• Proceedings of the Korean Society of Radiological Science
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• 2004.09a
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• pp.73.3-74
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• 2004

• Journal of Korea Association of Health Promotion
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• v.3 no.2
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• pp.267-279
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• 2005

• 대한치과보철학회:학술대회논문집
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• 2000.11a
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• pp.58-59
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• 2000

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.351-359
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• 2009

We have developed a computer simulator fur cone-beam computed tomography (CBCT) based on the commercial Monte Carlo code, MCNP. All the functions to generate input files, run MCNP, convert output files to image data, reconstruct tomographs were realized in graphical user-interface form. The performance of the simulator was demonstrated by comparing with the experimental data. Although some discrepancies were observed due to the ignorance of the detailed physics in the simulation, such as scattered X-rays and noise in image sensors, the overall tendency was well agreed between the measured and simulated data. The developed simulator will be very useful for understanding the operation and the better design of CT systems.

• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.221-233
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• 2020

CT(computed tomography, CT) examinations is one of the most useful diagnostic equipment for identifying information in the human body in diagnostic radiology. Recently, the number of CT scans is increasing every year due to the high reliability of CT scans. Increasing the number of tests will accelerate the aging of CT devices, which is why the importance of quality management for CT devices is on the rise. Particularly in CT, quality management refers to a behavior of figuring out and correcting all sorts of hindrance factors that can cause all the problems related to the equipment associated with the diminishment of diagnosed area due to the reduction of image quality in clinical imaging in advance and maintaining a consistent level of image quality and obtaining a proper image. Here, these researchers aim to summarize and report the general contents of quality management in CT.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.1
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• pp.36-42
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• 2009

We have developed software for converting the volumetric voxel data obtained from X-ray computed tomography(CT) into computer-aided design(CAD) data. The developed software can used for non-destructive testing and evaluation, reverse engineering, and rapid prototyping, etc. The main algorithms employed in the software are image reconstruction, volume rendering, segmentation, and mesh data generation. The feasibility of the developed software is demonstrated with the CT data of human maxilla and mandible bones.

• Journal of Chest Surgery
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• v.43 no.2
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• pp.204-207
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• 2010

A 68 year-old man visited our institution due to chest pain. Coronary angiography revealed triple vessel disease. A computed tomographic angiogram performed as a routine preoperative examination demonstrated an intraluminal spider-web-like mass from the infrarenal abdominal aorta to both common iliac arteries. The infrarenal aorta and both common iliac arteries were excised and replaced with concomitant off-pump coronary artery bypass grafts. Histologic examination of the aorta suggested an intimal sarcoma. A postoperative computed tomographic angiogram performed 3 months postoperatively showed no evidence of a residual or a recurred lesion.

• Journal of radiological science and technology
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• v.46 no.4
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• pp.295-301
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• 2023

In addition to protocol adjustments during CT examinations, the height of the CT table can also affect image quality. Therefore, this study aimed to investigate the change in image quality depending on the height of the table in brain CT, which accounts for a large proportion of CT examinations, by measuring signal to contrast to noise ratio (CNR) and noise power spectrum (NPS) using the head phantom and evaluating them. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. The CNR result showed the highest value at 965 mm, which is the height adjacent to the center of the head phantom. NPS showed the lowest NPS at 915 mm, the center of the head phantom in the low frequency region. From these results, it can be seen that the height of the table in CT examination is closely related to the image quality, and it can be seen the characteristics of image quality according to CT table through quantitative evaluation methods such as CNR and NPS.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.74-80
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• 2009

Purpose : To evaluate the characteristic MR imaging findings of Langerhans cell histiocytosis (LCH) in the skull and to compare them with those of plain radiography and computed tomography. Materials and Methods : A total of 10 lesions in 9 patients (Age range; 5-42 years, Mean age; 18, all women) with Langerhans cell histiocytosis in the skull were included in our study. Nine lesions in nine patients were histologically confirmed by surgery or fine needle aspiration biopsy. All patients performed with MRI, and plain radiography and CT scan were done in 7 patients (8 lesions). Two experienced neuroradiologists reviewed the radiological examinations independently with attention to location, size, shape and nature of the lesions in the skull and compared the extent and extension of the lesions to adjacent structures. Results : The lesions were distributed in all of the skulls without predilection site. On MRI, the masses were shown as well-enhancing soft tissue masses (10/10) mainly in diploic spaces (8/10) with extension to scalp (9/10) and dura mater (7/10). Dural enhancement (7/10) and thickening (4/10) were seen. The largest diameter of the soft tissue masses ranged 1.1 cm to 6.8 cm, shaped as round (5/10) or oval (5/10). On CT scans, the lesions were presented as soft tissue masses involving diploic space (6/8) and scalp extension (7/8) were also well visualized. Although bony erosion or destruction was more clearly seen on CT rather than those of MRI, enhancement of soft tissue masses and dura were not well visualized on CT. In contrast, all of the lesions in LCH were seen as punched out (4/8), beveled-edge appearance (4/8) osteolytic masses in plain radiography, but scalp and dural extension could not be seen. Conclusion : Characteristic MR findings in patients with LCH are soft tissue mass in diploic space with extension to dura and scalp, and MRI would be better imaging modality than plain radiography or CT.

• Journal of Veterinary Clinics
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• v.29 no.6
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• pp.488-493
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• 2012

Two Maltese (2-year-old, intact female and 4-month-old, intact female) and a Pekingese (10-year-old, intact male) dogs were referred due to vomiting, anorexia, head-pressing and hypersalivation. Physical examinations, complete blood count, serum chemical analysis, radiography, ultrasonography and computed tomography (CT) were evaluated. Laboratory findings in these dogs included high hepatic enzyme, serum bile acid and ammonia concentration. Microhepatia was found on abdominal radiographs in two dogs. The existence of portosystemic shunt was presented in abdominal ultrasonography. The shunt vessel was identified in all dogs by CT imaging. Based on three-dimensional CT reconstruction, the origin and termination of each shunt vessel were defined certainly. In consequence, each dog was diagnosed single extrahepatic portosystemic shunt. After diagnosis, surgical treatment was performed in all dogs. This case report describes clinical finding, imaging characteristics, and three-dimensional CT imaging of single extrahepatic portosystemic shunt cases.