• Imaging Science in Dentistry
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• 제43권2호
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• pp.123-128
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• 2013

Double tooth is a dental anomaly consequent to fusion of two or more teeth or gemination of a single tooth. This report describes a unique case of double tooth in relation to a mandibular lateral incisor exhibiting the presence of four root canals. The role of conventional radiography and advanced three-dimensional imaging techniques in the better assessment of complex root canal systems and their aid in endodontic management has also been highlighted.

• 한국가시화정보학회지
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• 제8권2호
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• pp.45-50
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• 2010

The objective of this study is to elucidate the feasibility of synchrotron X-ray micro CT as a non-destructive imaging method to visualize the three-dimensional morphological structures of biological and non-biological samples. The experiments were conducted in 7B2 X-ray micro CT beamline in Pohang Accelerate Laboratory (PAL). A rotational 3-axis stage was specially designed for $0^{\circ}-180^{\circ}$ scanning of test samples. Preliminary tests were performed for opaque samples including a mosquito head, a plant seed and gas diffusion layer (GDL) of polymer electrolyte fuel cell to verify the feasibility of the X-ray micro CT. It visualized clearly the internal structure of all the test samples, supporting its usefulness.

• Clinical and Experimental Pediatrics
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• 제57권7호
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• pp.297-303
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• 2014

Transcatheter closure of atrial septal defects has become a popular procedure. The availability of a preprocedural imaging study is crucial for a safe and successful closure. Both the anatomy and morphology of the defect should be precisely evaluated before the procedure. Three-dimensional (3D) echocardiography and cardiac computed tomography are helpful for understanding the morphology of a defect, which is important because different defect morphologies could variously impact the results. During the procedure, real-time 3D echocardiography can be used to guide an accurate closure. The safety and efficiency of transcatheter closures of atrial septal defects could be improved through the use of detailed imaging studies.

• 한국정밀공학회지
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• 제28권7호
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• pp.834-850
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• 2011

In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.

• Journal of Korean Neurosurgical Society
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• 제49권5호
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• pp.290-291
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• 2011

Persistent primitive olfactory artery (PPOA) is a rare anomaly of the anterior cerebral artery. We present one case of PPOA incidentally diagnosed with the aid of computed tomography (CT) angiography. A 24-year-old woman was admitted to our hospital after sudden onset of vertigo. Three-dimensional CT angiography revealed an anomalous artery arising from the terminal portion of the right internal carotid artery. The proximal portion of the anomalous artery coursed anteromedially and made a hairpin turn posterosuperior to the midline. PPOA may be overlooked because of its rarity, but CT angiography can be useful in detecting this rare vascular anomaly. Follow-up study is necessary in our case to confirm whether an aneurysm occurs on the PPOA.

• 대한치과의사협회지
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• 제48권10호
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• pp.724-728
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• 2010

Accurate analysis of facial asymmetry prior to any orthognathic or orthodontic treatment plan is essential in ensuring good treatment result. Dental CBCT (Cone-beam Computed Tomography) provides as actual three-dimensional measurements of distance and angle without any radiographic magnification as medical CT provides, while its field of view is limited to the oral and maxillofacial area. CBCT is a useful tool for the diagnosis of facial asymmetry. The coordinates of facial landmarks are obtained from the 3D reconstruction software which enables the establishment of perpendicular planes and the identification of the landmarks. Then, the bilateral discrepancies of the landmarks are obtained as spherical polar coordinates which can show the amount of asymmetry and its direction. A method of 3D analysis of facial asymmetry using CBCT is introduced in this report.

• Journal of Trauma and Injury
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• 제26권1호
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• pp.30-33
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• 2013

A 55-year-old woman was seen in the emergency department with posterior neck pain and a headache after a traffic accident. Physical examination revealed tenderness on palpation over the posterior skull and a midline spinous process of the cervical spine without neurologic deficit. A plain radiograph of the cervical spine demonstrated the absence of the lateral portion of the posterior arch of the atlas and very lucent shadowing of the anterior midline of the atlas, suggesting a fracture of the anterior arch. On three-dimensional computed tomography (CT) of the cervical spine, anterior and posterior bony defects of the atlas were noted. Well-corticated defects were noted with sclerotic change and with no evidence of soft tissue swelling adjacent to the bony discontinuities, consistent with a congenital abnormality. With conservative therapy, the patient gradually showed a lessening of the midline tenderness. Careful investigation with radiography or CT is needed for these patients to avoid confusion with a fracture, because these patients seldom need surgical treatment.

• Journal of Cardiovascular Imaging
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• 제26권4호
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• pp.189-200
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• 2018

Pulmonary hypertension (PH) is defined as resting mean pulmonary artery pressure ${\geq}25mmHg$ and is caused by multiple etiologies including heart, lung or other systemic diseases. Evaluation of right ventricular (RV) function in PH is very important to plan treatment and determine prognosis. However, quantification of volume and function of the RV remains difficult due to complicated RV geometry. A number of imaging tools has been utilized to diagnose PH and assess RV function. Each imaging technique including conventional echocardiography, three-dimensional echocardiography, strain echocardiography, computed tomography and cardiac magnetic resonance imaging has-advantages and limitations and can provide unique information. In this article, we provide a comprehensive review of the utility, advantages and shortcomings of the multimodality imaging used to evaluate patients with PH.

• 대한방사선기술학회지:방사선기술과학
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• 제44권6호
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• pp.623-627
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• 2021

Cervical foraminal stenosis is a disease in which the nerves that pass from the spinal canal to the limbs are narrowed and the nerves are compressed or damaged. Due to the lack of an imaging method that provides quantitatively stenosis, this study attempted to evaluate the area of the cervical vertebrae by reconstructing a three-dimensional computed tomography image, and to determine the area of the neural foramen in normal adults to calculate the stenosis rate. Using a three-dimensional image processing program, the surrounding bones including the posterior spinous process, lateral process, and lamellar bones of the cervical vertebra were removed so that the neural foramen could be observed well. A region of interest including the neural foraminal area of the three-dimensional image was set using ImageJ, and the number of pixels in the neural foraminal area was measured. The neural foraminal area was calculated by multiplying the number of measured pixels by the pixel size. To measure the largest neural foraminal area, it was measured between 40~50 degrees in the opposite direction and 15~20 degrees toward the head. The average area of the right C2-3 foramen was 44.32 mm², C3-4 area was 34.69 mm², C4-5 area was 36.41 mm², C5-6 area was 35.22 mm², C6-7 area was 36.03 mm². The average area of the left C2-3 foramen was 42.71 mm², C3-4 area was 32.23 mm², C5-6 area was 34.56 mm², and C6-7 area was 31.89 mm². By creating a reference table based on the neural foramen area of normal adults, the stenosis rate of patients with neural foraminal stenosis could be quantitatively calculated. It is expected that this method can be used as basic data for the diagnosis of cervical vertebral foraminal stenosis.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.131-134
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• 1995

A three dimensional fractal coding with a perceptually enhanced matching is proposed. Since most of medical images (e.g. computed tomography or magnetic resonance image) have three dimensional character, the searching region is extended to adjacent slices. For perceptually enhanced matching, a high frequency booster filter is used for prefiltering of the original image, and the least mean square error matching is applied to this edge enhanced image rather than the original image. From the simulation with the magnetic resonance images ($255{\times}255$, 8bits/pixel). the proposed algorithm provides excellent image quality with compression rations higher than 10. Compared to existing fractal coding the algorithm also provides better subjective image quality with higher compression ratio.