PURPOSE: To date, the high spatial frequency algorithm (HSFA) which reduces image smoothing and increases spatial resolution has been used for the evaluation of parenchymal lung diseases in thin-section high-resolution CT. In this study, we compared the ultrahigh spatial frequency algorithm (UHSFA) with the high spatial frequency algorithm in the assessment of thin section images of the lung parenchyma. METHODS AND MATERIALS: Three radiologists compared the UHSFA and HSFA on identical CT images in a line-pair resolution phantom, one lung specimen, 2 patients with normal lung and 18 patients with abnormal lung parenchyma. RESULTS: Scanning of a line-pair resolution phantom demonstrated no difference in resolution between two techniques but it showed that outer lines of the line pairs with maximal resolution looked thicker on UHSFA than those on HSFA. Lung parenchymal detail with UHSFA was judged equal or superior to HSFA in 95% of images. Lung parenchymal sharpness was improved with UHSFA in all images. Although UHSFA resulted in an increase in visible noise, observers did not found that image noise interfered with image interpretation. The visual CT attenuation of normal lung parenchyma is minimally increased in images with HSFA. The overall visual preference of the images reconstructed on UHSFA was considered equal to or greater than that of those reconstructed on HSFA in 78% of images. CONCLUSION: The ultrahigh spatial frequency algorithm improved the overall visual quality of the images in pulmonary parenchymal high-resolution CT.
Humans ; Lung Diseases ; Lung* ; Noise

Femoral arteriography has assumed in recent years a greater clinical and surgical significance, especiallysince the advent of arterial grafting for occlusive arterial disease. Evaluation of the site and extent ofocclusion, the state of distal arterial tree and degree of collateral circulation can best be obtained byserialographic studies. Authors analyzed 28 cases of clinically and radiologically diagnosed Buerger's disease inGURO hospital radiology, College of medicine, Korea university, during last 6 months from March to August, 1984.The results are as follows; 1. The age distribution were between 20 and 50 years old, and most commonly involvedage group was 20-29. 2. The most frequent finding was the obstruction of peripheral artery with or withougcollateral vessel and almost all patient had occlusion more than 1 segmental branch. 3. The most frequentlyinvolved arteries in Buerger's disease were trifurcation area below the knee joint, anterior and posterior tibialartery and peroneal artery. Peroneal artery was less commonly involved than anterior or posterior tibial artery.
Age Distribution ; Angiography ; Arteries ; Collateral Circulation ; Humans ; Knee Joint ; Korea ; Thromboangiitis Obliterans ; Tibial Arteries ; Transplants ; Trees

A total of 3,119 cardiac valves were replaced in 2,471 patients with acquired valvular heart diseases at Seoul National University Hospital during a period of 26 years from 1968 to 1994. Mechanical valves including St. Jude, Carbomedics, Bjork-Shiley and Duromedics were used in 1,609 cases(52%) and bioprosthetic valves including Lonescu-Shiley, Hancock and Angell Shiley were implanted for the rest of the patients(1,510 cases, 48%). A total of 308(12.5%) redo valve replacement was performed during the same period, and 10 of 308 patients underwent second redo valve replacements. The single valve replacement was done in 1,846 cases, double valve replacement in 602 cases and triple valve replacement in 23 cases. Among the single valve replacement, the mitral valve replacement was performed most frequently(1,377 cases). The male to female ratio was almost equal(1.223 : 1,248) and the mean age was 37.9+/-10.5 years old. But the mean age has been increasing year by year and it reached to 44.8 years old in the 1990's. The overall hospital mortality was 5.3%, and 6.8% in redo valve replacement. However, the hospital mortality for the recent 10 years dropped to 1 to 4%. The number of redo valve surgery has been increasing since the mid-1980's because of structural deterioration of bioprostheses that were replaced during the late-1970's and early 1980's. Redo valve surgery comprised 34% for all valve replacement in 1994. The causes of the redo valve operation were structural deterioration(81.5%), prosthetic valve endocarditis(11.7%), paravalvular leakage(5.6%), and valve thrombosis(0.9%). The actuarial freedom from overall valve failure in Ionescu-Shiley were 81.0+/-7.1%(5 year) in mitral position, 89.1+/-1.8%(7 year) in aortic position and 88.9+/-7.6% in double valve replacement. The 5 year actuarial freedom from all complications in Carbomedics were 90.1+/-3.1% in mitral position, 84.9+/-4.2% in aortic position and 81.7+/-5.1% in double valve replacement. The 10 year actuarial freedom from all complications in St. Jude were 80.9+/-3.8%, 81.4+/-6.1%, 72.4+/-10.7% in each positions. In conclusion, the mean age of patients was younger than that of western countries, but it showed increasing tendency year by year. Bioprosthetic valves were used during the initial period until mid-1980's when mechanical valves were used instead of bioprosthetic valves, mainly because of the structural deterioration of the bioprostheses. In terms of thromboembolism, both bioprostheses and mechanical valves seems to be almost comparable although the comparison of both valves was impossible because of the different period of operation, various surgeon and level of the prothrombin time and so on. Recently the number of valve replacement has been decreased since the 1990's and the number of redo valve surgery and valve repair has been increased.
Bioprosthesis ; Female ; Freedom ; Heart Valve Diseases ; Heart Valves* ; Hospital Mortality ; Humans ; Male ; Mitral Valve ; Prothrombin Time ; Seoul* ; Thromboembolism

PURPOSE: The purpose of this study was to evaluate the high-resolution CT features of Swyer-James syndrome with special attention to the airway lesions and to determine the clinical utility of high-resolution CT compared with that of chest radiography. MATERIALS AND METHODS: In seven patients with Swyer-James syndrome, we retrospectively reviewed chest radiographs obtained during inspiration and expiration and high-resolution CT scans obtained in inspiration. The high-resolution CT appearance was evaluated and compared with that of chest radiography. RESULTS: On both chest radiographs and high-resolution CT, the affected lung volume was relatively diminished in four patients and normal in three patients. In all seven patients, chest readiographs showed hyperlucency of the lung which was unilateral in four and bilateral in three patients. Unilateral small hilum was seen in six patients and bronchiectasis was demonstrated in one patient on chest radiographs. The hyperlucent lung volume was not diminished on expiratory radiographs in all seven patients. In all patients, high-resolution CT demonstrated low attenuation regions of the lung either bilaterally(n=5) or unilaterally(n=2). Pulmonary vessels were markedly decreased in size and number in the lung parenchyma with low attenuation. Six patients had bronchiectasis on high-resolution CT, which were cylindrical or varicose in five and cystic in one. Bronchiolectasis was observed in three patients on high-resolution CT. CONCLUSION: The high-resolution CT findings are characteristic of Swyer-James syndrome. High-resolution CT is more sensitive than chest radiography in detecting regions of low attenuation and bronchiectasis and may be useful for the diagnosis of Swyer-James syndrome. Our results suggest that bronchiectasis is a frequently associated airway lesion of Swyer-James syndrome and bronchiolectasis may be associated in some cases.
Bronchiectasis ; Diagnosis ; Humans ; Lung ; Lung, Hyperlucent* ; Radiography ; Radiography, Thoracic ; Retrospective Studies ; Thorax ; Tomography, X-Ray Computed

No abstract available.
Orbit*

No abstract available.
Renal Artery* ; Ureter* ; Veins*

Coronary artery steonosis can be effectively treated by non-operative percutaneous tansluminal coronaryangioplasty(PTCA). We performed PTCA in three patients with coronary artery stenosis, who were referred to thedepartment of radiology, from January to Dec. in 1985. The results were as follows; 1. The locations of coronaryartery stenosis were the proximal anterior descending branch of left coronary artery. 2. The number of stenoticlesions was single without calcium plaque in all three cases. 3. The extent of coronary artery disease is focal,under 2cm in length. 4. PTCA was performed successfully with satisfactory post-dilatation results in all cases. 5.Severe complications such as arterial intimal dissection, acute myocardial infarction, did not occurred. PTCA hasmany advantages over vascular surgery on surgical, economical, and psychological aspects.
Angioplasty, Balloon, Coronary ; Calcium ; Constriction, Pathologic ; Coronary Artery Disease ; Coronary Stenosis ; Coronary Vessels ; Humans ; Myocardial Infarction

Carotid artery angioplasty with stenting (CAS) is being performed in many hospitals in Korea. Most of the guidelines which are being used are similar, but the practical aspects such as techniques are different between hospitals. For example, usage of various protective devices, the oral antiplatelet regimen prior to procedure and placing of temporary pacemaker to prevent bradycardia are different between hospitals. In this article, we summarize and propose the guidelines for CAS which is currently being accepted in Korea. These guidelines may be helpful in providing protocol to neurointerventionalist who perform CAS and to standardize the process including reporting of CAS in the future comparative trials in Korea.
Angioplasty ; Bradycardia ; Carotid Arteries ; Korea ; Protective Devices ; Stents*

No abstract available.
Amebiasis* ; Diabetes Mellitus* ; Humans ; Kidney* ; Liver*

No abstract available.