A guide to diagnosing and treating endodontic and periodontal lesions

178 439 cases of patients exposed to iodinated contrast media (ICM) corresponding to 137 147 to patients for excretory urography and 41 292 to cholangiography were studied. A direct interrogation making emphasis on personal antecedents of allergy to contrast media, iodinated products usage, nervous system and cardiovascular illnesses was made. Cutaneous test for iodinated contrast media was applied. If the result was positive no study with the ICM was made or it was made with special guidelines. 4302 positives and 1276 false negatives were found. 287 positive cases were premeditated and preventive medication was administered in cases of urticaria asthma/and angioedema with negative cutaneous test histories. There were no deaths registered.     

Comparative morphologic study of the pathogenic properties of different agents of intestinal infections

Percutaneous transjugular cholangiography (PTJC) is a new technique for visualization of the biliary duct system and for diagnosis of obstructive jaundice. First experiences of the authors in 22 patients are described. The advantages and disadvantages of this procedure, which at the present time is used rather rarely, are discussed and compared to various other cholangiographic methods. The endoscopic retrograde cholangiography (ERC) was used for patients with obstructive jaundice of unknown origine in the first place. If the biliary duct system could not be visualized by ERC (failure of complete obstruction of the common bile duct), the antegrade technique (PTJC) was performed. The peritoneoscopic and the transjugular cholangiography yield about the same percentage of positive results (90%), as far as visualization of the biliary tree is concerned. However in contrast to the peritoneoscopic methods PTJC seems to bear a smaller risk of complications. Some further diagnostic and therapeutical advantages, which might result from the use of PTJC are pointed out.     

Chronic blockade of endothelin ETA receptors improves flow dependent dilation in resistance arteries of hypertensive rats

PURPOSE: To compare findings with magnetic resonance (MR) cholangiography with rapid acquisition with relaxation enhancement (RARE) and half-Fourier acquisition with single-shot turbo spin-echo (hereafter, half Fourier RARE) snapshot imaging techniques to those with endoscopic retrograde cholangiography (ERC). MATERIALS AND METHODS: Heavily T2-weighted thick-section (RARE) and thin-section (half-Fourier RARE) MR cholangiography were performed prospectively, on a 1.5-T imager, in the biliary tree of 61 consecutive patients before ERC. Findings at ERC were considered the standard of reference. The radiologist and endoscopist were blinded to each other's report. On- and off-site MR cholangiographic readings were performed to detect stones (n = 24), biliary dilatation (n = 34), or stenosis (n = 36). RESULTS: The sensitivity and specificity of MR cholangiography, respectively, calculated on a lesion-by-lesion basis, were 92.3% and 95.8% for cholangiolithiasis, 94.1% and 92.6% for duct dilatation, and 88.8% and 84.0% for stenosis. With snapshot MR cholangiography, on a patient-by-patient basis, differentiation between normal (n = 15) and abnormal (n = 46) results yielded a sensitivity of 92.4%, a specificity of 83.4%, and a positive predictive value of 95.6%. Pitfalls were caused by flow artifacts, compression by vessels, and low contrast between calculi and surrounding parenchyma. CONCLUSION: Snapshot MR cholangiography allowed noninvasive, accurate detection of biliary stones, strictures, and dilatation similar to that with ERC. Discrepancies regarding low-grade dilatation and strictures had no clinical relevance at retrospective review.     

A rotating iterative procedure (RIP) for estimating hybrid constants in multi-compartment analysis on desk computers

Selective renal artery catheterization and renal angiography are commonly performed diagnostic procedures; however, the effects of these procedures on renal blood flow (RBF) and renin release have only been partially described. A biphasic RBF response has been well documented furing selective angiography in dogs. The renal autoregulatory mechanisms governing the responses are uncertain. The renin-angiotensin system and the major parameters of contrast media, hypertonicity and viscosity, have been suggested as important factors. In the canine model, we examined the acute changes in renal venous renin activity along with the renal hemodynamic effects of hypertonicity and viscosity. Our results do not support a primary effect mediated by the renin-angiotensin system. Hypertonicity and the contrast medium per se are significant in active and passive autoregulatory responses at the smooth muscle cellular level.     

Apropos of a case of acute pancreatitis revealing cystic dilatation of the common bile duct

Dilatation of the common bile duct is rarely caused by cystic formations. Though the pathogenesis is uncertain, congenital disorders have been suggested. Most cases are observed in small children (80% female predominance) with only 20% of the cases reported in adults. Clinical signs vary. Recurrent acute pancreatitis has been reported but is rare. New imaging techniques using CT-scan cholangiography and sometimes MR cholangiography have greatly improved the diagnostic approach. MR of the bile ducts is a recent noninvasive technique enabling an analysis of the biliopancreatic ducts without contrast injection into the bile. To our knowledge, cystic dilatation of the common bile duct has not been previously reported in the literature. We report an interesting case in a 25-year-old woman who developed an episode of acute pancreatitis during the post partum period. We describe the clinical aspects and the different imaging findings, including magnetic resonance cholangiography results.     

Enhanced effects of adriamycin by combination with a new ribonucleotide reductase inhibitor, trimidox, in murine leukemia

For invasive catheter procedures both ionic and nonionic contrast media (CM) with excellent tolerability are available. The governing practical factors for CM are X-ray opacity and biocompatibility. Tolerability of a contrast medium is governed among its physical properties by its viscosity, osmolality, and ionic concentration. In Germany the nonionic CM are currently preferred. Because of its low thrombotic complications, the ionic CM Ioxaglat is an important alternative in high risk interventions. In patients with known CM incompatibility, the prophylactic application of H1-receptor antagonists and corticosteroids allows catheterization safely without complications. In impaired renal function, hydration is the most effective prophylactic measure to be taken.     

Centrifuge Study of DNAPL Transport in Granular Media

The migration potential of dense nonaqueous phase liquids (DNAPLs) in saturated soil was investigated experimentally using the elevated acceleration field of the geotechnical centrifuge. The transport of the DNAPL was monitored with a video camera in flight, through the transparent wall of the sample box. By using measurements of the velocity of the DNAPL front from models corresponding to the same prototype and applying the technique of “modeling of models,” the stable infiltration of a low density, high viscosity DNAPL in saturated homogeneous media was shown to scale properly in the centrifuge. The visual observations confirmed the correlations between the DNAPL physicochemical properties and transport patterns, which have important consequences for the characterization of DNAPL-contaminated sites. Infiltrating DNAPLs of high density and low viscosity displace water in an unstable manner and create extensive contaminated areas characterized by non-uniform DNAPL distributions. In contrast, the displacement of water by DNAPLs of low density and high viscosity is stable and efficient, and hence, results in smaller contaminated areas of high DNAPL saturation. Numerical simulations yielded predictions and sensitivity analysis results that agreed well with these experimental observations.     

HASTE MR cholangiography in the evaluation of hilar cholangiocarcinoma

OBJECTIVE: The objective of this study was to determine the usefulness of MR cholangiography using the half-Fourier acquisition single-shot turbo spin-echo sequence in the examination of patients with hilar cholangiocarcinoma. CONCLUSION: Half-Fourier acquisition single-shot turbo spin-echo MR cholangiography is a useful, noninvasive adjunct to other imaging techniques, particularly MR imaging, in the evaluation of hilar cholangiocarcinoma. MR cholangiography allows rapid visualization of the biliary tract without instrumentation and, therefore, without the risk of inducing sepsis in a patient with ductal obstruction. In the six patients presented. MR cholangiography allowed for determination of the proximal extent of disease and assessment of resectability and delineated the duct both proximal and distal to the stricture and isolated ductal obstructions. MR cholangiography provides three-dimensional images of the biliary tract that facilitate planning of surgery, palliative drainage, and radiation therapy.     

Relative merits of ultrasonography, computed tomography and cholangiography in patients of surgical obstructive jaundice

Fifty consecutive patients with surgical obstructive jaundice were evaluated prospectively with ultrasonography (US), computed tomographic scans (CT scan) and cholangiography-percutaneous transhepatic cholangiography (PTC) or endoscopic retrograde cholangio-pancreaticography (ERCP). The diagnostic accuracy of ultrasound in defining the level of obstruction was 86% as compared to 86% and 94.8% for CT scan and cholangiography, respectively. To measure the etiology of the obstruction, the accuracy of ultrasound, CT scan and cholangiography were 84%, 86% and 75%, respectively. The sensitivity of CT scans and cholangiography in the diagnosis of choledocholithiasis was 100%, 81.8% and 90%, respectively, whereas specificity was 97%, 100% and 100%, respectively. Sensitivity for a diagnosis of malignant disease was 100% for both US and CT scans whereas specificity was 90% and 81%, respectively. Ultrasonography as a single radiological investigation is sufficient in the evaluation of the majority of patients with surgical obstructive jaundice. CT scan and cholangiography should be done only when US gives equivocal findings or if concomitant therapeutic procedures like basketing and stenting are also planned.     

Magnetic resonance cholangiography for evaluation of cholestatic jaundice in neonates and infants

Distinguishing extrahepatic biliary atresia from other causes of cholestasis in neonates and infants is important because surgical intervention before 2 months of age allows for long-term survival. The purpose of this prospective study was to evaluate the usefulness of magnetic resonance (MR) cholangiography in differentiating biliary atresia from other causes of cholestatic jaundice in neonates and infants. Nine anicteric infants (control group) aged 10 to 224 days (mean +/- SD, 8 +/- 65 days) and 15 neonates and infants with cholestatic jaundice, aged 22 to 142 days (mean +/- SD, 71 +/- 37) underwent MR cholangiography. The final diagnosis of extrabiliary atresia (6 patients) was based on laparotomy findings (4 patients) or autopsy (2 patients), while neonatal hepatitis (9 patients) was diagnosed according to the liver biopsy findings and clinical recovery during follow-up. Percutaneous liver biopsies were performed in all 15 patients. Results showed that the gall bladder and common bile duct (CBD) could be visualized using MR cholangiography in all patients in the control group. Nonvisualization of the CBD (6/6 patients) and demonstration of a small gall bladder (6/6 patients) characterized MR cholangiography findings in patients with biliary atresia. MR cholangiography failed to depict the CBD in one infant with hepatitis. We conclude that demonstration of the CBD by MR cholangiography in neonates and infants with cholestasis can be used to exclude the diagnosis of biliary atresia. In patients with cholestatic jaundice considered for exploratory laparotomy, preoperative MR cholangiography is recommended to avoid unnecessary surgery.     

Influence of Cholografin and Renografin 76 on platelet function

Cholografin and Renografin 76 were studied to determine their effects on platelet function. In vitro platelet aggregation was significantly inhibited by at least 3.4 micron/ml Cholografin and 19.5 micron/ml Renografin 76. Patients who received Cholografin for intravenous cholangiography, and Renografin 76 for non-cardiac angiography, had low levels of plasma contrast agent, and hemostasis was clinically unimpaired. Patients who received Renografin 76 for cardiac angiography had inhibition of platelet aggregation at high levels of plasma contrast agent; there was no correlation with prolonged bleeding times, or with bleeding complications. High levels of plasma contrast agent may inhibit platelet aggregation in vitro and in vivo, although this may not be associated with clinically significant bleeding.     

MR cholangiography: technical advances and clinical applications

Magnetic resonance (MR) cholangiography is a fast, accurate, noninvasive alternative to endoscopic retrograde cholangiography (ERC) in the evaluation of biliary tract disease. Technical improvements in imaging sequences (eg, half-Fourier rapid acquisition with relaxation enhancement) and use of phased-array coils allow high-quality imaging comparable to that available with ERC. In choledocholithiasis, common bile duct stones as small as 2 mm can be detected with MR cholangiography and appear as low-signal-intensity foci within the high-signal-intensity bile. MR cholangiography may help establish the diagnosis of malignant obstruction and is useful in the evaluation of patients in whom ERC was unsuccessful or incomplete. The role of MR cholangiography in the evaluation of intrahepatic duct disease continues to evolve. MR cholangiography plays a crucial role in evaluating postsurgical biliary tract alterations and can be used to demonstrate a variety of congenital anomalies of the biliary tract (eg, aberrant ducts, choledochal cysts, pancreas divisum). In addition, intentional or incidental imaging of the gallbladder with MR cholangiography can be used to identify calculi or help determine the presence and extent of neoplastic disease.     

Effect of molecular weight on the diffusion of contrast media into cartilage

STUDY DESIGN: A comparison of contrast enhancement in the intervertebral disc from two magnetic resonance imaging contrast media in experimental animals. OBJECTIVES: To test the effect of molecular weight on the diffusion of ionic contrast media into the intervertebral disc. SUMMARY OF BACKGROUND DATA: Intravenously administered gadopentetate diffuses similarly into the fibrocartilage of intervertebral discs and herniated disc fragments. Differentiation between recurrent disc fragments and scar tissue via magnetic resonance imaging is optimized by using contrast media, which result in different contrast enhancement of these two tissues. Contrast media of higher molecular weight diffuse more slowly into cartilage; hypothetically, therefore, such media will produce better contrast between scar tissue and recurrent disc fragments. METHODS: Gadopentetate (molecular weight 546) or gadolinium-polylysine (molecular weight 40,000) was injected intravenously into rabbits. The signal intensities of intervertebral disc and muscle tissue were recorded by magnetic resonance imaging at baseline and at pre-determined intervals for 2 hours after injection of the contrast medium. Contrast enhancement in these tissues was calculated in each animal for each contrast medium, and differences in enhancement were tested for significance by a growth-curve model. RESULTS: Contrast enhancement in the intervertebral disc was significantly less with gadolinium-polylysine than with gadopentetate. In muscle, no significant difference between the two media was observed. CONCLUSIONS: Molecular weight affects the diffusion of paramagnetic contrast media into the intervertebral disc. Contrast media of a high molecular weight may produce better contrast between recurrent herniated disc fragments and scar tissue than contrast media of lower molecular weight. This possibility should be rested in further studies.     

Arterial-phase three-dimensional gadolinium magnetic resonance angiography of the renal arteries. Strategies for timing and contrast media injection: original investigation

RATIONALE AND OBJECTIVES: The authors review different imaging and contrast-media infusion strategies for arterial-phase three-dimensional (3D) gadolinium-enhanced magnetic resonance angiography (Gd-MRA). METHODS: The influence of physicochemical factors on the infusion of contrast media, including viscosity, flow rate, inline pressure, and cannula size, is assessed. The combination of manual or automated contrast-media administration with timing-dependent or -independent 3D Gd-MRA techniques is reviewed regarding the aspects of effectiveness, robustness, image quality, and costs. RESULTS: For effective bolus delivery with high flow rates, the type and temperature of the contrast media, the size of the cannula, and an immediate saline flush must be considered. Timing-dependent techniques based on a test bolus and using automated contrast-media infusion as well as timing independent techniques such as MR SmartPrep or multiphase 3D Gd-MRA by using a manual injection with a SmartSet tubing set, are all effective procedures for arterial phase 3D Gd-MRA. CONCLUSIONS: Manual contrast-media injection with a tubing set can be used for timing-independent MRA techniques. The multiphase 3D Gd-MRA approach seems to be favorable for different MR systems, robustness, and speed.     

Influence of structural properties and kinetic constraints on Bacillus cereus growth

The influence of structural properties and kinetic constraints on the behavior of Bacillus cereus was investigated on agar media. Dimensional criteria were used to study the growth in bacterial colonies. The architecture of the agar gel as modified by the agar content was found to influence the colony size, and smaller colonies were observed on media containing 50 to 70 g of agar liter-1. Except at low nutrient levels, colonies responded to nutrient gradients by decreasing in size the farther away they were from the nutrient source, and the decrease in colony size was influenced by the agar content. The diffusivities of glucose and a protein (insulin-like growth factor) were not affected by the gel architecture, suggesting that other factors, such as mechanical factors, could influence microbial growth in the agar systems used. Increasing the viscosity of the liquid phase of the agar media by adding polyvinylpyrrolidone resulted in a reduction in colony size. When the agar concentration was increased, the colony areas were not influenced by the viscosity of the system.     

球磨机介质配比方法的试验研究

对生产中简单实用的主要介质配比方法进行了试验比较。结果表明,确定适宜介质配比的方法是：根据给料粒度组成,先确定各主要窄给别对应的最佳介质尺寸,然后各直径球介质占球荷总质量的百分率等于给料中相应窄级别的产率确定介质配比;如果给料中粗粒级含量低,磨矿时间较长,磨机矿浆粘度较大,可按照各尺寸介质等质量百分比法计算介质配比,以适当增加大球介质的比例,提高磨矿效率。该研究结构对实际生产具有重要的指导意义。     

Percutaneous direct prograde cholangiography; experiences with application in preoperative diagnostics of obstructive jaundice (author's transl)]

A brief survey of the technique and application of the percutaneous direct prograde cholangiography is given. Percutaneous transhepatic cholangiography with transperitoneal and with extraperitoneal access and transjugular cholangiography are available as methods. As far as preoperative diagnostics of the extrahepatic obstructive jaundice is concerned, at first transjugular cholangiography is applied and percutaneous transhepatic cholangiography is only refered to when no clarification can be achieved. The advantages of this procedure are discussed.     

Cardiac transplantation in patients aged 60 years or older

The indications and best technique for peroperative cholangiography during laparoscopic cholecystectomy remain unclear, but the operation has been associated with an increased use of preoperative endoscopic retrograde cholangiography. Cystic duct cholangiography, particularly in the hands of the trainee, can be time consuming, and bile duct injury may be caused by attempts to cannulate the cystic duct. This study analyses 113 consecutive patients undergoing peroperative cholangiography through the gallbladder, or cholecystocholangiography. It was successful in 92 (81.4%) patients, the procedure adding less than 10 min to the operating time. There were no cholangiogram-related complications. Common anatomical variations included both short and particularly wide cystic ducts. This information helps to minimize the risk of damage to the common bile duct. This study demonstrates that cholecystocholangiography is a safe, simple, and effective alternative to cystic duct cholangiography with virtually no "learning curve." It provides a "road-map" of biliary anatomy and identifies common bile duct stones prior to the commencement of dissection. Unsuccessful cholecystocholangiography does not preclude the use of cystic duct cholangiography later in the operation. Difficult anatomy is demonstrated prior to dissection. When unsuspected bile duct calculi necessitate open exploration, further laparoscopic dissection is avoided.     

Routine intraoperative laparoscopic cholangiography

BACKGROUND: Whether intraoperative laparoscopic cholangiography should be routine is debatable. METHODS: We reviewed the cholangiography experience in 669 consecutive laparoscopic cholecystectomies. RESULTS: Mean age of the patients was 39 years, 78% were female, and 29% had acute cholecystitis. Cholecystectomy was completed laparoscopically in 606 (91%). Laparoscopic cholangiography was completed in 562 (93%) and 348 (62%) were routine (no preoperative indication). The mean operating time in 1996 was 61 minutes. Out of the 348 routine cholangiograms, 17 demonstrated evidence of unsuspected choledocholithiasis. Five patients had choledocholithiasis documented by laparoscopic common bile duct exploration and/or endoscopic retrograde cholangiopancreatography. Two patients had normal postoperative cholangiopancreatography. One of 10 patients managed expectantly was readmitted postoperatively with obstructive jaundice. In 4 patients, routine cholangiography revealed unexpected anatomy, and in 2, this prevented misidentification and transection of the common bile duct. CONCLUSION: Laparoscopic cholangiography is safe, quick, detects unsuspected choledocholithiasis, and can prevent common bile duct transection. It should be routine.