• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.7 no.1
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• pp.27-30
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• 1977

To insure accuracy in dental roentgenographs, it is important that the patient's head position and angulation of the x-ray tube. In 1907 Cieszynski applied the rule of isometry to dental radiography and established that in the production of an accurate image of a tooth, the central ray must be porjected perpendicularly to a plane bisecting angle formed by the longitudinal axis of the tooth and the film plane. Proper exposure of the film is a part of the production of a good dental radiograph, and correct processing also makes an essential contribution to the quality of the radiograph. The author analysed the failure of exposure and processing results, and recommended followings. 1. The patient head must be positioned that occlusal plane are parallel with the horizontal floor. 2. Central ray must be projected to the objective tooth and supporting structure and projected as perpendicularly to tooth axis and film surface as possible. 3. In processing, the temperature of the solution and the processing time must be correct.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.12 no.1
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• pp.115-121
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• 1982

In the study of the focal trough of panoramic radiograph, using the Moritta compony Panex-EC a series of 48 exposures were: taken with the 6-18 brass pins placed in the holes of the plastic model plate, then eveluated by 4 observers. The author analyzed the focal trough defined by the sharpness criteria and calcuated the vertical and horizontal magnification range in the corrected focal trough. The results were as follows; 1. Continuous focal trough was not defined in the anterior region using a very high degree of sharpness. 2. As degree of sharpness used in the analysis became less, focal trough was continuous in the anterior and posterior regions, symmetrized bilaterally, and the widths of the focal trough increased more in the posterior region. e. As sharpness criteria were reduced, the percentage range of image magnification increased on both vertical and horizontal magnification, and especially the percentage range of horizontal magnification was greater than that of vertical magnification.

• The Journal of the Korean dental association
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• v.27 no.8 s.243
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• pp.691-695
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• 1989

Raper가 1925년 소개한 교익방사선사진 촬영법은 나름대로의 독특한 특성을 갖고 있으므로 적절히 이용한다면 환자진료에 많은 도움을 받을 수 있을 것으로 생각되어 재조명해 보고자 한다.

• The Journal of the Korean dental association
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• v.43 no.12 s.439
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• pp.822-837
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• 2005

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.67-75
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• 1995

The progress of periodontal disease and the wound healing process after treatment result in alveolar bone bone change. So, detection of it is very important in the diagnosis and the radiograph of periodontal disease. Various effects have been made to assess the subtle alveolar bone change and digital subtraction radiography (DSR) has been reported to be the best method in evaluating it qualitatively and quantitatively. The present study was performed to estimate the detectable alveolar bone change qualitatively with digital subtraction radiography. For the in vitro study, 10 intraoral standard radiographs were taken from porcine dry mandible which a rectangular cortical bone chip of 0.1mm to 1.0mm thickness with 0.1mm increment was attached on the buccal surface. The radiographs without and with bone plates were reviewed at the same time by 10 observers and requested to detect the presence of cortical bone plates. Digital Subtraction radiograph was reviewed subsequently by using the DSR system(digital converter-256 grey-levels,DT 2851,Data Translation Co., U.S.A;IBM 386 ; CCD camera, FOTOVIX, Tamrom Co., Japan). The detectable thickness of cortical bone plate was O.4mm on the intraoral radiograph and 0.2mm on the subtaction images. For the human study, radiographs were taken from patients by using intraoral film holding device and aluminum reference wedge before and 3 month after bone graft and 1 week after osteoplasty. The grey level change was estimated in the subtraction images and calculated to aluminum equivalent thickness. The grey level of the grafted site was higher that that of healthy controls. Average grey levels of change on healthy controls were O.48mm aluminum equivalent. However, the amount of changes in grafted sites were 1.87mm aluminum thickness equivalent and in the site of osteoplasty were -1.49mm aluminum thickness equivalent. In conclusion, digital subtraction radiography was more effective in detecting as subtle change of alveolar bone than intraoral standard radiography. With the aid of quantitative analysis of digital subtraction radiography, alveolar bone resorption of apposition can be estimated during diagnosis and treatment of periodontally diseased patients.

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.394-399
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• 1995

Pneumocystis carinii pneumonia(PCP) remains the leading cause of death in patients with AIDS. Although the most common radiographic presentation of PCP is the development of diffuse, bilateral interstitial or alveolar infiltrates in 48 to 86 per cent of AIDS patients, PCP may also present with either a completely normal or only minimally abnormal chest radiograph in 6 to 23 per cent of patients. We experienced two patients with AIDS presenting high fever and chest pain but normal chest radiograph, who had been proved to have PCP by bronchoalveolar lavage and trans-bronchial lung biopsy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.4
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• pp.168-174
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• 2013

Objectives: The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. Materials and Methods: A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The patients were classified into two groups. Patients in group 1 were evaluated for symmetry in the middle 1/3 of the face and asymmetry in the lower 1/3 of the face, and those in group 2 for asymmetry of both the middle and lower 1/3 of the face. Results: In group 1, significant differences were observed in nine values out of 14 values. Values included three from anteroposterior cephalometric radiograph measurement values (cant and both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). In group 2, comparison between 2D and 3D showed significant difference in 10 factors. Values included four from anteroposterior cephalometric radiograph measurement values (both maxillary height, both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). Conclusion: Information from 2D analysis was inaccurate in several measurements. Therefore, in asymmetry patients, 3D analysis is useful in diagnosis of asymmetry.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.5
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• pp.483-489
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• 2002

The computer simulation has been done for non-insulated and insulated pipes which are vacant or half filled with liquid. The simulation results showed that the density profile on the radiography is continuous and symmetrical around the center of pipe in the case of vacant pipe. On the other hand the density profiles are not symmetrical and depend on geometrical setting for radiography in the case of half filled pipes. Finally, experimental testing on a non-insulated carbon steel pipe with artificial notches of different depth is carried out using Ir-192 and industrial film. Comparing the measured density profile on the radiograph to the calculated one, it has been shown that it is possible to evaluate thickness variation by measuring density profile on a radiograph.

• Journal of Korean Foot and Ankle Society
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• v.17 no.1
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• pp.34-39
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• 2013

Purpose: To evaluate the effectiveness of intraoperative stress test for diagnosis of occult Lisfranc injury. Materials and Methods: Between April 2009 and October 2012, 21 patients with occult Lisfranc injuries underwent intraoperative stress test and internal fixation. There were 11 males and 10 females with an average age of 45.3 years (range, 23~79 years). Injuries were caused by traffic accident in 10 cases, indirect force (twisting injury) in 8 cases, and crush in 2 cases, falling from a height in 1 case. Unstable injuries on stress radiograph in occult injury of Lisfranc joint were treated by open reduction or closed reduction and fixation with cannulated screw or K-wire. Radiological evaluation was assessed according to preoperative and postoperative diastasis between $1^{st}$ and $2^{nd}$ metatarsal base. Results: Assoicated injuries were 9 cases of metatarsal fractures, 6 cases of cuneiform fractures and 6 cases of both metatarsal and cuneiform fractures. Medial and middle column fixation was in 13 cases, and three columns fixation was in 8 cases. Initial diastasis between $1^{st}$ and $2^{nd}$ metatarsal base was 2.8 mm (1.3~4.7 mm) on AP radiograph and postoperative diastasis between $1^{st}$ and $2^{nd}$ metatarsal base was 1.2 mm (0.5~2.4 mm) on AP radiograph. Conclusion: Even there is no sign of clear Lisfranc injury, it is necessary to pay attention and give evaluation on circumstances of occult Lisfranc injuries with metatarsal or cuneiform fractures. Intraoperative stress test is helpful to diagnose an occult Lisfranc injury. For unstable injuries on stress radiographs of occult Lisfranc joint injury, operative treatment with open or closed reduction and internal fixation is useful method.

• Conservation Science in Museum
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• v.7
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• pp.11-24
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• 2006

Plate armour is an important cultural property that reflects the ancient weaponry and the manufacturing technology of ironware as they are. Among the kinds of iron armour, horizontal plate armour has been very rarely excavated, and there are a few artifacts in their unimpaired shape like the plate armour excavated from Mangisanseong. This report reviews the manufacturing technology of ancient plate armour through its radiograph using appliable nondestructive irradiation and scientific conservation treatment. The seven-tiered plate armour excavated from Mangisanseong has ring hinge to open and shut the right side neck guard. The readout result of radiograph proved iron safety guard of Godaepan (a plate that links neck plate and horizontal plate) and leather safety guard of the right armpit with plate overlap and perforation interval; perforations that seem to have linked shoulder strap on wearing the armour are also observed. In particular, it is identified that the perforation and riveting technique avoided the connection of more than three plates with a rivet. This is an important material to illustrate the best use of function of plate armour overcoming its limit.