• Korean Circulation Journal
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• v.54 no.7
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• pp.382-394
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• 2024

Background and Objectives: Fractional flow reserve (FFR) is an invasive standard method to identify ischemia-causing coronary artery disease (CAD). With the advancement of technology, FFR can be noninvasively computed from coronary computed tomography angiography (CCTA). Recently, a novel simpler method has been developed to calculate onsite CCTA-derived FFR (CT-FFR) with a commercially available workstation. Methods: A total of 319 CAD patients who underwent CCTA, invasive coronary angiography, and FFR measurement were included. The primary outcome was the accuracy of CT-FFR for defining myocardial ischemia evaluated with an invasive FFR as a reference. The presence of ischemia was defined as FFR ≤0.80. Anatomical obstructive stenosis was defined as diameter stenosis on CCTA ≥50%, and the diagnostic performance of CT-FFR and CCTA stenosis for ischemia was compared. Results: Among participants (mean age 64.7±9.4 years, male 77.7%), mean FFR was 0.82±0.10, and 126 (39.5%) patients had an invasive FFR value of ≤0.80. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR were 80.6% (95% confidence interval [CI], 80.5-80.7%), 88.1% (95% CI, 82.4-93.7%), 75.6% (95% CI, 69.6-81.7%), 70.3% (95% CI, 63.1-77.4%), and 90.7% (95% CI, 86.2-95.2%), respectively. CT-FFR had higher diagnostic accuracy (80.6% vs. 59.1%, p<0.001) and discriminant ability (area under the curve from receiver operating characteristic curve 0.86 vs. 0.64, p<0.001), compared with anatomical obstructive stenosis on CCTA. Conclusions: This novel CT-FFR obtained from an on-site workstation demonstrated clinically acceptable diagnostic performance and provided better diagnostic accuracy and discriminant ability for identifying hemodynamically significant lesions than CCTA alone.

• Korean Journal of Veterinary Research
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• v.51 no.2
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• pp.165-169
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• 2011

Barium suspension, oral iodine contrast medium and water were applied in eight dogs to evaluate (1) distension of gastrointestinal tract, (2) the effect of the oral contrast media on the identification of the pancreas from surrounding organs, and (3) image quality and the presence of artifacts in canine pancreas computed tomography (CT) images. Oral iodine contrast medium, gastrografin, produced significant artifacts that deteriorated the CT images of the pancreas. The use of water did not provide the fullness of the gastrointestinal lumens. Barium suspension was effective for the identification of the pancreas from the surrounding gastrointestinal tract, without significantly increasing image noise. Barium suspension can be used as an optimal contrast medium that will not cause an adverse effect on the pancreatic density and image quality.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.1
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• pp.51-56
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• 2021

Due to their rarity and the lack of associated dental symptoms, odontogenic cutaneous sinus tracts (OCSTs) are often misdiagnosed and confused with cutaneous lesions or non-odontogenic infections. It has been estimated that 50% of individuals affected by OCSTs are subjected to inappropriate treatments before the correct diagnosis is established. We describe the diagnosis and treatment of two cases of OCSTs. By using a computed tomography (CT) with soft tissue window setting, the extent of cortical bone destruction and the path of the sinus tract in the soft tissue was easily identified. Thus, we recommend the use of imaging techniques such as CT, which can confirm the odontogenic origin and the exact location of the OCST.

• Korean Journal of Veterinary Research
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• v.63 no.4
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• pp.39.1-39.5
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• 2023

A 14-year-old, spayed female, poodle was presented with dysuria and hematuria. A mass that appeared hypoechoic on ultrasound and hypoattenuating on computed tomography (CT) extended from the bladder neck to the urethra. Magnetic resonance imaging (MRI) showed the mass invading the muscular layer of the bladder, urethra, and prostate with distinct margins. Transitional cell carcinoma (TCC) was confirmed with the CADET-BRAF test. This study describes the CT and MRI features of suspected TCC lesions involving the bladder, prostate, and urethra. MRI showed superior soft tissue contrast resolution, enabling evaluation of invasion of the muscular layer of the bladder and urethra.

• Journal of the Korean Society of Radiology
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• v.81 no.6
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• pp.1364-1376
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• 2020

A pericardial recess is frequently seen in patients undergoing chest computed tomography (CT). It is important to be aware of the normal anatomy of the pericardium as it is often mistaken for normal variants and/or disease. Therefore, we will describe the anatomy and location of the pericardial recess and the specific findings in various diseases associated with the pericardial recess.

• Journal of Veterinary Clinics
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• v.41 no.4
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• pp.246-251
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• 2024

Herein, we present the ultrasonography and computed tomography (CT) characteristics of an intramural calcified leiomyoma of the bladder in a dog. A 16-year-old, neutered male, Shih Tzu dog was referred to our hospital owing to corneal perforation. Serum chemistry findings and complete blood counts were unremarkable. A rounded hypoechoic intramural mass with internal hyperechoic foci was incidentally discovered on the ventral aspect of the bladder neck on abdominal ultrasonography performed for screening prior to corneal surgery. CT revealed a rounded hypoattenuated mass with central hyperattenuated foci at the level of the bladder neck. The mass was surgically excised and was diagnosed as leiomyoma based on histopathological findings.

• The korean journal of orthodontics
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• v.52 no.1
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• pp.75-79
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• 2022

Objective: To investigate remineralizing effect of three fluoride regimens on artificially demineralized enamel around orthodontic bracket by analyzing mineral density (MD) acquired from micro-computed tomography (micro-CT). Methods: Forty-eight bracket bonded bovine incisors were prepared to create demineralized enamel (DE) surface. The samples were divided into four groups according to the fluoride regimen: 1) no fluoridation, 2) 1.23% acidulated phosphate fluoride (APF) gel, 3) fluoridated toothpaste, and 4) 0.05% sodium fluoride mouthwash. Micro-CT was scanned after demineralization (T0), and 2 weeks (T1) and 4 weeks (T2) of fluoridation. Results: APF gel showed highest remineralization of DE during T1-T0 interval among the groups (p < 0.05); followed by toothpaste, mouthwash and no fluoridation. APF gel and toothpaste demonstrated significant increase in MD after 4 weeks of application (p < 0.05). Conclusions: Remineralization effects of three fluoride regimens were depicted through micro-CT analysis, of which APF gel was most effective.

• Imaging Science in Dentistry
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• v.42 no.2
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• pp.65-70
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• 2012

Purpose : The aim of this study was to compare the effective dose for imaging of mandible between multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). An MDCT with low dose technique was also compared with them. Materials and Methods : Thermoluminescent dosimeter (TLD) chips were placed at 25 organ sites of an anthropomorphic phantom. The mandible of the phantom was exposed using 2 different types of MDCT units (Somatom Sensation 10 for standard-dose MDCT, Somatom Emotion 6 for low-dose MDCT) and 3 different CBCT units (AZ3000CT, Implagraphy, and Kavo 3D eXaM). The radiation absorbed dose was measured and the effective dose was calculated according to the ICRP 2007 report. Results : The effective dose was the highest for Somatom Sensation 10 (425.84 ${\mu}Sv$), followed by AZ3000CT (332.4 ${\mu}Sv$), Somatom Emotion 6 (199.38 ${\mu}Sv$), and 3D eXaM (111.6 ${\mu}Sv$); it was the lowest for Implagraphy (83.09 ${\mu}Sv$). The CBCT showed significant variation in dose level with different device. Conclusion : The effective doses of MDCTs were not significantly different from those of CBCTs for imaging of mandible. The effective dose of MDCT could be markedly decreased by using the low-dose technique.

• Hip & pelvis
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• v.30 no.4
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• pp.233-240
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• 2018

Purpose: This study aimed to evaluate the efficacy of simultaneous computed tomography (CT) and quantitative CT (QCT) in patients with osteoporotic hip fracture (OHF) by analyzing the osteoporosis detection rate and physician prescription rate in comparison with those of conventional dual-energy X-ray absorptiometry (DXA). Materials and Methods: This study included consecutive patients older than 65 years who underwent internal fixation or hip arthroplasty for OHF between February and May 2015. The patients were assigned to either the QCT (47 patients) or DXA group (51 patients). The patients in the QCT group underwent QCT with hip CT, whereas those in the DXA group underwent DXA after surgery, before discharge, or in the outpatient clinic. In both groups, the patients received osteoporosis medication according to their QCT or DXA results. The osteoporosis evaluation rate and prescription rate were determined at discharge, postoperative (PO) day 2, PO day 6, and PO week 12 during an outpatient clinic visit. Results: The osteoporosis evaluation rate at PO week 12 was 70.6% (36 of 51 patients) in the DXA group and 100% in the QCT group (P<0.01). The prescription rates of osteoporosis medication at discharge were 70.2% and 29.4% (P<0.001) and the cumulative prescription rates at PO week 12 were 87.2% and 60.8% (P=0.003) in the QCT and DXA groups, respectively. Conclusion: Simultaneous CT and QCT significantly increased the evaluation and prescription rates in patients with OHF and may enable appropriate and consistent prescription of osteoporosis medication, which may eventually lead to patients' medication compliance.

• Conservation Science in Museum
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• v.24
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• pp.75-80
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• 2020

X-ray computed tomography (X-ray CT), which is often applied to the investigation of the interior structures of cultural properties, is very useful for studying production methods used in lacquerware that would otherwise be difficult to observe with the naked eye. Lacquerware inlaid with mother-of-pearl is an important subject in the study of traditional Korean craft. However, it can be a challenge to specify the production methods used in the framework of a lacquerware item unless the object has been structurally damaged. Studies of lacquerware inlaid with mother-of-pearl have thus far focused on the techniques of lacquering and of inlaying the mother-of-pearl. Production methods for the framework of lacquerware has received little academic attention. This study conducted X-ray CT on a lacquerware item from the Joseon period to reveal the materials and woodworking techniques used for the framework. The study revealed that softwood was used for the framework, and the post (gidungmok) and apron (soemok) were joined using a three-way miter joint (sambang yeongwi jjaim). Other pieces were joined with nails.