• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.96-101
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• 2006

Four dogs with neurologic dysfunction resulted from intracranial hemorrhage by head trauma were referred to Veterinary Medical Teaching Hospital, Chungnam National University. There were no remarkable findings in survey radiography in four cases. CT and MRI scans were diagnostic in these cases. Three dogs underwent CT scanning. On CT images, the lesion was hyperdense and was not enhanced after intravenous contrast administration in dog 1 and dog 2. On CT of dog 4, there was no significant finding. All of four dogs were verified by dorsal, sagittal, and transverse T1-weighted (T1W) and T2-weighted (T2W) images. Appearance of the lesions in dog 1 and dog 2 was isointense (dog 2) or isointense with hyperintense rim (dog 1) on T1W images and hyperintense on T2W images. In dog 3 and dog 4, there were hypointense and hyperintense lesions on T1Wand T2W images respectively. The lesions in four dogs were located in the left intracerebral region, intracerebral and cerebellovestibular region, subdural space, and right cerebral hemisphere, respectively.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1287-1291
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• 2021

Testicular lymphoma is an uncommon testicular tumor that usually presents as a painless mass. It usually shows hypervascularity on color Doppler ultrasound (US) and a mild enhancement on enhanced CT or MRI. We present an unusual case of a testicular lymphoma mimicking a missed testicular torsion in a 67-year-old male patient with right scrotal swelling and intermittent pain for 2 months. Color Doppler US demonstrated the absence of vascularity in the enlarged right testis, and the initial diagnosis was a missed testicular torsion. CT demonstrated a poorly enhancing mass rather than a missed testicular torsion with enhanced small nodular foci at the periphery. The final pathological diagnosis was testicular lymphoma.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.3
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• pp.181-190
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• 1998

A computerized tomography system was developed using the X-ray source that has diameter of 5 micrometer. The system is used for the nondestructive testing of specimens with diameter below 20 mm. The convolution back projection algorithm was adopted for the reconstruction of cross sectional image, and the shape of the X-ray beam was let parallel beam or fan beam to compare each resultant image. Our CT system was constructed to operate based on the personal computer. The sectional images of the fabricated specimens were reconstructed and analyzed. The reconstructed images well coincided with real images taken with optical microscope and gave us enough reports on the defects in the ceramic specimen. The resolution of the system regarded as about $20{\sim}30$ micrometers.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.2
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• pp.75-83
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• 2010

Purpose: It aims to evaluate the location change and tendency of hepatic and intrahepatic tumors according to gastric volume and change of location. Materials and Methods: It studied 9 patients with hepatic tumors who visited Gangnam Severance Hospital from March 2009 to April 2010 and who underwent CT or PET (Positron Emission Tomography) within 2 weeks before CT-simulation. The patients fasted for 6 hours before CT-simulation and drank 240~250 cc of water just before CT or PET for image fusion. Those two types of images were fused to RTP (Radiation Treatment Planning, Pinnacle 8.0h) focusing on bone structure of individual patients. Results: They drank 240~260 cc of water but their stomach volume after drinking water varied from 259.3 cc to 495.4 cc. Even though individual differences existed in the change of stomach volume before and after drinking water, the volume was increased by 130 cc (174%) on average. The change in absolute distance between the centers of tumors ranged from 0.52 cm to 3.04 cm (1.52 cm on average); from 0.1 cm to 1.35 cm (0.44 cm on average) in cranial-caudal direction; from 0.05 cm to 2.75 cm (1.22 cm on average) in left-right direction; and from 0.05 cm to 1.85 cm (0.33 cm on average) in ventral-dorsal direction. Conclusion: It is hard to predict the movement of tumors by observing stomach movement, due to great individual differences; however, it was observed that the location of hepatic tumors was right-sided as the stomach was filled with water. Thus, it is recommended to maintain the fastened state to secure the accuracy of hepatic tumor treatment. If it cannot maintain the fastened state, it is recommended to measure stomach volumes and movement in the patient to consider the movement of hepatic tumors before radiation treatment.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.428-430
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• 1999

컴퓨터 단층촬영(Computed Tomography : CT)내의 위(stomach)에 대하여 연구하였다. 위는 모양이 변하면서 움직이는 정기이며 음식물로 채워진 부분과 공기로 채워진 부분으로 나뉘어져 있다. 위의 명암 값 정보와 위치 정보를 이용하여 자동적으로 추출을 한 다음, 음식물로 채워진 부분과 공기로 채워진 부분, 그리고 전체적인 위의 체적을 계산할 수 있는 알고리즘을 구현하였다.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.933-938
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• 2020

Brachiocephalic venous aneurysm (BVA) development is an extremely rare, particularly as a primary vascular disorder. BVAs may be misinterpreted as lymphadenopathies owing to the variable degrees of enhancement seen in imaging studies, especially among patients with underlying malignancy. We report a BVA that mimicked lymph node metastasis on CT in a 60-year-old female who had undergone subtotal gastrectomy for stomach cancer. After follow-up chest CT with different bolus times and Doppler ultrasonography, a venous aneurysm originating from the brachiocephalic vein was diagnosed. We emphasize that, to make an accurate diagnosis, physicians should be aware of the potential diagnostic pitfalls and have a high index of suspicion for BVA when encountering certain lesions in the cervical area.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1047-1065
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• 2023

Multi-detector CT (MDCT) is a highly accurate diagnostic tool that is commonly used to evaluate appendicitis and its complications. The diagnosis of appendicitis based on MDCT findings can be difficult and challenging when the observed findings are inconsistent with the typical features. Atypical appendicitis includes a wide spectrum of features, such as variable positions of the appendix and cecum, complications, and unusual pathological findings of secondary appendicitis that mimic or induce appendicitis. Our pictorial essay describes the diverse spectrum of atypical appendicitis and appendicitis-like conditions in terms of location abnormalities, complications, and uncommon pathologies, including related tumors, reactive appendicitis, appendiceal diverticulitis, and IgG4-related disease. Through this essay, the readers can become more familiar with MDCT findings of atypical appendicitis.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.235-239
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• 2024

An ilio-iliac arteriovenous fistula (AVF) is rare. Common factors leading to ilio-iliac AVF include congenital malformations, iatrogeny, and trauma. There is limited documentation in the literature of cases involving ilio-iliac AVF with May-Thurner syndrome. Here, we present a case of an ilio-iliac AVF with May-Thurner syndrome in an 80-year-old male. CT and angiography confirmed extensive ilio-iliac AVF. Successful endovascular procedures for ilio-iliac AVF were performed using several variable-sized coils and 1400-2000 ㎛ gelatin particles. After embolization, follow-up abdominopelvic CT revealed an improvement in edema in the left leg.

• Journal of Veterinary Clinics
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• v.28 no.5
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• pp.510-515
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• 2011

This study was performed to quantitatively assess the normal lung volume and density according to the position by multi-detector computed tomography (MDCT) in dogs. Helical CT of the thorax was performed on 4 different positions with dorsal, left lateral, right lateral and ventral recumbency in 6 Pekingese and 6 Maltese dogs. During CT scanning, dogs were kept hyperventilated. Through the 3-dimensional reconstruction of CT images, the lung parameters were measured as the volume and density of the left, right including accessory lobe, and total lung. 3D images represented the different lung shape between Pekingese and Maltese dogs. Their difference of total lung volume and total lung density was not significant on the each position in both breeds. Right lung volume was significantly higher than left. The difference of left and right volume was $66.91{\pm}25.1$ ml. Linear relationship was shown between body weight and lung volume of ventral recumbency position. The dependent lung had higher density and lower volume than nondependent lung in both breed dogs. The volume of nondependent lung was not changed compared with the volume on ventral or dorsal recumbency. The total lung volume measured with MDCT is correlated with the lung density, and the lung density is useful to predict the normal total lung volume.

• Journal of the Korea Computer Graphics Society
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• v.7 no.1
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• pp.37-49
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• 2001

We propose an optimization of mutual information for multiresolution image registration to represent useful information as integrated form obtaining from complementary information of multi modality images. The method applies mutual information as cost function to measure the statistical dependency or information redundancy between the image intensities of corresponding pixels in both images, which is assumed to be maximal if the images are geometrically aligned. As experimental results we validate visual inspection for accuracy, changning initial condition and addictive noise for robustness. Since our method uses the native image rather than prior feature extraction, few user interaction is required to perform the registration. In addition it leads to robust density estimation and convergence as applying non-parametric density estimation and stochastic multiresolution optimization.