• Title/Summary/Keyword: Computed tomography(CT)

검색결과 2,602건 처리시간 0.031초

전산화 단층검사 시 Bismuth와 CARE kV System을 이용한 선량 저감화에 대한 연구 (Research on Dose Reduction During Computed Tomography Scanning by CARE kV System and Bismuth)

  • 곽영곤;김종일;정성표
    • 한국콘텐츠학회논문지
    • /
    • 제14권8호
    • /
    • pp.233-242
    • /
    • 2014
  • 본 논문에서는 전산화 단층검사 시 방사선 투과 물질로 방사선량을 흡수하여 피폭 선량을 감소시키는 물질로 알려진 차폐용 Bismuth(비스무스)와 CARE kV(Automated Dose-Optimized Selection of X-ray Tube Voltage)을 사용하여 유용성을 평가하였다. 방사선 감수성이 높은 기관인 수정체(안와), 갑상선, 가슴(유방), 생식기의 선량 감소 효과와 각 기관의 심부선량 차폐 효과를 평가하기 위해 Rando Phantom과 유리 선량계를 이용하여 Bismuth 사용 전 후와, CARE kV의 적용에 따른 선량 감소 효과를 비교해 보았다. 그 결과, 뇌혈관 검사 시 CARE kV을 단독 설정한 검사 방법의 선량이 가장 적었으며, CARE kV 사용여부에 따라 63%의 선량 감소 효과가 있었다. 경동맥 검사 시 CARE kV+Bismuth의 설정 방법에서 선량이 13% 증가하였다. 심혈관 검사 시 CARE kV+Bismuth의 설정 방법이 31% 선량 감소 효과가 있었다. 하지 혈관 검사 시 Bismuth 전체의 설정 방법이 가장 선량이 적게 측정되었지만, 영상 평가 기준에 부적합 하였다. CARE kV을 설정한 검사 방법과는 약 9%의 선량 감소 효과가 있었다.

The Utility and Benefits of External Lumbar CSF Drainage after Endovascular Coiling on Aneurysmal Subarachnoid Hemorrhage

  • Kwon, Ou-Young;Kim, Young-Joon;Kim, Young-Jin;Cho, Chun-Sung;Lee, Sang-Koo;Cho, Maeng-Ki
    • Journal of Korean Neurosurgical Society
    • /
    • 제43권6호
    • /
    • pp.281-287
    • /
    • 2008
  • Objective : Cerebral vasospasm still remains a major cause of the morbidity and mortality, despite the developments in treatment of aneurysmal subarachnoid hemorrhage. The authors measured the utility and benefits of external lumbar cerebrospinal fluid (CSF) drainage to prevent the clinical vasospasm and its sequelae after endovascular coiling on aneurysmal subarachnoid hemorrhage in this randomized study. Methods : Between January 2004 and March 2006, 280 patients with aneurysmal subarachnoid hemorrhage were treated at our institution. Among them, 107 patients met our study criteria. The treatment group consisted of 47 patients who underwent lumbar CSF drainage during vasospasm risk period (about for 14 days after SAH), whereas the control group consisted of 60 patients who received the management according to conventional protocol without lumbar CSF drainage. We created our new modified Fisher grade on the basis of initial brain computed tomography (CT) scan at admission. The authors established five outcome criteria as follows : 1) clinical vasospasm; 2) GOS score at 1-month to 6-month follow-up; 3) shunt procedures for hydrocephalus; 4) the duration of stay in the ICU and total hospital stay; 5) mortality rate. Results : The incidence of clinical vasospasm in the lumbar drain group showed 23.4% compared with 63.3% of individuals in the control group. Moreover, the risk of death in the lumbar drain group showed 2.1 % compared with 15% of individuals in the control group. Within individual modified Fisher grade, there were similar favorable results. Also, lumbar drain group had twice more patients than the control group in good GOS score of 5. However, there were no statistical significances in mean hospital stay and shunt procedures between the two groups. IVH was an important factor for delayed hydrocephalus regardless of lumbar drain. Conclusion : Lumbar CSF drainage remains to playa prominent role to prevent clinical vasospasm and its sequelae after endovascular coiling on aneurysmal subarachnoid hemorrhage. Also, this technique shows favorable effects on numerous neurological outcomes and prognosis. The results of this study warrant clinical trials after endovascular treatment in patients with aneurysmal SAH.

3D 프린팅 비압박 유방 팬텀 제작을 위한 복셀 기반 수치 모델에 관한 연구 (A Numerical Voxel Model for 3D-printed Uncompressed Breast Phantoms)

  • 윤한빈;백철하;전호상;김진성;남지호;이자영;이주혜;박달;김원택;기용간;김동현;원종훈;김호경
    • 대한의용생체공학회:의공학회지
    • /
    • 제38권3호
    • /
    • pp.116-122
    • /
    • 2017
  • Physical breast phantoms would be useful for the development of a dedicated breast computed tomography (BCT) system and its optimization. While the conventional breast phantoms are available in compressed forms, which are appropriate for the mammography and digital tomosynthesis, however, the BCT requires phantoms in uncompressed forms. Although simple cylindrical plastic phantoms can be used for the development of the BCT system, they will not replace the roles of uncompressed phantoms describing breast anatomies for a better study of the BCT. In this study, we have designed a numerical voxel breast phantom accounting for the random nature of breast anatomies and applied it to the 3D printer to fabricate the uncompressed anthropomorphic breast phantom. The numerical voxel phantom mainly consists of the external skin and internal anatomies, including the ductal networks, the glandular tissues, the Cooper's ligaments, and the adipose tissues. The voxel phantom is then converted into a surface data in the STL file format by using the marching cube algorithm. Using the STL file, we obtain the skin and the glandular tissue from the 3D printer, and then assemble them. The uncompressed breast phantom is completed by filling the remaining space with oil, which mimics the adipose tissues. Since the breast phantom developed in this study is completely software-generated, we can create readily anthropomorphic phantoms accounting for diverse human breast anatomies.

Clinical Experiences and Usefulness of Cervical Posterior Stabilization with Polyaxial Screw-Rod System

  • Hwang, In-Chang;Kang, Dong-Ho;Han, Jong-Woo;Park, In-Sung;Lee, Chul-Hee;Park, Sun-Young
    • Journal of Korean Neurosurgical Society
    • /
    • 제42권4호
    • /
    • pp.311-316
    • /
    • 2007
  • Objective : The objective of this study is to investigate the safety, surgical efficacy, and advantages of a polyaxial screw-rod system for posterior occipitocervicothoracic arthrodesis. Methods : Charts and radiographs of 32 patients who underwent posterior cervical fixation between October 2004 and February 2006 were retrospectively reviewed. Posterior cervical polyaxial screw-rod fixation was applied on the cervical spine and/or upper thoracic spine. The surgical indication was fracture or dislocation in 18, C1-2 ligamentous injury with trauma in 5, atlantoaxial instability by rheumatoid arthritis (RA) or diffuse idiopathic skeletal hyperostosis (DISH) in 4, cervical spondylosis with myelopathy in 4, and spinal metastatic tumor in 1. The patients were followed up and evaluated based on their clinical status and radiographs at 1, 3, 6 months and 1 year after surgery. Results : A total of 189 screws were implanted in 32 patients. Fixation was carried out over an average of 3.3 spinal segment (range, 2 to 7). The mean follow-up interval was 20.2 months. This system allowed for screw placement in the occiput, C1 lateral mass, C2 pars, C3-7 lateral masses, as well as the lower cervical and upper thoracic pedicles. Satisfactory bony fusion and reduction were achieved and confirmed in postoperative flexion-extension lateral radiographs and computed tomography (CT) scans in all cases. Revision surgery was required in two cases due to deep wound infection. One case needed a skin graft due to necrotic change. There was one case of kyphotic change due to adjacent segmental degeneration. There were no other complications, such as cord or vertebral artery injury, cerebrospinal fluid leak, screw malposition or back-out, or implant failure, and there were no cases of postoperative radiculopathy due to foraminal stenosis. Conclusion : Posterior cervical stabilization with a polyaxial screw-rod system is a safe and reliable technique that appears to offer several advantages over existing methods. Further biomechanical testings and clinical experiences are needed in order to determine the true benefits of this procedure.

Missed Skeletal Trauma Detected by Whole Body Bone Scan in Patients with Traumatic Brain Injury

  • Seo, Yongsik;Whang, Kum;Pyen, Jinsu;Choi, Jongwook;Kim, Joneyeon;Oh, Jiwoong
    • Journal of Korean Neurosurgical Society
    • /
    • 제63권5호
    • /
    • pp.649-656
    • /
    • 2020
  • Objective : Unclear mental state is one of the major factors contributing to diagnostic failure of occult skeletal trauma in patients with traumatic brain injury (TBI). The aim of this study was to evaluate the overlooked co-occurring skeletal trauma through whole body bone scan (WBBS) in TBI. Methods : A retrospective study of 547 TBI patients admitted between 2015 and 2017 was performed to investigate their cooccurring skeletal injuries detected by WBBS. The patients were divided into three groups based on the timing of suspecting skeletal trauma confirmed : 1) before WBBS (pre-WBBS); 2) after the routine WBBS (post-WBBS) with good mental state and no initial musculoskeletal complaints; and 3) after the routine WBBS with poor mental state (poor MS). The skeletal trauma detected by WBBS was classified into six skeletal categories : spine, upper and lower extremities, pelvis, chest wall, and clavicles. The skeletal injuries identified by WBBS were confirmed to be simple contusion or fractures by other imaging modalities such as X-ray or computed tomography (CT) scans. Of the six categorizations of skeletal trauma detected as hot uptake lesions in WBBS, the lesions of spine, upper and lower extremities were further statistically analyzed to calculate the incidence rates of actual fractures (AF) and actual surgery (AS) cases over the total number of hot uptake lesions in WBBS. Results : Of 547 patients with TBI, 112 patients (20.4 %) were presented with TBI alone. Four hundred and thirty-five patients with TBI had co-occurring skeletal injuries confirmed by WBBS. The incidences were as follows : chest wall (27.4%), spine (22.9%), lower extremities (20.2%), upper extremities (13.5%), pelvis (9.4%), and clavicles (6.3%). It is notable that relatively larger number of positive hot uptakes were observed in the groups of post-WBBS and poor MS. The percentage of post-WBBS group over the total hot uptake lesions in upper and lower extremities, and spines were 51.0%, 43.8%, and 41.7%, respectively, while their percentages of AS were 2.73%, 1.1%, and 0%, respectively. The percentages of poor MS group in the upper and lower extremities, and spines were 10.4%, 17.4%, and 7.8%, respectively, while their percentages of AS were 26.7%, 14.2%, and 11.1%, respectively. There was a statistical difference in the percentage of AS between the groups of post-WBBS and poor MS (p=0.000). Conclusion : WBBS is a potential diagnostic tool in understanding the skeletal conditions of patients with head injuries which may be undetected during the initial assessment.

The preliminary study for three-dimensional alveolar bone morphologic characteristics for alveolar bone restoration

  • Cho, Hyun-Jae;Jeon, Jae-Yun;Ahn, Sung-Jin;Lee, Sung-Won;Chung, Joo-Ryun;Park, Chang-Joo;Hwang, Kyung-Gyun
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • 제41권
    • /
    • pp.33.1-33.7
    • /
    • 2019
  • Background: The concept of the ideal morphology for the alveolar bone form is an important element to reconstruct or restore the in maximizing esthetic profile and functional alveolar bone restoration. The purpose of this preliminary study is to evaluate the normal alveolar bone structure to provide the standard reference and guide template for use in diagnosing for implant placement, determining the correct amount of bone augmentation in actual clinical practice and producing prostheses based on three-dimensional imaging assessment of alveolar bone. Methods: This study was included 11 men and 11 women (average age, 22.6 and 24.5 years, respectively) selected from among 127 patients. The horizontal widths of alveolar bone of maxilla and mandible were measured at the crestal, mid-root, and root apex level on MDCT (multi-detector computed tomography) images reconstructed by medical imaging software. In addition, tooth dimensions of the central incisors, canines, second premolars, and first molars of maxilla and mandible, including the horizontal width of the interdental alveolar bone crest, were also measured and statistically analyzed. Results: The horizontal alveolar bone width of the palatal side of maxilla showed a distinct increment from the alveolar bone crest to the apical region in both anterior and posterior areas. The average widths of the maxillary alveolar ridge were as follows: central incisor, 7.43 mm; canine, 8.91 mm; second premolar, 9.57 mm; and first molar, 12.38 mm. The average widths of the mandibular alveolar ridge were as follows: central incisor, 6.21 mm; canine, 8.55 mm; second premolar, 8.45 mm; and first molar, 10.02 mm. In the buccal side, the alveolar bone width was not increased from the crest to the apical region. The horizontal alveolar bone width of an apical and mandibular border region was thinner than at the mid-root level. Conclusions: The results of the preliminary study are useful as a clinical guideline when determining dental implant diameter and position. And also, these measurements can also be useful during the production of prefabricated membranes and customized alveolar bone scaffolds.

간접골성 고정원을 이용한 상악 구치부 원심이동 장치 종류에 따른 치아 이동 양상 평가 (Three dimensional analysis of tooth movement using different types of maxillary molar distalization appliances)

  • 김수진;전윤식;정상혁;박선형
    • 대한치과교정학회지
    • /
    • 제38권6호
    • /
    • pp.376-387
    • /
    • 2008
  • 본 연구의 목적은 pendulum 장치, 미니임플란트를 동반한 pendulum장치(펜듈럼), 오픈코일 스프링 및 미니임플란트를 동반한 오픈코일 스프링 이용 시 각각의 치아이동 양상을 3차원적으로 분석하는 데 있었다. 상악 좌측 치조골 및 치아 모형을 제작하고, Calorific $machine^{(R)}$을 이용하여 모형상에서 대구치를 3 mm 원심 이동시켰다. 실험은 5회씩 반복 실시하였다. 모델을 전산화 단층 촬영한 후 V-$Works^{TM}$를 이용하여 3차원 모델을 제작하였다. $Rapidform^{TM}$상에서 3차원적으로 이동방향과 이동량을 계측하였고, 각각의 장치에 관한 통계적 유의성을 검정하였다. 교정용 미니임플란트를 간접 골성 고정원으로 이용하여 오픈코일 스프링으로 구치부를 원심으로 이동시켰을 때가 치체이동에 가장 가까운 이동양상을 보였고, 고정원 소실도 적게 나타났다 (p < 0.05). 오픈코일 스프링, 펜듈럼 장치 모두 미니임플란트를 부가적으로 이용했을 때 고정원 소실량이 적었다 (p < 0.05). 미니임플란트를 이용하지 않은 경우에는 두 장치의 고정원 소실량이 비슷하였다. 미니임플란트의 이용 여부와 관계없이 펜듈럼 장치로 상악 구치 원심 이동 시 오픈코일 스프링에 비해 제1대구치가 조절성 경사이동 양상으로 이동되었고 (p < 0.05), 제2대구치는 비조절성 경사이동 양상을 보였으며, 치관의 협측경사이동이 일어났다 (p < 0.05). 이와 같은 결과를 근거로 간접 골성 고정원을 이용한 오픈코일 스프링이 상악 구치의 원심 치체이동에 가장 효과적인 장치였으며, 펜듈럼 장치를 이용한 구치부 원심이동 시에는 추가적인 조절이 필요하다고 할 수 있다.

조기 폐암환자에서 광역동치료의 효과 (The Clinical Outcomes of Photodynamic Therapy in Early Lung Cancer Patients)

  • 이영석;오연목;심태선;김우성;안정선;최창민;장승훈
    • Tuberculosis and Respiratory Diseases
    • /
    • 제71권4호
    • /
    • pp.266-270
    • /
    • 2011
  • Background: Photodynamic therapy (PDT) is effective in managing small superficial early lung cancer patients who were deemed nonsurgical candidates. However, we do not have any previous report on the usefulness of PDT in early lung cancer in South Korea. Thus we report here our experience of PDT in early lung cancer patients. Methods: 10 patients who underwent PDT for managing early lung cancer between June 2006 and July 2010 were analyzed. PDT was carried out 48 hours after photosensitizer injection. Re-bronchoscopy was carried out 48 hours after PDT in order to remove a necrotic tissue from the PDT site. For evaluation of PDT response, bronchoscopy and chest computed tomography (CT) were performed after 3 months. Results: The median age of patients was 69 (49~77) and all patients were male. The smoking history of patients was 48 (20~75) pack-year and the median follow up of patients was 25 (11~52) months. Complete remission was observed in 10 patients and the recurrence of lung cancer was observed in 3 patients. Out of 10 patients, 3 patients died (one case of lung cancer progression and two cases of pneumonia). Conclusion: The PDT is a safe and effective treatment in early lung cancer patients who are not suitable for surgical resection. The PDT in clinical practice is an attractive option in the treatment of early lung cancer.

CAD-CAM assisted flapless 수술법으로 식립된 임플란트의 안정성 : 기초연구 (Implant stability installed with CAD-CAM assisted flapless surgery : A pilot study)

  • 박찬진;김대곤;조리라
    • 구강회복응용과학지
    • /
    • 제27권4호
    • /
    • pp.405-413
    • /
    • 2011
  • CAD-CAM기법과 CT의 도움으로 무판막임플란트 치료술식이 가능하게 되었다. 본 연구의 목적은 1년간 전향적 연구를 통해 이러한 술식의 신뢰성을 검토하고자 하였다. 하악무치악상태의 연속적인 환자 12명이 포함되었다. 71개의 임플란트가 이공사이에 $NobelGuide^{TM}$법을 이용하여 식립되었고 환자는 정해진 주기에 따라 검사되었다. 한 개의 임플란트가 조기실패하였으며 나머지는 만족할 만한 기능을 보였다. 연구기간 중 평균적인 변연골흡수량은 중앙부($0.3{\pm}0.1$ mm), 견치부($0.5{\pm}0.1$ mm), 원심부($0.7{\pm}0.2$ mm)였으며 임플란트 안정성 수치의 변화량은 중앙부($-1.05{\pm}2.76$ mm), 견치부($-0.85{\pm}2.59$ mm), 원심부($-1.27{\pm}2.18$ mm)를 나타내었고 위치간 통계학적인 차이는 없었다(P>.05). 본 전향적인 기초조사연구에서 CAD-CAM기반의 무판막임플란트 치료술식은 하악무치악환자에게 신뢰성 있는 술식이 될 수 있을 것으로 사료되었다.

과체중 및 비만인 직장인을 대상으로 한 체중관리 프로그램의 효과 (Effects of a Weight Management Program for Overweighted or Obese Office Workers)

  • 한세리;유옥경;변문선;박태선;차연수
    • 한국식품영양과학회지
    • /
    • 제42권10호
    • /
    • pp.1608-1617
    • /
    • 2013
  • 본 연구는 과체중 및 비만인 직장인을 대상으로 체중관리 프로그램을 실시하여 체중감량 및 체지방의 감소, 혈액생화학적 변화, 영양지식 및 운동 능력에 대한 효과를 알아보고자 하였다. 전라북도 내 공공기관의 BMI 23 이상 과체중 및 비만인 직원 39명을 연구대상자로 하여 6개월간 프로그램을 실시하였다. 연구결과 남자그룹에서 삼두근 피부두겹 두께가 유의적으로 감소하였고(P<0.05), 남녀 그룹 모두에서 허리둘레, 엉덩이 둘레가 유의적으로 감소하였다(P<0.05). 혈액 생화학적 검사에서는 남자그룹에서 총콜레스테롤(P<0.05)과 LDL-콜레스테롤(P<0.01)이 유의적으로 감소하였다. 복부 컴퓨터단층촬영 결과에서는 남자그룹에서 복부피하지방조직이 유의적으로 감소하였으며(P<0.01), 영양소 섭취 조사결과 여자 그룹에서 철, 비타민 B2와 나이 아신 섭취량이 유의적으로 증가하였다(P<0.05). 영양지식 점수는 남자 그룹에서 유의적으로 증가하였으며(P<0.05), 운동능력 검사에서는 근지구력이 유의적으로 증가하였다(P<0.01). 직장인들의 건강증진뿐만 아니라 근무 능률과 삶의 질 향상을 위해 사업장에도 건강 및 비만관리가 이루어질 수 있는 체계적인 프로그램이 필요하며, 교육 후에도 비만개선의 긍정적인 변화가 지속될 수 있도록 근로 현장과 국가차원의 프로그램이 개발 지원되어야 할 것이다.