989 resultados para Radionuclide Angiography
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Aims We conducted a meta-analysis to evaluate the accuracy of quantitative stress myocardial contrast echocardiography (MCE) in coronary artery disease (CAD). Methods and results Database search was performed through January 2008. We included studies evaluating accuracy of quantitative stress MCE for detection of CAD compared with coronary angiography or single-photon emission computed tomography (SPECT) and measuring reserve parameters of A, beta, and A beta. Data from studies were verified and supplemented by the authors of each study. Using random effects meta-analysis, we estimated weighted mean difference (WMD), likelihood ratios (LRs), diagnostic odds ratios (DORs), and summary area under curve (AUC), all with 95% confidence interval (0). Of 1443 studies, 13 including 627 patients (age range, 38-75 years) and comparing MCE with angiography (n = 10), SPECT (n = 1), or both (n = 2) were eligible. WMD (95% CI) were significantly less in CAD group than no-CAD group: 0.12 (0.06-0.18) (P < 0.001), 1.38 (1.28-1.52) (P < 0.001), and 1.47 (1.18-1.76) (P < 0.001) for A, beta, and A beta reserves, respectively. Pooled LRs for positive test were 1.33 (1.13-1.57), 3.76 (2.43-5.80), and 3.64 (2.87-4.78) and LRs for negative test were 0.68 (0.55-0.83), 0.30 (0.24-0.38), and 0.27 (0.22-0.34) for A, beta, and A beta reserves, respectively. Pooled DORs were 2.09 (1.42-3.07), 15.11 (7.90-28.91), and 14.73 (9.61-22.57) and AUCs were 0.637 (0.594-0.677), 0.851 (0.828-0.872), and 0.859 (0.842-0.750) for A, beta, and A beta reserves, respectively. Conclusion Evidence supports the use of quantitative MCE as a non-invasive test for detection of CAD. Standardizing MCE quantification analysis and adherence to reporting standards for diagnostic tests could enhance the quality of evidence in this field.
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OBJECTIVE: A giant fusiform aneurysm in the posterior cerebral artery (PCA) is rare, as is fenestration of the PCA and basilar apex variation. We describe the angiographic and surgical findings of a giant fusiform aneurysm in the P1-P2 PCA segment associated with PCA bilateral fenestration and superior cerebellar artery double origin. CLINICAL PRESENTATION: A 26-year-old woman presented with a 2-month history of visual blurring. Digital subtraction angiography showed a giant (2.5 cm) fusiform PCA aneurysm in the right P1-P2 segment. The 3-dimensional view showed a caudal fusion pattern from the upper portion of the basilar artery associated with a bilateral long fenestration of the P1 and P2 segments and superior cerebellar artery double origin. INTERVENTION: Surgical trapping of the right P1 -P2 segment, including the posterior communicating artery, was performed by a pretemporal approach. Angiograms performed 3 and 13 months after surgery showed complete aneurysm exclusion, and the PCA was permeated and filled the PCA territory. Clinical follow-up at 14 months showed the patient with no deficits and a return to normal life. CONCLUSION: To our knowledge, this is the first report of a giant fusiform aneurysm of the PCA associated with P1-P2 segment fenestration and other variations of the basilar apex (bilateral superior cerebellar artery duplication and caudal fusion). Comprehension of the embryology and anatomy of the PCA and its related vessels and branches is fundamental to the decision-making process for a PCA aneurysm, especially when parent vessel occlusion is planned.
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Introduction The perimedullary arteriovenous fistulas are located on the pial surface and are usually supplied by spinal medullary arteries, that is, either by the anterior or posterior spinal arteries, with no intervening nidus between the feeder arteries and the venous drainage. The clinical findings are, more commonly, caused by progressive radiculomedullary ischemic processes secondary to steal vascular mechanism. As the vascular supply to the spinal cord and to the arteriovenous fistulas (AVF) is not shared with one another, the vascular steal phenomenon cannot be implicated in this case`s physiopathology. Most probably, the mass effect caused by the giant venous dilatation was the pathophysiological mechanism involved in this lesion Case report The authors describe the case of a 6-year-old girl with an intradural ventral arteriovenous fistula, with a giant venous dilatation, fed directly by L2 and L3 radiculomedullary arteries at the conus medullaris. There was no arterial supply to the fistula from the anterior or posterior spinal arteries. Selective spinal angiography showed an arteriovenous fistula supplied directly by two radiculomedullary arteries, with a large draining vein caudally. Interposing the arterial and venous vessels was a giant venous aneurysmal dilatation located ventral to the conus medullaris and extending from L3 to T6. The patient was successfully treated by a surgical approach through a laminotomy from L3 to T11. Conclusion The type IV-C spinal arteriovenous malformations or perimedullary AVFs are rare lesions predominately described at the conus medullaris with various types of angio-architecture and controversial treatment.
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OBJECTIVE: We studied the angiographic findings in patients with small epidural hematomas and cranial fractures crossing over the trajectory of the middle meningeal artery and its branches. Additionally, the Occurrence of traumatic vascular lesions and their clinical relevance and treatment are discussed. METHODS: A consecutive analysis was performed for 24 patients who harbored small epidural hematomas in middle meningeal artery topography associated with cranial fractures. Computed tomographic scans and plain x-ray studies were used to diagnose linear cranial fractures. Patients with large epidural hematomas or associated traumatic lesions were excluded from the study. Selective ipsilateral external carotid angiograms were obtained, and an endovascular procedure was performed if any vascular injury was evidenced. RESULTS: In all patients with cranial fractures crossing over the middle meningeal artery and its branches, some kind of vascular lesion was seen. Two types of findings were noted: active extravasation of the contrast medium (71%) and pseudoaneurysms (29%). Early filling of diploic vessels was found in 8.3% of fractures concomitantly with active extravasation. Embolization was performed in all patients. No additional enlargement of the epidural hematoma was observed, and the postoperative period was uneventful. CONCLUSION: This study shows that pseudoaneurysms and active extravasation of contrast are common findings in this subset of patients. Although the natural history of these lesions is still poorly understood, additional investigation with ipsilateral external carotid angiography may be recommended, considering the potentially catastrophic consequences of late rupture.
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Purpose: To describe the presence of iris neovascularization in a rabbit-model of retinal neovascularization induced by the intravitreal injection of latex-derived angiogenic fraction microspheres (LAF). Materials and Methods: Eight New Zealand rabbits received one intravitreal injection of PLGA (L-lactide-coglycolide) microspheres with 50 ug of LAF in the right eye (Group A). Microspheres without the LAF (0.1 ml) were injected in controls (Group B; n = 8). Follow-up with clinical evaluation and iris fluorescein angiography was performed after 4 weeks when eyes were processed for light microscopy. Results: All eyes from Group A showed significant vascular dilation, conjunctival hyperemia and neovascularization on the iris surface, after LAF injection. No vascular changes were observed in Group B. Conclusions: The intravitreal injection of microspheres containing the LAF can induce rubeosis iridis in rabbits and could be used as a simple experimental model for iris neovascularization.
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Purpose: To create a retinal neovascularization experimental model using intravitreal injection of microspheres loaded with latex-derived angiogenic fraction. Methods: Thirty-two albino New Zealand rabbits, divided in 4 groups of 8 animals, were enrolled in this study. Rabbits in groups I, II, and III received one intravitreal injection of PLGA (L-lactide-co-glycolide) microspheres with 10, 30, and 50 mu g of latex-derived angiogenic fraction into their right eyes, respectively, and group IV received 0.1 ml of microspheres without the angiogenic fraction. Weekly follow-up with ophthalmoscopy and fluorescein angiography was performed; the rabbits were sacrificed in the 4th week and their eyes processed for light microscopy. Results: All eyes from group I demonstrated increased retinal vascular tortuosity, observed from 14 days after injection and maintained for 28 days, otherwise without new vessels detection. All group II eyes showed vascular changes similar to group I. Fifty percent of the eyes from group II rabbits developed retinal neovascularization 21 days after injection. All eyes from group III demonstrated significant vascular tortuosity and retinal new vessels 2 weeks after injection, progressing to fibrovascular proliferation and tractional retinal detachment. No vascular changes or retinal new vessels were observed in group IV eyes. Light microscopy confirmed the existence of new vessels previously seen on fluorescein angiography, in retinal sections adjacent to the optic disc, not observed in sections at the same area in the control group. Conclusion: Thirty- and 50-mu g microspheres containing latex-derived angiogenic fraction injected into the vitreous cavity induced retinal neovascularization in rabbits.
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Background. Bilioduodenal (BD) and biliojejunal (BJ) derivation induce enterobiliary reflux and bile stasis. Decompression of the excluded loop of the Roux-en-Y (BJD) was proposed to minimize these effects. The aim of this study was to compare the influence of these three modalities of biliary bypass on hepatic lesion repair in rats with secondary biliary fibrosis. Materials and Methods. Rats with 15 d of biliary obstruction underwent BD, BJ, and BJD drainage and were compared with a group submitted to simulated operation (SO) and biliary obstruction (CBO). The serum values of total and fractional bilirubin, alkaline phosphatase (ALP), and aminotransferases (AST and ALT), as well as hepatobiliointestinal excretion determined with (99m)Tc-Disida, were used for comparison. In addition, we used morphometric analyses to estimate the mass of the hepatocytes, bile ducts, and liver fibrosis. We also counted hepatic stellate cells (SC). Results. For each of the three modalities of biliary drainage, there were significant reductions in bilirubin, AST, ALP, and the number of SCs. The recovery of the estimated mass of all histologic components occurred only after BJ and BJD; in the BD group, the estimated hepatocyte mass was reduced compared with the SO group. The residual hepatic radioactivity of (99m)Tc-Disida was greater in the BJD group than in the SO group. Conclusions. The interposition of the jejunal loop between the biliary tree and the intestine may slow hepatobiliary clearance of radioactivity, even though it provides the resolution of cholestasis and is effective in recovering from hepatic lesions. (C) 2011 Elsevier Inc. All rights reserved.
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Purpose: The purpose of our study was to compare signal characteristics and image qualities of MR imaging at 3.0 T and 1.5 T in patients with diffuse parenchymal liver disease. Materials and methods: 25 consecutive patients with diffuse parenchymal liver disease underwent abdominal MR imaging at both 3.0 T and 1.5 T within a 6-month interval. A retrospective study was conducted to obtain quantitative and qualitative data from both 3.0 T and 1.5 T MRI. Quantitative image analysis was performed by measuring the signal-to-noise ratios (SNRs) and the contrast-to-noise ratios (CNRs) by the Students t-test. Qualitative image analysis was assessed by grading each sequence on a 3- and 4-point scale, regarding the presence of artifacts and image quality, respectively. Statistical analysis consisted of the Wilcoxon signed-rank test. Results: the mean SNRs and CNRs of the liver parenchyma and the portal vein were significantly higher at 3.0 T than at 1.5 T on portal and equilibrium phases of volumetric interpolated breath-hold examination (VIBE) images (P < 0.05). The mean SNRs were significantly higher at 3.0 T than at 1.5 T on T1-weighted spoiled gradient echo (SGE) images (P < 0.05). However, there were no significantly differences on T2-weighted short-inversion-time inversion recovery (STIR) images. Overall image qualities of the 1.5 T noncontrast T1- and T2-weighted sequences were significantly better than 3.0 T (P < 0.01). In contrast, overall image quality of the 3.0 T post-gadolinium VIBE sequence was significantly better than 1.5 T (P< 0.01). Conclusions: MR imaging of post-gadolinium VIBE sequence at 3.0 T has quantitative and qualitative advantages of evaluating for diffuse parenchymal liver disease. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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Background: Most cases of congenital clubfoot treated with the Ponseti technique require percutaneous Achilles tenotomy to correct the residual equinus. Clinical evidence suggests that complete healing occurs between the cut tendon stumps, but there have not yet been any detailed studies investigating this reparative process. This study was performed to assess Achilles tendon repair after percutaneous section to correct the residual equinus of clubfoot treated with the Ponseti method. Method: A prospective study analyzed 37 tenotomies in 26 patients with congenital clubfoot treated with the Ponseti technique, with a minimum follow-up of 1 year after the section. The tenotomy was performed percutaneously with a large-bore needle bevel with patient sedation and local anesthesia. Ultrasonographic scanning was performed after section to ascertain that the tenotomy had been completed and to measure the stump separation. In the follow-up period, the reparative process was followed ultrasonographically and assessed at 3 weeks, 6 months, and 1 year posttenotomy. Results: The ultrasonography performed immediately after the procedure showed that in some cases, residual strands between the tendon ends persisted, and these were completely sectioned under ultrasound control. A mean retraction of 5.65 mm +/- 2.26 mm (range, 2.3 to 11.0 mm) between tendon stumps after section was observed. Unusual bleeding occurred in one case and was controlled by digital pressure, with no interference with the final treatment. After 3 weeks, ultrasonography showed tendon repair with the tendon gap filled with irregular hypoechoic tissue, and also with transmission of muscle motion to the heel. Six months after tenotomy, there was structural filling with a fibrillar aspect, mild or moderate hypoechogenicity, and tendon scar thickening when compared with a normal tendon. One year after tenotomy, ultrasound showed a fibrillar structure and echogenicity at the repair site that was similar to a normal tendon, but with persistent tendon scarring thickness. Conclusions: There is a fast reparative process after Achilles tendon percutaneous section that reestablishes continuity between stumps. The reparative tissue evolved to tendon tissue with a normal ultrasonographic appearance except for mild thickening, suggesting a predominantly intrinsic repair mechanism.
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Objectives Alterations in the enzymes involved in homocysteine (Hcy) metabolism or vitamin deficiency could play a role in coronary artery disease (CAD) development. This study investigated the influence of MTHFR and MTR gene polymorphisms, plasma folate and MMA on Hcy concentrations and CAD development. MMA and folate concentrations were also investigated according to the polymorphisms. Methods Two hundred and eighty-three unrelated Caucasian individuals undergoing coronary angiography (175 with CAD and 108 non-CAD) were assessed in a case-control study. Plasma Hcy and MMA were measured by liquid chromatography/tandem mass spectrometry. Plasma folate was measured by competitive immunoassay. Dietary intake was evaluated using a nutritional questionnaire. Polymorphisms MTHFR and MTR were investigated by polymerase chain reaction (PCR) followed by enzyme digestion or allele-specific PCR. Results Hcy mean concentrations were higher in CAD patients compared to controls, but below statistical significance (P = 0.246). Increased MMA mean concentrations were frequently observed in the CAD group (P = 0.048). Individuals with MMA concentrations > 0.5 mu mol/l (vitamin B(12) deficiency) were found only in the CAD group (P = 0.004). A positive correlation between MMA and Hcy mean concentrations was observed in both groups, CAD (P = 0.001) and non-CAD (P = 0.020). MMA mean concentrations were significantly higher in patients with hyperhomocysteinemia in both groups, CAD and non-CAD (P = 0.0063 and P = 0.013, respectively). Folate mean concentration was significantly lower in carriers of the wild-type MTHFR 1298AA genotype (P = 0.010). Conclusion Our results suggest a correlation between the MTHFR A1298C polymorphism and plasma folate concentration. Vitamin B(12) deficiency, reflected by increased MMA concentration, is an important risk factor for the development both of hyperhomocysteinemia and CAD.
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PURPOSE: To evaluate the effects of intravitreal bevacizumab in patients with diabetic macular edema (DME) associated with severe capillary loss. DESIGN: Multicenter, open-label, nonrandomized study. METHODS: SETTING: Two tertiary ophthalmic referral centers in Brazil. STUDY POPULATION: Ten consecutive patients with DME and ""severe"" capillary loss. OBSERVATION PROCEDURES: Intravitreal injection(s) of bevacizumab (1.5 mg). Standardized ophthalmic evaluation was performed at baseline and at weeks 8, 16, 24, and 54. MAIN OUTCOME MEASURES: Changes in best-corrected visual acuity (BCVA) and in optical coherence tomography variables (central macular thickness [CMT] and total macular volume [TMV]). RESULTS: Significant changes in BCVA and in CMT/TMV were noted throughout the study (P<.001, P=.009, and P<.001, respectively). The mean logarithm of the minimal angle of resolution Early Treatment Diabetic Retinopathy Study BCVA was 0.786 (similar to 20/125(+1)) at baseline, 0.646 (similar to 20/80(-2)) at week 8, 0.580 (20/80(+1)) at week 16, 0.574 (similar to 20/80(+1)) at week 24, and 0.558 (similar to 20/80(+2)) at week 54. Compared with baseline, a significant change in BCVA was noted at all follow-up visits (P <=.008). The mean CMT/TMV values were, respectively, 472.6/10.9 at baseline, 371.4/9.9 at week 8, 359.5/9.8 at week 16, 323.9/9-4 at week 24, and 274.6/8.7 at week 54. Compared with baseline, a significant change in both CMT and TMV was noted only at 24 and 54 weeks (P <=.007). At 54 weeks, fluorescein angiography demonstrated no change in the extent of macular capillary loss and reduced dye leakage as compared with baseline in all patients. CONCLUSIONS: Favorable changes in BCVA and in CMT/TMV observed throughout 1 year suggest that intra-vitreal bevacizumab may be a viable alternative treatment for the management of patients with DME and severe capillary loss. (Am J Ophthalmol 2009;147:1022-1030. (C) 2009 by Elsevier Inc. All rights reserved.)
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Background: This in vivo study assessed and compared the effectiveness of an aqueous indocyanine green (ICG) formulation (R-ICG) and a lipid ICG formulation (L-ICG) in occluding the rabbit choriocapillaris, and determined the singlet oxygen quantum yields and aggregation properties of both formulations in vitro. Methods: Singlet oxygen production and aggregation were compared. The eye fundus of 30 albino rabbits was irradiated 0-15 min after dye injection using an 810 nm diode laser. Fluorescein angiography and light microscopy were used to evaluate the safety and efficacy of R-ICG and L-ICG. Results: L-ICG decreased the dimerisation constant and the tendency of ICG to form aggregates, and increased the efficiency of ICG in generating singlet oxygen (R-ICG, Phi Delta= 0.120 and L-ICG, Phi Delta= 0.210). Using a 10 mg/kg dose, choriocapillaris occlusion was achieved at a light dose of 35.8 J/cm(2) with L-ICG and 71.6 J/cm(2) with R-ICG with minimal damage to the neurosensory retina. Conclusion: Restrictions to the use of ICG in aqueous solution, low singlet oxygen quantum yields and high aggregation tendency, were overcome with L-ICG. The lower laser irradiance required to obtain choriocapillaris occlusion may suggest that L-ICG is a more potent and selective photosensitiser than R-ICG.
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Purpose: To evaluate the short-term (10 months) safety of a single intravitreal injection of autologous bone marrow-derived mononuclear cells in patients with retinitis pigmentosa or cone-rod dystrophy. Methods: A prospective, Phase I, nonrandomized, open-label study including 3 patients with retinitis pigmentosa and 2 patients with cone-rod dystrophy and an Early Treatment Diabetic Retinopathy Study best-corrected visual acuity of 20/200 or worse. Evaluations including best-corrected visual acuity, full-field electroretinography, kinetic visual field (Goldman), fluorescein and indocyanine green angiography, and optical coherence tomography were performed at baseline and 1, 7, 13, 18, 22, and 40 weeks after intravitreal injection of 10 X 10(6) autologous bone marrow-derived mononuclear cells (0.1 mL) into 1 study eye of each patient. Results: No adverse event associated with the injection was observed. A 1-line improvement in best-corrected visual acuity was measured in 4 patients 1 week after injection and was maintained throughout follow-up. Three patients showed undetectable electroretinography responses at all study visits, while 1 patient demonstrated residual responses for dark-adapted standard flash stimulus (a wave amplitude approximately 35 mu V), which remained recordable throughout follow-up, and 1 patient showed a small response (a wave amplitude approximately 20 mu V) recordable only at Weeks 7, 13, 22, and 40. Visual fields showed no reduction (with a Goldman Standard V5e stimulus) for any patient at any visit. No other changes were observed on optical coherence tomography or fluorescein and indocyanine green angiograms. Conclusion: Intravitreal injection of autologous bone marrow-derived mononuclear cells in eyes with advanced retinitis pigmentosa or cone-rod dystrophy was associated with no detectable structural or functional toxicity over a period of 10 months. Further studies are required to investigate the role, if any, of autologous bone marrow-derived mononuclear cell therapy in the management of retinal dystrophies. RETINA 31: 1207-1214, 2011
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Moyamoya disease (MMD) is an uncommon cerebrovascular disorder characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. Direct and indirect bypass techniques have been devised with the aim of promoting neoangiogenesis. The current study aimed to investigate the role of multiple cranial burr hole (MCBH) operations in the prevention of cerebral ischemic attacks in children with MMD. Seven children suffering from progressive MMD were submitted to the MCBH and arachnoid opening technique. Ten to 20 burr holes were drilled in the fronto-temporo-parieto-occipital area of each hemisphere in each patient, depending on the site and extent of the disease. All patients were evaluated pre- and postoperatively by means of Barthel index (BI), CT, MR, angio-MR, and angiography. Patients had no recurrence of ischemic attacks postoperatively. Neoangiogenesis was observed in both hemispheres. One patient developed a persistent subdural collection after surgery, thus requiring placement of a subdural-peritoneal shunt. Postoperative BI was statistically significantly improved (P = 0.02). This report suggests that MCBH for revascularization in MMD is a simple procedure with a relatively low risk of complications and effective for preventing cerebral ischemic attacks in children. In addition, MCBH may be placed as an adjunct to other treatments for MMD.