Although autopsy studies have demonstrated valves in 28-70% of right and 4-36% of left renal veins, they have rarely been detected or described during life. In an analysis of 98 renal venograms, valves were found in 16% of patients on the right side and in 15% on the left, without predilection for any particular location. Angiographically, they appeared as thin, web-like structures which may block passage of the catheter or of contrast material, and hence cause poor venographic filling. Rarely, valves produce total obstruction to the retrograde flow of contrast material.
A forty-four-year-old woman was evaluated for filling defects in the renal pelvis by intravenous pyelography and was found to have varicosities of the renal vein by renal vein angiography.
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Invest Radiol. ;15 (2):129-33 7372422
Balloon-occlusion superior mesenteric arteriography for improved visualization of the mesenteric and portal venous anatomy of dogs.
The superior mesenteric arteries of twelve dogs were occluded with an inflated balloon on the tip of an endhole catheter while diatrizoate meglumine and diatrizoate sodium (Renografin 76) was injected distal to the occlusion. The balloon was immediately deflated at the end of contrast injection. Films taken over a 33-second period showed consistently excellent visualization of the mesenteric arteries and veins as well as the portal veins. Comparison with studies performed by the conventional, nonocclusion technique confirmed the superiority of the films obtained with the balloon occlusion method. Histologic examination of the mesenteric artery at the site of balloon inflation and of the small and large bowel revealed no abnormalities.
To determine the incidence of renal vein varices, an analysis of 132 consecutive renal venograms was performed. Varices were found in 8 patients (6%), always on the left side. Four were solitary, and four represented a dilated venous network adjacent to the renal pelvis and upper ureter. Only a single patient had hematuria attributed to renal vein varices. It is concluded that varices in association with hematuria cannot be assumed to be causative; they may equally well be incidental findings.
Renal venography: anatomy, technique, applications, analysis of 132 venograms, and a review of the literature.
Selective renal venography is a simple but important diagnostic procedure which has few complications. A thorough knowledge of renal venous anatomy is essential for its proper performance and clinical application. This is particularly true because renal venous variations are frequent and may interfere with the successful appraoch to retroperitoneal surgery. The method is widely accepted for the evaluation of the renal venous bed in patients with suspected renal vein thrombosis or hematuria of unknown etiology. It depicts the extent of renal venous involvement in renal carcinoma and clarifies the diagnosis in some patients with avascular tumors, renal pelvic carcinoma, and retroperitoneal tumors. It may also be useful in defining the morphologic abnormality when the kidney fails to visualize on urography, in delineating the extent and nature of renal parenchymal disease, and in enhancing the precision of renal vein renin collection.
Balloon occlusion superior mesenteric arteriography for improved venous opacification: a clinical trial.
Balloon occlusion superior mesenteric arteriography and nonocclusion superior mesenteric arteriography were compared prospectively and retrospectively for adequacy of mesenteric and portal venous visualization. Prospective, occlusion studies in 20 patients were uniformly judged of excellent visual quality, while retrospectively, only 30% of nonocclusion studies from 20 other patients were considered optimal. In 10 of the patients who had balloon occlusion superior mesenteric arteriography, the procedure was preceded by a control nonocclusion superior mesenteric arteriography study. In only two (20%) patients was the nonocclusion study rated of excellent visual quality. Each study was assessed a rating of 0-3, according to how well the mesenteric and portal venous system visualized. Prospectively, all 20 balloon occlusion superior mesenteric arteriography studies were given the highest obtainable rating (3). Retrospectively, only six (30%) 20 nonocclusion superior mesenteric arteriography studies received a rating of 3; hence, 14 (70%) of the nonocclusion studies were rated less than excellent in visual quality when looked at retrospectively. No complications occurred with balloon occlusion superior mesenteric arteriography, and the occlusion procedure consistently gave excellent visualization of the mesenteric and portal venous anatomy.
A left circumaortic renal vein was found in 11% of 74 left renal venograms, an incidence similar to that at autopsy. Cavography proved to be an unsatisfactory method of demonstrating the renal veins. Prior knowledge of a venous ring is important when blood samples from the adrenal or renal veins are to be collected. When caval interruption is planned, a circumaortic venous ring may provide a fully developed collateral pathway immediately after surgery if the procedure is planned without awareness of its presence.
N Filippini, L D Nickerson, C F Beckmann, K P Ebmeier, G B Frisoni, P M Matthews, S M Smith, C E Mackay
University Department of Psychiatry, Oxford, UK.
Several studies have demonstrated age-related regional differences in the magnitude of the BOLD signal using task-based fMRI. It has been suggested that functional changes reflect either compensatory or de-differentiation mechanisms, both of which assume response to a specific stimulus. Here, we have tested whether ageing affects both task-based and resting brain function, and the extent to which functional changes are mediated by reductions in grey matter (GM) volume. Two groups, of 22 healthy younger and 22 older volunteers, underwent an imaging protocol involving structural and functional MRI, both during a memory task and at rest. The two groups had similar socio-demographical characteristics and cognitive performance. Image analysis revealed both structural and functional differences. Increased BOLD signal in older relative to younger volunteers was mainly observed in the frontal lobes, both during the task and at rest. Functional changes in the frontal lobes were largely located in brain regions spared from GM loss, and adding GM covariates to the fMRI analysis did not significantly alter the group differences. Our results are consistent with the suggestion that, during normal ageing, the brain responds to neuronal loss by fine-tuning connections between spared neurons. Longitudinal studies will be necessary to fully test this hypothesis.
Department of Psychology, Royal Holloway, University of London, London, UK.
Recent research has characterized the anatomical connectivity of the cortico-cerebellar system - a large and important fibre system in the primate brain. Within this system, there are reciprocal projections between the prefrontal cortex and Crus II of the cerebellar cortex, which both play important roles in the acquisition and execution of cognitive skills. Here, we propose that this system also plays a particular role in sustaining skilled cognitive performance in patients with Relapsing-Remitting Multiple Sclerosis (RRMS), in whom advancing neuropathology causes increasingly inefficient information processing. We scanned RRMS patients and closely matched healthy subjects while they performed the Paced Auditory Serial Addition Test (PASAT), a demanding test of information processing speed, and a control task. This enabled us to localize differences between conditions that change as a function of group (group-by-condition interactions). Hemodynamic activity in some patient populations with CNS pathology are not well understood and may be atypical, so we avoided analysis strategies that rely exclusively on models of hemodynamic activity derived from the healthy brain, using instead an approach that combined a ;model-free' analysis technique (Tensor Independent Component Analysis, TICA) that was relatively free of such assumptions, with a post-hoc 'model-based' approach (General Linear Model, GLM). Our results showed group-by-condition interactions in cerebellar cortical Crus II. We suggest that this area may have in role maintaining performance in working memory tasks by compensating for inefficient data transfer associated with white matter lesions in MS.
N Filippini, K P Ebmeier, B J MacIntosh, A J Trachtenberg, G B Frisoni, G K Wilcock, C F Beckmann, S M Smith, P M Matthews, C E Mackay
University Department of Psychiatry, University of Oxford, Oxford, UK.
Increasing age and carrying an APOE ε4 allele are well established risk factors for Alzheimer's disease (AD). The earlier age of onset of AD observed in ε4-carriers may reflect an accelerated aging process. We recently reported that APOE genotype modulates brain function decades before the appearance of any cognitive or clinical symptoms. Here we test the hypothesis that APOE influences brain aging by comparing healthy ε4-carriers and non-carriers, using the same imaging protocol in distinct groups of younger and older healthy volunteers. A cross-sectional factorial design was used to examine the effects of age and APOE genotype, and their interaction, on fMRI activation during an encoding memory task. The younger (N=36; age range 20-35; 18 ε4-carriers) and older (35 middle-age/elderly; age range 50-78 years; 15 ε4-carriers) healthy volunteers taking part in the study were cognitively normal. We found a significant interaction between age and ε4-status in the hippocampi, frontal pole, subcortical nuclei, middle temporal gyri and cerebellum, such that aging was associated with decreased activity in e4-carriers and increased activity in non-carriers. Reduced cerebral blood flow was found in the older ε4-carriers relative to older non-carriers despite preserved grey matter volume. Overactivity of brain function in young ε4-carriers is disproportionately reduced with advancing age even before the onset of measurable memory impairment. The APOE genotype determines age-related changes in brain function that may reflect the increased vulnerability of ε4-carriers to late-life pathology or cognitive decline.
Division of Experimental Medicine, Imperial College London, London, W12 0NN, United Kingdom.
Stopping an action in response to an unexpected event requires both that the event is attended to, and that the action is inhibited. Previous neuroimaging investigations of stopping have failed to adequately separate these cognitive elements. Here we used a version of the widely used Stop Signal Task that controls for the attentional capture of stop signals. This allowed us to fractionate the contributions of frontal regions, including the right inferior frontal gyrus and medial frontal cortex, to attentional capture, response inhibition, and error processing. A ventral attentional system, including the right inferior frontal gyrus, has been shown to respond to unexpected stimuli. In line with this evidence, we reasoned that lateral frontal regions support attentional capture, whereas medial frontal regions, including the presupplementary motor area (pre-SMA), actually inhibit the ongoing action. We tested this hypothesis by contrasting the brain networks associated with the presentation of unexpected stimuli against those associated with outright stopping. Functional MRI images were obtained in 26 healthy volunteers. Successful stopping was associated with activation of the right inferior frontal gyrus, as well as the pre-SMA. However, only activation of the pre-SMA differentiated stopping from a high-level baseline that controlled for attentional capture. As expected, unsuccessful attempts at stopping activated the anterior cingulate cortex. In keeping with work in nonhuman primates these findings demonstrate that successful motor inhibition is specifically associated with pre-SMA activation.
D C Glahn, A M Winkler, P Kochunov, L Almasy, R Duggirala, M A Carless, J C Curran, R L Olvera, A R Laird, S M Smith, C F Beckmann, P T Fox, J Blangero
Olin Neuropsychiatry Research Center, Institute of Living, Hartford Hospital, Hartford, CT 06106.
The default-mode network, a coherent resting-state brain network, is thought to characterize basal neural activity. Aberrant default-mode connectivity has been reported in a host of neurological and psychiatric illnesses and in persons at genetic risk for such illnesses. Whereas the neurophysiologic mechanisms that regulate default-mode connectivity are unclear, there is growing evidence that genetic factors play a role. In this report, we estimate the importance of genetic effects on the default-mode network by examining covariation patterns in functional connectivity among 333 individuals from 29 randomly selected extended pedigrees. Heritability for default-mode functional connectivity was 0.424 +/- 0.17 (P = 0.0046). Although neuroanatomic variation in this network was also heritable, the genetic factors that influence default-mode functional connectivity and gray-matter density seem to be distinct, suggesting that unique genes influence the structure and function of the network. In contrast, significant genetic correlations between regions within the network provide evidence that the same genetic factors contribute to variation in functional connectivity throughout the default mode. Specifically, the left parahippocampal region was genetically correlated with all other network regions. In addition, the posterior cingulate/precuneus region, medial prefrontal cortex, and right cerebellum seem to form a subnetwork. Default-mode functional connectivity is influenced by genetic factors that cannot be attributed to anatomic variation or a single region within the network. By establishing the heritability of default-mode functional connectivity, this experiment provides the obligatory evidence required before these measures can be considered as endophenotypes for psychiatric or neurological illnesses or to identify genes influencing intrinsic brain function.
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Department of Cardiology, Children's Hospital Boston and Pediatrics, Harvard Medical School, Boston, MA, USA.
OBJECTIVE: In patients with a left-sided congenital diaphragmatic hernia (CDH), the left ventricle (LV) is often compressed and smaller than normal. The objective of this study was to investigate whether small left heart dimensions prenatally normalize after birth in patients with CDH, or whether prenatal indices of left heart size and flow predict postnatal outcome. METHODS: Clinical and echocardiographic data were reviewed for patients diagnosed with left-sided CDH prenatally. Cardiac dimensions and flows were compared with normative data. Among liveborn patients, pre- and postnatal Z-scores of left heart structures were compared, and associations between prenatal indices and outcome were assessed. RESULTS: Of 125 patients diagnosed prenatally with CDH, 111 had a left-sided defect. Of these, 85 were liveborn, including 20 with congenital heart disease. Gestational age-adjusted dimensions of fetal left heart structures, including aortic valve diameter, mitral valve (MV) diameter, LV long-axis, LV short-axis and LV volume, were all smaller than normal (P < 0.001). On average, the LV contributed 33 +/- 8% of combined ventricular output, lower than the normal 40-50%. Z-scores of left heart structures increased from the prenatal echocardiogram to the postnatal study, with average changes ranging from 0.56 +/- 1.68 (aortic valve) to 1.39 +/- 1.85 (LV volume). Among liveborn patients, there was no association between prenatal left heart Z-scores and postnatal survival. CONCLUSIONS: Hypoplasia of and reduced flow through the left heart are common among fetuses with CDH. After birth and CDH repair, left heart dimensions generally normalize, with adequate size to support a biventricular circulation, even when there is very low flow through the left heart in mid- and late-gestation. Copyright (c) 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Department of Cardiology (Drs. Calderon, Guerrero, Medina, Mesa, and Rozo), Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030; and the Corbic Research Foundation-HMUA (Dr. Mesa), Envigado, Colombia.
Accessory mitral valve is a rare congenital abnormality and an unusual cause of subvalvular obstruction of the left ventricular outflow tract. Accessory mitral valves are usually detected in children due to symptomatic obstruction; isolated nonobstructive accessory mitral valve is rarely seen in adults. We describe the echocardiographic diagnosis of accessory mitral valve as an isolated congenital anomaly not associated with a substantial degree of obstruction of the left ventricular outflow tract in an asymptomatic adult patient. This case highlights the importance of transthoracic and transesophageal echocardiography in the diagnosis and follow-up of this uncommon congenital anomaly.
Comparison of a new polytetrafluoroethylene-covered metallic stent to a noncovered stent in canine ureters.
Hwan-Hoon Chung, Seung Hwa Lee, Sung Bum Cho, Hong Suk Park, Young Sik Kim, Byung Chul Kang, Joan K Frisoli, Mahmood K Razavi
Department of Radiology, Ansan Hospital, Korea University College of Medicine, Gojan Dong 516, Ansan City, Kyonggido 425-707, South Korea. firstname.lastname@example.org
The aim of this study was to determine the feasibility of using a newly designed polytetrafluoroethylene (PTFE)-covered metallic stent in the ureter by comparing its effectiveness with that of the noncovered stent in a canine model. We placed 14 stents in the ureters of seven mongrel dogs that weighed 30-40 kg each. The covered and noncovered stents were deployed in the right and left ureters, respectively, of six dogs. In the seventh dog, a covered stent and a double-J catheter were inserted in the right ureter, and a covered stent only was inserted in the left ureter. The first six dogs were sacrificed at 5, 10, and 15 weeks after deployment of the stents (two for each follow-up period), and the seventh dog was sacrificed at 30 weeks. There was no migration or poor expansion of any of the stents observed on plain radiography. On intravenous pyelogram and retrograde pyelogram, all of the covered stents at each follow-up period had patent lumens at the stented segments without hydronephrosis, and the passage of contrast material through it was well preserved. The noncovered stents in the dogs sacrificed at 5 and 10 weeks and one of the two dogs sacrificed at 15 weeks showed near-complete occlusion of the stent lumen due to ingrowth of the soft tissue, and severe hydronephrosis was also noted. The noncovered stent in the other dog sacrificed at 15 weeks showed the passage of contrast material without hydronephrosis, but the lumen of the stent was still nearly occluded by the soft tissue. There was no evidence of hydronephrosis or passage disturbance of the contrast material in both ureters of the dog sacrificed at 30 weeks. We conclude that the newly designed PTFE-covered stent effectively prevented the luminal occlusion caused by urothelial hyperplasia compared to the near-total occlusion of the noncovered stents, and no migration of the covered stents was noted.
Primary tumors of the heart are rare; the most common cardiac tumor is atrial myxoma. Sudden death may occur in patients with atrial myxoma, tumor embolization, or obstruction of blood flow at the mitral or tricuspid valve. This report describes an unusual cause of sudden death and the autopsy findings for a 73-year-old man with left atrial myxoma.
Department of Anatomy, Manipal College of Medical Sciences, Pokhara, Nepal. email@example.com
OBJECTIVES Foramen Vesalius is an inconstant foramen that gives passage to an emissary vein that connects pterygoid venous plexus with cavernous sinus, the importance of which lies in the fact that an infected thrombus from an extracranial source may reach cavernous sinus. This study presents some data on characteristics of foramen vesalius. METHODS We studied 70 sides of 35 dried adult human skulls available in the Department of Anatomy, Manipal College of Medical Sciences, Pokhara, Nepal. Variation in number and incidence of foramen Vesalius were noted. Differences between the right and the left side and between the male and the female sex are discussed. MAIN FINDINGS Foramen Vesalius was present in 23 sides (14 right, 9 left) out of the 70 sides observed, the incidence being 32.85%(20.0% right side, 12.85% left side) of all the sides observed. Incidence of bilateral and unilateral foramen vesalius was 22.85%(8 out of 35 skulls) and 20%(7 out of 35 skulls) respectively. Foramen vesalius was found in 10 sides in males and in 13 sides in females. No remarkable differences were observed in the incidence of foramen vesalius between the sides within same sex but the incidence was more in females compared to male skulls. SIGNIFICANCE OF FINDINGS: Anatomic variations of the foramen vesalius could be explained by developmental reasons. Knowledge about characteristics of foramen vesalius and its incidence is not only important for anatomists but equally essential for an operating surgeon.
[Hemodynamic characteristics and surgical treatment of varicose disease with primary involvement of deep vein valves].
Results of clinical examinations and ultrasonic duplex scanning of the venous system of the lower extremities performed in 31 patients with the varicose disease were analyzed. The disease developed due to the primary valve insufficiency of the profound veins. This form is characterized by total-subtotal refluxes of blood along the subcutaneous veins, multiple lesions of the perforant veins, the presence of the hemodynamically valuable blood refluxes in the profound and muscle veins. The hemodynamic parameters of blood flow and the technology of surgical treatment of the deep, superficial, perforant and muscle blood refluxes are shown allowing to restore the quality of life in 76.7% of the patients and considerately improve it in 23.3%.
Andrology Unit, Department of Obstetrics and Gynecology, Rabin Medical Center, Beilinson Campus, Petah Tiqva, Israel.
OBJECTIVES To evaluate the incidence of left and right varicocele in adolescents. METHODS The study group consisted of 28 adolescents who underwent evaluation for varicocele at our clinic. In 19 patients, varicocele was detected on routine physical examination, and 9 patients presented with scrotal pain or discomfort. All patients were evaluated by three methods. Physical examination was followed in all cases by contact thermography and venography studies of both testes. RESULTS The rate of left and right retrograde flow in the spermatic veins by the three methods used was as follows: physical examination 92.8% and 10.7%; contact thermography 100% and 89%; and venography 100% and 85.7%, respectively. Varicocele was not detected by physical examination in 2 (7.2%) of the 28 patients on the left side and in 21 (87.5%) of 24 on the right side. CONCLUSIONS The main finding of this study was that varicocele is a bilateral disease in 85.7% of adolescents. The high percentage of bilateral varicocele in our sample may explain the pathophysiologic mechanism whereby what has traditionally been considered a unilateral disease can produce bilateral testicular dysfunction. The high incidence of subclinical bilateral varicocele may indicate that we should consider varicocele a bilateral disease. The second finding was that only 10% of patients with right varicocele were diagnosed by physical examination and more than 85% were diagnosed by thermography, with confirmation by venography. Therefore, we suggest that thermography and venography should play a major role in the diagnosis of varicocele.
The Hospital for Sick Children, 555 University Avenue, M5G 1X8, Toronto, Ontario, Canada.
Bronchial varices, which have rarely been described in the radiology literature, can be the result of pulmonary venous obstruction and may present with hemoptysis. This case is an illustration of this rare condition, which correlates CT findings with bronchoscopic findings. We also describe the findings on phase-contrast MR that demonstrated reversed diastolic flow in the branch pulmonary artery supplying the affected lung.
Bubble contrast echocardiography in detecting pulmonary arteriovenous malformations after modified Fontan operations.
Department of Pediatric Cardiology, The Queen Silvia Children's Hospital, Göteborg University, Sweden. firstname.lastname@example.org
The development of pulmonary arteriovenous malformations is a well-known complication after Fontan operations, and may result in significant morbidity due to increasing arterial desaturation. We compared the use of bubble contrast echocardiography and pulmonary angiography in detecting such malformations. We also examined which anatomical and haemodynamic variables were associated with their development. Our study includes 20 patients who had undergone modified Fontan procedures, 10 with atriopulmonary and 10 with total cavopulmonary connections, in Gothenburg between 1980 and 1991. All patients underwent cardiac catheterisation and pulmonary angiography. Bubble contrast echocardiography was performed at the same time, with injection of agitated polygelin colloid solution (Haemaccel, Hoechst) into the right and left pulmonary arteries, respectively. Transoesophageal echocardiography was used to detect the appearance of bubble contrast in the pulmonary venous atrium. The aim was also to evaluate the role of hepatic venous blood. Of the 20 patients, 9 (45%) had a positive contrast echocardiography study, compared with only 2 (10%) detected by pulmonary angiography. Patients with positive contrast echocardiography had a significantly lower arterial oxygen saturation than those with negative studies, both at rest (88% vs 95%, p < 0.01) and during exercise testing (78% vs 89%, p = 0.01). Bubble contrast echocardiography is much more sensitive in detecting pulmonary arteriovenous malformations than pulmonary angiography. By injecting echo contrast into the right and left pulmonary arteries, the method can be made highly selective. Pulmonary arteriovenous malformations develop much more frequently in patients with the Fontan circulation than previously reported.
Department of Internal Medicine, James H. Quillen VAMC and College of Medicine, East Tennessee State University, Johnson City, USA.
Cicatricial pemphigoid is an unusual mucocutaneous disease that is characterized by subepidermal blister formation involving the oral and conjunctival membranes. The oral lesions are expressed as erythema and induration and have rarely been associated with upper airway obstruction. We report the case of a patient with dyspnea and an abnormal flow-volume loop who was found to have subglottic compromise due to cicatricial pemphigoid. Immunosuppressive therapy improved his symptoms and air flow.