• Imaging Science in Dentistry
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• v.40 no.4
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• pp.197-201
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• 2010

Osteopetrosis is a rare bone disease characterized by systemic osteosclerosis due to an osteoclast dysfunction that decreases bone resorption. This report demonstrates two cases of adult osteopetrosis with secondary osteomyelitis of the maxilla, in siblings who are 43-year old female and 55-year old, male respectively. The common radiographic features of these cases were increased radiopacity in skull, rib and vertebra. The radiographic features that differed between these two cases were the osteosclerotic pattern of the jaw bones, that is, diffuse patterns in the female case, while the male case showed nodular patterns that were confined to the root apices. The diagnosis of osteopetrosis may be complicated due to the varying degree of osteosclerosis on panoramic radiograph. Additional radiographs such as the chest and skull radiograph may be helpful for the diagnosis of osteopetrosis.

• Archives of Craniofacial Surgery
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• v.20 no.3
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• pp.181-185
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• 2019

Intraosseous hemangioma is a rare, slow-growing, benign tumor of blood vessels. Primary hemangioma of the skull is a benign lesion that may appear as a palpable mass or accidentally detected during image evaluation. Simple radiography is the most commonly used technique to localize a lesion and computed tomography (CT) may help determine the effect of a lesion. We report a case of multifocal intraosseous calvarial hemangioma developed in the subgaleal plane of an elderly male patient. Ultrasonography examination revealed hyperechoic striated septae parallel to the skin and discontinuity of the focal cortex, however, the underlying bone cortex appeared relatively intact. No significant flow is observed on Doppler ultrasonography. Based on these evaluations, the mass was interpreted by a radiologist as a subgaleal lipoma. This case highlights the importance of additional CT examination in a patient presenting with a scalloping sign of the underlying calvarium. Clinicians also should be aware of the possibility of intraosseous calvarial hemangiomas in lesion. Furthermore, the proper choice of congenital vascular malformation term is still quite confusing with misconception present in the literature.

• Journal of radiological science and technology
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• v.36 no.2
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• pp.111-122
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• 2013

This study was carried out to reduce patient dose through focus-detector distance, kilovoltage, and a combination of copper filters. In the C, L-spine lateral, Skull AP views were obtained by making changes of 60-100 kV in tube voltage and of 100-200 cm in focus-detector distance and by adding a copper filter when using an auto exposure control device in the digital radiography equipment. The incident dose showed 90 kV, 0.3 mmCu in C-spine lateral with 0.06 mGy under the condition of 200 cm; 100 kV, 0.3 mmCu with 0.40 mGy under the condition of 200 cm and 90 kV 0.3 mmCu in Skull AP with the lowest value of 0.24 mGy under the condition of 140 cm. It was observed that entrance surface dose decreased the most when was increased by 150 cm, 70 kV (C-spine lateral), 81 kV (L-spine lateral). It was also found out that as the between the focus-detector increased in the expansion of the video decreased but the difference was not significant when the distance was 180 cm or more. Skull AP showed the most reduction in the entrance surface dose when the tube voltage was changed by 80 kV, 0.1 mmCu, and 120 cm. Therefore, when using the automatic exposure control device, it is recommended to use the highest tube voltage if possible and to increase focus-detector distance at least by 150~200 cm in wall and 120~140 cm in table in consideration of the radiotechnologist's physical conditions, and to combine 0.1~0.3 mmCu and higher filters. It is thus expected to reduce patient dose by avoiding distortion of images and reducing the entrance surface dose.

• Archives of Craniofacial Surgery
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• v.11 no.2
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• pp.103-106
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• 2010

Purpose: Giant cell tumors of the bone are rare, locally aggressive lesions that primarily affect the epiphysis of the long bones in young adults. These tumors occur very rarely on the skull, principally in the sphenoid and temporal bones. The occipital bone is an unusual site. We report a rare case of a giant cell tumor of the occipital bone with a review of the relevant literature. Methods: A 7-year-old boy presented with a mass of the right occipital area, which was accompanied by localized tenderness and mild swelling. The mass was first recognized approximately 1 year earlier and grew slowly. There was no significant history of trauma. The physical examination revealed a nonmobile and non-tender bony swelling on the occipital region. The neurological evaluation was normal. The serial skull radiography and CT scan showed focal osteolytic bone destruction with a bulged soft tissue mass in the right occipital bone. The patient underwent a suboccipital craniectomy and a complete resection of the epidural mass. The lesion was firm and cystic. The mass adhered firmly to the dura mater. Results: The postoperative clinical course was uneventful, and the patient was discharged 5 days later. The histopathology report revealed scattered multinucleated giant cells and mononuclear stromal cells at the tumor section, and the giant cells were distributed evenly in the specimen, indicating a giant cell tumor. Conclusion: Giant cell tumors are generally benign, locally aggressive lesions. In our case, the lesion was resected completely but a persistent long term follow up will be needed because of the high recurrence rate and the possible transformation to a malignancy.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.415-420
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• 2011

The purpose of this study is to know the exposure dose nearby table on the general radiography(skull AP, chest PA, abdomen AP, lumbar lateral, hip joint, knee joint) and to find the reducing it. We measured beside the 45cm and 75cm table center, and 70cm, 80cm, 130cm, 150cm height from the bottom. That were measured highly from the radiography of lumbar lateral, abdomen AP and hip joint as followed $66.21{\mu}Sv$, $34.22{\mu}Sv$, and $32.35{\mu}Sv$ at the 80cm height beside 45cm from the center of table. Measured doses were reduced in order of chest PA, abdomen, hipjoint, skull, knee joint projection. It appears exposure dose of nearby radiographic table was extremely low amount compared with limit of dose(1mSv). If it protected by Pb apron, exposure dose of assisting person will not be exceed a limit of dose. Conclusively, Wearing apron is very important to avoid radiation from the general radiography.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.292-299
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• 2017

Radiation protection aims to prevent a deterministic effect and minimize a stochastic effect. Overestimating a deterministic effect and a stochastic effect can result in an inaccurate assessment of the risks that will occur in the future, and thus accurate evaluation of the absorbed dose of these fundamental amounts is especially important. This study was intended to measure Kerma using PCXMC 2.0 based on Monte Carlo simulations and to assess the exact absorbed dose by comparing doses produced using multipurpose dosimeter and glass dosimeter. It has been decided to conduct experiments for skull, abdomen and pelvis, and Kerma measured PCXMC 2.0 based on Monte Carlo simulations. The absorbed dose was measured using muli purpose dosimeter and glass dosimeter. The results for the experiments conducted in skull, abdomen, pelvis show that the difference in dose appears great in the order of PCXMC 2.0, muli purpose dosimeter, and the glass dosimeter, and muli purpose dosimeter showed a value closer to that of Kerma. As a result, it has been found that the glass dosimeter was the most advantageous in measuring the actual absorbed dose.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.347-357
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• 1997

An accurate working length is an essential factor in the success of endodontic treatment. There are several methods for determining working length; electronic apex locator, tactile sense by clinician, and radiography. Among these methods, the most commonly used method is radiography. But this method requires excessive radiation, long developing time, and many equipments. In additon, it could give an image distortion and two dimensional image. To improve these disadvantages, an intraoral digital radiographic system (Digora$^{(R)}$) which use an imaging plate instead of a film, was developed. The purpose of this investigation was to compare Digora imaging with conventional radiography in determining the working length. Maxillary first or second molars of human dried skull were used. Files were inserted into canals at randomly selected lengths, from 2mm short of the radiographic apex to 2rnm beyond. Radiographs and Digora images(Digora positive and Digora negative) were evaluated to determine the adjustment needed to place the file 0.5mm from the radiographic apex. The results were as follows ; 1. There was no significant difference in accuracy between those evaluated in ${\pm}0.5mm$ and those accurately evaluated in the 3 images. 2. When comparing the accuracy of each image without distinguishing the 3 images, in the group accurately determined within ${\pm}0.5mm$, the mesiobuccal group showed significantly higher accuracy compared to the palatal group(p<0.05).

• Journal of Korean Neurosurgical Society
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• v.53 no.4
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• pp.249-251
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• 2013

Pneumocephalus is a condition characterized by the presence of air in the cranium, and it is mainly caused by trauma or a neurosurgical procedure. In the absence of head trauma or a neurosurgical procedure, meningitis is an extremely rare cause of pneumocephalus. Here, the authors present a rare case of spontaneous pneumocephalus caused by pneumococcal meningitis, in which simple lateral radiography and computed tomography (CT) findings of the skull suggested the diagnosis. Cerebrospinal fluid analysis showed bacterial meningitis which later revealed streptococcus pneumonia. The patient was treated with antibiotics and responded remarkably well. Repeat CT performed after 2 weeks of treatment showed complete resolution of the intracranial gas. Here, the authors report an unusual case of a pneumocephalus caused by meningitis in the absence of head trauma or a neurosurgical procedure.

• Journal of Korean Neurosurgical Society
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• v.59 no.3
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• pp.219-226
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• 2016

The purpose of this article is to review imaging findings and to discuss the optimal imaging methods for craniosynostosis. The discussion of imaging findings are focused on ultrasonography, plain radiography, magnetic resonance imaging and computed tomography with 3-dimensional reconstruction. We suggest a strategy for imaging work-up for the diagnosis, treatment planning and follow-up to minimize or avoid ionized radiation exposure to children by reviewing the current literature.

• Imaging Science in Dentistry
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• v.30 no.4
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• pp.281-285
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• 2000

An uncommon case of a patient with recurrent mandibular ameloblastoma involving various adjacent soft tissues is presented with plain film radiography, computed tomography and magnetic resonance imaging (MRI) and bone scan. The tumor involved mandible and eroded several bones including foramen ovale. This case shows that although an ameloblastoma primarily affect mandible, exact radiographic evaluation of tumor extent will assist the surgeon in the progress of rational approaches to the management of ameloblastoma.