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Objective: Quantitative image quality assessment in terms of image noise (IN), contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) in relation to required radiation dose (RD) for dual-energy (DE), standard and low-kVp contrast-enhanced computed-tomography (CT) cholangiography., Materials and Methods: For each of 22 DECT-cholangiography examinations, 3 image datasets were analyzed as independent single-source CT-acquisitions at different tube potential, i.e. 80 kVp, 120 kVp-equivalent (linear blended dataset M0.3: 30% 80 kVp, 70% 140 kVp), and 140 kVp. Analysis comprised determination of IN, CNR and SNR in regions of interest (ROI) placed in liver parenchyma and contrasted bile ducts. IN was evaluated as mean standard deviation of 3 ROI placed within liver parenchyma (segments 6/7, 5/8, 2/3); CNR was assessed as bile duct-to-liver parenchyma ratio, and SNR as bile duct-to-image noise ratio. RD in terms of CT dose index (CTDI(vol)), dose-length product (DLP) and effective dose (ED) has been determined for each of the datasets, and compared to console prediction and scan summary values. Using phantom measurements of CTDI(vol), a method for separating comprehensive RD values of DE-acquisitions into the original RD contribution of each tube (80 kVp/140 kVp) has been developed, enabling comparison of all 3 datasets as if independently acquired using single-source "single-energy" technique., Results: Highest IN was detected for 80 kVp- (38.6 ± 5.1HU), lowest for 120 kVp-equivalent linear blended M0.3-datasets (23.1 ± 3.4HU) with significant differences between all datasets (P<0.001). Highest SNR and CNR were measured for M0.3- (SNR: 14.8 ± 4.1; CNR: 11.6 ± 3.8) and 80 kVp-datasets (SNR: 13.8 ± 4.8; CNR: 11.2 ± 4.5); lowest for 140 kVp-datasets (SNR: 9.5 ± 2.5; CNR: 7.1 ± 2.3) with significant differences between M0.3- and 140 kVp-datasets as well as between 80 kVp- and 140 kVp-datasets (both P<0.001 for both CNR, SNR). CTDI(vol), DLP and ED were reduced by 50% for low-kilovoltage acquisitions (CTDI(vol): 5.5 ± 1.4 mGy; DLP: 127.8 ± 40.1 mGy cm; ED: 1.9 ± 0.6 mSv) compared to comprehensive DE-acquisitions (CTDI(vol): 11.0 ± 2.3 mGy; DLP: 253.8 ± 67.5 mGy cm; ED: 3.8 ± 1.0 mSv, tube contribution: 80 kVp: 44.5%; 140 kVp: 55.5%), and by 20% compared to conventional acquisitions at 120 kVp (CTDI(vol): 6.71 mGy; DLP: 153.5 ± 16.9 mGy cm; ED: 2.3 ± 0.3 mSv)., Conclusions: Despite higher IN, low-kilovoltage CT-cholangiography reveals no significant difference with respect to CNR and SNR when compared to linear blended images yielded by DECT. Compared to DECT or conventional CT at 120 kVp, contrast-enhanced low-kVp CT cholangiography potentially allows reduction of patient dose by up to 50% or 20%, respectively. Therefore, CT-cholangiography at 80 kVp should be considered as an alternative to DECT-cholangiography whenever DECT is unavailable, or if increased image quality of DECT regarding quantitative bile duct evaluation is not needed for diagnosis., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Dynamic contrast-enhanced magnetic resonance imaging (MRI) is a technique used to study and track contrast kinetics in an area of interest in the body over time. Reconstruction of images with high contrast and sharp edges from undersampled data is a challenge. While good results have been reported using a radial acquisition and a spatiotemporal constrained reconstruction (STCR) method, we propose improvements from using spatially adaptive weighting and an additional edge-based constraint. The new method uses intensity gradients from a sliding window reference image to improve the sharpness of edges in the reconstructed image. The method was tested on eight radial cardiac perfusion data sets with 24 rays and compared to the STCR method. The reconstructions showed that the new method, termed edge-enhanced spatiotemporal constrained reconstruction, was able to reconstruct images with sharper edges, and there were a 36%±13.7% increase in contrast-to-noise ratio and a 24%±11% increase in contrast near the edges when compared to STCR. The novelty of this paper is the combination of spatially adaptive weighting for spatial total variation (TV) constraint along with a gradient matching term to improve the sharpness of edges. The edge map from a reference image allows the reconstruction to trade-off between TV and edge enhancement, depending on the spatially varying weighting provided by the edge map., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: To evaluate whether virtual non-enhanced imaging (VNI) is effective to replace true non-enhanced imaging (TNI) applying iodine removal in intravenous dual-energy CT-cholangiography., Materials and Methods: From April 2009 until February 2010, fifteen potential donors for living-related liver transplantation (mean age 37.6±10.8 years) were included. Potential donors underwent a two-phase CT-examination of the liver. The first phase consisted of a single-energy non-enhanced CT-acquisition that provided TNI. After administration of hepatobiliary contrast agent, the second phase was performed as a dual-energy cholangiographic CT-acquisition. This provided VNI. Objective image quality (attenuation values [bile ducts and liver parenchyma] and contrast-to-noise ratio) and subjective overall image quality (1 - excellent; 5 - non diagnostic) were evaluated. Effective radiation dose was compared., Results: For TNI and VNI, attenuation values for bile ducts were 16.8±11.2HU and 5.5±17.0HU (p<0.05) and for liver parenchyma 55.3±8.4HU and 58.1±10.6HU (n.s.). For TNI and VNI, contrast-to-noise ratio was 2.6±0.6HU and 6.9±2.1HU (p<0.001). For VNI, subjective overall image quality was 1 in ten datasets, 2 in four datasets and 3 in one dataset. Effective radiation dose for the dual-energy cholangiographic CT-acquisition was 3.6±0.9mSv and for two-phase single-energy CT-cholangiography 5.1±1.3mSv (p<0.001)., Conclusion: In this study on iodine removal in intravenous dual-energy CT-cholangiography, subjective image quality is equivalent, contrast-to-noise ratio is improved and effective radiation dose is reduced when VNI is performed. The differences between TNI and VNI with respect to attenuation values seem to have limited clinical relevance and therefore we consider VNI as effective to replace TNI., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background/purpose: To assess the feasibility of intravenous 64-multi-detector row computed tomography (CT)-cholangiography of porcine livers with definition of the temporal window for optimal bile duct delineation., Methods: Six healthy Landrace pigs, each weighing 28.97 +/- 2.99 kg, underwent 64-multi-detector row CT-cholangiography. Each pig was infused with 50 ml of meglumine iotroxate continuously over a period of 20 min and, starting with the initiation of the infusion, 18 consecutive CT scans of the abdomen at 2-min intervals were acquired. All series were evaluated for bile duct visualization scores and maximum bile duct diameters as primary study goals and bile duct attenuation and liver enhancement as secondary study goals., Results: Of the 16 analyzed biliary tract segments, maximum bile duct visualization scores ranged between 4.00 +/- 0.00 and 2.83 +/- 1.47. Time to maximum bile duct visualization scores ranged between 10 and 34 min. Average bile duct visualization scores for the 10- to 34-min interval ranged between 3.99 +/- 0.05 and 2.78 +/- 0.10. Maximum bile duct diameters ranged between 6.47 +/- 1.05 and 2.65 +/- 2.23 mm. Time to maximum bile duct diameters ranged between 24 and 34 min. Average bile duct diameters for the 10- to 34-min interval ranged between 6.00 +/- 0.38 and 2.40 +/- 0.13 mm., Conclusions: Intravenous 64-multi-detector row CT-cholangiography of non-diseased porcine liver is feasible, with the best bile duct delineation acquired between 10 and 34 min after initiation of the contrast agent infusion.

Blunt gallbladder injury is rare, and bleeding from the cystic artery due to blunt trauma is even rarer. We report herein a case of extraluminal bleeding of the gallbladder in a patient following blunt abdominal trauma. Contrast-enhanced computed tomography revealed pericholecystic fluid and extravasation of contrast material in the subcapsular liver space adjacent to the gallbladder. Abdominal digital subtraction angiography revealed pseudoaneurysm originating from a branch of the cystic artery. Successful treatment was achieved using selective transcatheter embolization, and cholecystectomy was not required.

Cholecystoenteric fistulas are often not diagnosed preoperatively and delineation of fistula can have an influence on surgical planning. We report a case of cholecystocolonic fistula diagnosed preoperatively using CT-i.v. cholangiography and review the published reports.

This study aimed to assess the ability of CT-i.v. cholangiography to show the perihilar biliary and cystic duct anatomy and to assess the relative performance of axial, maximum intensity projection and surface rendered displays. We also assessed the correlation between serum bilirubin levels and adequacy of biliary opacification. Spiral CT was carried out following infusion of 100 mL of Biliscopin in 181 patients with suspected biliary disease. The display of biliary anatomy was of high quality, with 91% of patients having good opacification of at least first-order bile ducts and 84% having good opacification of at least third-order right and left hepatic ducts. The quality of biliary opacification correlated inversely to serum bilirubin levels, with levels above two to three times the normal value being associated with lower rates of good opacification. Maximum intensity projection and surface rendered reformats aided anatomical interpretation to a similar degree. The relative frequency of types of perihilar branching patterns and cystic duct junctional anatomy correlated closely to those reported from previous anatomical studies.

The purpose of this study was to evaluate the diagnostic potential of prolonged drip infusion CT cholangiography (DIC-CT) using meglumine iotroxate (Biliscopin) and 3D volume rendering in patients with suspected obstructive biliary disease. From a material of 142 patients who had undergone a drip infusion CT, all cases with a verified surgical or endoscopic retrograde cholangiography (ERC) diagnosis (n=33) were selected. Age-matched controls were selected from the remaining examinations. Three radiologists reviewed all 66 examinations in retrospect, independently as well as in consensus. The image quality and the estimated diagnostic quality were rated as good or moderate in 91% of the 198 reviews. The consensus sensitivity and specificity for diagnosing biliary stones was 88% and 94%, respectively (with sensitivities ranging from 88% to 94% for individual observers, and specificities from 86% to 96%). Two out of three strictures were observed. No false positive strictures were described. The use of volume rendering technique (VRT) improved diagnostic certainty in 28/198 (14%) of the evaluations. The visualization of ductal stones was improved in 18/48 (38%). No differences in diagnostic quality between single and multislice CT were observed. We conclude that a detailed image of the biliary tree with good sensitivity and specificity can be obtained by means of bilirubin-governed infusion time DIC-CT with volume rendering reconstruction.

The purposes of this study were to investigate the feasibility of drip infusion cholangiography computed tomography (CTCh) for choledocholithiasis and to compare the detection of the stone on CTCh with that of MR cholangiopancreatography (MRCP). CTCh examinations were performed after infusion of intravenous biliary contrast material (iotroxic acid meglumine, 100 ml) for patients with suspected biliary diseases and were reconstructed to maximum intensity projection (MIP) and multiplanar reformation (MPR). Of 432 patients who underwent CTCh, we identified 15 who underwent surgery or cholangioscopic removal for choledocholithiasis and 32 patients who underwent cholecystectomy due to cholecystolithiasis. Their MRCP images were compared with the CTCh images. The sensitivity and specificity of CTCh for detecting choledochal stones were 87% and 96% whereas those of MRCP were 80% and 88%. The sensitivity and specificity of CTCh for detecting gallstones were 78% and 100% whereas those of MRCP were 94% and 88%. CTCh allowed high sensitivity and specificity for detecting choledochal stones but diminished the detection for cholecystolithiasis compared with MRCP.

To determine the accuracy of computed tomographic intravenous cholangiography (CT-IVC) for detection of choledocholithiasis. Sixty-five patients undergoing endoscopic retrograde cholangiography (ERC) underwent CT-IVC prior to ERC, using a single detector helical CT following intravenous infusion of 100 ml iotroxate. Patients with bilirubin levels >3 times normal were excluded. ERC was indeterminate in three patients (4.7%) and CT-IVC in four (6.3%). Twenty-three patients had ductal calculi at ERC, and CT-IVC was positive in 22, with two false positives and one false negative: sensitivity 95.6%, specificity 94.3%. Stones were multiple in nine and solitary in 14. Of the 14 solitary stones, ten were

Objective: To assess the stability of doxorubicin combined with Radioselectan., Methods: Solutions of doxorubicin 5 mg/mL were prepared from commercially available 50 mg powder with 10 mL of Radioselectan. They were stored in glass syringes at 4, 25 and 45 degrees C. The concentrations of doxorubicin were determined using a stability-indicating high-performance liquid chromatography method. The initial and final pHs of solutions were compared. The times (t90) needed for doxorubicin to fall to 90% of its initial concentration were calculated by a linear regression analysis., Results: The t90 [95% confidence limits] were 79 [75-83], 56 [53-59] and 22 [21-23] hours for the solutions stored at 4, 25 and 40 degrees C respectively. The initial pH of the solutions stored at 4, 25 and 40 degrees C were 6.52, 6.50 and 6.51 respectively. The final pH of solutions stored at 25 and 40 degrees C decreased significantly by 0.3 and 0.9 respectively. No change of pH solution stored at 4 degrees C was observed., Conclusion: Doxorubicin combined with Radioselectan stored at room temperature is stable for 48 h.

Background/aims: It is important to recognize the distribution of the bile ducts in the caudate lobe of the liver for the hepato-biliary surgery. To map the spatial relationship between the bile ducts and the liver parenchyma under physiological conditions, we performed an anatomical analysis of them using computed tomography combined with drip infusion cholangiography (DIC-CT)., Methodology: We identified the bile ducts in the caudate lobe, which was divided into the Spiegel lobe, paracaval portion, and caudate process, with DIC-CT. We then investigated their number and confluence pattern in 132 patients without any abnormality in the hilar bile ducts., Results: The mean number of the bile ducts in the caudate lobe was 2.68 per liver. In the Spiegel lobe, the branches drained into the left hepatic duct system in about 83%. The confluence of the paracaval branch was the left hepatic duct, right hepatic duct, and posterior segmental branch, all with the same frequency of approximately 30%. Almost all of the caudate process branches (92.4%) drained into the posterior segmental branch., Conclusions: DIC-CT is a useful method for the anatomical analysis of the intrahepatic bile ducts under physiological conditions, and we obtained novel and important findings for surgery.

Background: We evaluated the feasibility and accuracy of virtual computed tomographic cholangiography (VCTC) in detecting choledocholithiasis and imaging anatomic variations of the biliary tree., Methods: Thirty-three consecutive patients with clinical and biological signs of choledocholithiasis underwent spiral CT after intravenous infusion of iotroxindimeglumine. Patients with total serum bilirubin levels above 3 mg/dL were not included in this study. Spiral data sets were used to construct intralumenal images of the biliary tree. The images were reviewed by two abdominal radiologists. The biliary ducts were divided into three segments, so the analysis was based on 99 segments. The diagnosis obtained by VCTC was compared with the final diagnosis established by endoscopic retrograde cholangiography or intraoperative cholangiography., Results: VCTC correctly depicted biliary stones in nine of 10 patients and anatomic variations in all five patients, and no false-positive cases were observed. VCTC showed excellent endolumenal visualization of 87 of 99 segments of the biliary tree. The processing time (9.3 +/- 2.1 min) was particularly short., Conclusion: VCTC with intravenous infusion of iotroxindimeglumine may be a feasible clinical tool, with acceptable accuracy in selected cases.

Objective: To validate multi-slice three-dimensional spiral CT cholangiography (3-D CTC) in clinical diagnosis of biliary diseases., Methods: This study included 146 patients with biliary diseases, involving 73 cases of biliary tumor, 87 cases of radioparent calculus, 12 cases of post cholangio-jejunostomy and one case of congenital choledochocyst. The data of thin-slice volumetric CT scan were sent to the workstation (GE Advantage Windows 3.1). Rational 3-D CTC including maximum intensity projection, minimum intensity projection, surface shaded display, CT virtual endoscopy and ray sumption was performed. The diagnostic accuracy of 3-D CTC was compared with that of conventional CT, ultrasonography and endoscopic retrograde cholangiopancreaticography (ERCP)., Results: Different biliary diseases showed distinct imaging manifestations on 3-D CTC. As a new technique for assessing the status of post cholangio-jejunostomy, 3-D CTC was superior to conventional CT, ultrasonography and ERCP in diagnosis of negative biliary calculus, extrahepatic cholangiocarcinoma, cancer embolus of the biliary duct, carcinoma of the pancreas head and periampullar carcinoma. It was also superior to conventional CT, ultrasonography or equal to ERCP in diagnosis of hilar cholangiocarcinoma, but inferior to conventional CT and ultrasonography in diagnosis of gallbladder cancer., Conclusion: 3-D CTC as a non-invasive and sensitive technique for the diagnosis of biliary diseases with high diagnostic accuracy will greatly increase the detection rate of biliary diseases.

A 57-year-old man was admitted to our hospital because of high fever and generalized tonic seizure. Brain magnetic resonance imaging (MRI) delineated multiple abnormal intensity areas. Thallium-201 (201Tl) scintigraphy revealed abnormal uptake in the brain. The imaging findings did not allow definitive exclusion of brain tumor, even though brain abscess was the more strongly suspected diagnosis. As the patient improved, the multiple abnormal intensity areas in the brain on MRI and the abnormal areas of accumulation on 201Tl scintigraphy were reduced, and eventually completely disappeared. A final diagnosis of brain abscess was therefore made. Since relatively few studies have reported 201Tl accumulation in cases of brain abscess, we report here our patient in whom the changes in the accumulation of 201Tl in a brain abscess were observed over time.

Purpose: The aim of this study was to demonstrate three-dimensional biliary anatomy by using spiral CT scanning for patients prior to laparoscopic cholecystectomy., Materials and Methods: We studied 22 patients (11 men, 11 women; mean age, 60 years) with preoperative imaging. All patients had normal serum bilirubin levels. Either 50 ml (in 10 cases) or 100 ml (in 12 cases) of meglumine iotroxate was infused intravenously over 30 minutes. Spiral CT scanning was started immediately after the infusion was finished. Volumetric data through the entire biliary tracts were obtained during one breath-hold. The data were reconstructed by using a maximum intensity projection algorithm and three-dimensional shaded surface rendering., Results: In all patients, the anatomical relationship between the cystic duct and the common bile duct was clearly depicted, including one with junctional anomaly. The intrahepatic biliary ducts and the confluence of the hepatic ducts were displayed from all angles. The third or higher intrahepatic branches were delineated in 11 of the 12 (92%) patients with the use of 100 ml of the cholangiographic agent and in seven of the 10 (70%) with 50 ml., Conclusion: Three-dimensional CT cholangiography was able to provide adequate information about precise biliary anatomy.

Objective: We describe the use of helical CT cholangiography or helical CT after administration of biliary i.v. contrast material to verify and localize bile duct leakage., Conclusion: Helical CT cholangiography revealed bile leaks in seven patients after penetrating trauma or liver or gallbladder surgery and excluded bile leaks in two patients with blunt liver trauma. Endoscopic retrograde cholangiography was performed in only one of seven patients with bile leakage and was avoided in an additional two patients in whom CT cholangiography excluded leakage. The method is a feasible, noninvasive tool for the detection and localization of bile leaks and may help avoid endoscopic retrograde cholangiography.

Objective: To compare MR and CT cholangiography (MRC and CTC) in evaluating the anatomy of the extrahepatic biliary tract and the pathology related to the gallbladder., Material and Methods: Twenty-three patients underwent MRC and CTC with a biliary contrast medium for investigation of biliary disease. 3D displays of both were also obtained. Endoscopic retrograde cholangiography was performed in 17 patients, and the pathology of all 23 was evaluated., Results: Overall, the image quality was higher with CTC than with MRC (4.7 vs 3.9, p < 0.05). The cystic duct was demonstrated better by CTC than MRC (p < 0.05). Multiplanar reformation (MPR) and source images provided additional information to that obtained from 3D MRC and CTC images. Gallstones were revealed in 6 patients by CTC and in 5 of these 6 by MRC. In 2 patients with cholecystitis, CTC demonstrated gallbladder wall thickening but MRC did not. In 3 patients with adenomyomatosis. MRC demonstrated Rokitansky-Aschoff sinuses (RAS) while CTC demonstrated focal gallbladder wall thickening in all 3 and RAS in 1 of them., Conclusion: Both MRC and CTC provided anatomical and pathological information about the biliary system. With both techniques, however, either MPR or source images proved necessary in addition for evaluating the biliary system anatomy and pathology. The gallbladder wall was depicted clearly in source CTC, but MRC is recommended for the evaluation of adenomyomatosis because it depicts RAS clearly.

Variations in the anatomy of intrahepatic bile ducts complicate operations in living related hepatic transplantation (LRHT). Preoperative delineation of the biliary system is important to achieve successful results. The purpose of this study was to assess the utility and accuracy of three-dimensional helical computed tomographic cholangiography (3DHCTC) as a replacement for endoscopic retrograde cholangiography (ERC) in evaluating the anatomy of the intersegmental biliary connection of the potential donors in LRHT. Helical CT was performed in 16 potential donors after a slow infusion of 100 cm3 meglumine iodipamide. By using the maximum intensity projection and shaded surface displaced image reconstruction technique, three-dimensional images of the bile ducts were isolated from the surrounding hepatic parenchyma. Among the 16 potential donors, 3 cases underwent an ERC study and another 7 cases donated liver graft during LRHT. In all 16 cases the anatomy of the bilateral essential intrahepatic ducts was well displayed with and without the liver parenchyma background in an axial and three-dimensional fashion which had good correlation with images from ERC and intra-operative cholangiography. Two variants were found, including drainage of the right posterior intrahepatic duct into the left hepatic duct and direct drainage of the segment II bile duct into the common hepatic duct, respectively. It is concluded that unusual routes of intrahepatic ducts may necessitate a change in the cutting plane during graft retrieval and patterns of ductoenteral anastomosis to avoid potential complications to both donors and recipients. With the advantages of non-invasiveness and comparable accuracy in demonstrating biliary anatomy, 3DHCTC may replace the traditional ERC in the pre-transplant survey of potential donors for LRHT.

Purpose: Evaluation of CT cholangiography compared to i.v. cholangiography concerning its diagnostic value before laparoscopic cholecystectomy and optimisation of CT cholangiography., Method: I.v. and CT cholangiographies of 54 patients were retrospectively evaluated by two radiologists. The time interval between contrast infusion and CT was correlated with the assessment of CT cholangiographies to detect the optimal timing for CT scanning., Results: CT cholangiography was judged to be generally better than i.v. cholangiography. The optimal time interval for CT scanning is between 30 min and 60 min post contrast infusion., Conclusion: CT cholangiography should replace the conventional tomograms if i.v. cholangiography does not yield sufficient depiction of the biliary tree. It should be performed within 60 min post contrast infusion. Complete abolishment of i.v. cholangiography is not warranted. This is due to the fact that conventional cholangiography can sufficiently delineate the biliary tree and thereby reduce x-ray exposure and cost compared to initial performance of CT cholangiography.

Purpose: To study the feasibility of using an iodinated particulate contrast agent, iodipamide ethyl ester (IDE), for angiography., Materials and Methods: IDE at doses of 40-100 mg of iodine per kilogram was diluted to a total volume of 5-20 mL and used for digital subtraction angiography in nine dogs under general anesthesia. Equivalent images were obtained by using water-soluble contrast medium (WSCM) for comparison (iohexol) in seven animals. All images were reviewed by blinded reviewers and graded subjectively on a five-point scale., Results: Angiographic studies of multiple vascular territories performed with IDE yielded images of slightly lower overall quality compared with images obtained with WSCM (P = .14, Mann-Whitney U test). Arterial phase images were subjectively superior with WSCM when compared with IDE (P < .0001, chi 2.) Depiction of the corresponding veins during the venous phase on the IDE angiograms was superior to that on WSCM angiograms in 12 of 21 cases, although this did not reach statistical significance (P > .05 chi 2). Images of the renal vein and portal vein achieved with IDE were graded as superior to those achieved with WSCM in eight of 10 reviews., Conclusion: Angiography is feasible with IDE. Compared with WSCM, IDE produced images of lesser quality during the arterial phase, but of equal or superior quality in the venous phase depending on the vessel studied. Because it is excreted slowly in bile and is isotonic, it may prove useful in patients with renal insufficiency, diabetes, multiple myeloma, or severe coronary disease.

Thirty-eight patients admitted for elective cholecystectomy were preoperatively evaluated by means of liver function tests, ultrasonographic examination and intravenous cholangiography (IVC). Common bile duct stones (CBS) were found in four patients (11%, 95% confidence limits 3-25%). Due to a history of jaundice and/or elevated liver function tests, CBS were suspected in three of these patients, and unexpected in one. Totally, CBS were suspected in eight patients, either because of their history and/or elevated liver function tests. No side effects were observed during or after the IVC procedure. It can be concluded that IVC is a lenient procedure for radiological assessment of the common bile duct prior to elective laparoscopic cholecystectomy. It can be recommended as an alternative to diagnostic endoscopic retrograde cholangiography in patients in whom CBS are suspected.

We describe CT findings of a case of mucin-hypersecreting papillary cholangiocarcinoma (MHPC), with extrahepatic bile leakage to the rectus abdominis muscle via the ligamentum teres hepatis forming an abdominal wall abscess. Endoscopic retrograde cholangiography was unsatisfactory. Spiral three-dimensional CT cholangiography was helpful in assessing the resectability of MHPC by offering anatomic details of the uninvolved biliary tree.

Rationale and Objectives: Eleven ionic and nonionic contrast media were compared in parallel regarding their effects on various biochemical parameters in vitro. Partition coefficient, protein binding, release of histamine, hemolysis inhibition and complement activation were determined as well as inhibition of various enzymes. Additionally, incompatibilities between contrast media and intravascular drugs that often are coadministered were determined., Methods: Partition coefficients were determined in the system n-butanol/water by spectrophotometry. Protein binding was measured by equilibrium dialysis. Histamine release from rat peritoneal mast cells was measured by radioassay. Hemolysis inhibition and complement activation was determined in beagle dog serum using antibody-coated sheep erythrocytes. The inhibition of enzyme systems was measured photometrically. Incompatibility with coadministered drugs was registered by appearance of precipitations., Results: Hydrophilicity as determined by partition coefficients was highest for iotrolan and lowest for iotetrol. Protein binding ranged from practically zero for most substances to 14% for ioxaglate. Histamine release was highest for diatrizoate (77% at 100 mg I/mL) and lowest for iodixanol (1%). Complement activation at 100 mg I/mL ranged from 0% (diatrizoate, iopamidol) to 77% (iopentol). The inhibition of the enzyme systems urokinase, streptokinase, collagenase, tissue plasminogen activator, and lysozyme was lowest for the nonionic dimers., Conclusions: All compounds influenced the parameters tested. However, the degree of interaction was different. Although there was no significant correlation between hydrophilicity (partition coefficient) or osmolality and the tested parameters, nonionic dimers seemed to be superior to nonionic monomers. The reason might lie in reduced chemotoxicity of this class of contrast media.

The preoperative diagnosis of choledocholithiasis simplifies the laparoscopic management of biliary tract disease. Slow infusion intravenous cholangiography (SI-IVC) may be an accurate and cost-effective screening test for choledocholithiasis, and it is safer than traditional intravenous cholangiography. Forty-nine patients underwent SI-IVCs for suspected choledocholithiasis. These patients subsequently had endoscopic retrograde cholangiograms (ERC) or intraoperative cholangiograms (IOC) during laparoscopic cholecystectomies. Sixteen SI-IVCs demonstrated choledocholithiasis; 13 were confirmed by ERCs or by IOCs. The remaining 33 patients with negative SI-IVCs had negative ERCs or IOCs. The sensitivity, specificity, and accuracy of detecting choledocholithiasis by SI-IVC were 100%, 92%, and 94%. Only one patient had a mild reaction to the contrast agent. In our hospital the cost of an SI-IVC is $324, the cost of an IOC is $393 (including operating room and anesthesia costs), and the cost of an ERC is $1,085. SI-IVC is an accurate method of preoperative screening for choledocholithiasis. It is safe and cost-effective.

Rationale and Objectives: We conducted a pilot study to determine the potential advantages of using liver-specific targeted computed tomography (CT) contrast agents for lesion detection., Methods: Eight dogs had liver infarcts created by percutaneous injections of ethanol. Each dog underwent CT scans with four imaging techniques: unenhanced, intravenous contrast enhanced (IVCE), CT arterial portography (CTAP), and targeted liver enhancement with iodipamide ethylester (IDE) particles. Lesions were assessed quantitatively to determine liver-to-lesion density differences and the drop in density across liver edge as a quantitative measure of edge sharpness. Expert readers subjectively analyzed data to determine lesion visibility and edge sharpness., Results: Liver-to-lesion density differences were greatest with CTAP (56.4 +/- 35.5 Hounsfield units [H]) followed by IDE (41.1 +/- 7.0 H), i.v. (22.7 +/- 6.0 H), and unenhanced scans (13.6 +/- 4.1 H; ps < .05 for CTAP versus unenhanced and IDE versus unenhanced). Edges were best defined both subjectively and quantitatively on IDE-enhanced scans., Conclusion: Targeted liver-specific contrast agents have potential to increase lesion visibility when compared with standard i.v. contrast enhancement of the liver by increasing lesion edge definition and liver-to-lesion attenuation differences. Further work in animal tumor models, and clinical trials as agents become available, appears justified.

We report here the operative findings, the incidence of successful laparoscopic treatment, and the perioperative complications in patients with nonvisualized gallbladder on drip infusion cholangiography (DIC). Eighty-five patients with a nonvisualized gallbladder on DIC were entered into the study. None of the patients had a minimal adhesive gallbladder; 51 to 85 patients (60.0%) had moderate adhesive gallbladders, and 34 (40.0%) had severely adhesive ones. The rate of successful laparoscopic treatment, including laparoscopy-assisted abdominal surgery, was 97.6% (83 of 85 patients). Perioperative complications occurred in only three patients (3.5%), and there were no deaths related to the operation. Thus, when patients with a nonvisualized gallbladder on DIC undergo laparoscopic cholecystectomy, meticulous procedures must be carried out; however, as the rate of successful laparoscopic treatment is high, cholecystectomy under laparoscopy is feasible for experienced surgeons.

Spiral computed tomography (SCT) is a recently introduced technique which enables scanning of one large volume with no interscan intervals. Three-dimensional reconstruction using this technique is emerging as an effective means of identifying complex anatomical relationships. Ninety-two patients with cholecystolithiasis including ten with choledocholithiasis were investigated. All underwent SCT after oral and intravenous infusion cholangiography (IVC-SCT) and 22 were also examined by endoscopic retrograde cholangiography (ERC). IVC-SCT showed significantly more anatomical detail than conventional intravenous infusion cholangiography (IVC). The junction between the cystic duct and the common bile duct could be identified before surgery in 19 of 22 patients undergoing ERC, in 18 of 22 receiving IVC-SCT and in five of 22 undergoing IVC. Significant differences were noted between IVC-SCT, ERC and conventional IVC. Three-dimensional surface reconstruction of the biliary tract is useful in the evaluation of anatomical relationships between the cystic duct and the common bile duct (clearly seen in 86 per cent of cases). Three-dimensional reconstruction using SCT scanning is useful for anatomical assessment before laparoscopic cholecystectomy.

Purpose: To determine whether helical computed tomography (CT) performed during intravenous cholangiography can provide useful images of the biliary tree and to compare this technique with endoscopic retrograde cholangiography (ERC)., Materials and Methods: Eighteen adult patients with clinically suspected biliary disease who were referred for ERC were first examined with helical CT cholangiography performed 75 minutes after intravenous infusion of 100 mL of 10.3% iodipamide meglumine., Results: Helical CT cholangiography revealed good opacification of the biliary tree in 13 of 14 patients with serum bilirubin levels less than 2 mg/dL (34 mumol/L) and poor opacification in three of four patients with levels greater than 2 mg/dL. In six of seven patients with choledocholithiasis, the diagnosis was made by means of helical CT cholangiography., Conclusion: Helical CT cholangiography may be a clinically useful method for visualization of the biliary tree in some patients with suspected biliary disease with normal bilirubin levels and in patients in whom attempts at ERC fail.

This study examines the role of intravenous cholangiography in the preoperative assessment of the first 100 patients considered for laparoscopic cholecystectomy at this institution. Intravenous cholangiography detected common bile duct (CBD) stones in 10 patients, of whom only five had a dilated CBD (> 8 mm). There were no cases of inadequate visualization of the CBD using IVC and no allergic reactions to the contrast medium. All CBD stones were confirmed by either endoscopic retrograde cholangiopancreatography (ERCP) or exploration of the CBD. There have been no cases of missed CBD stones during a follow-up period of 8 to 18 months. In contrast, ultrasound scanning was only able to detect one CBD stone, and there was a 14% incidence of inadequate visualisation of the CBD. Intravenous cholangiography is a safe, inexpensive, and highly accurate technique for assessing the CBD in patients undergoing laparoscopic cholecystectomy, with false-positive and false-negative rates of 0 in this study. The timing of the investigation permits preoperative clearance of the duct by ERCP and, should this fail, the option of a single procedure of open exploration of the CBD.

The purpose of this study was to verify and compare the different types of reactions to iodinated contrast media available at the Social Security Metropolitan Hospital Complex: Conray 60%, Vascoray and Uromiron. These are ionic, high osmolality compounds. The authors found that, in 400 patients not only the osmolality had an important role in the reactions observed, but that the intrinsic nature of the molecule of the contrast medium used was the determining factor.

Rationale and Objectives: Contrast-enhanced computed tomography (CT) images of canine renal cortex were analyzed to determine if the heterogeneous pixel intensity patterns met the requirements for fractal analysis and if the heterogeneity could be quantified by a fractal dimension, Df., Methods: Contrast-enhanced CT images were obtained after injection of iodipamide ethyl ester (IDE), a vascular marker, or iohexol, a freely filtered interstitial marker, into the catheterized renal artery of an anesthetized dog. Images were mounted on a graphics workstation for analysis. A computer program was written to determine the fractal dimension of the pixel-intensity pattern within selected regions., Results: All regions of renal cortex examined met the requirements for fractal analysis. Three seconds after injection of IDE, the mean fractal dimension decreased significantly from 1.21 +/- 0.05 to 1.12 +/- 0.06 (P < .05). Although the mean fractal dimensions were not significantly different, the variation in the fractal dimension around the renal cortex was significantly different with IDE as compared with iohexol at 3 seconds (P < .05). Differences in the change in fractal dimension over time were also observed with IDE as compared with iohexol., Conclusions: Fractal dimension measurement provides a new means to examine the in-vivo organization of renal vascular perfusion by quantifying pixel heterogeneity in contrast-enhanced CT. This may prove useful in understanding and quantifying the pathophysiologic changes in renal disease.

With the advent of laparoscopic cholecystectomy, pre-operative identification of calculi in the common bile duct has become increasingly important. In patients without clinical or biochemical evidence of common bile duct calculi, debate continues as to the value of intravenous cholangiography (IVC) as a screening modality for the detection of unsuspected choledocholithiasis. In a prospective series of 180 patients, IVC was used to assess the common bile duct in 113 patients at low risk of choledocholithiasis, 51 patients at high risk underwent endoscopic retrograde cholangiography (ERC) and sphincterotomy if indicated, and in 16 patients, for a variety of reasons, no pre-operative cholangiography was performed. 31% of those who had ERC and two (1.8%) of those who had IVC had duct calculi. These data do not support the routine use of IVC in patients with no evidence of common bile duct calculi and its routine use has been discontinued.

In previous work with the method of multiple indicator dilution (MID), we have established that a spatially distributed model of transcapillary exchange proposed by Goresky, Ziegler, and Bach (GZB) accurately describes, at the in vivo whole-organ level, the handling of extracellular indicators in the canine renal cortex. To date, however, it has not been possible to assess the key hypothesis that GZB corresponds to the actual local mechanism of exchange in vivo and is not just a compact summary of the kidney's average whole-organ behavior. By adapting the MID method to high speed computed tomography (CT), we are now able to report that the GZB mechanism is an accurate description of renal cortical transcapillary exchange down to volumes of cortical tissue comprising no more than a few per cent of the total cortical mass, i.e., containing no more than a few thousand nephrons. A small bolus of iohexol (radiopaque extracellular indicator) or iodipamide ethyl ester microparticles (radiopaque plasma indicator) injected into the renal artery was followed by CT as it passed through the kidney and into the renal vein. Time-attenuation value curves of the two contrast media obtained from the renal vein and from regions of interest in the cortex were then modeled with the GZB mechanism and with a more complex formulation that includes GZB as a limiting case. When applied to the data, the models converged to GZB as the best fit for each region examined. The GZB mechanism is found to provide excellent agreement with the regional data.

Intraoperative cholangiography during laparoscopic cholecystectomy has been considered to be a necessary examination because incidental injury to the common bile duct must be avoided. We performed 93 intraoperative drip infusion cholangiographies among 103 laparoscopic cholecystectomized patients as simple examinations by using iotroxic acid. The best drip infusion time was determined to be 20 min and good pictures were obtained from 10 to 60 min after the end of the drip. Nine patients with liver dysfunction and a poor radiograph had poor cholangiograms. Clear cholangiograms were obtained in 79 patients: four had a long remnant cystic duct and, in one case, a common bile duct stenosis was found by endoclip. The findings in these five cases helped us to correct failures during operation.

The results from a hysterographic study on women with bicornuate uterus are discussed. It is established that its frequency is 2.2% of 1623 performed hysterosalpingographies. A detailed analysis is made on the form and dimensions of the cornua [correction of corns], total isthmic part and cervical canal. Some metric parameters (height and width, sizes of the isthmus the an angle between the corns) are given with the purpose of greater precision of roentgenological interpretation.

Complex contact activation systems may have major involvement in side effects of i.v. contrast media. To investigate this, quantitative measurements of several factors (plasma prekallikrein, kallikrein inhibitory activity, haematocrit, alpha-2-macroglobulin, antithrombin III, alpha-1-antitrypsin and beta-thromboglobulin) were made before and after i.v. contrast phlebography in two groups of patients (each containing 21 patients) with no thrombosis, using a high- (meglumine iodamide) and a low-osmolality (ioxaglate) contrast medium. A statistically significant decrease in plasma prekallikrein was observed after the high-osmolality contrast medium, which is a sign of the activation of the kallikrein-kinin system and an indicator of the activation of the intrinsic coagulation. These events may play an important role in the adverse effects of contrast media.

After application of contrast media a rise in FT4 concentration was detected by use of the ultrafiltration method (Amicon) and the Dow-Lepetit method, especially after injection of Biliscopin, whereas the determination of FT4 concentration with the Amerlex method revealed a significant drop in FT4 concentration after contrast medium application. The results obtained with the Dow-Lepetit test have to be regarded as correct. The decrease detected by the Amerlex test is probably the result of a changed affinity of albumin to the labeled T4. Within 1 hr after application of contrast media blood for the determination of FT4 should not be collected.

The concentration of iodine in the bile of patients with indwelling T-tubes has been measured following administration of the new cholangiographic agent Iotroxamide. Studies have been performed after administration of the contrast agent by both 10 min bolus injection and 1 h drip infusion techniques. Comparison has been made with the iodine concentrations obtained after administration of equimolar amounts of Ioglycamide. There was no significant difference in the biliary iodine levels obtained with the two methods of administration when Iotroxamide was the contrast agent employed. However, with Ioglycamide the slow infusion technique produced higher iodine levels than the bolus injection method (P less than 0.05). Comparison between the two agents reveals that, whichever administration technique is used, Iotroxamide provides higher iodine levels than Ioglycamide. After bolus injection the superiority for Iotroxamide is in the region of 20% and after slow infusion is of the order of 10--15%. It is concluded that Iotroxamide is likely to prove superior to Ioglycamide as a cholangiographic agent. In terms of opacification of the biliary tree there is little to choose between bolus injection and slow infusion techniques when using Iotroxamide and the relative toxicity of the two techniques should be the major factor in determining which method is employed in clinical practice.

Losefamate, a hepatobiliary contrast agent, was encapsulated into liposomes to increase its ability to opacify the liver and spleen on computed tomographic (CT) images. Multilamellar lipid vesicles (lecithin, cholesterol, and stearylamine, in 4:1:1 molar ratio) containing iosefamate in their aqueous phase were prepared. Seven dogs received intravenous injections of 100-300 mg I/kg in one of three forms: encapsulated, unencapsulated, or a mixture of the two in equal parts. Animals that received the opaque vesicles had marked opacification of their livers, bile ducts, gallbladders, spleens (maximum 106 H enhancement), and gastrointestinal tracts. Spleen CT values (an indicator of encapsulated material uptake) were always higher in these dogs than in the animals receiving equivalent amounts of unencapsulated iosefamate alone. At the high-dose level, liver uptake of the encapsulated materials was also greater. Liposome-encapsulated hepatobiliary contrast agents are effective liver and spleen opacifiers for CT imaging in the dog.

The authors refer the results of a double blind hysterosalpingographic study with a traditional ionic contrast medium (Isteropac) and a new non-ionic one (B-15000). Both the contrast have provided good quality images, without significant intolerance. Moreover the new non-ionic contrast medium has shown an easier utero-tubal transit with a sensible reduction of the examination length and a better diagnostic result.

Rabbits pretreated with methylprednisolone acquired significant protection against an intravenous challenge of meglumine iodipamide. In comparison to controls, the pretreated rabbits showed moderate elevations of Factor XII, and rather striking elevations of C1-esterase inhibitor. Treated rabbits also showed significantly less granulocytosis. It is believed that the protective effect can be ascribed to the modulation of acute phase reactants by increased concentrations of C1-esterase inhibitor.

Radiologic contrast materials activate complement by both the classical and alternative pathways. This activation is time, dose, and temperature dependent and is able to proceed with equal facility in either the presence or absence of Ca++ or Mg++ chelating reagents (EGTA, EDTA). All the components examined (C1, C4, C2, Factor B, C3, and C5) were consumed during complement activation. Immune complexes are produced during interaction of serum with contrast materials. The activation of complement by contrast materials appears to be principally initiated by the activation of plasminogen to plasmin. Inhibition of plasminogen activators by epsilon-aminocaproic acid affects complement activation markedly.