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

No abstract available.
Teratoma*

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*

Magnetic resonance imaging(MRI)has proved to be a valuable method for evaluation of the head and neck. Unfortunately, metallic devices associated with certain dental fillings and applicances often cause variable artifacts that can obscure normal or pathologic conditions on MR and computed tomography. In this work, we assessed the MR appearance of dental prosthetic materials in vitro and in vivo including precious alloys. Nonprecions alloys, resin, amalgam and titanium alloy, For in vivo studies, these materials were placed in healthy volunteer's mouths and then images were assesed. Analyis of the appearance of shape and extent of artifact,and observed influence of these artifacts on the image interpretation at 0.2 Tesla permanent type MR scanner were valuated. Material used as temporary or permanent filling of crowns such as amalgam. precious alloy and, microfilled resin did not cause artifact on the image. The size of the artifact produced by the nonprecious alloys was influenced by the ferromagnetism of the object and the volume prosthesis, and was related to the scanning sequence. Nonprecious alloys produced minimal local signal distortions, where precious alloys, and dental resin had no effect on the MR image in vivo. These results were mainly from a low field strength MR scanner used in this study.
Alloys ; Artifacts* ; Crowns ; Dental Materials* ; Equidae ; Head ; In Vitro Techniques ; Magnetic Resonance Imaging* ; Magnets ; Methods ; Mouth ; Neck ; Prostheses and Implants ; Resins, Synthetic ; Silicone Elastomers ; Titanium

PURPOSE: The chemoembolization with Lipiodol and doxorubicin hydrochloride is used in patients with hepatocellular carcinoma. What condition is the ideal emulsion of Lipiodol and doxorubicin for excellent anticancer effect? METHOD AND MATERIALS: Microscopic evaluation was performed on the emulsions, which were varied with different specific gravities of doxorubicin solutions, degrees in mixing of the emulsion, and amount of Lipiodol. RESULT: 1. Maximal amount of doxorubicin solution was contained in Lipiodol droplets and the release of doxorubicin from the droplets were delayed, when specific gravity of doxorubicin was equal to that of Lipiodol (SG, 1.28). 2. The optimal therapertic ratio of Lipiodol and doxorubicin was 3:2 at least, as in the emulsion less than 3:2, unmixed free forms of doxorubicin solution were increased. 3. The emulsion mixed by pumping 50--100 times had smaller Lipiodol droplets and contained larger amount of doxorubicin solution in the droplets than by pumping 20 times. CONCLUSION: We recommend the emulsion with specific gravity of doxorubicin equal to Lipiodol (SG. 1.28), the ratio of Lipiodol and doxorubicin closo to 3:2, and the mixture prepased with puming 50--100 times.
Carcinoma, Hepatocellular* ; Doxorubicin ; Emulsions ; Ethiodized Oil ; Humans ; Specific Gravity

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

No abstract available.
Bile Ducts, Extrahepatic* ; Carcinoma, Hepatocellular*

BACKGROUND: Reactive oxygen species (ROS) are known to be related to cardiovascular diseases. Many studies have demonstrated that angiotensin-converting enzyme inhibitors have beneficial effects against ROS. We investigated the antioxidant effect of captopril and enalapril in nitric oxide mediated vascular endothelium-dependent relaxations. MATERIALS AND METHODS: Isolated rabbit abdominal aorta ring segments were exposed to ROS by electrolysis of the organ bath medium (Krebs-Henseleit solution) after pretreatment with various concentrations (range, 10-5 to 3x10-4 M) of captopril and enalapril. Before and after electrolysis, the endothelial function was measured by preconstricting the vessels with norepinephrine (10-6 M) followed by the cumulative addition of acetylcholine (range, 3x10-8 to 10-6 M). The relevance of the superoxide anion and hydrogen peroxide scavenging effect of captopril and enalapril was investigated using additional pretreatments of diethyldithiocarbamate (DETCA, 0.5 mM), an inhibitor of Cu/Zn superoxide dismutase, and 3-amino-1,2,4-triazole (3AT, 50 mM), an inhibitor of catalase. RESULTS: Both captopril and enalapril preserved vascular endothelium-dependent relaxation after exposure to ROS in a dose-dependent manner (p<0.0001). Pretreatment with DETCA attenuated the antioxidant effect of captopril and enalapril (p<0.0001), but pretreatment with 3AT did not have an effect. CONCLUSION: Both captopril and enalapril protect endothelium against ROS in a dose-dependent fashion in isolated rabbit abdominal aortas. This protective effect is related to superoxide anion scavenging.
Acetylcholine ; Amitrole ; Angiotensin-Converting Enzyme Inhibitors ; Antioxidants ; Aorta, Abdominal ; Baths ; Captopril ; Cardiovascular Diseases ; Ditiocarb ; Electrolysis ; Enalapril ; Endothelium ; Estradiol ; Hydrogen Peroxide ; Nitric Oxide ; Norepinephrine ; Oxygen ; Reactive Oxygen Species ; Superoxide Dismutase ; Superoxides ; Vasodilation

No abstract available.
Colorectal Neoplasms* ; Fluorouracil* ; Leucovorin*