• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.97-102
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• 2004

We developed an x-ray cone-beam micro computed tomography (micro-CT) system for small-animal imaging. The micro-CT system consists of a 2-D flat-panel x-ray detector with a field-of-view (FOV) of 120${\times}$120 mm2, a micro-focus x-ray source, a scan controller and a parallel image reconstruction system. Imaging performances of the micro-CT system have been evaluated in terms of contrast and spatial resolution. The minimum resolvable contrast has been found to be less than 36 CT numbers at the dose of 95 mGy and the spatial resolution about 14 lp/mm. As small animal imaging results, we present high resolution 3-D images of rat organs including a femur, a heart and vessels. We expected that the developed micro-CT system can be greatly used in biomedical studies using small animals.

• Korean Journal of Veterinary Research
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• v.62 no.1
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• pp.6.1-6.4
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• 2022

A 10-year-old, spayed female, Doberman Pinscher dog presented with right forelimb lameness. On physical examination, painful reaction and crepitation were present at the right shoulder. Radiographic evaluation of the shoulder revealed nothing remarkable. On the ultrasonography of the right shoulder joint, 2 small echogenic masses accompanied by reverberation artifacts were observed in the right biceps tendon near its origin at the supraglenoid tuberosity. Based on these findings, we suspected biceps calcifying tendinopathy. Clinical signs resolved intermittently after administration of nonsteroidal anti-inflammatory drug. This study described the ultrasonographic findings of calcifying biceps brachii tendinopathy which is an unusual finding in dogs.

• Journal of Sensor Science and Technology
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• v.26 no.4
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• pp.245-250
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• 2017

A novel method to implement a birdcage-type receiving coil sensor for use in a magnetic resonance imaging(MRI) system has been demonstrated employing a flexible printed circuit board (FPCB) fabrication technique. Unlike the conventional methods, the two-dimensional shape of the coil sensor is first implemented as a FPCB and then it is attached to the surface of a cylindrical supporting structure to implement the three-dimensional birdcage-type coil sensor. The proposed method is very effective to implement object-specific MRI coil sensors especially for small animal measurements in research and preclinical applications since the existing well-developed FPCB-based techniques can easily meet the requirements on accuracies and costs during coil implement process. The performances of the coil sensor verified through $^1H$ 1.5T MRI measurements for small animals and it showed excellent characteristics by providing a high spatial precision and a high signal-to-noise ratio.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2646-2651
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• 2021

A rectangular-shaped PET system with an adjustable gantry (AGPET) has been developed for imaging small animals. The AGPET system employs a new depth of interaction (DOI) method using a depth dependent reflector patterns and a new digital time pickoff method based on the pulse reconstruction method. To evaluate the performance of the AGPET, timing resolution, intrinsic spatial resolution and point source images were acquired. The timing resolution and intrinsic spatial resolution were measured using two detector modules and Na-22 gamma source. The PET images were acquired in two field of view (FOV) sizes, 30 mm and 90 mm, to demonstrate the characteristic of the AGPET. As a result of in the experiment results, the timing resolution was 0.9 ns using the pulse reconstruction method based on the bi-exponential model. The intrinsic spatial resolution was an average of 1.7 mm and the spatial resolution of PET images after DOI correction was 2.08 mm and 2.25 mm at the centers of 30 mm and 90 mm FOV, respectively. The results show that the proposed AGPET system provided higher sensitivity and resolution for small animal imaging.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.270-275
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• 2012

In this study, we have developed a mobile-based visible/NIR(Near InfraRed) imaging equipment for the animal testing. This equipment can provide visible, NIR and merged image through the viewer program. Especially, merged image help researcher to understand visual messages at animal in-vivo test. Also, it is available to send real-time images through the smart phone. Researcher can communicate with another researcher who is a long distance away. Also, the equipment was made with portable small size to enable it to commercialize.

• Journal of Veterinary Clinics
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• v.38 no.3
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• pp.163-168
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• 2021

A 6-year-old, spayed female, Maltese dog with tachypnea and dry cough was presented to Gyeongsang National University Veterinary Medical Teaching hospital. On physical examination, its respiration rate was 132 per minute. Decreased partial pressure of oxygen, partial pressure of carbon dioxide, and hyperlactatemia were found on arterial blood gas analysis. Its diastolic blood pressure was 80 mmHg. Auscultation revealed arrhythmia. Electrocardiogram revealed P pulmonale, P mitrale, and ventricular premature complexes. Thoracic radiographs revealed mild enlargement of both atrium and moderate enlargement of the left ventricular. There was also a moderate alveolar pattern in the right and caudal part of the left cranial lung lobe. Two-dimensional echocardiography showed enlargement of generalized four chambers without remarkable findings of valvular degeneration. M-mode echocardiography showed decreased left ventricular fractional shortening and enlarged left ventricular internal diameter at both end-systolic and end-diastolic. Color-flow Doppler imaging revealed eccentric turbulent flow starting below the left ventricular outflow tract and extending into the left atrium during systole. Spectral Doppler recordings revealed a high velocity flow through the mitral, tricuspid, aorta, and pulmonic regurgitation. Restrictive transmitral flow revealed high E-wave velocity, short E-wave deceleration time, and reduced A-wave velocity. There was also low ejection velocity thorough left ventricular out tract flow. Based on echocardiographic examination, dilated cardiomyopathy was the tentative diagnosis. The dog was medicated with inotropes, angiotensin converting enzyme inhibitor, and diuretics. At the 10-day following-up, the dog died suddenly. This report describes echocardiographic diagnosis and prognosis of dilated cardiomyopathy rarely reported in small breed dogs.

• Korean Journal of Veterinary Research
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• v.63 no.3
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• pp.26.1-26.5
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• 2023

Syringobulbia is a rare neurological disorder characterized by a fluid-filled cavity in the brainstem. In this study, clinical signs, features on magnetic resonance imaging (MRI), and the diseases present concurrently with syringobulbia were investigated in 33 small breed dogs. Most dogs (97%) had concurrent syringomyelia, and some dogs (24%) presented with vestibular or cranial nerve symptoms associated with the medulla oblongata. MRIs revealed slit-like, bulbous, and vertical linear shapes of the cavities on T2-weighted hyperintense and T1-weighted hypointense signals similar to the cerebrospinal fluid. Chiari-like malformations were identified in all dogs. This study highlights the association of syringobulbia with syringomyelia and Chiari-like malformations in small breed dogs with or without brainstem-associated clinical signs.

• Journal of Veterinary Clinics
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• v.31 no.3
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• pp.237-240
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• 2014

A 12-year-old, intact, female Alaskan malamute presented with severe spinal pain and hind limb lameness. On radiographs, a round, demarcated lytic lesion was identified in the central fifth lumbar vertebra. On magnetic resonance imaging (MRI), the lesion involving the spinal cord appeared hypointense on T1 weighted, hyperintense on T2 weighted, heterogeneously enhanced on post-contrast T1 weighted, and hypointense on GE images. A focal, small, ill-defined, lytic lesion was also observed radiographically in the sixth lumbar vertebra, it appeared as a focal hyperintense lesion on T1 weighted, T2 weighted, and GE images and showed focal enhancement on post-contrast T1 weighted images. She was euthanized owing to extreme pain and severe and progressive clinical signs; a plasmacytoma was histopthologically diagnosed. This report presents an unusual type of spinal tumor, plasmacytoma. MRI is a useful modality to evaluate the anatomic location and extension of spinal lesions.

• Journal of Veterinary Clinics
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• v.37 no.2
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• pp.88-90
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• 2020

A one year old spayed female Bichon Frise dog presented with gait abnormalities and seizure. Serum biochemical results showed elevated levels of alkaline phosphatase, alanine aminotransferase, and ammonia. Serum bile acid level was also increased to be over 30 μmol/L on preprandial. Urinalysis identified the presence of ammonium urate crystal. Abdominal ultrasonography and CT revealed aberrant, tortuous, and multiple small vessels connected to the caudal vena cava between left kidney and caudal vena cava. Macroscopic specific findings associated with extrahepatic congenital portosystemic shunts (PSS) or other liver diseases were not identified. Liver biopsy was performed. Histopathologic evaluation revealed hepatic lobular hypoplasia with portal arterial duplication and vascular shunts. Based on these finding, this case was diagnosed as multiple acquired PSS secondary to hepatic microvascular dysplasia (HMD) and hepatic encephalopathy. A liver biopsy is recommended to differentiate HMD from other liver diseases and to confirm HMD when a young dog has multiple acquired PSS.

• Journal of Biomedical Engineering Research
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• v.26 no.1
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• pp.43-47
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• 2005

We have developed a small bore x-ray CT for small animal imaging with a linear x-ray detector array and small-scale slip rings. The linear x-ray detector array consists of 1024 elements of 400□m×400□m with a gadolinium oxysulfide (GOS) scintillator on top of them. To avoid use of expensive large diameter slip rings for projection data transmission from the X­ray detector to the image reconstruction system, we used the wireless LAN technology. The projection data are temporally stored in the data acquisition system residing on the rotating gantry during the scan and they are transmitted to the image reconstruction system after the scan. With the wireless LAN technology, we only needed to use small-scale slip rings to deliver the AC electric power to the X-ray generator and the power supply on the rotating gantry. The performances of the small animal CT system, such as SNR, contrast, and spatial resolution, have been evaluated through experiments using various phantoms. It has been experimentally found that the SNR is almost linearly proportional to the tube current and tube voltage, and the minimum resolvable contrast is less than 30 CT numbers at 40kVp/3.0㎃. The spatial resolution of the small animal CT system has been found to be about 0.9Ip/㎜. Postmortem images of a piglet is also presented.