• Journal of the Korea Society of Computer and Information
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• v.24 no.3
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• pp.41-47
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• 2019

In this paper, we propose a application of conditional generative adversarial network (cGAN) for generation of contrast enhanced computed tomography (CT) image. Two types of CT data which were the enhanced and non-enhanced were used and applied by the histogram equalization for adjusting image intensities. In order to validate the generation of contrast enhanced CT data, the structural similarity index measurement (SSIM) was performed. Prepared generated contrast CT data were analyzed the statistical analysis using paired sample t-test. In order to apply the optimized algorithm for the lymph node cancer, they were calculated by short to long axis ratio (S/L) method. In the case of the model trained with CT data and their histogram equalized SSIM were $0.905{\pm}0.048$ and $0.908{\pm}0.047$. The tumor S/L of generated contrast enhanced CT data were validated similar to the ground truth when they were compared to scanned contrast enhanced CT data. It is expected that advantages of Generated contrast enhanced CT data based on deep learning are a cost-effective and less radiation exposure as well as further anatomical information with non-enhanced CT data.

• Korean Journal of Veterinary Research
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• v.59 no.2
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• pp.105-108
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• 2019

A 4-year-old cat was referred for a suspected pulmonary mass. True diaphragmatic hernia presence was diagnosed via computed tomography (CT). There was a thin membrane covering the diaphragmatic defect. The membrane was thinner than the diaphragm. After contrast injection, the membrane was less enhanced than that of the normal diaphragm. The membrane was identified as a remnant of the parietal pleura. In addition, contrast-enhanced CT images provided clarity in viewing the herniated liver and falciform fat. A thinner membrane, covering the diaphragmatic defect, and attached to the thicker normal diaphragm, is considered a unique CT feature of true diaphragmatic hernia.

• Journal of Veterinary Clinics
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• v.40 no.5
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• pp.375-381
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• 2023

A large abdominal mass was incidentally found in a 13-year-old mixed-breed dog and was confirmed to be a cecal gastrointestinal stromal tumor (GIST). Contrast-enhanced ultrasound and post-contrast computed tomography (CT) showed mild contrast enhancement of the mass, indicating low blood flow. The tumor origin was determined to be the cecum by identifying the vessels supplying the mass on post-contrast CT. The exophytic growth of the tumor left the cecal lumen intact without obstruction. This report described the CEUS and CT perfusion of the cecal GIST and perfusion evaluation can help diagnose and characterize GISTs in dogs.

• Korean Journal of Digital Imaging in Medicine
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• v.10 no.2
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• pp.39-49
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• 2008

Extravasation of contrast material is a not infrequent complication of enhanced imaging studies and large volume extravasation may result in severe damage. Subcutaneous extravasation of the radiographic contrast medium is one of the complications of the contrast medium-enhanced procedures. Automated power injectors enable the contrast material to be delivered at a uniform high-flow-rate and as a nonfragmented bolus, and this is essential for many contrast material enhanced CT(computed tomography) applications. The major risk associated with the use of automated power injectors is the well known complication of contrast material extravasation at the injection site. Automated injection of CT contrast material can produce the compartment syndrome. Selection of the nonionic contrast material after careful evaluation of the intravenous administration site and monitoring of the patient during the use of a mechanical power injector may help minimize or prevent extravasation injuries. Early identification is important and conservative management is effective in most cases. Prevention of these injuries with the education of radiological technologist remains the ultimate aim.

• Journal of Korean Neurosurgical Society
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• v.58 no.4
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• pp.321-327
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• 2015

Objective : To determine whether the use of contrast enhancement (especially its extent) predicts malignant brain edema after intra-arterial thrombectomy (IAT) in patients with acute ischemic stroke. Methods : We reviewed the records of patients with acute ischemic stroke who underwent IAT for occlusion of the internal carotid artery or the middle cerebral artery between January 2012 and March 2015. To estimate the extent of contrast enhancement (CE), we used the contrast enhancement area ratio (CEAR)-i.e., the ratio of the CE to the area of the hemisphere, as noted on immediate non-enhanced brain computed tomography (NECT) post-IAT. Patients were categorized into two groups based on the CEAR values being either greater than or less than 0.2. Results : A total of 39 patients were included. Contrast enhancement was found in 26 patients (66.7%). In this subgroup, the CEAR was greater than 0.2 in 7 patients (18%) and less than 0.2 in the other 19 patients (48.7%). On univariate analysis, both CEAR ${\geq}0.2$ and the presence of subarachnoid hemorrhage were significantly associated with progression to malignant brain edema (p<0.001 and p=0.004), but on multivariate analysis, only CEAR ${\geq}0.2$ showed a statistically significant association (p=0.019). In the group with CEAR ${\geq}0.2$, the time to malignant brain edema was shorter (p=0.039) than in the group with CEAR <0.2. Clinical functional outcomes, based on the modified Rankin scale, were also significantly worse in patients with CEAR ${\geq}0.2$ (p=0.003) Conclusion : The extent of contrast enhancement as noted on NECT scans obtained immediately after IAT could be predictive of malignant brain edema and a poor clinical outcome.

• Korean Journal of Head & Neck Oncology
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• v.32 no.2
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• pp.85-89
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• 2016

Pleomorphic adenomas is the most common tumor of parotid gland and usually located and confined in superficial lobe of parotid gland. Computed tomography (CT) is commonly used to initially evaluate salivary gland lesion, but contrast-enhanced CT may sometimes fail to reveal lesions in spite of a high clinical suspicion. For this reason, ultrasonography (US) can be used as the first-line image work-up in some cases of parotid gland benign tumors. We experienced a case of a 60-year-old woman without underlying disease presenting a palpable parotid mass in which the initial CT examination was reported as 'no obvious mass detected'. However, the lesion was revealed in US and histologically confirmed as pleomorphic adenoma. The patient underwent superficial parotidectomy through modified facelift incision. To the best of our knowledge, this is the first report of invisible major salivary gland tumor on CT in the Korean literature.

• Tuberculosis and Respiratory Diseases
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• v.63 no.2
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• pp.178-182
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• 2007

A venous air embolism is a complication of various venous access procedures such as contrast-enhanced computed tomography (CECT). Although most cases of iatrogenic venous air embolisms during CECT involve a few milliliters of air and are asymptomatic, a massive venous air embolism can be fatal. We report a case of a massive intraventricular air embolism after CECT with a review of the literature regarding the pathophysiology and treatment of air embolisms.

• Journal of Veterinary Clinics
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• v.35 no.2
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• pp.53-56
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• 2018

Computed tomography (CT) findings of hepatic adenoma in veterinary medicine are variable and unlike in human medicine, not defined clearly. A 12-year-old neutered male Shih Tzu presented after a seizure, with weight loss, salivation, and cachexia. An abdominal mass was identified on radiography, and ultrasonographic images showed a mixed echo pattern with marked vascularity. CT showed that the mass originated from caudate lobe, was heterogeneously hypoattenuated compared with the hepatic parenchyma, and had irregular margins. Contrast enhanced CT showed that the mass enhanced like the surrounding liver parenchyma. However, it contained unenhanced areas and enhanced vessels were observed in the arterial phase at the periphery of the mass. The margins of mass were more enhanced in the venous phase than the arterial phase and the hypoattenuating regions within the mass were not enhanced. Greater enhancing in the venous phase is seen with adenomas; however, the heterogeneous enhancement pattern, especially the marginal vascular enhancement and internal hypoattenuating regions, is seen with malignancy. Although this is a single case of hepatic adenoma, the atypical enhanced pattern of this case can provide useful information to predict the malignancy of primary liver tumor.

• Childhood Kidney Diseases
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• v.26 no.2
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• pp.101-106
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• 2022

Nephrotic syndrome (NS) is a hypercoagulable state in which children are at risk of venous thromboembolism. A higher risk has been reported in children with steroid-resistant NS than in those with steroid-sensitive NS. The mortality rate of cerebral venous sinus thrombosis (CVST) is approximately 10% and generally results from cerebral herniation in the acute phase and an underlying disorder in the chronic phase. Our patient initially manifested as a child with massive proteinuria and generalized edema. He was treated with albumin replacement and diuretics, angiotensin-converting enzyme inhibitor, and deflazacort. Non-contrast computed tomography showed areas of hyperattenuation in the superior sagittal sinus when he complained of severe headache and vomiting. Subsequent magnetic resonance imaging revealed empty delta signs in the superior sagittal, lateral transverse, and sigmoid sinuses, suggesting acute CVST. Immediate anticoagulation therapy was started with unfractionated heparin, antithrombin III replacement, and continuous antiproteinuric treatment. The current report describes a life-threatening CVST in a child with steroid-dependent NS, initially diagnosed by contrast non-enhanced computed tomography and subsequently confirmed by contrast-enhanced magnetic resonance imaging, followed by magnetic resonance venography for recanalization, addressing successful treatment.

• Korean Journal of Veterinary Research
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• v.58 no.2
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• pp.99-101
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• 2018

A 5-year-old intact female Persian cat was referred with anorexia and vomiting. Physical examination revealed icterus in the pinna, oral mucosa, and sclera. Ultrasonography revealed several findings including uniformly hyperechoic hepatic parenchyma compared to adjacent falciform fat, increased attenuation of the ultrasound beam, and poor visualization of intrahepatic vessel borders. Computed tomography revealed hypoattenuation of the hepatic parenchyma with a radiodensity value of -60 Hounsfield units. The adjacent intrahepatic vessels appeared hyperattenuated relative to the hepatic parenchyma as if the vessels were contrast-enhanced. Based on ultrasonography and computed tomography results, the cat was tentatively diagnosed as feline hepatic lipidosis.