• Imaging Science in Dentistry
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• 제34권3호
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• pp.123-128
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• 2004

Purpose: To evaluate the reliability of measurements in spiral tomography through assessing the visibility of the alveolar crest and the measurements between the alveolar crest and other anatomic structures. Materials and Methods: 110 spiral tomograms of the jaws were taken by Scanora X-ray unit from the patients. The visibility of the alveolar crests was estimated by 3 observers and classified as clearly visible, questionable visibility, or not visible. 3 observers measured the distance between the alveolar crest and the reference points of anatomic structures. The measurements were repeated 2 weeks later. Results: 52.9% of alveolar crests on upper jaws and 61.5% of alveolar crests on lower jaws were visible. The interobserver and intraobserver agreements on the visibility were low. The mean ranges of the measurements were 1.39 mm (SD = 1.37 mm) on maxilla and 1.03 mm (SD = 1.01 mm) on mandible in the interobserver evaluation. The interobserver variance was greater than the intraobserver variance in the measurements of distance. Conclusion: Spiral tomography showed a relatively low reliability in the visibility and measurements of the alveolar crest.

• Imaging Science in Dentistry
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• 제36권2호
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• pp.111-116
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• 2006

PET/CT is a new imaging technology that combines high-quality Positron Emission Tomography (PET) and Computed Tomography (CT). This imaging provides simultaneous anatomical and metabolic information. Therefore PET/CT is useful diagnostic modality for early detection of malignant tumor, accurate staging, decision on therapeutic plan, monitoring response to therapy and rapid detection of recurrence. We report oral and maxillofacial cancers diagnosed by using PET/CT and the usefulness of PET/CT in the evaluation of postoperative recurrence.

• Journal of the Optical Society of Korea
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• 제13권3호
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• pp.341-348
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• 2009

We report the development of full-field swept-source optical coherence tomography (SS-OCT) in the wavelength range of 815-870 nm using a unique combination of super-luminescent diode (SLD) as broad-band light source and acousto-optic tunable filter (AOTF) as a frequency-scanning device. Some new applications of full-field SS-OCT in forensic sciences and engineering materials have been demonstrated. Results of simultaneous topography and tomography of latent fingerprints, silicon microelectronic circuits and composite materials are presented. The main advantages of the present system are completely non-mechanical scanning, wide-field, compact and low-cost.

• 대한수의학회지
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• 제53권2호
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• pp.137-141
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• 2013

To report retinal image of in a 6-year-old male castrated poodle dog with a 2-month history of nyctalopia using optical coherence tomography (OCT). Ocular reflexes were present in both eyes and slit lamp examination showed anterior subscapular cataract in the right eye. There were fundus abnormalities in both eyes similar to retinal degeneration. Scotopic electroretinograms (ERGs) revealed significantly subabnormal amplitudes and prolonged implicit time, whereas photopic ERGs were better maintained, although far from normal. OCT of affected dogs revealed generalized retinal thinning much more than a normal age-matched dog. Therefore, OCT scanning is considered to be a useful method for retinal evaluation in dogs with retinal degeneration.

• Imaging Science in Dentistry
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• 제36권3호
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• pp.123-129
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• 2006

The use of computed tomography for dental procedures has increased recently. Cone beam computed tomography (CBCT) systems have been designed for imaging hard tissues of the dentomaxillofacial region. CBCT is capable of providing high resolution in images of high diagnostic quality. This technology allows for 3-dimensional representation of the dentomaxillofacial skeleton with minimal distortion, but at lower equipment cost, simpler image acquisition and lower patient dose. Because this technology produces images with isotropic sub-millimeter spatial resolution, it is ideally suited for dedicated dentomaxillofacial imaging. In this paper, we provide a brief overview of cone beam scanning technology and compare it with the fan beam scanning used in conventional CT and the basic principles of currently available CBCT systems.

• Imaging Science in Dentistry
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• 제46권1호
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• pp.47-51
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• 2016

Herein, we report and discuss the detection of fossa navicularis magna, a close radiographic anatomic variant of canalis basilaris medianus of the basiocciput, as an incidental finding in cone-beam computed tomography (CBCT) imaging. The CBCT data of the patients in question were referred for the evaluation of implant sites and to rule out pathology in the maxilla and mandible. CBCT analysis showed osseous, notch-like defects on the inferior aspect of the clivus in all four cases. The appearance of fossa navicularis magna varied among the cases. In some, it was completely within the basiocciput and mimicked a small rounded, corticated, lytic defect, whereas it appeared as a notch in others. Fossa navicularis magna is an anatomical variant that occurs on the inferior aspect of the clivus. The pertinent literature on the anatomical variations occurring in this region was reviewed.

• 동력기계공학회지
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• 제2권1호
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• pp.17-24
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• 1998

The combustion regime was discussed using a laser tomography and flame structure diagram. It was shown first how to represent the turbulent burning velocity and flame structural parameters in the dimensionless plane referred to as the flame structure diagram. And then, turbulent flame structure from the obtained images by laser tomography was compared with combustion regime in the Re-Da plane, one of the diagrams, specified by different researchers. As the result, the $u'/S_{L0}$ ratio at the boundary between the wrinkled laminar flame regime and reactant islands flame regime was found to be about 1.5.

• 한국가시화정보학회지
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• 제18권1호
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• pp.44-49
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• 2020

Neutron radiography has been widely used in many research areas due to its different characteristics from X-rays. Neutron tomography is a powerful tool because it can clearly show the inside of an object that the eye cannot see. However, generally, commercial software is used for the reconstruction of neutron tomography. It means that maintenance costs are incurred and analysis is inefficient in some cases. In this respect, our own image processing code is required to reconstruct neutron images efficiently. In this study, an image processing code is developed for reconstruction of cross-sectional images from neutron radiography taken from the side of the object. Using the developed code, cross-sectional images of the sample are successfully reconstructed.

• 대한수학회논문집
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• 제16권3호
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• pp.519-541
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• 2001

Magnetic Resonance Electrical Impedance Tomography(MREIT) is a new medical imaging technique for the cross-sectional conductivity distribution of a human body using both EIT(Electrical Impedance Tomography) and MRI(Magnetic Resonance Imaging) system. MREIT system was designed to enhance EIT imaging system which has inherent low sensitivity of boundary measurements to any changes of internal tissue conductivity values. MREIT utilizes a recent CDI (Current Density Imaging) technique of measuring the internal current density by means of MRI technique. In this paper, a mathematical modeling for MREIT and image reconstruction method called the alternating J-substitution algorithm are presented. Computer simulations show that the alternating J-substitution algorithm provides accurate high-resolution conductivity images.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.39-44
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• 2011

고압의 주위 압력 영역에서 토모그래피 기법을 이용하여 분무의 단면을 구성하였다. 구성된 분무 단면은 Indirect Photography method를 이용한 이미지와 함께 비교되어 분무 단면의 크기를 확인하였고 토모그래피에 의해 재구성된 단면의 경계를 설정할 수 있었다. 이를 통해 고압의 주위 압력 영역에서도 토모그래피를 적용하여 분무를 구성할 수 있다는 것을 확인하였다.