• 제목/요약/키워드: cone-beam CT

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Cone beam computed tomography로 합성된 두부규격 방사선사진에서의 각 계측점의 정확도와 재현성에 관한 연구 (Accuracy and reproducibility of landmark of cone beam computed tomography (CT) synthesized cephalograms)

  • 권대근;민승기;전인철;팽준영
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제36권2호
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    • pp.78-86
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    • 2010
  • Introduction: Cone beam computed tomography (CBCT) has various advantages and is used favorably in many fields in dentistry. Especially, CBCT is being used as basic diagnostic tool for 3-dimensional analysis in orthognathic patient. Two-dimensional cephalograms can be synthesized from CBCT digital imaging and communications in medicine (DICOM) data. In this study, conventional cephalograms and CBCT were taken simultaneously, and representative landmarks were located and analyzed in its accuracy and reproducibility. Materials and Methods: Ten patients who had orthognathic surgery in Wonkwang University Daejeon Dental Hospital participated in this study. For each patient, CBCT and conventional cephalogram was taken. By using Ondemand (Cybermad, Korea), 2-dimensional cephalograms was established on CBCT. In addition, 19 landmarks were designated and measured by 3 orthodontists twice a week. After these landmarks were transferred to a coordinate, distance of landmark and axis, standard error, distribution degree were measured, compared and analyzed. Results: Comparing the CT ceph group and conventional cephalogram group, CT ceph group had shown shorter distance of landmark and axis in S, Hinge axis, Bpt, Ba, Or, Corpus left. Standard error of the mean shows that CT ceph group has better reproducibility in Or, Corpus left, Hinge axis at X axis and Na, U1R, U1T, Bpt, PNS, Ba Corpus left, Hinge axis at Y axis. In both groups, mean error was less than 1.00 mm, no significant difference were found between CT ceph group and conventional cephalogram group in all measurements. Furthermore, comparing two groups, each 17 landmarks out of 19 had its characteristic in distribution degree. Conclusion: No significant difference were found between CBCT composed cephalographic radiograph and conventional cephalograghic radiograph, clinical application may be possible if improved.

A cone-beam computed tomography study of the prevalence and location of the second mesiobuccal root canal in maxillary molars

  • Seong-Ju Lee ;Eun-Hye Lee ;Se-Hee Park ;Kyung-Mo Cho ;Jin-Woo Kim
    • Restorative Dentistry and Endodontics
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    • 제45권4호
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    • pp.46.1-46.8
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    • 2020
  • Objectives: This study aimed to investigate the incidence and location of the second mesiobuccal root (MB2) canal in maxillary molars with the aid of various measuring points and lines using cone-beam computed tomography (CT). Materials and Methods: A total of 205 images of patients who underwent cone-beam CT examinations between 2011 and 2015 as part of their dental diagnosis and treatment were included. There were 76 images of the maxillary first molar and 135 images of the maxillary second molar. Canal orifices were detected at -1 mm from the top of the pulpal floor on cone-beam CT images. Image assessment was performed by 2 observers in reformatted image planes using software. Assessments included measurement of the distance between the MB1 and MB2 canals, and the angles between the lines connecting the MB1-MB2 and distobuccal (DB)-palatal (P) canals. The data were analyzed using the student's t-test. Results: The prevalence of the MB2 canal was 86.8% in the first molar and 28.9% in the second molar. The angle between the lines connecting the MB1-MB2 and DB-P canals was 2.3° ± 5.7° in the first molar and -3.95° ± 7.73° in the second molar. The distance between the MB1 and MB2 canals was 2.1 ± 0.44 mm in the first molar and 1.98 ± 0.42 mm in the second molar. Conclusions: The angles between the lines connecting the MB1-MB2 and DB-P canals was almost parallel. These findings may aid in the prediction of the location of the MB2 canal orifice.

간동맥 화학 색전술 후 발생한 급성 담낭염의 발생률과 위험인자: Cone Beam CT 소견과의 상관관계 (Incidence and Risk Factors of Acute Ischemic Cholecystitis after Transarterial Chemoembolization: Correlation with Cone Beam CT Findings)

  • 김종영;오정석;천호종;김수호
    • 대한영상의학회지
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    • 제85권2호
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    • pp.363-371
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    • 2024
  • 목적 급성 담낭염은 간동맥 화학 색전술 후에 발생하는 비교적 드물지 않게 발생하는 합병증이며, 대부분 수술적 혹은 중재적 치료 없이 호전된다. 간동맥 화학 색전술 직후에 촬영한 cone beam CT 소견을 이용하여, 수술적 혹은 중재적 치료를 필요로 하는 담낭염의 발생률과 위험인자를 분석하고자 하였다. 대상과 방법 본 연구에서는 6년 동안 시행된 2633건의 간동맥 화학 색전술에 대해 후향적으로 분석하였다. 그중 시술 직후에 촬영한 cone beam CT에서 담낭에 색전 물질이 남아 있는 120명을 선택하여 급성 담낭염의 발생률과 위험인자에 대해 분석하였다. 결과 수술적 혹은 중재적 치료를 필요로 하는 담낭염의 전체 발생률은 0.45%였다. 색전 물질이 남아 있는 환자들 중에서는 10%에서 담낭염이 발생했다. 담낭염이 발생한 12명 중 8명은 담낭동맥의 색전술을 받은 환자들이었다. 결론 대부분의 담낭의 색전물질 침적은 추가적인 치료를 필요로 하지 않고 호전되지만, 담낭동맥의 색전술을 받은 경우에는 담낭염의 발생률이 높아 면밀한 모니터링이 필요하다.

근관치료 영역에서 Cone Beam CT의 활용 (Cone Beam Computed Tomography in Endodontics)

  • 조형훈
    • 대한치과의사협회지
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    • 제57권7호
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    • pp.392-402
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    • 2019
  • The most important part of everyday root canal treatment is diagnosis about the morphology of tooth, root and root canal. Usually this procedure is performed by visual examination and radiographic (panoramic/periapical) examination. However, 2-dimentional radiography has several limitations such as imposition of anatomic structures including buccal/lingual root canals and distortion of images. Recently, owing to the increased interest in dental implant and affordable cost of CBCT equipment, CBCT has been introduced widely in local dental clinics. CBCT is characterized by their lower radiation dose and shorter exposure time than conventional CT scan, and ability of 3-dimentional reconstruction of the dento-alveolar structure. Also in endodontic field, the data from CBCT could be very helpful in diagnosing complex root canal anatomy, apical periodontitis, cause of failure and in determining treatment plan. However, there are some limitations such as radiation dose and artifact. Therefore, clinicians should know about indication, advantages and limitations of CBCT, and properly use it for successful root canal treatment to save the natural teeth.

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Cone-beam CT에서 웨이브렛 역치값을 이용한 x-ray 영상에서의 노이즈 제거 (Noise Reduction of medical X-ray Image using Wavelet Threshold in Cone-beam CT)

  • 박종덕;허영;진승오;전성채
    • 전자공학회논문지SC
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    • 제44권6호
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    • pp.42-48
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    • 2007
  • X-ray 영상 시스템에서는, 크게 2 종류의 noise 성분이 함유되어있다. 먼저 x-ray 방사선이 조사되어질 때, 검출기에서의 방사선의 상호작용으로부터 발생되어지는 것으로서 랜덤하게 발생되어지는 Poisson noise 성분이다. 다음으로 noise 성분은 readout electronics noise, pixel pattern noise 그리고 off-set noise 등으로부터 발생되어지는 Gaussian noise 성분이다. 그러나, x-ray 영상에서는 Gaussian noise가 아닌, Poisson noise로 모델링 되어진다. Gaussian noise에 의해서 발생되어지는 noise 성분은 위너필터 혹은 웨이브렛을 사용하여 쉽게 제거가 가능하지만, Poisson noise와 같은 랜덤 noise를 제거하기 위해서는 복잡한 분석기법이 필요하게 한다. 이 논문에서는 웨이브렛 영역에서 x-ray 영상의 Poisson noise를 제거하고자 하였으며, 적용된 분석 기법은 최적화된 웨이브렛 분석기법인 IBS(Improved BayesShrink)을 사용하였다. 적용된 IBS 기법은 cone-beam CT의 x-ray 영상에서의 기존의 방법에 비해 향상된 결과를 보여주었다.

Cone-Beam CT를 이용한 악교정 수술용 스텐트 제작과 임상 적용 (SURGICAL STENT FABRICATION AND CLINICAL APPLICATION FOR ORTHOGNATHIC SURGERY USING Cone-Beam CT)

  • 김용일;김종렬;김성식;손우성;박수병
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제31권2호
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    • pp.158-166
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    • 2009
  • The application of CT with basis on 3 dimensional-reconstruction is getting more widely practiced. With the data obtained from cone-beam computed tomography(CBCT), not only the diagnosis of the patient with skeletal abnormality but also the virtual simulation of the orthognathic surgery were performed and its application would be popular in orthodontic field. We reported a case, a 19-year old man who was diagnosed mandibular prognathism and required orthognatic surgery. In this case, the virtual orthognathic surgery was simulated and surgical wafer was fabricated by using CBCT data. That wafer was applied the actual orthognathic surgery. After preoperative orthodontic treatment, we prepared surgery as follows. : (l)Acquisition of 3D image data, (2)Reconstruction of 3-dimensional virtual model, (3)Virtual model surgery, (4)Extraction of stere-olithographic image, (5)Check-up for occlusal interference, (6)Fabrication of surgical stent by stereolithography. Bilateral sagittal split ramus osteotomy was operated and used stereolithographic surgical stent. 1 month later, we superimposed CBCT datas of virtual surgery and that of actual surgery, and then compared the result. CT data's application for othognathic surgery yielded satisfactory outcomes.

Assessment of CT numbers in limited and medium field-of-view scans taken using Accuitomo 170 and Veraviewepocs 3De cone-beam computed tomography scanners

  • Oliveira, Matheus L.;Tosoni, Guilherme M.;Lindsey, David H.;Mendoza, Kristopher;Tetradis, Sotirios;Mallya, Sanjay M.
    • Imaging Science in Dentistry
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    • 제44권4호
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    • pp.279-285
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    • 2014
  • Purpose: To assess the influence of anatomic location on the relationship between computed tomography (CT) number and X-ray attenuation in limited and medium field-of-view (FOV) scans. Materials and Methods: Tubes containing solutions with different concentrations of $K_2HPO_4$ were placed in the tooth sockets of a human head phantom. Cone-beam computed tomography (CBCT) scans were acquired, and CT numbers of the $K_2HPO_4$ solutions were measured. The relationship between CT number and $K_2HPO_4$ concentration was examined by linear regression analyses. Then, the variation in CT number according to anatomic location was examined. Results: The relationship between $K_2HPO_4$ concentration and CT number was strongly linear. The slopes of the linear regressions for the limited FOVs were almost 2-fold lower than those for the medium FOVs. The absolute CT number differed between imaging protocols and anatomic locations. Conclusion: There is a strong linear relationship between X-ray attenuation and CT number. The specific imaging protocol and anatomic location of the object strongly influence this relationship.

Cone Beam CT를 이용한 하악 제 1대구치 맹출 양상에 관한 연구 (ERUPTION PATTERN OF THE MANDIBULAR FIRST MOLAR USING THE CONE BEAM CT)

  • 신정근;김재곤;백병주;양연미;정진우
    • 대한소아치과학회지
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    • 제36권3호
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    • pp.325-336
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    • 2009
  • 건강한 정상 교합 어린이 83명(남자 42명, 여자 41명)을 대상으로 보호자 동의하에 cone beam CT 영상을 촬영하여, 하악 제 1대구치의 맹출 양상을 연구하였다. 대상을 발육 정도에 따라 Nolla stage(4-10단계)로 구분한 후 삼차원 기준 평면인 전두면(frontal), 시상면(sagittal), 수평면(horizontal)에서 각각 하악 제 1대구치의 맹출 양상을 관찰하였다. 1. 전두면과 수평면에서, 하악 제 1대구치간 폭경은 감소하였는데, stage 5에서 stage 8까지 가장 크게 감소했다가 약간 증가하였다. 2. 시상면과 전두면에서, 하악 제 1대구치 맹출량은 교합평면을 기준으로 stage 5에서 stage 7까지 가장 많은 맹출 이동을 보였다. 3. 수평면과 시상면에서, 하악 제 1대구치는 제 2유구치 원심면으로부터 stage 4에서 stage 6까지 원심으로 이동하였고 이후 큰 변화가 없었다. 4. 시상면에서, 교합 평면과 하악 제 1대구치의 근원심 치축이 이루는 각은 stage 4에서 stage 8까지 증가하였다. 5. 전두면에서, 교합 평면과 하악 제 1대구치의 협설측 치축이 이루는 각은 지속적으로 증가하였다. 6. 수평면에서, 정중 시상면과 하악 제 1대구치의 치축이 이루는 각은 stage 5부터 stage 8까지 증가하다 stage 8이후에는 다시 약간 감소하였다.

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치과용 cone beam CT를 이용한 한국인 소아 및 청소년의 매복 정중과잉치에 대한 3차원적 분석 (Three-Dimensional Evaluation of Impacted Mesiodens Using Dental Cone-Beam Computed Tomography in Korean Children and Adolescents)

  • 김상덕;이상호;이난영;전상윤
    • 대한소아치과학회지
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    • 제40권3호
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    • pp.149-158
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    • 2013
  • 이 연구의 목적은 치과용 3차원 Come-beam CT 영상을 이용하여 정중과잉치의 형태와 매복 양상 및 연관된 합병증에 대해 평가하는 것이다. 2007년부터 2012년까지 정중과잉치를 주소로 조선대학교 치과병원 소아치과에 내원한 280명의 환아의 cone-beam CT 영상을 평가하였다. 매복된 정중과잉치는 여아보다 남아에서 더 빈번했고, 약 3.3 : 1의 비율을 보였으며 6~8세에서 가장 많이 관찰되었다. 환자당 정중과잉치의 개수는 1.38개였다. 대부분의 정중과잉치는 원추형(79.5%)이었으며, 역위방향(48.6%)으로 위치하고 있었다. 근원심적 위치로는 정중부(81.8%)가 가장 흔했고, 수직적으로는 치경부 근처(60.3%)에 가장 많이 분포하였으며, 순구개측 위치로는 구개측(73.8%)에 가장 많이 위치였다. 정중과잉치의 47.5%에서 합병증이 관찰되었고 인접치 변위와 맹출 지연이 가장 흔했다. 과잉치의 형태와 수직적 위치, 그리고 순구개측 위치가 합병증과 상관관계를 보였다. Cone-beam CT는 매복된 정중과잉치에 대한 3차원적 위치 정보와 정확한 영상을 제공하였다.