• Title, Summary, Keyword: Cone-beam CT

Search Result 206, Processing Time 0.029 seconds

Study on the Validation of the Gated Cone-Beam Computed Tomography on Radiation Therapeutic Linear Accelerator (방사선치료용 선형가속기를 이용한 Gated Cone-Beam CT의 유용성 연구)

  • Seo, Jeong-Min;Kim, Chan-Hyeong;Park, Byoung-Suk;Park, Cheol-Soo;Jang, Hyon-Chol;Kim, Joung-Dae
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.16 no.10
    • /
    • pp.6932-6939
    • /
    • 2015
  • The respiration is one of important factor in the radiation therapy. The existing commercial method of cone-beam computed tomography on LINAC does not consider respiratory motion of patient hence the images are both distorted and inaccurate. In this study, the cone-beam computed tomography images have been reconstructed from back projection radiography of specific phase on breathing cycle which concerned about respiratory movement in radiation therapy. This study investigated how different between cone-beam CT images with and without gating respiratory movement, and this paper provides that guide and implementation of gated cone-beam CT on radiation therapeutic equipment.

The Study on the Implementation of the X-Ray CT System Using the Cone-Beam for the 3D Dynamic Image Acquisition (3D 동영상획득을 위한 Cone-Beam 형 X-Ray CT 시스템 구현에 관한 연구)

  • Jeong, Chan-Woong;Jun, Kyu-Suk
    • The Journal of the Acoustical Society of Korea
    • /
    • v.28 no.4
    • /
    • pp.370-374
    • /
    • 2009
  • In this paper, we presents a new cone beam computerized tomography (CB CT) system for the reconstruction of 3 dimensional dynamic images. The system using cone beam has less the exposure of radioactivity than fan beam, relatively. In the system, the reconstruction 3-D image is reconstructed with the radiation angle of X-ray in the image processing unit and transmitted to the monitor. And in the image processing unit, the Three Pass Shear Matrices, a kind of Rotation-based method, is applied to reconstruct 3D image because it has less transcendental functions than the one-pass shear matrix to decrease a time of calculations for the reconstruction 3-D image in the processor. The new system is able to get 3~5 3-D images a second, reconstruct the 3-D dynamic images in real time.

Analysis of Image Distortion by Mandibular Arch Form in Cone Beam CT and Panoramic Image (Cone Beam형 CT와 파노라마 영상에서 하악궁의 영상 왜곡 분석)

  • Jeong, Cheonsoo;Lee, Geeheun
    • Journal of the Korean Society of Radiology
    • /
    • v.7 no.4
    • /
    • pp.301-305
    • /
    • 2013
  • This thesis intends to analyze tooth distortion by mandibular arch form by reproducing existing panorama image and reconstructed panorama image of Cone Beam CT data with the three-dimensional computer program. The diameter of tooth measured in Cone Beam CT's cross-section image and reconstructed panorama was synchronized without any big change from incisors to posteriors. But, panorama showed serious distortion as going to posteriors after showing a little distortion in incisors. The panorama reconstructed for patients' individual arch showed reduced distortion than panoramas used generally. In addition, panorama showed serious distortion from incisors to posteriors and it means that distortion is reduced in reconstructed panorama.

EFFECTIVE DOSE FROM CONE BEAM CT FOR IMAGING OF MESIODENS (상악 정중과잉치 진단을 위한 cone beam CT의 유효선량)

  • Han, Won-Jeong;Kim, Jong-Soo
    • JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
    • /
    • v.39 no.3
    • /
    • pp.273-279
    • /
    • 2012
  • Purpose : This study was aimed to calculate effective dose from cone beam CT and compare effective dose from periapical and panoramic radiography for mesiodens. Materials and Methods : Upper anteiror periapical, panoramic radiography and cone-beam CT were taken for diagnosis of mesiodens. The effective dose were calculated by using an anthropomorphic phantom loaded with thermoluminescent dosimeters at the 23 sites related to sensitive organs. Results : The highest absorbed doses were received by the mandibular body, parotid gland and cheek from periapical, panoramic and cone-beam CT, respectively. The effective doses for periapical, panoramic radiography and cone-beam CT measured 2, 18 and 48 ${\mu}Sv$. Conclusion : Cone-beam CT, although providing additional diagnostic benefits, exposes patients to higher levels of radiation than conventional periapical and panoramic radiography.

Cone beam CT findings of retromolar canals: Report of cases and literature review

  • Han, Sang-Sun;Park, Chang-Seo
    • Imaging Science in Dentistry
    • /
    • v.43 no.4
    • /
    • pp.309-312
    • /
    • 2013
  • A retromolar canal is an anatomical variation in the mandible. As it includes the neurovascular bundle, local anesthetic insufficiency can occur, and an injury of the retromolar canal during dental surgery in the mandible may result in excessive bleeding, paresthesia, and traumatic neuroma. Using imaging analysis software, we evaluated the cone-beam computed tomography (CT) images of two Korean patients who presented with retromolar canals. Retromolar canals were detectable on the sagittal and cross-sectional images of cone-beam CT, but not on the panoramic radiographs of the patients. Therefore, the clinician should pay particular attention to the identification of retromolar canals by preoperative radiographic examination, and additional cone beam CT scanning would be recommended.

Three dimensional evaluation of impacted mesiodens using dental cone beam CT (치과용 콘빔 CT를 이용한 상악 정중과잉치의 3차원 분석)

  • Lee, Dong-Ho;Lee, Jea-Seo;Yoon, Suk-Ja;Kang, Byung-Cheol
    • Imaging Science in Dentistry
    • /
    • v.40 no.3
    • /
    • pp.109-114
    • /
    • 2010
  • Purpose : This study was performed to analyze the position, pattern of impacted mesiodens, and their relationship to the adjacent teeth using Dental cone-beam CT. Materials and Methods : Sixty-two dental cone-beam CT images with 81 impacted mesiodenses were selected from about 2,298 cone-beam CT images at Chonnam National University Dental Hospital from June 2006 to March 2009. The position, pattern, shape of impacted mesiodenses and their complications were analyzed in cone-beam CT including 3D images. Results : The sex ratio (M : F) was 2.9 : 1. Most of the mesiodenses (87.7%) were located at palatal side to the incisors. 79% of the mesiodenses were conical in shape. 60.5% of the mesiodenses were inverted, 21% normal erupting direction, and 18.5% transverse direction. The complications due to the presence of mesiodenses were none in 43.5%, diastema in 19.4%, tooth displacement in 17.7%, delayed eruption or impaction in 12.9%, tooth rotation in 4.8%, and dentigerous cyst in 1.7%. Conclusions : Dental cone-beam CT images with 3D provided 3-dimensional perception of mesiodens to the neighboring teeth. This results would be helpful for management of the impacted mesiodens.

Assessment of the relationship between the mandibular third molar and the mandibular canal using panoramic radiograph and cone beam computed tomography (파노라마 방사선사진과 cone beam CT에서 제3대구치와 하악관의 관계 평가)

  • Jung, Yun-Hoa;Nah, Kyung-Soo;Cho, Bong-Hae
    • Imaging Science in Dentistry
    • /
    • v.38 no.3
    • /
    • pp.163-167
    • /
    • 2008
  • Purpose : The purpose of this study is to evaluate the position of the mandibular canal in relation to the mandibular third molar by cone beam CT in cases showing a close relationship between the third molar and the mandibular canal on the panoramic radiograph. Materials and Methods : The panoramic images and cone beam CT scans of 87 impacted mandibular third molars in 60 patients were evaluated to assess the tooth relationship to the mandibular canal. The clearness of the canal wall and the vertical depth of the lower third molar were evaluated on panoramic radiographs. The lower third molars were assessed using cone beam CT to determine the proximity and position of the canal relative to the roots. Results : In the 66 cases where the canal wall was unclear on the panoramic radiographs, 58 (87.9%) of the third molars had contact between the canal and root; 34 (51.5%) canals were showed an inferior position and 22 (33.3%) showed a linguoinferior position on cone beam CT. Conclusion : Interruption of the canal wall on panoramic radiographs was highly predictive of contact between the mandibular canal and the third molar. Cross sectional CT may be indicated for localization of the mandibular canal in such cases.

  • PDF

Detection of maxillary second molar with two palatal roots using cone beam computed tomography: a case report (두개의 구개측 치근을 갖는 상악 제2대구치에서 cone beam computed tomography 활용: 증례보고)

  • Kim, Jeong-Hee;Song, Byeongcheol
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.32 no.1
    • /
    • pp.87-92
    • /
    • 2016
  • The purpose of this clinical report was to show anatomical variations in permanent maxillary second molar using computed tomography (CT). This case report describes the application of CT to detect the unusual root anatomy of maxillary second molar with 2 separate palatal roots for successful endodontic treatment procedures. The use of cone beam computed tomography (CBCT) can overcome the limitation of the periapical standard radiography caused by the overlap of buccal and secondary palatal roots.

Analysis of Beam Hardening of Modulation Layers for Dual Energy Cone-beam CT (에너지 변조 필터로 구현한 이중 에너지 콘빔 CT의 에너지 스펙트럼 평가 연구)

  • Ahn, Sohyun;Cho, Sam Ju;Keum, Ki Chang;Choi, Sang Gyu;Lee, Rena
    • Progress in Medical Physics
    • /
    • v.27 no.1
    • /
    • pp.8-13
    • /
    • 2016
  • Dual energy cone-beam CT can distinguish two materials with different atomic compositions. The principle of dual energy cone-beam CT based on modulation layer is that higher energy spectrum can be acquired at blocked x-ray window. To evaluate the possibility of modulation layer based dual energy cone-beam CT, we analyzed x-ray spectrum for various thicknesses of modulation layers by Monte Carlo simulation. To compare with the results of simulation, the experiment was performed on prototype cone-beam CT for 50~100 kVp with CdTe XR-100T detector. As the result of comparing, the mean energy of energy spectrum for 80 kVp are well matched with that of simulation. The mean energy of energy spectrum for 80 and 120 kVp were increased as 1.67 and 1.52 times by 2.0 mm modulation layer, respectively. We realized that the virtual dual energy x-ray source can be generated by modulation layer.