Comparison of gray-scale contrast-enhanced ultrasonography with contrast-enhanced computed tomography in different grading of blunt hepatic and splenic trauma: an animal experiment

To compare the diagnostic value of contrast-enhanced ultrasonography (CEUS) with contrast-enhanced computed tomography (CECT) for the detection of different grading of solid organ injuries in blunt abdominal trauma in animals. A self-made miniature tools were used as models to simulate a blunt hepatic or splenic trauma in 16 and 14 anesthetized dogs, respectively. Baseline ultrasound, CEUS and CECT were used to detect traumatic injuries of livers and spleens. The degree of injuries was determined by CEUS according to the American Association for the Surgery of Trauma (AAST) scale and the results compared with injury scale based on CECT evaluation. CEUS showed 22 hepatic injury sites in 16 animals and 17 splenic injury sites in other 14 animals. According to AAST scale, 2 grade I, 4 grade II, 3 grade III, 5 grade IV and 2 grade V hepatic lesions were present in 16 animals; 2 grade I, 4 grade II, 6 grade III and 2 grade IV splenic lesions in 14 animals. On CECT scan, 21 hepatic and 17 splenic injuries were demonstrated. According to Becker CT scaling for hepatic injury, 1 grade I, 2 grade II, 4 grade III, 5 grade IV and 2 grade V hepatic injuries were present. On the basis of Buntain spleen scaling, 2 grade I, 5 grade II, 5 grade III, 2 grade IV splenic injuries were showed. After Spearman rank correlation analysis, the agreement of CEUS with CECT on the degree of hepatic and splenic injury is 93.3% and 92.9%, respectively. CT is currently considered as the reference method for grading blunt abdominal trauma, according to experiment results, CEUS grading showed high levels of concordance with CECT. CEUS can accurately determine the degree of injury and will play an important role in clinical application.

Utility of contrast-enhanced endoscopic ultrasonography for diagnosis of small pancreatic carcinomas

The aim of our study was to assess the utility of endoscopic ultrasonography (EUS) and contrast-enhanced EUS (CE-EUS) for the depiction and differential diagnosis of pancreatic tumors focusing in particularly those 2 cm or smaller. We compared different diagnostic procedures, contrast-enhanced multidetector computed tomography (CE-CT) and EUS with the use of power Doppler (PD-EUS) and CE-EUS for detection and differential diagnosis of pancreatic tumors. The study included 156 consecutive patients with suspected pancreatic tumors, who underwent CE-CT, and EUS followed by PD-EUS and CE-EUS. CE-EUS was performed by power Doppler mode using sonographic contrast agent Levovist. Thirty-six of 156 patients examined had tumors of < or =2 cm. EUS had significantly higher sensitivity (94.4%) for detection of pancreatic carcinomas of 2 cm or less in comparison to CE-CT (50%). For small pancreatic tumor of 2 cm or less, sensitivities for differentiating ductal carcinomas from other tumors were 50.0%, 11.0% and 83.3% for CE-CT, PD-EUS and CE-EUS. CE-EUS was significantly more sensitive than PD-EUS and CE-CT. EUS and subsequent CE-EUS are more sensitive than CE-CT in the detection and the differentiation of small pancreatic tumors.

Efficacy of pre-scan beta-blockade and impact of heart rate on image quality in patients undergoing coronary multidetector computed tomography angiography

OBJECTIVE

While beta-blockers are routinely administered to patients prior to coronary computed tomography angiography (CTA), their effectiveness is unknown. We therefore assessed the efficacy of beta-blockade with regards to heart rate (HR) control and image quality in an unselected patient cohort.

METHODS

We studied 150 consecutive patients (104 men/46 female; mean age, 56+/-13 years) referred for coronary CTA. Intravenous metoprolol (5-20mg) was administered to patients with a HR >65 beats per minute (bpm). The goal HR was defined as an average HR <65 bpm without a single measurement above 68 bpm.

RESULTS

Overall, 45% (68/150) of patients met the HR criteria for beta-blocker administration of which 76% (52/68) received metoprolol (mean dose 12+/-10mg). Of the 52 patients who received beta-blocker versus the 98 who did not, 18 (35%) versus 62 (64%) patients achieved the goal HR, respectively. All patients who achieved the target HR had an evaluable CTA while five patients who did not achieve the target HR had at least one non-evaluable coronary artery due to motion artifact. There was also a significant reduction in any motion artifact among those who achieved the goal HR as compared to those who did not (p=0.001). Logistic regression revealed an increase in the odds of stair step artifact of 11.6% (95% CI: 2.4% decrease, 27.5% increase) per 1 bpm increase in the standard deviation of scan HR.

CONCLUSION

Overall, efficacy of beta-blocker administration to reach target HR is limited. Improvements in CT scanner temporal resolution are mandatory to achieve consistently high image quality independent of HR and beta-blocker administration.

In vivo peritoneal surface area measurement in rats by micro-computed tomography (microCT)

Peritoneal dialysis (PD) uses the dynamic dialysis properties of the peritoneal membrane. The fraction of the anatomic peritoneal surface area (PSA) recruited is of importance for maximizing exchanges and is potentially impacted by parameters such as fill volume. We describe an in vivo assessment of the contact surface area by micro-computed tomography (microCT) using an iodinated contrast medium added to the PD fluid, a contrast agent presumed without surfactant property. In the isotropic volume (reconstructed voxel size 186 microm x 186 microm x 186 microm), the iodinated PD fluid is automatically selected, thanks to its contrast difference with soft tissues, and its surface area is computed. The method was first tested on phantoms showing the ability to select the PD fluid volume and to measure its surface area. In vivo experiments in rat consisted of microCT acquisition of rat abdomen directly after intraperitoneal administration (10 mL/100 g rat body weight) of a dialysis fluid containing 10% by volume iodinated contrast agent. Fluorescein isothiocyanate albumin was used as dilution marker. We found a strong linear relationship (R(2) = 0.98) between recruited PSA (cm(2)) and rat weight (g) in the range of 235 to 435 g: recruited PSA = (1.61 weight + 40.5) cm(2). Applying microCT with a fill volume of 10 mL/100 g rat body weight, the in vivo measured PSA was in the order of magnitude of the ex vivo anatomic PSA as determined by Kuzlan's formula, considered in most instances as the maximal surface area that can be recruited by PD fluid. This new methodology was the first to give an in vivo high-resolution isotropic three-dimensional (3-D) determination of the PSA in contact with dialysate. Its sensitivity allows us to take into account the recruitment of fine 3-D structures of the PSA membrane that were not accessible to previous 2-D-based imaging methodologies. Its in vivo application also integrates the physiological natural tensile stress of tissues.

Endovascular treatment of anastomotic pseudoaneurysms after aorto-iliac surgical reconstruction

PURPOSE

To assess the effectiveness of endovascular treatment of anastomotic pseudoaneurysms (APAs) following aorto-iliac surgical reconstruction.

MATERIALS

We retrospectively evaluated 21 men who, between July 2000 and March 2006, were observed with 30 APAs, 13 to the proximal anastomosis and 17 to the distal anastomosis. The patients had had previous aorto-iliac reconstructive surgery with a bypass due to aneurysm (15/21) or obstructive disease (6/21). The following devices were used: 12 bifurcated endoprostheses, 2 aorto-monoiliac, 4 aortic extenders, 1 stent-graft leg, and 2 covered stents. Follow-up was performed with CT angiography at 1, 3, and 6 months after the procedure and yearly thereafter.

RESULTS

Immediate technical success was 100%. No periprocedural complications occurred. Four patients died during follow-up from causes not related to APA, and 1 (treated for prosthetic-enteric fistula) from sepsis 3 months after the procedure. During a mean follow-up of 19.7 months (range 1-72 months), 2 of 21 occlusions of stent-graft legs occurred 3 and 24 months after the procedure (treated with thrombolysis and percutaneous transluminal angioplasty and femorofemoral bypass, respectively) and 1 type I endoleak. Primary clinical success rate was 81% and secondary clinical success was 91%.

CONCLUSION

Endovascular treatment is a valid alternative to open surgery and can be proposed as the treatment of choice for APAs, especially in patients who are a high surgical risk. Further studies with larger series and longer follow-up are necessary to confirm the long-term effectiveness of this approach.

Pancreas allografts: comparison of three-dimensional rotational angiography with standard digital subtraction angiography

PURPOSE

To define the role of three-dimensional (3D) rotational angiography (RA) for the evaluation of pancreas allografts and compare 3D RA to standard digital subtraction angiography (DSA).

MATERIALS AND METHODS

DSA and 3D RA were performed in patients with vascular abnormalities diagnosed on contrast medium-enhanced magnetic resonance (MR) angiography. Patency of the allograft vasculature, confidence in the ability to make a therapeutic decision, and value of the study for definition of the optimal projection for an intervention was assessed on a graded scale.

RESULTS

Seventeen standard DSA projections (mean, 3.4; range, 2-6) and 10 3D RA images (mean, 2; range, 1-3) were obtained in five patients. An average iodinated contrast agent dose of 14.4 mL (range, 8-22 mL) was administered for DSA. An average CO2 dose of 54 mL (range, 0-120 mL) was administered for 3D RA. Five 3D RA procedures were timed for the arterial phase and five were timed for the arterial and venous phases. Average contrast agent doses were 17.6 mL (range, 11-22 mL) for arterial 3D RA and 24.4 mL (range, 16-34 mL) for arterial- and venous-phase 3D RA. Of 68 vascular segments available for direct comparison of patency, complete concordance was present in 96%. There was no difference in the reviewers' diagnostic confidence (10 +/- 0 for both techniques). Three-dimensional RA was considered significantly superior for planning the optimal projection for intervention (10 +/- 0 for 3D RA vs 7.2 +/- 1.6 for DSA; P = .0052).

CONCLUSIONS

Three-dimensional RA of pancreatic allografts is feasible and does not differ in accuracy from conventional DSA. It provides similar reviewer confidence in the ability to make an accurate treatment decision, but its key advantage is its superior ability to define the optimal projection for planned endovascular interventions.

Fractionation of subcellular membrane vesicles of epithelial and nonepithelial cells by OptiPrep density gradient ultracentrifugation

Density gradient ultracentrifugation (DGUC) is widely used for physical isolation (enrichment rather than purification) of subcellular membrane vesicles. It has been a valuable tool to study specific subcellular localization and dynamic trafficking of proteins. While sucrose has been the main component of density gradients, a few years ago synthetic OptiPrep (iodixanol) began being used for separation of organelles because of its iso-osmotic property. Here, we describe a detailed protocol for density gradient fractionation of various mammalian subcellular vesicles, including endoplasmic reticulum (ER), Golgi apparatus, endosomes, and lipid rafts, as well as apical and basolateral membranes of polarized epithelial cells.

Multislice CT angiography in the selection of patients with ruptured intracranial aneurysms suitable for clipping or coiling

Introduction

We sought to establish whether CT angiography (CTA) can be applied to the planning and performance of clipping or coiling in ruptured intracranial aneurysms without recourse to intraarterial digital subtraction angiography (IA-DSA).

Methods

Over the period April 2003 to January 2006 in all patients presenting with a subarachnoid haemorrhage CTA was performed primarily. If CTA demonstrated an aneurysm, coiling or clipping was undertaken. IA-DSA was limited to patients with negative or inconclusive CTA findings. We compared CTA images with findings at surgery or coiling in patients with positive CTA findings and in patients with negative and inconclusive findings in whom IA-DSA had been performed.

Results

In this study, 224 consecutive patients (mean age 52.7 years, 135 women) were included. In 133 patients (59%) CTA demonstrated an aneurysm, and CTA was followed directly by neurosurgical (n = 55) or endovascular treatment (n = 78). In 31 patients (14%) CTA findings were categorized as inconclusive, and in 60 (27%) CTA findings were negative. One patient received surgical treatment on the basis of false-positive CTA findings. In 17 patients in whom CTA findings were inconclusive, IA-DSA provided further diagnostic information required for correct patient selection for any therapy. Five ruptured aneurysms in patients with a nonperimesencephalic SAH were negative on CTA, and four of these were also false-negative on IA-DSA. On a patient basis the positive predictive value, negative predictive value, sensitivity, specificity and accuracy of CTA for symptomatic aneurysms were 99%, 90%, 96%, 98% and 96%, respectively.

Conclusion

CTA should be used as the first diagnostic modality in the selection of patients for surgical or endovascular treatment of ruptured intracranial aneurysms. If CTA renders inconclusive results, IA-DSA should be performed. With negative CTA results the complementary value of IA-DSA is marginal. IA-DSA is not needed in patients with negative CTA and classic perimesencephalic SAH. Repeat IA-DSA or CTA should still be performed in patients with a nonperimesencephalic SAH.

ECG-gated chest CT angiography with 64-MDCT and tri-phasic IV contrast administration regimen in patients with acute non-specific chest pain

The purpose of this study was to evaluate chest CTA protocol using retrospective ECG-gating and triphasic IV contrast regimen for comprehensive evaluation of patients with acute non-specific chest pain. ECG-triggered dose modulation was used with a 64-MDCT scanner in 56 non-critically ill patients with acute nonspecific chest pain using triphasic IV regimen: 50 ml contrast followed by 50 ml 60% contrast/saline and 30 ml normal saline. Lungs, aorta, pulmonary and coronary arteries were graded on a 5-point scale (5, best). Aorta and pulmonary artery attenuation was measured and three coronary artery groups were evaluated. Comparison with invasive coronary angiography was obtained in nine patients on a per segment (16 total) basis. Dosimetry values were obtained. Studies were satisfactory in all patients (score >3). Aorta and pulmonary artery attenuation was >200 HU in 90.5%. Lung or pleura, non-cardiac vascular and coronary arteries disease were detected in 20, 11 and 16 patients, respectively. Median coronary angiography (grade 5) was significantly higher than acceptable for diagnosis grade 4 (p < 0.001). Per segment, weighted kappa statistic was 0.79 indicating substantial agreement with catheter angiography (p<0.001). Average DLP was 1,490 +/- 412 mGy-cm. Gated 64-MDCT angiography with triphasic IV contrast is a robust multipurpose technique for patients with acute non-specific chest pain.

Definitive exclusion of biliary atresia in infants with cholestatic jaundice: the role of percutaneous cholecysto-cholangiography

Definitive exclusion of biliary atresia in the infant with cholestatic jaundice usually requires operative cholangiography. This approach suffers from the disadvantage that sick infants are subjected to a time-consuming and potentially negative surgical exploration. The purpose of this study was to determine if percutaneous cholecystocholangiography (PCC) prevents unnecessary laparotomy in infants whose cholestasis is caused by diseases other than biliary atresia. This study is a 10 year retrospective review of all infants with persistent direct hyperbilirubinemia and inconclusive biliary nuclear scans who underwent further evaluation for suspected biliary atresia. A gallbladder ultrasound (US) was obtained in all patients. When the gallbladder was visualized, further imaging by PCC was done under intravenous sedation; otherwise, the standard operative cholangiogram (OCG) was performed, with liver biopsy as indicated. The primary outcome was the diagnostic accuracy of PCC, especially with respect to preventing a laparotomy. There were 35 infants with suspected biliary atresia, with a mean age of 8 weeks (range 1-14 weeks). Nine infants whose gallbladder was visualized by ultrasound underwent PCC that definitively excluded biliary atresia. Of this group, the most frequent diagnosis (five patients) was total parenteral nutrition-associated cholestasis. The other 26 infants with absent or decompressed gallbladder had laparotomy and OCG, which identified biliary atresia in 16 patients (61%). Laparotomy was avoided in all 9 patients who underwent PCC, thus reducing the negative laparotomy rate by 47%. There were no complications associated with PCC. Several alternative techniques to operative cholangiogram have been described for the definitive exclusion of biliary atresia, but many of these have distinct drawbacks. Advances in interventional radiology techniques have permitted safe percutaneous contrast evaluation of the biliary tree. Identification of a normal gall bladder on sonogram is highly predictive of the absence of biliary atresia. Further confirmation can be accurately obtained by a combination of PCC and percutaneous liver biopsy.

Computerized analysis of digital subtraction angiography: a tool for quantitative in-vivo vascular imaging

The purpose of our study was to develop a user-independent computerized tool for the automated segmentation and quantitative assessment of in vivo-acquired digital subtraction angiography (DSA) images. Vessel enhancement was accomplished based on the concept of image structural tensor. The developed software was tested on a series of DSA images acquired from one animal and two human angiogenesis models. Its performance was evaluated against manually segmented images. A receiver's operating characteristic curve was obtained for every image with regard to the different percentages of the image histogram. The area under the mean curve was 0.89 for the experimental angiogenesis model and 0.76 and 0.86 for the two clinical angiogenesis models. The coordinates of the operating point were 8.3% false positive rate and 92.8% true positive rate for the experimental model. Correspondingly for clinical angiogenesis models, the coordinates were 8.6% false positive rate and 89.2% true positive rate and 9.8% false positive rate and 93.8% true positive rate, respectively. A new user-friendly tool for the analysis of vascular networks in DSA images was developed that can be easily used in either experimental or clinical studies. Its main characteristics are robustness and fast and automatic execution.

Infection scintigraphy: added value of single-photon emission computed tomography/computed tomography fusion compared with traditional analysis

PURPOSE

Positron emission tomography (PET)/computed tomography (CT) imaging is a powerful dual-modality integrating physiology and anatomy. Analogously, fusing separate single-photon emission computed tomography (SPECT) and CT images can overcome interpretive challenges in characterizing and localizing abnormalities. This study explores the value of SPECT/CT image fusion compared with traditional "side-by-side" SPECT-CT image review for infectious /inflammatory processes.

METHODS AND MATERIALS

We identified 17 abnormal infection/inflammation SPECT scans in 16 patients (11 indium 111 WBC and 6 gallium citrate Ga 67) with a contemporary CT scan. The SPECT and CT images were uploaded onto "side-by-side" workstations, one with fusion software. Two nuclear radiologists reviewed "side-by-side" SPECT and CT images and fused SPECT/CT images. They scored 2 parameters (anatomical localization and diagnostic confidence) using a 4-point scale (1 "not helpful" to 4 "very helpful"). Score differences more than 1 indicated "added value" and less than 0, "no added value".

RESULTS

Compared with "side-by-side" SPECT-CT, fused SPECT/CT images yielded "added value" for anatomical localization in 65%, diagnostic confidence in 71%, and altered interpretations in 47% of cases. Greater confidence was achieved in 75% of cases with altered interpretations and 55% of unaltered cases.

CONCLUSIONS

The SPECT/CT image fusion outperformed "side-by-side" SPECT/CT review for anatomical localization and diagnostic confidence of infectious/inflammatory abnormalities. Therefore, SPECT/CT fusion potentially influences clinical decisions and treatment options.

Triphasic dynamic CT findings of 63 hepatic focal nodular hyperplasia in 46 patients: correlation with size and pathological findings

BACKGROUND

To correlate the dynamic computed tomography (CT) of hepatic focal nodular hyperplasia (FNH) with its size and pathology.

METHODS

The clinical data, pathological and dynamic CT findings of 36 FNHs in 24 males and 27 lesions in 22 females were reviewed. The pathological and CT findings of the 32 small FNHs (diameter < 3 cm) and 31 large FNHs (diameter >or= 3 cm) were compared and analyzed.

RESULTS

All FNHs were hypervascular at arterial phase except for central scarring. The mean diameter of FNHs with hypoattenuating, isoattenuating, hyperattenuating on delayed scans were 5.05 cm, 3.06 cm, and 2.70 cm, respectively (p = 0.026). As compared with small FNHs, large ones were significantly more likely to reveal central scarring (p = 0.005), vascular displacement (p < 0.001), and abnormal vessels around lesions (p < 0001). Coexistent bile ductile proliferation and bridging septa were more commonly observed in small FNHs (p = 0.028 for both). FNHs without aberrant vessels tended to feature hyperattenuating during the portal venous phase (p = 0.041).

CONCLUSIONS

FNHs with different tumor sizes may manifest various dynamic CT findings that are more or less related to the different pathological findings.

Angiographic frequency of blunt cerebrovascular injury in patients with carotid canal or vertebral foramen fractures on multidetector CT

PURPOSE

Blunt carotid injuries (BCI's) and blunt vertebral artery injuries (BVI's), known jointly as BCVI's, are common in "high risk" patients. The purpose is to evaluate the rate of occurrence of BCI/BVI in patients screened purely by the radiologic criteria of fracture through the carotid canal or vertebral transverse foramina, or significant cervical subluxation, noted by multidetector CT.

METHODS

Seventy-one patients with 108 catheterized vessels were included over a 13-month interval. The angiographic examinations were prompted by current hospital protocol, solely by the presence of fractures involving/adjacent to the carotid canal, cervical fractures involving/adjacent to the foramen transversarium, or cervical fractures with significant subluxation. The incidence of each grade of blunt injury was calculated after review of the CT scans and catheter angiograms by two neuroradiologists.

RESULTS

Two thousand and seventy-three total blunt trauma admissions occurred during the time period, with a BCVI rate of 0.92-1.0% (depending on the reviewer), similar to previous studies. Mean time to catheter angiography was 16.6 h. Of the 71 included patients, there were 11-12 BCI's and 10-12 BVI's, an overall rate of 27-30% of BCVI in the patients with foraminal fractures. Interobserver agreement in reviewing the catheter angiograms was excellent (Kappa 0.795). Of note, three internal carotid pseudoaneurysms resolved spontaneously after anticoagulation or aspirin.

CONCLUSION

This study confirms that there is a high rate of BCVI in the presence of carotid canal or vertebral foramen fractures that are noted by multidetector CT. Utilization of purely radiologic criteria of foraminal involvement may be a significant screening tool in the decision of whether to evaluate these patients acutely by catheter or CT angiography, and for early detection of patients at risk for symptomatology, to initiate prompt, prophylactic treatment.

The use of iodixanol for the purification of rat pancreatic islets

Transplantation of pancreatic islets is a promising therapeutic treatment for type 1 diabetes mellitus. For clinical and experimental transplantation, a large number of pure pancreatic islets are required for transplantation. Thus, the improvement of islet isolation and purification techniques are crucial. In this context, iodixanol-based solution, successfully used for the purification of porcine islets, seems to be a possible alternative to Ficoll for purification of islets. The aim of this study was to test the efficacy of iodixanol compared with Ficoll density gradients for the purification of rat pancreatic islets. Twelve Wistar rats were used for isolation and purification of pancreatic islets. Pancreata were digested with Liberase R1 and islets purified by two gradients: Ficoll or iodixanol gradient. The number and the purity of the pancreatic islets were assessed. To analyze the response of isolated pancreatic islet to glucose challenge, in vitro experiments were performed by measuring the insulin concentration in the Supernatant. The results demonstrated that the iodixanol gradient provided a higher purity of pancreatic islets compared to the Ficoll gradient. In addition, the rat islet yield by iodixanol gradient was significantly higher compared to a Ficoll gradient (751 +/- 16 versus 464 +/- 19 pancreatic islets, respectively; P < .001). The viability of pancreatic islets isolated by an iodixanol gradient was confirmed by high glucose challenge, with more than twofold higher increase in insulin secretion. The present study demonstrated that iodixanol density gradient overcomes Ficoll density gradient, providing a greater number of pure and functional rat pancreatic islets.

64 MDCT in multiple trauma patients: imaging manifestations and clinical implications of active extravasation

The finding of active hemorrhage on computed tomography (CT) in trauma patients has been shown to have significant clinical implications and has been incorporated into numerous CT grading schema. As CT technology has advanced, the sensitivity for detection of active hemorrhage in the trauma population has significantly improved. Currently, with the improved spatial and temporal resolution afforded by 64 multidetector computed tomography (64 MDCT) technology, the clinical implications of the CT findings of active extravasation may need to be reconsidered. This article illustrates the various imaging manifestations of active extravasation throughout the body using 64 MDCT. Additionally, protocol issues specific to the findings of active hemorrhage using 64 MDCT are detailed, including novel interpretation techniques, which offer aid in detecting and characterizing hemorrhage. Finally, the clinical implication of active extravasation using this new technology is discussed. Although more sensitive to the detection of small hemorrhagic foci and with clinical implications highly dependent upon location, active bleeding remains as a salient finding that affects subsequent clinical management of trauma patients.

Image quality of the aortic and mitral valve with CT: relative versus absolute delay reconstruction

RATIONALE AND OBJECTIVE

The purpose of this study was to compare image quality and artifacts of 16-detector row CT imaging of the aortic and mitral valve when performing ECG-gated synchronization using relative and absolute reconstructions.

MATERIALS AND METHODS

Cardiac CT was performed in 22 consecutive patients; 20 data sets per RR interval were reconstructed with relative and absolute reconstructions. Mean and variability of heart rate during data acquisition were noted. Two readers assessed contrast media-related artifacts, calcification-related artifacts, ECG gating-related artifacts, and image quality in parallel and perpendicular planes.

RESULTS

Contrast media-related and calcification-related artifacts similarly occurred with both reconstruction techniques. ECG gating-related artifacts occurred in both valves more often with relative reconstructions than with absolute reconstructions (p = .001). Image quality was significantly better for absolute reconstructions for the open aortic cusp surface (p = .014) and edge (p = .008) in both planes, and of the closed mitral valve leaflets (p = .003) and apposition zone (p = .003) in perpendicular planes. Occurrence of ECG gating-related artifacts in both valves significantly correlated (p = .01) with heart rate variability for relative reconstructions, whereas no correlation was found using the absolute technique.

CONCLUSION

Absolute reconstructions allow CT imaging of the aortic and mitral valve with fewer artifacts and are less sensitive to heart rate variability as compared to relative reconstructions.

Spectrum of biliary abnormalities in hepatic hereditary hemorrhagic telangiectasia: demonstration by multidetector computed tomography

We present a case in which multidetector computed tomography demonstrated a specific pattern of biliary disease associated with hepatic hereditary hemorrhagic telangiectasia: multiple intrahepatic stenoses, focal cystic dilatations along the course of the intrahepatic ducts, and large biliary cysts in conjunction with a normal-appearing extrahepatic bile duct.

Intradiscal corticosteroid injections in spondylotic cervical radiculopathy

The purpose of this study was to evaluate treatment outcomes with intradiscal injection of corticosteroids (IDIC) in cervical spondylotic radiculopathy. Twenty consecutive patients were treated with intradiscal injection of 25 mg of acetate of prednisolone under fluoroscopic control. All patients had previously received a nonsurgical treatment for at least 3 months without success. Outcomes were assessed 1, 3 and 6 months after IDIC. Radicular pain reduction as scored on a visual analogue scale (VAS 100-mm length) was statistically significant at 1 month (19.0+/-28.0 mm; p=0.008), 3 months (25.2+/-27.5 mm; p=0.002), and 6 months (24.6+/-28.4 mm; p=0.001). In all, 40% of treated patients described at least 50% pain improvement 6 months after treatment. Four patients had complete relief of radicular pain. In conclusion, IDIC should be an alternative in the nonsurgical management of cervical spondylotic radiculopathy.

Superior sensitivity of angiographic detection of arteriovenous fistula after biopsy in a renal allograft with CO2 compared with iodinated contrast medium

Arteriovenous (AV) fistulas are potential complications of renal transplant biopsy procedures. In the setting of renal transplant failure, angiography with CO2 as a contrast agent is a useful adjunct to angiography with conventional contrast medium in the diagnosis and treatment of such fistulas with minimal nephrotoxicity. The present report describes a case of a renal transplant AV fistula seen after biopsy that could be detected angiographically only with CO2 contrast medium.

Evaluation of a cushioned method for centrifugation and processing for freezing boar semen

The purpose of this investigation was to evaluate the use of an iodixanol cushion during centrifugation on sperm recovery and yield after centrifugation (sperm recovery, sperm motility, viability, membrane lipid disorder, acrosome reaction and ROS generation); and to investigate how this procedure affects sperm function after freezing-thawing (sperm motility, membrane lipid disorder, acrosomal status and homologous in vitro penetration test). The sperm-rich fractions from fertile boars were centrifuged under two centrifugation régimes: 800xg for 10min (standard method) and 1000xg for 20min with an iodixanol (60% w/v) cushion at the bottom of the centrifuge tubes (Cushion method). The highest recovery was achieved using the cushion method (sperm loss for cushion method was 0.50%+/-0.18 versus 2.97%+/-0.43 for standard method, P<0.01) and sperm quality was not significantly affected by the centrifugation régime. The motion parameters (% progressive motility, % motility, VCL, VSL, VAP, ALH, BCF, P<0.05) of frozen-thawed samples showed higher values using the standard method. However, a higher number of viable spermatozoa with lower lipid disorders were found in spermatozoa processed with the cushion method. The in vitro penetration assay showed that the individual boar influenced the parameters studied but there were no differences between the two centrifugation régimes used. Our results support the hypothesis that the proportion of sperm loss in frozen-thawed semen was significantly influenced by the centrifugation régime. Therefore, the iodixanol cushion method is a suitable tool for cryopreservation of boar semen in order to reduce sperm loss without affecting sperm quality.

Exceptional localization of extramedullary hematopoiesis: presacral and periureteral masses

We report an exceptional case of periureteral and presacral localizations of extramedullary hematopoiesis. To our knowledge, the association of presacral or periureteral masses has not been described before. Diagnosis was suggested by the association of computed tomography (CT) imaging findings and knowledge of the clinical context. Guided CT biopsy is a safe and efficient means to obtain final diagnosis of atypical extramedullary hematopoiesis localizations.