1.Cardiac CT.
Journal of the Korean Medical Association 2007;50(1):5-17
Multislice computed tomography (CT) is emerging technology that enables imaging the moving heart with high resolution. The current technology of CT is represented by 64-slice CT. CT is becoming the first-line evaluation tool for the detection of significant coronary artery stenosis and is applied for the detection of plaque composition and functional imaging. Significant coronary artery stenosis can be detected with a high accuracy over 90% and can be reliably excluded with a high negative predictive value approaching 100% by using 64-slice CT. CT coronary angiography is recommended not only to exclude significant stenosis in patients with equivocal symptoms or intermediate results on stress test but also to assess obstructive disease in symptomatic patients. Quantification of coronary artery calcium with CT is helpful to select patients for lipid-lowering therapies, who have intermediate coronary artery disease risk. With technical improvement, spatial and temporal resolution of CT will reach the level enough to establish the diagnoses of in-stent restenosis, plaque composition, and ventricular and valvular function in the foreseeable future. Myocardial imaging including myocardial perfusion and viability may be possible without increasing radiation exposure. CT is a very promising technology for cardiac imaging because, with technical improvement, clinical benefits are expected to be greater than the risk of radiation exposure. This short review is for readers (1) to understand CT technology for cardiac imaging, (2) to understand the limitation of current technology of CT for cardiac imaging, (3) to learn the current application of CT in cardiac diseases, (4) to get a perspective on the future directions of cardiac CT.
Calcium
;
Constriction, Pathologic
;
Coronary Angiography
;
Coronary Artery Disease
;
Coronary Stenosis
;
Coronary Vessels
;
Diagnosis
;
Exercise Test
;
Heart
;
Heart Diseases
;
Humans
;
Multidetector Computed Tomography
;
Perfusion
2.Differentiation of Acute Myocardial Infarction from Chronic Myocardial Scar with MRI.
Korean Journal of Radiology 2006;7(1):1-3
No Abstract available.
Myocardium/*pathology
;
Myocardial Infarction/*diagnosis
;
*Magnetic Resonance Imaging, Cine
;
Humans
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Dogs
;
Diagnosis, Differential
;
Cicatrix/*diagnosis
;
Animals
3.MDCT Application for Coronary Artery Intervention.
Journal of the Korean Medical Association 2007;50(2):134-142
Multidetector computed tomography (MDCT) has recently been used as a diagnostic tool for the evaluation of coronary artery morphology and stenosis. The accuracy of MDCT has improved as the number of detectors of MDCT has increased. A 64-MDCT reliably detects significant coronary artery stenosis with a sensitivity and specificity higher than 90%. With its high negative predictive value near 100%, 64-MDCT is very practical for excluding significant coronary artery disease and avoiding unnecessary invasive coronary angiography. Furthermore, preprocedural MDCT coronary angiography is useful to provide additional information and predict the procedural outcomes particularly in patients who have chronic total occlusion and those referred for percutaneous coronary intervention. Postprocedural MDCT coronary angiography usually involves evaluation of in-stent restenosis. Recently, drug-eluting stents are widely used and has notably reduced the rate of in-stent restenosis. However, the rate of in-stent restenosis of drug-eluting stents are still 5~10%. Considering the large number of patients who receive coronary artery stents, MDCT would be clinically useful as a noninvasive tool for the reliable detection of in-stent restenosis. Even with 64-MDCT, 30~40% of stents are not evaluable because the spatial and temporal resolutions are not sufficient for the detection of in-stent restenosis. With the 64-MDCT technology, the accessibility of in-stent restenosis mainly depends on stent size and severity of metal artifact of stents. Although the current MDCT does not permit reliable detection of in-stent restenosis, MDCT can be accepted as a first-line alternative to coronary angiography for the evaluation of stents, especially those with a large diameter such as left main coronary artery stents.
Artifacts
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Constriction, Pathologic
;
Coronary Angiography
;
Coronary Artery Disease
;
Coronary Stenosis
;
Coronary Vessels*
;
Drug-Eluting Stents
;
Humans
;
Multidetector Computed Tomography
;
Percutaneous Coronary Intervention
;
Sensitivity and Specificity
;
Stents
4.Renovascular Hypertension in Children.
Byoung Chul KANG ; Il Soo HA ; In One KIM ; Hae Il CHEONG ; Yong CHOI ; Kwang Wook KO
Journal of the Korean Society of Pediatric Nephrology 1997;1(2):101-108
The application of fine needle aspiration (FNA) cytology to the soft tissue tumors had been neglected. In recent years, however, FNA has been used increasingly in the preoperative diagnosis of these tumors due to its usefulness and accuracy. We present 3 cases of liposarcoma, myxoid, myxoid with round cell, and pleomorphic, diagnosed by FNA cytology with histologic confirmation. Good correlation between his- tologic and FNA cytologic findings was found. Although the cytologic appearances of liposarcomas varied with histologic type, the main criterion was the presence of atypical multivacuolated lipoblast with characteristically scalloped nuclei.
Biopsy, Fine-Needle
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Child*
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Diagnosis
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Humans
;
Hypertension, Renovascular*
;
Liposarcoma
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Liposarcoma, Myxoid
;
Pectinidae
5.Coronary CT Angiography.
Journal of the Korean Medical Association 2003;46(11):1009-1015
With the advent of multislice computed tomography (MSCT), noninvasive coronary angiography by using CT has become practical for clinical purposes. The accuracy of MSCT in evaluation of coronary artery stenosis challenges that of conventional X-ray coronary arteriography. The essential component of the CT technique in evaluation of coronary arteries on a beating heart consists of a multidetector row system, which enables thin-sliced volume scan during one breath-hold, and the fast rotation speed of gantry, which is most important to increase the time resolution. However, the technical development so far achieved just allows CT to acquire diagnostic-quality images only with lowering the heart rate less than 65 beats per minute using a beta-blocker. Motion artifacts caused by physiologic or diseased complex movement of the heart and blooming artifacts from dense calcification are the major limitations compromising accurate interpretation of coronary CT angiograms. Although many problems related to coronary CT angiography has not been solved at present, we should remember that the present CT technique is just at its infancy, and CT has many benefits as a noninvasive diagnostic modality. In addition, measurement of a cross-sectional area at stenosis of coronary artery will improve diagnostic accuracy, which is also a major advantage over the projection image of X-ray angiography. Characterization of a vulnerable plaque by density measurement of an atherosclerotic plaque of the coronary vessel wall and evaluation of in-stent restenosis should be other possibilities of CT.
Angiography*
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Artifacts
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Constriction, Pathologic
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Coronary Angiography
;
Coronary Disease
;
Coronary Stenosis
;
Coronary Vessels
;
Heart
;
Heart Rate
;
Multidetector Computed Tomography
;
Plaque, Atherosclerotic
6.Advanced Cardiac MR Imaging for Myocardial Characterization and Quantification: T1 Mapping.
Sung Ho HWANG ; Byoung Wook CHOI
Korean Circulation Journal 2013;43(1):1-6
Magnetic resonance as an imaging modality provides an excellent soft tissue differentiation, which is an ideal choice for cardiac imaging. Cardiac magnetic resonance (CMR) allows myocardial tissue characterization, as well as comprehensive evaluation of the structures. Although late gadolinium enhancement after injection of the gadolinium extracellular contrast agent has further extended our ability to characterize the myocardial tissue, it also has limitations in the quantification of enhanced myocardial tissue pathology, and the detection of diffuse myocardial disease, which is not easily recognized by enhancement contrast. Recently, the remarkable advances in CMR technique, such as T1 mapping, which can quantitatively evaluate myocardial status, showed potentials to overcome limitations of existing CMR sequences and to expand the application of CMR. This article will review the technical and clinical points to be considered in the practical use of pre- and post-contrast T1 mapping.
Cardiomyopathies
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Fibrosis
;
Gadolinium
;
Magnetic Resonance Imaging
;
Magnetic Resonance Spectroscopy
;
Myocardial Infarction
;
Myocardium
7.A Case of Cornelia de Lange syndrome.
Byoung Hong AHN ; Song Nyeon CHOI ; Young Wook KIM ; Ki Bok KIM
Journal of the Korean Pediatric Society 1990;33(2):234-240
No abstract available.
De Lange Syndrome*
8.Magnetic Resonance Imaging in Thorax.
Tuberculosis and Respiratory Diseases 2004;56(6):571-592
Magnetic Resonance Imaging (MRI) is one of the most advanced imaging techniques in clinical and research medicine. However, clinical application of MRI to the lung or thorax has been limited due to various drawbacks. Low signal intensity of the lung and cardiac and respiratory movements are the most serious problems with MRI in thorax. Nevertheless, MRI is superior to CT in some selected patients with thoracic diseases. The role of clinical MRI in thoracic disease has been widened with improvement of MR equipments and development of new pulse sequences. Otherwise, functional assessment of lung by MRI has been studied for the last decade. These include perfusion MRI with or without contrast enhancement and ventilation MRI with oxygen-enhancement or hyperpolarized noble gas, (3)He and (129)Xe.
Humans
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Lung
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Magnetic Resonance Imaging*
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Perfusion
;
Pulmonary Circulation
;
Pulmonary Ventilation
;
Thoracic Diseases
;
Thorax*
;
Ventilation
9.Etiology of Pediatric Healthcare-associated Infections in a Single Center (2007-2011).
Ki Wook YUN ; Mi Kyung LEE ; Sin Weon YUN ; Soo Ahn CHAE ; In Seok LIM ; Eung Sang CHOI ; Byoung Hoon YOO
Korean Journal of Nosocomial Infection Control 2012;17(1):13-20
BACKGROUND: Healthcare-associated infections (HAIs) are among the most important threats to patient safety. When hospitalized children face these threats, there is morbidity, mortality, prolonged hospitalization, and increased healthcare costs. Research on local healthcare epidemiology is necessary to enhance collective knowledge and evidence formanaging this problem. METHODS: We performed a retrospective analysis of databases of patients who were diagnosed with HAIs at Chung-Ang University Hospital (CAUH) from 2007 through 2011. Cases were selected from the microbiology registry databases. The data on prevalence of HAIs in various wards and its annual trends were compared to previously reported nationwide data. Moreover, we analyzed the patterns of antibiotic susceptibility results for HAI pathogens. RESULTS: A total of 181 HAIs were identified in 122 patients. The HAI rate among pediatric patients at CAUH was 2.4/1,000 person-hospital days. Urinary tract infections (UTIs) (53 episodes, 29.3%) were the most common, followed by pneumonia (33 episodes, 18.2%). Staphylococcus aureus was found to be the most common gram-positive organism, whereas Escherichia coli was the most common gram-negative organism. Methicillin-resistant S. aureus (MRSA) comprised 84% of the S. aureus infections. Imipenem resistance was detected in 58.8% and 55.0% of Acinetobacter baumannii and Pseudomonas aeruginosa isolates, respectively. CONCLUSION: Between 2007 and 2011, UTIs were the most common type of HAIs, and MRSA was the most common pediatric HAI pathogen, both in the general ward and intensive care unit at the CAUH. Further research on the epidemiology and pathogenesis of HAIs is necessary and prevention measures should be implemented to prevent HAIs in children.
Acinetobacter baumannii
;
Child
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Child, Hospitalized
;
Delivery of Health Care
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Escherichia coli
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Health Care Costs
;
Hospitalization
;
Humans
;
Imipenem
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Intensive Care Units
;
Methicillin Resistance
;
Methicillin-Resistant Staphylococcus aureus
;
Microbial Sensitivity Tests
;
Patient Safety
;
Patients' Rooms
;
Pneumonia
;
Prevalence
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Pseudomonas aeruginosa
;
Retrospective Studies
;
Staphylococcus aureus
;
Urinary Tract Infections
10.Outcome following hepatectomy for HBs Ag positive Hepatocellular Carcinoma Patients.
Byoung Ki KIM ; Kwang Ho LEE ; Dong Wook CHOI
Korean Journal of Hepato-Biliary-Pancreatic Surgery 2000;4(2):51-60
BACKGROUND/AIMS: In Korea about 70% of hepatocellular carcinoma(HCC) are associated with hepatitis B surface antigenemia. And hepatic resection is regarded as best treatment option for selected HCC patients. So we conducted this study to analyze the outcome and to identify the factors associated with outcome after hepatectomy for HBs Ag associated HCC. METHODS: We retrospectively analyzed the clinicopathological data of 104 HBs Ag associated HCC patients who underwent hepatic resection from Sep-1987 through Oct-1997 in KCCH. Median follow-up period was 21.5 month. Survival rates were estimated by Kaplan-Meier method and difference was detected by Log-rank test using SPSS program for Windows. Multivariate analysis was done using Cox regression hazard model. RESULTS: Overall 5 year survival rate was 62.9% and 5 year disease free survival rate was 42.2%. Factors which influence on survival were multiplicity, portal vein invasion, perioperative transfusion, tumor stage. Recurrence occurred in 42 cases and 33 cases developed intrahepatic recurrence. 3 year survival rate after recurrence was 34.7%. CONCLUSION: Hepatic resection plays a significant role for selected HBs Ag related HCC and tumor number, portal vein invasion, transfusion and TNM stage were statistically significant prognostic factors( p<0.05). So meticulous technique is required to avoid transfusion perioperatively. For the high risk patients, further study to reduce the recurrence should be followed.
Carcinoma, Hepatocellular*
;
Disease-Free Survival
;
Follow-Up Studies
;
Hepatectomy*
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Hepatitis B
;
Humans
;
Korea
;
Multivariate Analysis
;
Portal Vein
;
Proportional Hazards Models
;
Recurrence
;
Retrospective Studies
;
Survival Rate