PURPOSE: To determine the accuracy of automated computer aided volumetry for simulated small pulmonary nodules at computed tomography using various types of phantoms MATERIALS AND METHODS: Three sets of synthetic nodules (small, calcified and those adjacent to vessels) were studied. The volume of the nodules in each set was already known, and using multi-slice CT, volumetric data for each nodule was acquired from the three-dimensional reconstructed image. The volume was calculated by applying three different threshold values using Rapidia(R) software (3D-Med, Seoul, Korea). RESULTS: Relative errors in the measured volume of synthetic pulmonary nodules were 17.3, 2.9, and 11.5% at -200, -400, and -600 HU, respectively, and there was good correlation between true volume and measured volume at -400 HU (r=0.96, p<0.001). For calcified nodules, relative errors in measured volume were 10.9, 5.3, and 16.5% at -200, -400, and -600 HU, respectively, and there was good correlation between true volume and measured volume at -400 HU (r=1.03, p<0.001). In cases involving synthetic nodules adjacent to vessels, relative errors were 4.6, 16.3, and 31.2 % at -200, -400, and -600 HU, respectively. There was good correlation between true volume and measured volume at -200 HU (r=1.1, p<0.001). CONCLUSION: Using computer-aided volumetry, the measured volumes of synthetic nodules correlated closely with their true volume. Measured volumes were the same at each threshold level, regardless of window setting.
Cone-Beam Computed Tomography ; Seoul

Patent ductus arteriosus(PDA) is a common congenital heart disease encountered in premature neonates infants and children. Patent ductus arteriosus was the first surgically managed congenital heart disease,. Classic surgical interruption of patent ducturs arteriosus was partially replaced by a transcatheter endovascular closure, After a 5-7 mm video-assisted thoracoscopic interruption of the patent ductus arteriosus first applied in 1991, this minimally invasive technique came to be used in many centers, Video-assisted thoracoscopic interruption of the patent ductus arteriosus is feasible in low-weight infants whereas transcatheter endovascular closure of the ductus is usually not possible. We experienced successful outcome for the treatment of patent ductus arteriosus with 2 mm video-assisted thoracoscopic titanium clipping, We believed that this technique is a simple safe and rapid method for closure of the patent arteriosus.
Child ; Ductus Arteriosus, Patent ; Heart Defects, Congenital ; Humans ; Infant ; Infant, Newborn ; Thoracoscopes* ; Thoracoscopy ; Titanium

On page 545, the fifth author's name has been incorrectly spelled as Jin Mo Koo. The correct spelling is Jin Mo Goo.

No abstract available.
Child* ; Hearing Loss, Sensorineural* ; Humans ; Temporal Bone*

PURPOSE:To investigate the changes of abnormal signal intensity of liver infarction in scheduled intervals after ligation of portal vein in rabbit livers with histopathologic correlation. MATERIALS AND METHODS:Liver infarction were induced by selective ligation of the posterior branch of right portal vein in 12 rabbits. T1- and T2-weighted MRI at 2.0T with spin-echo techniques as well as contrastenhanced Tl-weighted MRI with Gd-DTPA(0.1 mmol/kg) were performed 3 hours, 6 hours, 1 day, 3 days, 1 week, and 2 weeks after ligation using two rabbits at each interval. Histopathologic specimens were prepared from six removed livers for comparing the MR findings with the histopathologic findings. The other six rabbits were sectioned transversely in frozen state for comparing MR findings with the macroscopic findings of pathologic areas of the liver. RESULTS: The signal intensity of pathologic hepatic segment showed more hyperintense signal than that of normal segments of the liver on TI-, proton density-, and T2-weighted MR images at every interval after ligation, except both T2WI of 3 hours interval and one T1WI of 2 weeks interval. Main histopathologic findings 3 hours, 6 hours, 1 day, 3 days, and 1 week after ligation were congestion, hemorrhage with necrosis, coagulation necrosis, complete necrosis, and necrosis with scar tissues, respectively. Microscopic specimens with Prussian blue stain 6 hours, and 1 week after ligation showed bluish hue indicating the existence of methemoglobin, and blue particles in giant cells and monocytes indicating engulfing hemosiderin, respectively. CONCLUSION: Changes of the signal intensities on sequential MR images of acutely induced hemorrhagic liver infarction might be due to the rapid oxidative denaturation of hemoglobin in hemorrhages and high signal intensity on Tl-weighted images from the hyperacute stage of a hemorrhagic liver infarction could be due to methemoglobin. Therefore, acutely induced hemorrhagic liver infarction should be included in the differential diagnoses of the hyperintense liver lesions on Tl-weighted images.
Cicatrix ; Diagnosis, Differential ; Estrogens, Conjugated (USP) ; Giant Cells ; Hemorrhage ; Hemosiderin ; Infarction ; Ligation* ; Liver* ; Magnetic Resonance Imaging* ; Methemoglobin ; Monocytes ; Necrosis ; Portal Vein* ; Protons ; Rabbits*

BACKGROUND: ATS mechanical valve is a recently introduced pyrolytic carbon bileaflet prosthesis. This report is to evaluate the results of hemodynamic and anticoagulant therapy after ATS valve replacement. MATERIAL AND METHOD: From May 1995 to October 1998, 53 patients received 65 ATS prosthesis; 38 Mitral(27-33 mm), 27 Aortic(19-25 mm). 2 CABGs and 5 Tricuspid annuloplasty were taken concomitantly. The follow up period was 769 patient-months(mean 16.2+/-10.0), varied from 1 month to 39 months with 92.5% follow up rate. All patients were evaluated with Doppler echocardiography, 7-14 days after operation. RESULT: NYHA functional class was improved significantly, from 2.6+/-0.8 preoperatively to 1.3+/-0.4 postoperatively. The average value of peak and mean transvalvular pressure gradients were 25.7+/-13.5 mmHg, 12.7+/-8.3 mmHg in aortic position. In the mitral position, the average values of peak and mean transvalvular pressure gradient and valve area were 5.9+/-2.5 mmHg, 3.1+/-0.8 mmHg and 2.9+/-0.5 cm2, respectively. In the anticoagulant therapy, mean INR was 2.5+/-0.6 in mitral valve replacement and 1.9+/-0.5 in aortic valve replacement. There was no anticoagulant related complication. During that period, there were 3 hospital death(5.9%) and 1 late death(1.9%). CONCLUSION: The early clinical results of the ATS heart valve replacement is quite satisfactory, and low target INR reginmen is safe. And long term follow of hemodynamic characteristics is also necessary.
Aortic Valve ; Carbon ; Echocardiography, Doppler ; Follow-Up Studies ; Heart Valve Prosthesis ; Heart Valves* ; Heart* ; Hemodynamics ; Humans ; International Normalized Ratio ; Mitral Valve ; Prostheses and Implants

PURPOSE: The purpose of our study was to compare the diagnostic value of contrast-enhanced spiral CT scanning and pulmonary angiography in detecting central and peripheral pulmonary embolism (PE) in pigs. MATERIALS AND METHODS: Experiments were performed in a porcine model of acute pulmonary embolism. Five pigs underwent contrast-enhanced spiral CT and pulmonary angiography after central venous administration of embolic material (Konyak). Three thoracic radiologists read the films and the results were compared with the findings of pathologic specimens. RESULTS: Of 85 cases of PE detected pathologically, 78 (91.8 %) were visible with spiral CT and 65 (76.5 %) with pulmonary angiography. Sensitivity and specificity for the detection of central emboli were 95 % and 100 %, respectively, with spiral CT, and 89 % and 100 %, respectively, with pulmonary angiography. Sensitivity and specificity for the detection of peripheral emboli were 88 % and 99 %, respectively, with spiral CT, and 64% and 100 %, respectively, with pulmonary angiography. CONCLUSION: Contrast-enhanced spiral CT is a very useful method for the diagnosis of both peripheral and central pulmonary embolism. Compared to pulmonary angiography its sensitivity and specificity are high.
Angiography ; Diagnosis ; Pulmonary Embolism* ; Sensitivity and Specificity ; Swine ; Tomography, Spiral Computed*

PURPOSE: The purpose of our study was to compare the diagnostic value of contrast-enhanced spiral CT scanning and pulmonary angiography in detecting central and peripheral pulmonary embolism (PE) in pigs. MATERIALS AND METHODS: Experiments were performed in a porcine model of acute pulmonary embolism. Five pigs underwent contrast-enhanced spiral CT and pulmonary angiography after central venous administration of embolic material (Konyak). Three thoracic radiologists read the films and the results were compared with the findings of pathologic specimens. RESULTS: Of 85 cases of PE detected pathologically, 78 (91.8 %) were visible with spiral CT and 65 (76.5 %) with pulmonary angiography. Sensitivity and specificity for the detection of central emboli were 95 % and 100 %, respectively, with spiral CT, and 89 % and 100 %, respectively, with pulmonary angiography. Sensitivity and specificity for the detection of peripheral emboli were 88 % and 99 %, respectively, with spiral CT, and 64% and 100 %, respectively, with pulmonary angiography. CONCLUSION: Contrast-enhanced spiral CT is a very useful method for the diagnosis of both peripheral and central pulmonary embolism. Compared to pulmonary angiography its sensitivity and specificity are high.
Angiography ; Diagnosis ; Pulmonary Embolism* ; Sensitivity and Specificity ; Swine ; Tomography, Spiral Computed*

INTRODUCTION: Understanding the normal distribution of the tracheal diameter and crross- sectional area is one of the key elements in the management of various tracheal pathologies or tracheal reconstruction for the patients in growing age. However, data for Korean standard has been lacking. This study was designed to analyze retrospectively the distribution of tracheal diameter and cross-sectional area in young Koreans, which can afford fundamental data for the management of tracheal diseases. MATERIAL AND METHOD: Of the patients who underwent computerized tomogram of the chest between May 1996 and August 1998, one hundred six young patients(age range: 0-20 years) were included. Patients with any conditions which might affect the tracheal cross-sectional area or diameter, such as tracheal disease, previous operation, mediastinal tumor, or obstructive lung disease were excluded from the study. Gender distribution was 69 males and 37 females. Tracheal diameters, anterior-posterior and transverse, were measured at the level of the thoracic inlet(level I) and the aortic arch(level II). Types of the trachea were divided into round, oval, or horseshoe shaped on cross-sectional view, and the dimension was calculated by using the equation of A=1/4(pi)ab(A; area, (pi); 3.14, a; anterior-posterior diameter, b; transverse diameter). We analyzed the distribution of the diameter at each level and compared the cross-sectional area with respect to age and gender. A p-value lower than 0.05 wa considered significant. RESULT: The trachea of patients less than 5 years old were round in shape at both of level I and II, and no differences in cross-sectional area was observed between the levels(p=NS). As the age increased, the trachea become oval in shape at level I while it remained round in shape at level II(p=0.020). The tracheal diameter and cross-sectional area increased as the age increased with a linear correlation(r>0.9). In patients less than 5 years of age, female patients showed larger cross-sectional area than male patients (p=0.020), and it was reversed in patients older than 15 years of age(p=0.002). CONCLUSION: From the above results, we suggest chest computerized tomogram as a safe and reliable tool in measuring the tracheal diameter and cross-sectional area. We also provide the data as a standard for distribution of the tracheal diameter and cross-sectional area in young Korean population.
Age Factors ; Child, Preschool ; Female ; Humans ; Lung Diseases, Obstructive ; Male ; Pathology ; Retrospective Studies ; Thorax ; Trachea ; Tracheal Diseases