• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권4호
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• pp.391-396
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• 2006

The CT number is called Hounsfield unit(HU). Generally HU has a score between +1000 from -1000, and it is standardized usingthe air(-1000), water(0), and compact bone(+1000). Hounsfield Unit to standardize the density in computed tomography using the air and water has been used to analysis of lesion in other medical field. Computed tomography is popular method to analysis of lesion in oral & maxillofacial field but the analysis about density of lesion by Hounsfield unit is still obscure. For this study, computed tomography taken in Dankook University Dental Hospital and Hounsfield unit was measured to compare the difference of jaw bone lesion as cystic lesion, benign tumor, malignant tumor.

• 치과방사선
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• 제21권2호
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• pp.307-316
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• 1991

The purpose of this study is to improve the availabilities of radiographic technics as diagnostic method related to mandibular canal in dental clinic. For this study 12 dry mandibles were used and 12 orthopantomograms were taken for measuring the gonial angle and the angle of mandibular canal to inferior border of mandible. 12 sites located between the 1st premolar to the 3rd molar region of 3dry mandibles were selected randomly, for measuring the vertical image magnification rates on three films; intraoral film, orthopantomogram, and computed tomogram, respectively and the thickness of cortical bone, and for observing bucco-lingually and supero-inferiorly location of the mandibular canal. The acquired results were as follows: 1. The means of the gonial angle and the angle of mandibular canal to inferior border of mandible were 123.9° and 143.5° And the two angles of dry mandible in alveolar crest stage were greater than in alveolar socket stage. 2. The vertical image length on intraoral film by paralleling technic was magnified by 3.07% on the average, the length on orthopantomogram by 18.49%, and the length on computed tomogram by 0.27%. 3. Observation of the bucco-lingually positional relationship of the mandibular canal was impossible by occlusal projection with the cross section technic and intraoral standard projection with the Clack's rule, however, possible by computed tomogram. 4. The thickness of the cortical bone of mandible was thickest in inferior border, and thicker by 6.59% at buccal side than at lingual side.

• 대한치과교정학회지
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• 제16권1호
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• pp.85-106
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• 1986

The purpose of this investigation was to know the means of the T.M.J. space and to compare spational differences in centric relation and centric occlusion by the T.M.J. Tomogram and to study the correlation between the articular eminence slope and the lingual surface slope of the maxillary central incisor by the Cephalogram in near normal occlusion subjects. These results could give contribution for the diagnosis of orthodontic treatment and T.M.J. dysfunction and the assessment of orthopedic treatment and orthognathic surgery. 44 young adults (28 men and 16 women, 21 to 27 years of age) were selected from the Dental students in Yonsei Univ. Criteria for selection was normal occlusion, no clinical signs and T.M.J. dysfunction, no history of orthodontic treatment, and no missing tooth. After submental vertex view analysis. each subject was given the T.M.J. Tomogram in centric relation and centric occlusion and the Cephalogram was given with Quint Sectograph. All data was recorded and statistically processed with the CYBER computer system. Results were analyzed: the following findings and conclusions were derived. 1. The mean value for the combined right and left anterior joint space was 2.549mm, the posterior space was 2.260mm, and superior space was 3.31mm in centric relation. The anterior space was 2.316mm, posterior space was 2.474mm, and superior space was 3.435mm in centric occlusion. 2. In the centric relation position, both condyles were placed more posterioly and superioly in their fossae than in the centric occlusion position by the spatial difference. 3. In the centric occlusion position, both condyles were more symmetrically placed in their fossae with equal anterior-posterioly rather than in the centric relation position. 4. The mean articular eminence angle was $48.19^{\circ}$ and the mean fossa height was 7.911mm. A strong positive correlation between the articular eminence angle and fossa height in T.M.J. Tomogram was found. 5. In Cephalometric analysis, there was a strong positive correlation between the articular eminence slope and the lingual surface slope of the upper central incisor to the FH plane, occlusal plane, and S-N plane. 6. There was moderate positive correlation between the S-E measurements and the fossa height, articular eminence angle, and DcGn < F-H.

• 터널과지하공간
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• 제3권1호
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• pp.50-53
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• 1993

Geotomography, which reconstructs underground structures, is very important task in recent geophysical data processing. In this study, the field data acquired by U.S.Army was used for tomographic inversion and the result was compared with the tomographic inversion and the result was compared with the tomogram from theoretical model data.

• Journal of Chest Surgery
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• 제25권10호
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• pp.1093-1097
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• 1992

Injury to the esophagus varies from a minor superficial tear to complete rupture of the esophageal wall. We have recently seen one healthy adult male who sustained submucosal dissection of the esophagus while endoscopy. The diagnosis has been made by esophagogram and chest computed tomogram. The therapy was conservative management and good prognosis without complications.

• Journal of Trauma and Injury
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• 제23권1호
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• pp.49-52
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• 2010

A hemothorax usually occur, due to injuries to the intercostal and great vessels, pulmonary damage, and sometimes fractured ribs. We report a case in which the hemothorax that occurred, neither intrathoracic injury nor injury to internal thoracic vessels and organs, via lacerated diaphragmatic and liver laceration due to a right upper part of anterior chest stab injury caused by a sharp object. The patient's general conditions gradually worsened, so chest and abdominal computed tomogram were taken. The abdominal computed tomogram revealed diaphragmatic injuries and bleeding from the lacerated liver. We performed an exploratory laparotomy to control the bleeding from the lacerated liver with simple primary sutures. In addition exploration was performed in the right pleural space through the lacerated diaphragm with a thoracoscopic instrument. There were no bleeding foci in the right pleural space, the vessels, or the lung on the thoracoscopic video. Closure of the lacerated diaphragm was achieved with simple, primary sutures. The postoperative course of the patient was uneventful, and the patient was discharged.

• 지구물리와물리탐사
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• 제6권2호
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• pp.71-76
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• 2003

정확한 초동 발췌는 고해상 속도 토모그램 도출에 중요한 요소이다. 주시 발췌의 정확도에 영향을 주는 2가지 요인은 지질학적 요인과 기계적인 요인이 있다. 중요한 기계적인 요인은 발파시간 제어이다. 임펄시브형 시추공 탄성파 송신원에 의한 기록에서 다음과 같은 문제가 확인되었다. 즉, 불규칙한 발파시간 제어 문제와 기록에 나타난 발파시간의 불확실성이다. 이러한 발파시간 문제는 발췌된 초동에 정확도를 저하시키게 되며, 따라서 속도 토모그램을 왜곡시키게 된다. 본 연구에서는 수평방향의 속도와 NMO 속도를 반복적으로 비교함으포써 최적의 발파시간을 산출하는 방법을 제시하였다.

• 지구물리와물리탐사
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• 제6권2호
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• pp.101-107
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• 2003

프레넬 볼륨을 이용하는 B차원 탄성파 주시 토모그래피 기법을 개발하고 수치자료를 이용하여 알고리즘의 타당성을 검증하였다. 3차원 주시 토모그래피 기법의 현장자료에의 적용성을 고찰하고자 시추공 간 탄성파 현장자료에 대한 주파수 특성 및 송수신 배열 커버리지를 검토하여 약 8m의 분해능의 3차원 입방체의 속도정보를 도출하였다. 3차원 속도분포를 기존의 2차원 토모그램과 비교하였을 때 두 결과가 잘 일치함을 확인함으로써 3차원 토모그래피 알고리즘의 현장 적용성을 확인하였다.

• 지구물리와물리탐사
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• 제9권4호
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• pp.255-260
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• 2006

인접한(대략 1.5 m) 두 개의 시추공에서 확인한 화강암 전단대는 그 폭과 물성(투수율)에서 상당한 차이가 있다. 시추공 간 전단대의 투수율의 분포 특성을 규명하고자 고주파수(>10 kHz) 신호에 의한 시추공 탄성파 토모그래피 탐사를 실시하였다. 시추공에서 획득한 투수율과 탄성파 속도 토모그램에 표출된 속도 패턴을 대비한 결과는 고해상 공대공 속도 토모그램이 전단대의 특성, 즉 균열빈도, 폭, 연장 등에 대한 유용한 정보를 제공할 수 있다는 사실을 제시하였다.

• 지구물리와물리탐사
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• 제10권4호
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• pp.377-382
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• 2007

우리나라에서는 심부 소형 터널의 탐사를 위하여 여러 가지 탐사법이 응용되고 있다. 지금까지 탄성파 자료 처리에서는 주로 주시를 이용한 주시역산법이 많이 이용되어 왔으나, 측정 시추공간의 짧은 거리와 초동의 피킹 오차 등에 의해서 터널의 정확한 위치 해석은 매우 부정확하였다. 본 연구에서는 복수파동원에 의한 진폭법을 이용한 오차 토모그램 방법을 제안하였다. 이론 모형자료와 실제 현장 자료에서 여러 개의 파동원을 조합한 자료들을 이용하여 터널의 위치를 계산하였다.