• 대한의용생체공학회:의공학회지
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• 제19권1호
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• pp.53-58
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• 1998

본 연구에서는 슬개골의 골밀도와 Von Mises 응력의 분포를 조사하였다. 18개 슬개골의 골밀도는 컴퓨터 단층촬영과 영상분석 소프트웨어를 사용하여 결정하였다. 슬개골의 골밀도는 위치에 따라 변화됨을 발견하였다. 골밀도값은 상외측부에서 가장 크고 아래쪽 혹은 내쪽으로 갈수록 감소하였다. 이 분포는 슬개골 안에서 소주의 조직과 일치됨을 보였다. 각 슬개골에서 2차원 유한요소법을 실행한 결과 슬개골의 최대 Von Mises응력은 비관절 표면 위에 있는 피질외피에 따라 발생하였다. 소주의 최대 Von Mises응력은 슬개골의 후방부에 존재했다. 이 발견들은 생체내의 유한요소 연구에 대한 잠재적 가능성을 증명하였다. 따라서 이러한 연구들은 주문형, 환자특성에 맞는 슬개골 인공보철물들의 개발을 유도할 수 있게 한다.

• 대한두개안면성형외과학회지
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• 제16권2호
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• pp.53-57
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• 2015

Background: Surgical outcomes after orbital wall decompression have focused on the degree of exophthalmos and intraocular pressure. The aim of this research was to evaluate intraorbital volume using computed tomography (CT) images following two-wall decompression using a combined subcilliary and endoscopic approaches. Methods: A retrospective review was performed for all patients who had undergone the two-wall decompression method. The pre/postoperative CT images were used to evaluate changes in intraocular volume. Intraocular pressure was evaluated using applanation tonometry. Surgical details are discussed within the body of text. Results: Two-wall decompression thru the medial wall and floor was associated with an average intraorbital volume change of $7.3cm^3$, with maximal accommodation up to $13cm^3$. Changes in intraocular pressures were not statistically significant. Conclusion: Two-wall decompression was effective in accommodation of up to $13cm^3$ of soft tissue herniation. There was no statistically significant association between changes in volume to pressure.

• Journal of Korean Neurosurgical Society
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• 제54권4호
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• pp.280-288
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• 2013

Objective : Perfusion computed tomography (PCT) has the ability to measure quantitative value and produce maps of mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV). We assessed cerebral hemodynamics by using these parameters and acetazolamide (ACZ) challenge for pre- and post-procedural evaluation in patients with unilateral cerebrovascular stenotic disease. Methods : Thirty patients underwent pre-procedural PCT with ACZ challenge, and 24 patients (80%) was conducted follow up PCT after angioplasty with same protocol. The mean MTT, CBF, and CBV were measured and compared in both middle cerebral arterial (MCA) territories before and after ACZ challenge. Hemispheric ratio and percent change after ACZ challenge were calculated before and after angioplasty. Results : The mean stenosis rate was 76.6%. Significant increases in MTT (32.6%, p=0.000) and significant decreases in CBF (-14.2%, p=0.000) were found in stenotic side MCA territories. After ACZ challenge, there were significant changes in MTT (37.4%, p=0.000), CBF (-13.1%, p=0.000), and CBV (-10.5%, p=0.001) in pre-procedural perfusion study. However, no significant increases were found in MTT, or decreases in CBF and CBV in post-procedural study. There were no significant changes after ACZ challenge also. In addition, the degrees of these changes (before and after ACZ challenge) were highly correlated with the stenotic degrees in pre-procedural perfusion study. Conclusion : PCT with ACZ challenge appears to be a useful tool to assess the cerebral perfusion status especially in patients with unilateral symptomatic stenotic disease.

• Radiation Oncology Journal
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• 제35권1호
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• pp.65-70
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• 2017

Purpose: To evaluate the utility of implanted surgical clips for detecting interfractional errors in the treatment of hepatobiliary and pancreatic cancer with postoperative radiotherapy (PORT). Methods and Materials: Twenty patients had been treated with PORT for locally advanced hepatobiliary or pancreatic cancer, from November 2014 to April 2016. Patients underwent computed tomography simulation and were treated in expiratory breathing phase. During treatment, orthogonal kilovoltage (kV) imaging was taken twice a week, and isocenter shifts were made to match bony anatomy. The difference in position of clips between kV images and digitally reconstructed radiographs was determined. Clips were consist of 3 proximal clips (clip_p, ${\leq}2cm$) and 3 distal clips (clip_d, >2 cm), which were classified according to distance from treatment center. The interfractional displacements of clips were measured in the superior-inferior (SI), anterior-posterior (AP), and right-left (RL) directions. Results: The translocation of clip was well correlated with diaphragm movement in 90.4% (190/210) of all images. The clip position errors greater than 5 mm were observed in 26.0% in SI, 1.8% in AP, and 5.4% in RL directions, respectively. Moreover, the clip position errors greater than 10 mm were observed in 1.9% in SI, 0.2% in AP, and 0.2% in RL directions, despite respiratory control. Conclusion: Quantitative analysis of surgical clip displacement reflect respiratory motion, setup errors and postoperative change of intraabdominal organ position. Furthermore, position of clips is distinguished easily in verification images. The identification of the surgical clip position may lead to a significant improvement in the accuracy of upper abdominal radiation therapy.

• 대한한방부인과학회지
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• 제28권4호
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• pp.11-20
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• 2015

Objectives The purpose of this study was to examine the relationship between cold hypersensitivity and bone mineral density. Methods 28 outpatients who visited OO University Oriental Hospital from July 11th, 2013 to August 28th, 2013 were analyzed. Patients were subjected to thermometer, and those with thermal difference greater than 0.3 ℃ between upper arm and palm and also with more than VAS 4 of cold hypersensitivity were diagnosed with cold sensitivity. Lumba spine (L2-4) and heel bone measurement were obtained on dual energy X-ray absorptiometry (DEXA) and Quantitative Computed Tomography (QCT). Results 1. There was statistically significant correlation between T-score of DEXA and body weight (0.522), BMI (0.643), OSTA (Osteoporosis elf-assesment Tool for Asians, 0.579), BMI, T-score and Z-score of QCT. OSTA and T-score of QCT (0.521) also had statistically significance. 2. There was no statistically significant correlation between body fat, abdominal obesity rate, degree of cold hypersensitivity, upper arm and palm's temperature difference, palm temperature, height and Z-score, T-score of QCT or T-sore of DEXA. Conclusions Bone mineral density was lower in women who had cold hypersensitivity of hand and feet. But there was no statistically significant correlation between bone mineral density and degree of cold hypersensitivity, upper arm and palm’s temperature difference.

• Journal of Acupuncture Research
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• 제18권2호
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• pp.91-100
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• 2001

Objective : The purpose of this study is to investigate the role of the osteoporosis in low back pain(LBP). Methods : We use method of projection with Quantitative computed tomography(QCT) to estimate Bone mineral density(BMD) of lumbar spine more precisely. From January 1999 to August 2000 we studied lumbar BMD of 46 women with LBP and 53 women with non-LBP, musculoskeletal symptoms who visited Dong-Guk University Bundang Hospital by QCT. Results : 1. Lumbar BMDs in women with LBP and women with non-LBP, musculoskeletal symptom were lower than in normal women and BMDs in women with LBP was higher than in women with non-LBP, musculoskeletal symptom but the significant difference was not revealed between two group in statistics(p<0.05).. 2. Radiological study shows that the number of degenerative spondylosis was 19, compression fracture was 11, non-radiological study was 10, normal was 5 in women with LBP. 3. Radiological study shows that the number of degenerative change was 7, compression fracture was zero, non-radiological study was 33, normal was 5 in women with non-LBP, musculoskeletal symptom. Conclusion : BMDs in women with LBP was higher than in women with non-LBP, musculoskeletat symptom but the significant difference was not revealed between two group in statistics(p<0.05).

• 한국음향학회지
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• 제31권4호
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• pp.244-252
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• 2012

본 연구의 목적은 골절 위험도가 높은 대퇴골에서 음속 및 광대역 초음파 감쇠와 같은 음향특성과 골밀도 사이의 상관관계를 조사하는 것이다. 이를 위해 0.5 및 1.0 MHz의 중심주파수를 갖는 두 쌍의 초음파 트랜스듀서와 함께 투과법을 이용하여 생체 외 조건에서 15개의 소 대퇴골 해면질골 샘플의 음속 및 광대역 초음파 감쇠를 측정하였다. 또한 마이크로 컴퓨터 단층촬영법을 이용하여 해면질골 샘플의 단위체적당 골밀도를 측정하였다. 골밀도는 0.5 및 1.0 MHz 초음파 트랜스듀서를 이용하여 측정된 음속 및 광대역 초음파 감쇠와 모두 강한 상관관계를 나타냈으며, 골밀도와 0.5 MHz 초음파 트랜스듀서를 이용하여 측정된 광대역 초음파 감쇠 사이에 가장 높은 상관관계가 존재하였다. 이와 같은 결과는 생체 외 조건의 대퇴골에서 측정된 음향특성이 대퇴골의 골밀도를 예측하기에 충분한 지표라는 것을 의미한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제36권3호
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• pp.94-102
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• 2014

Purpose: This study aims to validate the effect of autoclaved autogenous bone (AAB), incorporating Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2), on critical-sized, segmental radius defects in rabbits. Delivery systems using absorbable collagen sponge (ACS) and fibrin glue (FG) were also evaluated. Methods: Radius defects were made in 12 New Zealand white rabbits. After autoclaving, the resected bone was reinserted and fixed. The animals were classified into three groups: only AAB reinserted (group 1, control), and AAB and ErhBMP-2 inserted using an ACS (group 2) or FG (group 3) as a carrier. Animals were sacrificed six or 12 weeks after surgery. Specimens were evaluated using radiology and histology. Results: Micro-computed tomography images showed the best bony union in group 2 at six and 12 weeks after operation. Quantitative analysis showed all indices except trabecular thickness were the highest in group 2 and the lowest in group 1 at twelve weeks. Histologic results showed the greatest bony union between AAB and radial bone at twelve weeks, indicating the highest degree of engraftment. Conclusion: ErhBMP-2 increases bony healing when applied on AAB graft sites. In addition, the ACS was reconfirmed as a useful delivery system for ErhBMP-2.

• 대한의용생체공학회:의공학회지
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• 제19권2호
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• pp.171-176
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• 1998

본 연구에서는 뼈의 특성을 파악하는 초음파감쇠 파라미터를 재평가하였다. 초음파 속도, 특정 주파수(0.5MHz)에서의 초음파감쇠 및 광역 밴드 초음파감쇠와 같은 초음파 파라미터들을 해면골 입방체 시편의 세 직교방향(전/후, 내/외, 상/하)에서 측정하였다. 그리고 컴퓨터 영상장치를 사용하여 골밀도를 측정했으며, 골 시편의 무게와 부피를 이용하여 외형밀도도 함께얻었다. 이와같이 구해진 외형밀도와 초음파 속도로부터 초음파 탄성영률을 계산하였다. 주파수 0.5MHz에서의 초음파감쇠와 광역밴드감쇠는 골밀도 및 세 직교방향의 초음파 영률과 서로 관련시켜 연관성을 조사하였다. 그 결과 특정 주파수 초음파감쇠가 골밀도 및 탄성영률을 평가하는 능력에 있어서 광역밴드 감쇠보다 우수함을 알 수 있었다. 따라서 광역밴드 초음파감쇠를 측정하여 골의 상태를 평가하는 형행 초음파 진단 기법이 재검토 되어야 하며 본 연구에서 증명된 특정주파수(0.5MHz) 초음파감쇠를 이용하여 골 다공증 진단 예측율을 향상시킬 수 있다.

• 한국지반공학회논문집
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• 제36권9호
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• pp.45-55
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• 2020

X-ray CT는 암석시편의 공극 및 균열과 같은 내부 미세구조와 손상들의 정량적 분석에 활용되어 왔다. 원위치 CT는 외력 등 다양한 외적 요인에 영향을 받고 있는 암석 시편의 내외부 변화 과정을 관찰할 수 있게 해준다. 이의 확인을 위해, 암반/지반재료 특성분석에 활용한 원위치 X-ray CT 기술에 관한 최신 연구동향을 파악하였으며, 원위치 CT이미징이 가능한 암석의 수리-역학적 실험용 삼축셀을 개발하였다. 직경 25~50 mm 화강암 및 사암 코아시편의 원위치 CT이미징이 성공적으로 진행되었으며, 34~105 ㎛ 범위의 픽셀피치의 해상도를 취득할 수 있었다. 본 사전검토 촬영 실험을 통해 마이크로미터 스케일에서 암석의 내부구조 변화의 원위치 CT관찰이 가능한 것을 파악하였다. 요오드화 칼륨 용액은 CT이미지의 대비를 증가시키고 암석의 수리-역학 실험에서 주입유체로 사용할 수 있다.