[en] This paper reports on the hepatic effects of conventional and experimental MR imaging contrast agents that were compared by means of high-resolution in vivo video microscopy, which permits direct assessment of microvascular flow, sinusoidal cell morphology, endothelial activation, and Kupffer cell phagocytosis during and after administration of contrast agents. The left lateral liver lobe of Sprague-Dawley rats was exteriorized, transilluminated, and visualized with x10-x50 water-immersion objectives. Rats received either Gd-DTPA, paramagnetic iron oxide colloids AMI-25 or AG-USPIO or a perfluoro-carbon emulsion (FC-43) via the tail vein. Data were recorded onto video tape for 30 minutes prior to and for 1 hour after drug administration. Kupffer cell phagocytosis was measured with use of India ink. Kupffer cell phagocytosis was reduced in all rats receiving Gd-DTPA and FC-43. After administration of FC-43, microvascular flow abnormalities (intrahepatic shunting, Kupffer cell swelling, sinusoidal occlusion) were noted. Neutrophi endothelial adherence, indicating endothelial activation, was seen in three rates receiving AMI-25

[en] An instrument/hardware package for air and condenser cooling water inleakage location employing the helium and freon techniques was designed and fabricated. The package consists of design details for tracer gas distribution hardware, injection plenums, and a sample preconditioner and instrument module. Design of the package was based on an evaluation of helium and freon leak detectors and a survey of utility user's experience with the helium and freon techniques. The applicability of the instrument/hardware package to air and cooling water inleakage location was demonstrated at Pacific Gas and Electric Company's Moss Landing Station. The use of calibrated leaks indicated that cooling water leaks down to 1.5 x 10^-4 gpm (0.56 ml/min) and air leaks down to 0.05 cfm were readily detectable with the helium technique, whereas a 4 x 10^-4 gpm (1.5 ml/min) liquid leak was the readily detectable minimum via the freon technique. The field demonstration and in-house detector testing showed the helium technique to be preferable to the freon technique for inleakage location at PWRs, BWRs, and fossil-fueled systems

[en] Liver and spleen may be imaged with F-19 MR imaging of injected perfluorocarbons that have been absorbed by the reticuloendothelial system. Unfortunately, F-19 MR signals from perfluorocarbons exhibit short T2s and long T1s, leading to rapid signal loss during echo tim (TE) and slow recovery during repetition time. The authors have circumvented these difficulties by using a driven-equilibrium spin-warp imaging approach with a short TE. Magnetization remaining at the end of the sequence is not allowed to decay but instead is refocused. This technique has been used to enhance the F-19 image quality at 4.7 T for rat livers containing metastases induced by injection of the poorly differentiated colon cell line WB-1756

[en] Since lead can accelerate IGA/IGSCC of Alloy 600 steam generator tubing, lead transport studies were performed at several pressurized water reactors to establish a basis for recommendations regarding transport reduction techniques. Special emphasis was given to sampling and analysis procedures since lead concentrations in the feedwater generally were very low, i.e., 5 to 20 parts per trillion. Lead sources were determined to be highly distributed in the secondary cycle, e.g., turbine and pump bearings and seals and valve packing materials. The major materials of construction (carbon steel, stainless steel, and copper alloy tubing) were not major lead sources in the study plants. Most of the lead that entered the steam generators via the feedwater deposited on the tubes or in the sludge pile leading to concentrations in the range of 1000 ppM. The ubiquitous nature of the lead release phenomenon is expected to lead to significant difficulties in identifying techniques for reducing lead concentrations in the steam generator sludge. 8 refs., 19 figs., 13 tabs

[en] Recent reports indicate that computed tomography (CT) after bolus injection of contrast material is diagnostically specific for hemangioma, replacing the need for angiography in a high percentage of patients. The authors report a unique hepatic hemangioma that showed early diffuse intense opacification by angiography and contrast-enhanced CT

[en] Thirteen consecutive patients who had undergone renal transplantation were scanned 24 hours after glucoheptonate injection to document the incidence of gastrointestinal activity mimicking urinary extravasation. In six of the 13 patients, the activity was clearly within the small bowel or the colon but, in seven patients, the activity was noted surrounding the renal allograft. Using scintigraphy alone, it could not be determined whether this appearance represented cecal activity or urinary extravasation

[en] P-31 and Na-23 spectroscopy was used to assess perfused mouse livers. During anoxia at 37⁰C, B-ATP decreased to zero over 57 +- 9 minutes (n = 16) with high field shift of Pi indicating a pH decrease from 7.16 to 7.04. Using Dy(TTHA)/sup 3-/, only a minor change in the intracellular Na-(120%+-5%) was noted; extracellular Na increased to 260% +- 20% of control. Reoxygenation resulted in further accumulation of extracellular sodium, but intracellular sodium signal decreased to be below control. Enzymes increased with length of anoxia and continued with reoxygenation for 5 minutes before falling to near baseline levels. Extensive centrilobular and midlobular necrosis was seen only after 60 minutes of anoxia, and electron microscopic examination revealed variable grades of cell damage

[en] Twenty-five patients with focal splenic disease were analyzed retrospectively to determine the relative strengths and weaknesses of ultrasound and computed tomography (CT) in the detection and analysis of focal splenic lesions. Lesions were detected in all 25 patients by ultrsonography and in 22 of 25 patients by CT. Ultrasonography appears to be more sensitive in the detection of focal lymphoma within the spleen and may be slightly more sensitive in the detection of microabscesses. CT may offer more specific information regarding the nature of certain lesions, including the detection of cyst wall calcification, gas within an abscess, and the specific site of origin of tumor invading the spleen. Ultrasonography may at times be more specific in the diagnosis of cystic lesions. We recommend ultrasonography as the first method for splenic imaging with CT used when necessary for further characterization of focal lesions

[en] A 75-year-old woman, who presented with obstructive jaundice, was shown by percutaneous transhepatic cholangiography to have a markedly dilated biliary system and stones within the common bile duct. The stones were removed percutaneously using the transduodenal approach, and an internal drainage catheter was placed. Following the procedure, the patient experienced gastrointestinal bleeding manifested by melanotic stools. Blood-tinged bile was withdrawn from the biliary drainage catheter, leading to the suspicion that the bleeding might be originating from the biliary tract. A Tc-99m red blood cell (Tc-99m RBC) scan was performed to try to designate the biliary tract as the site of bleeding, and to determine if there were any other bleeding sites present. The study demonstrated bleeding from the biliary tract, which was confirmed by angiography and endoscopy. The technique for the detection of gastrointestinal bleeding using Tc-99m RBCs is well described. This case suggests that when doing studies to localize occult bleeding, the liver should be included in the field-of-view to exclude bleeding from the liver

[en] To determine the role of radionuclide imaging in diagnosing sphincter of Oddi stenosis, 21 patients with symptoms suggesting this disorder underwent endoscopic retrograde cholangiopancreatography, cholescintigraphy, and, when possible, endoscopic manometry. Those patients with abnormal hepatobiliary scintigraphy results had a mean basal sphincter pressure of 38.5 mm Hg. Sphincter pressures could not be measured in six patients with sphincters too tight to cannulate. Ten patients who underwent hepatobiliary scanning both before and after sphincter surgery had normal scan results of the repeat study. Hepatobiliary imaging appears useful for diagnosis of sphincter of Oddi stenosis in selected patients in whom manometry cannot be performed and for objective assessment of response to therapy