• Korean Circulation Journal
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• 제54권7호
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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.

• 대한수의학회지
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• 제51권2호
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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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• 제47권1호
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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.

• 대한수의학회지
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• 제63권4호
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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.

• 대한영상의학회지
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• 제81권6호
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• pp.1364-1376
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• 2020

심낭오목은 흉부 컴퓨터단층촬영을 받는 환자에서 종종 확인이 된다. 심낭은 종종 정상 변이나 질환과 오인될 수 있어 심낭의 정상 해부학 구조를 알고 있는 것이 중요하다. 그러므로 이 논문에서는 심낭오목의 해부학 및 위치 그리고 심낭오목과 관련된 다양한 질환에서 보일 수 있는 특징적인 소견에 대해 기술할 것이다.

• 한국임상수의학회지
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• 제41권4호
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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.

• 대한치과교정학회지
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• 제52권1호
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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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• 제42권2호
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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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• 제30권4호
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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.

• 박물관보존과학
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• 제24권
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• pp.75-80
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• 2020

엑스선 컴퓨터 단층면의 관찰은 문화재의 내부 구조조사를 위한 것으로 육안으로 확인할 수 없는 칠기 공예품의 제작 기법을 조사하는데 매우 유용한 방법이다. 특히 나전칠기는 옻칠과 나전을 사용하여 제작한 한국 전통공예품으로써 매우 중요한 연구 대상품이다. 하지만 특수한 환경에서 구조적으로 손상되어 있지 않는 한 백골의 제작기술을 파악하기에는 어렵다. 그 동안의 나전칠기 공예품의 가치 연구는 옻칠 기법과 나전 공예기술에 관한 연구가 주류가 되고 있지만 나전칠기의 뼈대가 되는 백골의 제작기법에 관한 연구는 이루어지지 않고 있는 실정이다. 본 연구는 조선시대 나전칠기에 대하여 컴퓨터 단층촬영[CT: Computed Tomography]을 실시하여 나전칠기 백골의 재질과 목공기술에 대한 결과를 제공하였다. 목재는 침엽수를 사용하였고 기둥목과 쇠목(기둥과 기둥 사이를 가로질러 대는 목재)의 결합은 삼방연귀짜임 방식을 사용하였으며 그 외의 결구 방법은 못을 사용하였음을 알 수 있었다.