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*

Sternal fractures, once thought of as an uncommon phenomenon, have occurred with an increasing frequency, paralleling the incidence of motor vehicle accidents. The tremendous force necessary to cause sternal fracture and this bone's prominent position overlying major intrathoracic and mediastinal structures, have important implications in the assessment and treatment of patients. This evaluation is based on the review of 72 patients of traumatic sternal fracture treated at the Department of Thoracic and Cardiovascular Surgery, Seoul Adventist Hospital during the last 4 years from March 1993 to February 1997. The frequency was 12.2% of nonpenetrating chest trauma and average age was 43.2 years old. Automobile accidents (84%) and sternal body fractures (95.8%) with anterior displacements (19.4%) was the most common cause and fracture site. Increase of cardiac isoenzymes was more frequent and higher in sternal fracture than chest contusion but there was no relationship between the time to take normalization of them and the mode of trauma.
Automobiles ; Contusions ; Humans ; Incidence ; Isoenzymes ; Motor Vehicles ; Seoul ; Thorax

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

BACKGROUND: As coronary arterial disease is increasing, we evaluated the patients who underwent CABG (Coronary Artery Bypass Grafting) and thus report the early results and risk factors related to mortality and morbidity. MATERIALS AND METHODS: Between July 1996 and February 1998, 42 patients underwent CABG. We analyzed age, sex, preoperative ejection fraction, Canadian heart classification, prevalence factors of CAD (Coronary Artery Disease), angiographic findings, graft vessel numbers, IMA (Internal Mallary Artery) use, ECC* (extracorporeal circulation) time and morbidity. We also evaluated the mortality rate and the causes of death. RESULTS: Complication was developed at 17cases. The average age of the complication group was 61+/-11.9 years and that of the noncomplication group was 51+/-10.5 years (p=0.004). ECC time was 198+/-42.5 (min) in the complication group and 158+/-47.4 (min) in the noncomplication group (p=0.008). The other factors had no correlation to the morbidity, statistically. The average follow up duration was 12.5 months and all the patients were alive except for the 2 expired cases. The mortality rate was 4.7%, among which one patient who underwent CABG with aortic valve replacement died due to multiorgan failure and the other died due to sepsis with pneumonia and wound infection. CONCLUSIONS: We conclude that the risk factors related to morbidity were age and ECC time, and that there were no correlations between other factors and morbidity.
Aortic Valve ; Arteries ; Cause of Death ; Classification ; Coronary Artery Bypass ; Follow-Up Studies ; Heart ; Humans ; Mortality ; Pneumonia ; Postoperative Complications ; Prevalence ; Risk Factors ; Sepsis ; Transplants ; Wound Infection

OBJECTIVE: To determine the usefulness of a computer-aided diagnosis (CAD) system for the automated detection of lung nodules at low-dose CT. MATERIALS AND METHODS : A CAD system developed for detecting lung nodules was used to process the data provided by 50 consecutive low-dose CT scans. The results of an initial report, a second look review by two chest radiologists, and those obtained by the CAD system were compared, and by reviewing all of these, a gold standard was established. RESULTS : By applying the gold standard, a total of 52 nodules were identified (26 with a diameter < or =5 mm; 26 with a diameter > 5 mm). Compared to an initial report, four additional nodules were detected by the CAD system. Three of these, identified only at CAD, formed part of the data used to derive the gold standard. For the detection of nodules > 5 mm in diameter, sensitivity was 77% for the initial report, 88% for the second look review, and 65% for the CAD system. There were 8.0+/-5.2 false-positive CAD results per CT study. CONCLUSION : These preliminary results indicate that a CAD system may improve the detection of pulmonary nodules at low-dose CT.
Adult ; Aged ; Aged, 80 and over ; Diagnosis, Computer-Assisted/*methods/*standards ; Human ; Lung Neoplasms/classification/*radiography ; Mass Screening/methods ; Middle Aged ; Radiation Dosage ; Support, Non-U.S. Gov't ; Tomography, X-Ray Computed/*methods/*standards