions: Delayed intentional replantation has many advantages compared to immediate intentional replantation and could serve as an alternative treatment for periodontally involved hopeless teeth. However, techniques for maintaining the vitality of periodontal structures on the tooth surface should be developed for improved and predictable results.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권2호
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• pp.220-229
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• 2008

Purpose: The present study was aimed to examine the effect of acellular dermal matrix ($AlloDerm^{(R)}$) grafted to the experimental tissue defect on tissue regeneration. Materials and Methods: Male albino rabbits were used. Soft tissue defects were prepared in the external abdominal oblique muscle. The animals were then divided into 3 groups by the graft material used: no graft, autogenous dermis graft, and $AlloDerm^{(R)}$ graft. The healing sites were histologically examined at weeks 4 and 8 after the graft. In another series, critical sized defects with 8-mm diameter were prepared in the right and left iliac bones. The animals were then divided into 5 groups: no graft, grafted with autogenous iliac bone, $AlloDerm^{(R)}$ graft, $AlloDerm^{(R)}$ graft impregnated with rhBMP-2, and $AlloDerm^{(R)}$ graft with rhTGF-${\beta}1$. The healing sites of bone defect were investigated with radiologic densitometry and histological evaluation at weeks 4 and 8 after the graft. Results: In the soft tissue defect, normal healing was seen in the group of no graft. Inflammatory cells and foreign body reactions were observed in the group of autogenous dermis graft, and the migration of fibroblasts and the formation of vessels into the collagen fibers were observed in the group of $AlloDerm^{(R)}$ graft. In the bone defect, the site of bone defect was healed by fibrous tissues in the group of no graft. The marked radiopacity and good regeneration were seen in the group of autogenous bone graft. There remained the traces of $AlloDerm^{(R)}$ with no satisfactory results in the group of $AlloDerm^{(R)}$ graft. In the groups of the $AlloDerm^{(R)}$ graft with rhBMP-2 or rhTGF-${\beta}1$, there were numerous osteoblasts in the boundary of the adjacent bone which was closely approximated to the $AlloDerm^{(R)}$ with regeneration features. However, the fibrous capsule also remained as in the group of $AlloDerm^{(R)}$ graft, which separated the $AlloDerm^{(R)}$ and the adjacent bone. Conclusions: These results suggest that $AlloDerm^{(R)}$ can be useful to substitute the autogenous dermis in the soft tissue defect. However, it may not be useful as a bone graft material or a carrier, since the bone defect was not completely healed by the bony tissue, regardless of the presence of osteogenic factors like rhBMP-2 or rhTGF-${\beta}1$.

• 대한방사선기술학회지:방사선기술과학
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• 제39권4호
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• pp.661-667
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• 2016

본 연구는 보건 계열 방사선과 학생들을 대상으로 스마트러닝 강의에 대한 학습법을 진행한 후에 스마트러닝 강의에 대한 설문조사를 토대로 학생들에게 학습효능감 및 학습만족도의 관계를 실증적으로 분석하여 학습 성과향상을 위한 시사점을 제시하고 실질적인 교육을 활성화할 수 있는 방안을 모색하고자 한다. 2016년 3월부터 6월까지 총 120명을 설문하여 응답자 수 102명(남자: 65명 여: 37명)의 설문지가 회수되었다. 자료 수집방법은 자가보고형 질문지 방식으로 진행하였으며, 자기주도적 학습능력은 5점 만점에 평균 $3.46{\pm}0.50$, 학업적 자기효능감은 6점 만점에 평균 $3.60{\pm}0.89$, 학습만족도는 5점 만점에 평균 $3.62{\pm}0.62$으로 나타났다. 자기주도적 학습능력은 학업적 자기효능감(r=0.639, p<0.01)과 학습만족도(r=0.435, p<0.01)와 통계적으로 유의한 상관관계가 있는 것으로 나타났다. 그리고 학업적 자기효능감은 학습만족도와 통계적으로 유의한 상관관계가 있는 것으로 나타났다(r=0.513, p<0.01). 스마트러닝을 통한 학습법을 진행하는 경우 자기주도적 학습능력, 학업적 자기 효능감, 학습 만족도에서 유의한 결과를 보여 주고 있으며, 스마트러닝을 통한 학습법의 인식과 필요성에 대해 긍정적인 반응이 나타났으며, 스마트러닝 학습법을 통한 학습만족도와 학업적 자기효능감의 유의한 상관관계를 통해 방사선과에서도 쌍방향 커뮤니케이션을 통한 강의법의 적용이 필요하다고 사료된다.

• 한국전문물리치료학회지
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• 제5권3호
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• pp.72-87
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• 1998

This study examined the rates of spinal abnormal curvature and the correlation of the Body Mass Index (BMI), Low Back Pain (LBP) and spinal curvature by measuring scoliosis, kyphosis, and lordosis in university students. The study population included 67 male, 92 female university students, making a total of 159, in Wonju City. Spinal curvature was measured by an electrogoniometer in a computerized skeletal analysis system. Lateral curvature of spine of more than 10 degrees was considered as nonspostural scoliosis. The correlation of BMI, LBP and the spinal curvature was analysed by Pearson's correlation coefficient and t-test. The following results were obtained: 1. The overall incidence and rate of scoliosis in cases with a greater than 10 degree curve in males was an incidence of 8 and a rate of 11%. In females the incidence was 36 and the rate 39.2%. 2. The overall incidence and rate of kyphosis of less than 20 degrees in males was a rate of 9 and an incidence of 11.9%. In females, the rate was 5 and the incidence 5.4%. In kyphosis cases of more than 40 degrees, the male rate was 5 and the incidence 7.7%. For female the rate was 13 and the incidence 14.2%. 3. The overall incidence and rate of lordosis with curves of less than 20 degrees was a rate of 6 for males and an incidence of 9.0%. For females, the rate was 5 and the incidence 5.4%. In cases of more than 50 degrees lordosis, the female rate was 2 and the incidence 2.2%. There were no males in this category. 4. There was a negative correlation between kyphosis and BMI. The greater the kyphotic curve, the less the BMI in males (p<0.05). There was no significant BMI difference by gender in either scoliosis or lordosis. There was, however, a significantly decreased sacral angle in the female group with LBP. The results of this study cannot be generalized to the general population because the subjects were all from one university. The measurements were quite reliable because the angles determined by the Metrocom System were highly correlated with radiologic findings. This study shows the need for a regular screening system for spinal curvatures in university health examination procedures.

• 대한방사선기술학회지:방사선기술과학
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• 제44권2호
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• pp.101-107
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• 2021

The purpose of this study was to evaluate optimal CT scan parameters to minimize patient dose to the irradiation and maintain satisfactory image quality in low-dose chest computed tomography (CT) scans. In a chest anthropomorphic phantom, chest CT scans were performed at different kVp and mA within reference of 3.4mGy in volume CT Dose Index (CTDI_vol). The following quantitative parameters had been statistically evaluated: image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM). Nine radiographers conducted the blind test to select the optimal kVp-mA combination. Results indicated that the kVp-mA combination of 80kVp-90mA, 100kVp-50mA, 120kVp-30mA and 140kVp-30mA were obtained high SNR and CNR. The 120kVp-30mA combination offered good compromise in the FOM, which showed the quality and dose performance. In the blind test, an image of 80kVp-90mA obtained a high score with 4.7 points, and 120kVp-10mA or 140kVp-10mA with a low tube current were observed severe noise and poor image quality, thus resulting in decreased diagnostic accuracy. On the other hand, in the combination of high kVp and high mA(140kVp-90mA), the image quality was improved, but the radiation dose was also increased. the FOM value of 140kVp-90mA was lower than 120kVp-30mA. The application of appropriate scan parameters in low-dose chest CT scans produced satisfactory results in dose and image quality for the accuracy of the clinical diagnosis.

• 한국산학기술학회논문지
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• 제22권4호
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• pp.513-519
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• 2021

봉합 나사못을 이용한 견관절 수술 환자들의 예후를 확인하기 위하여 MRI(Magnetic Resonance Imaging)를 이용하여 추적검사를 시행한다. 봉합나사못을 삽입한 경우에는 임상적 관찰을 용이하게 하기 위하여 지방소거법을 이용한 영상촬영 기법이 이용되는데, 이때 이용되는 지방 신호 억제 기법으로 CHESS(Chemical Shift Selective), STIR(Short Tau Inversion Recovery), Dixon 기법 등이 주로 이용되고 있다. 봉합나사못은 비자성 재료를 이용해서 제작되지만, 환부에 삽입되는 티타늄 재질의 금속물질은 비자성체임에도 불구하고 국소자장을 왜곡시켜 결과 영상의 기하학적인 왜곡은 물론 심각한 영상신호의 감소 현상을 발생시킨다. 봉합나사못을 삽입하여 환부를 관찰하는 경우에는 뼈 혹은 뼈 인접 부위의 영상을 획득하여야 하는데 뼈와 주변 조직의 임상적 관찰을 위해서는 뼈의 지방 신호를 억제할 필요가 있다. 이때 이용되는 지방 신호 억제 기법은 금속 삽입물로 인한 자기장 불균일의 영향을 받는다. 본 연구에서는 3가지 지방억제 영상기법(CHESS, STIR, Dixon)을 이용하여 금속물질을 삽입한 환자로부터 영상을 획득하여 비교, 분석하였으며, 그 결과로 봉합나사못을 삽입한 환자의 병변 관찰 및 수술 후 예후를 관찰하기 위한 영상기법으로 STIR 영상기법이 가장 적합함을 알 수 있었다. 연구 결과에 따르면 금속 물질을 인체에 삽입한 환자의 경우, 지방 신호 억제가 필요한 MRI 검사에서는 STIR 기법을 이용하는 것이 임상적 가치가 높은 영상을 얻을 수 있을 것이다.

• 대한방사선기술학회지:방사선기술과학
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• 제42권3호
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• pp.217-222
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• 2019

The purpose of this study is to evaluate the dose distribution by gantry rotation and MLC moving speed on treatment planning system(TPS) and linear accelerator. The dose analyzer phantom(Delta 4) was scanned by CT simulator for treatment planning. The planning target volumes(PTVs) of prostate and pancreas was prescribed 6,500 cGy, 5,000 cGy on VMAT(Volumetric Modulated Arc Therapy) by TPS while MLC speed changed. The analyzer phantom was irradiated linear accelerator using by planned parameters. Dose distribution of PTVs were evaluated by the homogeneity index, conformity index, dose volume histogram of organ at risk(rectum, bladder, spinal cord, kidney). And irradiated dose analysis were evaluated dose distribution and conformity by gamma index. The PTV dose of pancreas was 4,993 cGy during 0.1 cm/deg leaf and gantry that was the most closest prescribed dose(5,000 cGy). The dose of spinal cord, left kidney, and right kidney were accessed the lowest during 0.1 cm/deg, 1.5 cm/deg, 0.3 cm/deg. The PTV dose of prostate was 6,466 cGy during 0.1 cm/deg leaf and gantry that was the most closest prescribed dose(6,500 cGy). The dose of bladder and rectum were accessed the lowest during 0.3 cm/deg, 2.0 cm/deg. For gamma index, pancreas and prostate were analyzed the lowest error 100% at 0.8, 1.0 cm/deg and 99.6% at 0.3, 0.5 cm/deg. We should used the optimal leaf speed according to the gantry rotation if the treatment cases are performed VMAT.

• 한국방사선학회논문지
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• 제15권3호
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• pp.355-359
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• 2021

본 연구에서는 교내 실습 중 방사선(학)과 에 지정된 방사선작업종사자 및 수시출입자의 피폭 정도를 분석하여 방사선(학)과에 대한 원자력안전법의 방사선 방호에 대한 타당성과 최적화에 대한 기초 연구에 목적을 두었다. 연도별 작업종사자의 평균 피폭선량 2014년과 2016년에 0.01 mSv로 가장 낮은 수치가 나타났으며. 가장 높은 수치는 2018년도로 0.12 mSv이다. 연도별 수시출입자의 평균 피폭선량은 2018년 0.013 mSv로 가장 낮은 수치를 보였으며, 2016년 0.022 mSv로 가장 높은 수치가 나타났다. 본 연구를 통하여 방사선 발생장치만을 사용하는 대학의 담당교수, 실습 조교 및 방사선(학)과의 학생들은 교내실습 과정에서 받는 연간 피폭선량은 일반인의 선량한도인 1mSv에도 미치지 못하는 수준이다. 그러므로 방사선(학)과 학생들의 피폭선량이 일반인의 선량한도 보다 낮게 나오는 시점에서 현재 원자력안전법의 안전규제는 과도한 규제라고 판단된다. 따라서 현재의 원자력안전법에서 방사선 발생장치의 규정을 개정하거나 대학의 재학생에 대한 방사선안전관리 체계를 수정하는 것은 필요하다고 사료된다.

• 한국방사선학회논문지
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• 제15권3호
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• pp.371-379
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• 2021

기존 대학의 인성교육은 주로 직업윤리 교육이나 기초교양에 초점을 맞추어 이루어지고 있지만, 최근 4차 산업에 대비하여 인성교육 프로그램의 목적 및 방식이 변화되며 이와 관련된 직업인성교육 프로그램이 필요하다. 그러나 국내에서는 아직까지 보건의료종사자가 갖추어야 할 직업인성에 대한 교육 프로그램 개발에 대한 연구가 부족한 실정이다. 따라서, 본 연구에서는 사례기반학습을 기초로 하여 4차 산업혁명에 요구되는 맞춤형 직업인성교육을 위한 프로그램을 개발하고 적용하여 효과를 확인하고자 한다. 본 연구에서는 일반 사례 및 직업 현장에서의 사례를 개발하고 직업인성교육 프로그램 효능 검증을 위해 연구 도구를 개발하였다. 본 연구에서 개발 된 4차 산업혁명에 요구되는 맞춤형 직업인성교육을 위한 프로그램은 1회(120분), 4회차 프로그램으로 제공되었으며, 단일집단 사전사후 설계로 2019년 11월 26일부터 2020년 01월 05일까지 대구시 소재의 방사선과 및 임상병리과 2, 3학년 학생 52명을 대상으로 수행되었다. 자료 분석은 평균과 표준편차, Paired t-test로 분석하였다. 본 연구에서 개발된 4차 산업혁명에 요구되는 직업인성교육을 위한 프로그램 적용을 통해 보건의료종사자의 핵심직업인성 영역인 책임, 정직, 배려, 협업, 소통, 역량에 대해 향상된 것으로 확인되며, 직업인성교육의 긍정적인 효과를 확인하였다.

• Korean Journal of Radiology
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• 제25권5호
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• pp.481-492
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• 2024

Objective: To evaluate the clinical and imaging characteristics of SARS-CoV-2 breakthrough infection in hospitalized immunocompromised patients in comparison with immunocompetent patients. Materials and Methods: This retrospective study analyzed consecutive adult patients hospitalized for COVID-19 who received at least one dose of the SARS-CoV-2 vaccine at two academic medical centers between June 2021 and December 2022. Immunocompromised patients (with active solid organ cancer, active hematologic cancer, active immune-mediated inflammatory disease, status post solid organ transplantation, or acquired immune deficiency syndrome) were compared with immunocompetent patients. Multivariable logistic regression analysis was performed to evaluate the effect of immune status on severe clinical outcomes (in-hospital death, mechanical ventilation, or intensive care unit admission), severe radiologic pneumonia (≥ 25% of lung involvement), and typical CT pneumonia. Results: Of 2218 patients (mean age, 69.5 ± 16.1 years), 274 (12.4%), and 1944 (87.6%) were immunocompromised an immunocompetent, respectively. Patients with active solid organ cancer and patients status post solid organ transplantation had significantly higher risks for severe clinical outcomes (adjusted odds ratio = 1.58 [95% confidence interval {CI}, 1.01-2.47], P = 0.042; and 3.12 [95% CI, 1.47-6.60], P = 0.003, respectively). Patient status post solid organ transplantation and patients with active hematologic cancer were associated with increased risks for severe pneumonia based on chest radiographs (2.96 [95% CI, 1.54-5.67], P = 0.001; and 2.87 [95% CI, 1.50-5.49], P = 0.001, respectively) and for typical CT pneumonia (9.03 [95% CI, 2.49-32.66], P < 0.001; and 4.18 [95% CI, 1.70-10.25], P = 0.002, respectively). Conclusion: Immunocompromised patients with COVID-19 breakthrough infection showed an increased risk of severe clinical outcome, severe pneumonia based on chest radiographs, and typical CT pneumonia. In particular, patients status post solid organ transplantation was specifically found to be associated with a higher risk of all three outcomes than hospitalized immunocompetent patients.