Renal carcinoma: detection of venous extension with gradient-echo MR imaging.

Magnetic resonance (MR) imaging has been proposed as a noninvasive alternative to vena cavography and computed tomography for the detection of venous extension of renal adenocarcinoma. However, spin-echo MR images may be compromised by the presence of flow-related artifacts, extrinsic compression, and respiratory or cardiac motion artifacts. Use of gradient-recalled echo (GRE) sequences is advantageous for imaging of vascular structures. To investigate the detection of vascular extension of tumor with the GRE technique, findings in the preoperative GRE MR images of 26 patients with renal adenocarcinoma were compared with findings at surgery and pathologic examination. Vena cava thrombus was correctly identified in 13 of 13 patients (100%). Renal vein thrombus was correctly identified in 23 of 26 patients (88%), and right atrial thrombus was correctly identified in four of five patients (80%). Use of GRE sequences allows accurate assessment of vascular structures that is sufficient for surgical planning.     

Invasive thymoma with venous intraluminal extension: CT and MRI findings

We herein report an unusual case of invasive thymoma with venous intraluminal extension. The thymoma extended into the superior vena cava, the left brachiocephalic vein, and the proximal portion of the left jugular and subclavian veins intraluminally. It was suggested that the tumor had a discrete intravascular growth via the thymic vein into the left brachiocephalic vein and extended into the proximal portion of the left jugular and subclavian veins in the opposite direction of the venous stream.     

Frequency and topographic distribution of brain lesions in pediatric cerebral venous thrombosis

BACKGROUND AND PURPOSE: Cerebral sinovenous thrombosis (CSVT) is increasingly encountered in children, including neonates. The purpose of this study was to assess the frequency and topographic distribution of parenchymal brain lesions associated with CSVT in children and to compare these with the known anatomic venous drainage pathways.MATERIALS AND METHODS: Brain CT/CT venograms and/or MR imaging/MR venograms of 71 consecutive patients with CSVT were reviewed retrospectively. The patients were grouped into neonates, infants, and older children. The site of CSVT, the location and size of the brain lesions, and the presence of hemorrhage were documented. The frequency of the brain lesions was calculated.RESULTS: There were 34 neonates, 10 infants, and 27 older children with CSVT who were included. The most common sites of CSVT were the transverse sinuses, the superior sagittal sinus, and the straight sinus. Overall, 37 of 71 children with CSVT had parenchymal brain lesions. There were 21 of 34 neonates, 4 of 10 infants, and 12 of 27 older children who had brain lesions. The most common locations were in the frontal and parietal lobes. The topographic distribution of lesions correlated with the corresponding venous drainage territory in 16 of 21 neonates, all infants, and all older children. The neonates had smaller-sized lesions. Brain lesions were hemorrhagic in 76% of neonates, 75% of infants, and 33% of older children.CONCLUSION: The topographic distribution of brain lesions associated with CSVT correlates with the known drainage territories of the dural venous sinus in children.

Cerebral sinovenous thrombosis (CSVT) in children is increasingly diagnosed mainly because of improved neuroimaging techniques and increasing awareness of the disease. The true incidence of CSVT is also probably increasing because of more aggressive treatment and improved survival in various childhood diseases (eg, childhood cancers). The incidence of CSVT in children is estimated at 0.67 per 100,000 children, occurring most commonly in neonates.¹Focal brain abnormalities have been identified in approximately 50% to 60% of patients with sinus venous thrombosis despite the reported protective role of the venous collateral pathways in preventing parenchymal injury during sinus occlusion.^2-4 The pathophysiologic mechanism of parenchymal injuries related to CSVT is not fully understood. The severity of parenchymal injuries in experimental CSVT models has been considered proportional to the degree of venous occlusion.⁵ The lack of correlation between the extent and site of thrombosis in the dural sinuses and location of brain lesions has been suggested in adults.⁶ In this study, our aims were to evaluate the frequency and topographic distribution of brain lesions associated with CSVT in children and to try and compare the topographic distribution of brain lesions with known normal venous drainage and anatomy.     

MRI demonstrates the extension of juxta-articular venous malformation of the knee and correlates with joint changes

Objective  

Juxta-articular venous malformations (VMs) are uncommon, but may cause early arthropathy of the knee in children and adolescents. We sought to describe the prevalence, extent and initial magnetic resonance imaging (MRI) features of knee arthropathy in children with VM adjacent to the knee joint.     

Normal venous anatomy and collateral pathways in upper extremity venous thrombosis.

Collateral pathways are well known in superior vena cava occlusion but not in axillary or subclavian vein occlusion, even though these occlusions are becoming more common. In a series of 127 arm venograms obtained for suspected venous thrombosis, the authors found 32 instances of subclavian or axillary vein occlusion. The authors reviewed the cases for site of occlusion and definition of collateral pathways. In 15 cases, the occlusion was in the subclavian vein, with collateral flow established chiefly via veins in the neck. Ten cases of axillary vein occlusion with chest wall collateral pathways were identified. Seven cases could not be categorized. Knowledge of these pathways is useful for accurate interpretation of upper extremity venograms. A more thorough understanding of venous pathways in the upper body may aid in the treatment of patients with chronic disease and longterm indwelling central venous catheters.     

Supine pedal venous measurement in patients with venous disease.

The measurement of supine pedal venous pressure as a screening test for deep venous thrombosis is re-evaluated. In 83 extremities studied in 50 patients, the false-positive rate was 62%, the false-negative rate 8%. Chronic venous disease, whatever its etiology but particularly in association with the post-phlebitis syndrome, can be a source of error in relying upon this measurement.     

Intracranial extension of orbital pseudotumour.

Radiologically demonstrable intracranial extension of orbital pseudotumour is rare, and only four cases appear to have been reported previously in the literature. A review of the computed tomographic (CT) images of 90 biopsy proven cases of orbital pseudotumour seen over a 10 year period revealed eight cases with intracranial meningeal spread.     

MR evaluation of developmental venous anomalies: medullary venous anatomy of venous angiomas.

PURPOSETo present characteristic MR findings of developmental venous anomalies (DVAs) in terms of location of caput and draining veins, to correlate these findings with normal medullary venous anatomy, and to suggest an approach to the evaluation of DVAs by means of MR imaging.METHODSWe reviewed the contrast-enhanced MR examinations of 61 patients with DVA, which were selected from 4624 consecutive cranial MR examinations. Site of the DVA and size and direction of draining veins were recorded.RESULTSSeventy-two DVAs with 78 draining veins were located: 18 were juxtacortical, 13 were subcortical, and 41 were periventricular or deep. Twenty-six of the DVA caputs were frontal, 16 were parietal, 13 were in the brachium pontis/dentate, seven were in the temporal lobe, three were in the cerebellar hemisphere, three were in the occipital lobe, three were in the basal ganglia, and one was in the pons. The draining veins were superficial in 29 cases and deep in 49. Of the 36 supratentorial deep draining veins, 16 were in the trigone/occipital horn, 11 were in the mid-body of the lateral ventricle, seven were in the frontal horn, and two were in the temporal horn. Among the 14 infratentorial deep draining veins, five were in the lateral recess of the fourth ventricle, four were anterior transpontine veins, three were lateral transpontine veins, and two were precentral cerebellar veins.CONCLUSIONThe DVA caputs and their draining veins occurred in typical locations that could be predicted from the normal medullary venous anatomy, with the frontal, parietal, and brachium pontis/dentate being the most common locations. Drainage can occur in superficial cortical veins or sinuses or in deep ventricular veins or in both, no matter where the caput is located. Whether drainage was superficial or deep could not be predicted on the basis of the site of the DVA caput. Contrast-enhanced T1-weighted MR images showed the DVAs best, but diagnosis could be made from T2-weighted MR images.     

Incidence of upper limb venous thrombosis associated with peripherally inserted central catheters (PICC)

The objective of this study was to prospectively determine the incidence of venous thrombosis (VT) in the upper limbs in patients with peripherally inserted central catheters (PICC). We prospectively investigated the incidence of VT in the upper limbs of 26 patients who had PICC inserted. The inclusion criteria were all patients who had a PICC inserted, whilst the exclusion criterion was the inability to perform a venogram (allergies, previous contrast medium reaction and inability of gaining venous access). Both valved and non-valved catheters were evaluated. Prior to removal of the PICC, an upper limb venogram was performed. The number of segments involved with VT were determined. The duration of central venous catheterization was classified as; less than 6 days, between 6 days and 14 days and more than 14 days. VT was confirmed in 38.5% (10/26) of the patients. The majority 85.7% (12/14) were complete occlusive thrombi and the majority of VT only involved one segment. There was no statistical correlation between the site of insertion of the PICC and the location of VT. Neither was there any observed correlation between the occurrence of VT with the patient's history of hypertension, hypercholesterolaemia, coronary artery disease, diabetes mellitus, cardiac insufficiency, smoking or cancer. There was also no statistical correlation with the size of the catheter. In conclusion, PICCs are associated with a significant risk of upper extremity deep vein thrombosis (UEVT).     

肺肾双能量CTA筛查肾病综合征患者静脉血栓栓塞的发生率

目的：利用CT筛查肾病综合征患者静脉血栓栓塞事件的发生率及其临床意义。方法：2010年5月-2012年8月974例患者行双能量CT肺动脉成像（CTPA）,其中451例肾病综合征患者（包括66例儿童）进行了肺肾联合双能量CT扫描以筛查肺栓塞和肾静脉栓塞。153例患者同时进行了下肢超声检查用于筛查深静脉血栓。记录肺栓塞、肾静脉栓塞、下肢深静脉血栓的发生率及其相互关系。结果：177（39．2％）例患者至少有一个静脉血栓栓塞事件,其中以肺栓塞最常见（149／177,84．1％）,76例肺栓塞患者合并肾静脉栓塞,孤立性肺栓塞54例。大多数肺栓塞患者（118／149,79．2％）无临床症状。106例（106／451,23．5％）例患者有肾静脉栓塞,26例（26／153,17．0％）患者有深静脉栓塞。儿童患者静脉血栓事件发生率（13／66,19．7％）低于成人（164／385,42．6％）。在组织学证实的肾病类型中,膜性肾病最常伴有静脉血栓事件（72／153,47．1％）。结论：肺栓塞是肾病综合征患者最常见的血栓并发症且大多是无症状的,常伴有肾静脉血栓或孤立发生,因此对本病的可疑静脉血栓患者的筛查是需要的。     

Incidence of tibial fracture in child skiers.

Skiing is an increasingly popular sport amongst both adults and children. Opportunities for skiing within the United Kingdom are limited, but the introduction of increasing numbers of dry ski slopes has made the sport more available. The nature of injuries sustained by adults on snow and dry slopes is well documented, but this is less true of childhood injury, especially on dry slopes. A consecutive series of 92 patients with skiing injuries is presented. Both dry slope and snow slope injuries are included. The incidence of tibial fracture in children was ten times that of adults. The nature of all injuries sustained during the study period is documented, the childhood tibial fractures are described in detail, and possible aetiological factors are discussed.     

太空减压病的发病率与预防

通过对太空减压病同高空减压病进行比较，阐明太空减压病应由高空减压病独立出来的必要性。太空减压病与高空减压病的病因学和发病机理相同，但引起发病率有不同的规律（包括影响因素等）和各自独特的特征。为了得对太空减压病有一个系统明确的认识，利于更有效地制定预防方案和建立学科，太空减压病应成为独立的专业术语。     

Leg extension power and muscle fiber composition.

The purpose of this investigation was to relate muscle fiber composition to the isokinetic measure of peak torque production through a range of leg extension velocities. Twenty-one males were biopsied from the vastus lateralis muscle to determine their percent distribution of slow twitch (%ST) and fast twitch (%FT) muscle fibers as identified through myofibrillar adenosine triphosphatase activity. All subjects showed a decline in peak torque with increasing velocities. Subjects with predominantly FT fibers were able to generate 11, 16, 23 and 47 percent greater relative peak torque than could predominantly ST subjects at lever arm velocities of 115, 200, 287 and 400 degrees/second respectively. Likewise the correlation between relative torque production and % FT were significant (p less than .05) and increased from r = 0.44 to r = 0.75 as velocity increased from 115 to 400 degrees/second respectively. These data suggest that muscle fiber composition becomes increasingly more related to power performance as the velocity of movement increases.     

Cerebral developmental venous anomalies associated with head and neck venous malformations.

PURPOSETo study cerebral developmental venous anomalies in patients with extensive venous malformations of the head and neck.METHODSAll patients had undergone carotid angiography 10 to 15 years previously. Four-vessel cerebral angiography was carried out in 40 patients with venous malformations. All patients had a physical examination, 16 had CT, and 22 were examined with MR imaging. One patient had MR angiography.RESULTSEighteen developmental venous anomalies were noted in 8 (20%) of 40 patients. Four patients had multiple anomalies, and these were bilateral in 1 patient. Developmental venous anomalies seen in association with cervicofacial, cutaneous, and mucosal venous malformations were remarkable in their absence of neurologic events and associated cavernoma; significance of ectatic venous convergence, extension, and preponderance of deep drainage routes; and frequency with which they multiple in occurrence.CONCLUSIONDevelopmental venous anomalies have a remarkable prevalence of 20% in patients with extensive superficial venous malformations. Therefore, it is important to search for a cerebral developmental venous anomaly when confronted with a cervicofacial venous malformation.