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1.
Based on the current concept of the obvious prevalence of surgical treatment of vascular angiodysplasias over low-invasive methods of interventional radiology, the author assesses the capacities of sclerotic therapy performed by the improved visual controlling procedure. By using the well-known semiotics of ultrasound studies of angiodysplasias, the author has made significant methodological amendments to the techniques of sclerotic therapy. The principle of the proposed procedure is a result of complex use of the potentialities of ultrasound visualization and interventional X-ray contrast studies of the vascular system. The procedure was successfully used in 9 patients. It is concluded that that the study of soft tissue angiodysplasias via direct puncture performed under ultrasound guidance, followed by mass contrasting and sclerotic therapy.  相似文献   

2.
BACKGROUND: The purpose of this study was to investigate the feasibility of using high frequency ultrasound to study the chick embryo in a noninvasive and longitudinal fashion. METHODS: A total of 10 SPF White Leghorn chick embryos (GDs 11-17; Hamburger and Hamilton stage 37-43) were consecutively examined with a GE Logiq 400 ProSeries ultrasound unit using an 11-MHz small parts ultrasound probe. Access for ultrasound visualization of the embryos was accomplished by opening a 2-3-cm window either in the air cell over the blunt end of the egg or laterally over the embryo-dependent side of the egg. Warmed ultrasound coupling gel was used for imaging, and thermal regulation was maintained with infant heel warmers. The ultrasound images were recorded directly on digital video using a Sony TRV 900 DV camcorder. The images were directly converted to jpeg and mjeg2 files for further analysis. RESULTS: Effective visualization of each embryo was possible on each day of the study period. The embryos were best visualized through the opening made in the air cell at the blunt end of the egg. The extent of the anatomic survey of the chick embryo was dependent upon the position of the embryo in the egg relative to the opening in the air cell. Doppler color flow mapping studies were obtained of the embryonic and extraembryonic circulation. CONCLUSIONS: This preliminary investigation clearly shows the feasibility of high frequency ultrasound imaging to study chick embryo development in a longitudinal and noninvasive fashion. Further studies are presently ongoing regarding earlier embryo development, as well as to determine the stability and dynamics of the methodology.  相似文献   

3.
三维超声心脏图像的模糊聚类分割   总被引:3,自引:0,他引:3  
采用三维超声心动图对小儿先天性心脏病进行诊断与治疗能达到比传统二维超声心动图更直观的效果。然而由于超声图像质量较差,三维超声心动图的可视化效果往往无法达到医生的要求。本文对三维超声心脏图像进行分割,以改进超声图像的可视化效果,并为参数提取等提供基础。首先采用快速的模糊c均值聚类得到初始分割结果;然后利用图像多分辨率技术进行修正;接着结合图像的对比度进行进一步的分割;最后,把处理后的图像用绘制的方法显示出来。本文的结果对超声图像的可视化效果有一定的改善.  相似文献   

4.
The data obtained from studies of 84 patients with polyps of the stomach and colonic were used to consider the capacities of transabdominal and transrectal ultrasound studies and their diagnostic efficiency in the diagnosis of polyps of the stomach and colon. The ultrasound semiotics of polyps of the gastric and colon was described. A place of transabdominal ultrasound sonography (US) in the algorithm of radiation and endoscopic studies was established. This investigation led to the conclusion that transabdominal US, along with indirect diagnosis, permits solution of number of fundamental problems facing prior to polypectomy--these are primarily to define the nature of a detected polyp (epithelial and non-epithelial), based on an analysis of the laminar structure of the wall of an organ at the polyp base, a possible polyp malignancy and the degree of invasion into the depths of the gastric wall, as well as to detect a feeding vessel (in the CDC mode) and to predict the likelihood of possible complications. It is advisable to use transabdominal US in a complex of diagnostic techniques for polyps of the stomach and colon.  相似文献   

5.
Classical venous occlusion plethysmography (VOP) of the leg, often used to assess venous compliance, measures properties of the whole calf, including volume changes at the arterial side and the interstitial fluid accumulation that occurs as a result of the enhanced capillary pressure during venous occlusion. We present an ultrasound technique to measure the compliance of one major conduit vein in the leg. Ultrasound measurements of the popliteal vein were compared with classical VOP measurements, which were performed simultaneously in one subject. Six healthy individuals were measured on three occasions to assess short- and long-term reproducibility of the measurements. Six motor complete spinal cord-injured (SCI) individuals were included to compare venous compliance in subjects with known pathological changes of the venous system with controls. The ultrasound and VOP measurements of venous compliance correlated significantly (r(2) = 0.39, P = 0.001). Ultrasound provides reproducible measurements with short- and long-term coefficients of variation ranging from 10 to 15% for popliteal vein compliance and from 2 to 9% for absolute diameters at the different venous pressure steps. In addition, by using ultrasound, we were able to detect an 80% reduction in the compliance of the popliteal vein in SCI individuals compared with controls (P < 0.01). In conclusion, ultrasound is a suitable and reproducible method to measure conduit vein compliance and provides the possibility to specifically assess compliance of one vein instead of the whole calf.  相似文献   

6.
The purpose of the present study was to determine whether ultrasound is a useful tool to measure the venous characteristics of the lower extremity during a standard venous collecting cuff deflation protocol. To accomplish this, lower extremity pressure-cross-sectional area (CSA) and pressure-volume relationships were measured in eight (25 +/- 1 yr) supine subjects. Popliteal vein CSA was assessed by using high-resolution ultrasound, while calf volume changes were simultaneously assessed by using venous occlusion plethysmography (VOP). Pressure-CSA and pressure-volume relationships were assessed at baseline, during the cold pressor (CP) test, and following sublingual nitroglycerin (NTG) administration. Relationships were modeled with a quadratic regression equation, and beta(1) and beta(2) were used as indexes of venous compliance. Popliteal vein regression parameters beta(1) (8.485 +/- 2.616 vs. 7.638 +/- 2.664, baseline vs. CP; 8.485 +/- 2.616 vs. 7.734 +/- 3.076, baseline vs. NTG; both P > 0.05) and beta(2) (-0.0841 +/- 0.0241 vs. -0.0793 +/- 0.0242, baseline vs. CP; -0.0841 +/- 0.0241 vs. -0.0771 +/- 0.0280, baseline vs. NTG; both P > 0.05) were not affected by CP or NTG. Similarly, calf regression parameters beta(1) and beta(2), obtained with VOP, were not altered during either trial. Intraclass correlations for venous compliance assessed with ultrasound and VOP were 0.92 and 0.97, respectively, indicating acceptable reproducibility. These data suggest that ultrasound is a functional and reproducible tool to assess the venous characteristics of the lower extremity, in addition to VOP. Additionally, popliteal vein and calf compliance were not affected by the CP test or NTG.  相似文献   

7.
Physical inactivity or deconditioning is an independent risk factor for atherosclerosis and cardiovascular disease. In contrast to exercise, the vascular changes that occur as a result of deconditioning have not been characterized. We used 4 wk of unilateral lower limb suspension (ULLS) to study arterial and venous adaptations to deconditioning. In contrast to previous studies, this model is not confounded by denervation or microgravity. Seven healthy subjects participated in the study. Arterial and venous characteristics of the legs were assessed by echo Doppler ultrasound and venous occlusion plethysmography. The diameter of the common and superficial femoral artery decreased by 12% after 4 wk of ULLS. Baseline calf blood flow, as measured by plethysmography, decreased from 2.1 +/- 0.2 to 1.6 +/- 0.2 ml.min(-1).dl tissue(-1). Both arterial diameter and calf blood flow returned to baseline values after 4 wk of recovery. There was no indication of a decrease in flow-mediated dilation of the superficial femoral artery after ULLS deconditioning. This means that functional adaptations to inactivity are not simply the inverse of adaptations to exercise. The venous pressure-volume curve is shifted downward after ULLS, without any effect on compliance. In conclusion, deconditioning by 4 wk of ULLS causes significant changes in both the arterial and the venous system.  相似文献   

8.
9.
The authors present their experience with the Dual Echo Steady State pulse sequence used to evaluate brain cerebrospinal fluid (CSF) flow by low-field magnetic resonance imaging. Normal and pathologic CSF flow patterns are discussed. The capacities of the technique as an auxiliary tool to have additional diagnostic information via visualization of flows in the brain CSF pathways are shown.  相似文献   

10.
We have devised a simple procedure for immunostaining of sections that have previously undergone autoradiographic visualization of mRNAs by in situ hybridization. Classical hybridocytochemistry techniques were performed first on cryostat sections of formaldehyde-fixed tissue. Standard methods were used for slide coating by emulsion dipping and for revelation, fixation, and coverslipping steps. The key to this method is the emulsion removal, or permeabilization, by a short trypsin incubation (0.2% for 20-30 sec) which facilitates the good access of antibodies used in a subsequent immunocytochemical technique to section epitopes. Usual immunofluorescence and immunoperoxidase procedures were successfully performed after this treatment. The immunoreactivity of several neuropeptides was well preserved after this procedure. In addition to its usefulness in our studies, this general method should be applicable to many other situations in which autoradiographic and immunocytochemical detections must be coupled.  相似文献   

11.
Real-time three-dimensional (RT3D) ultrasound is a relatively new imaging modality that uses a special ultrasound transducer consisting of a matrix array of elements. The array electronically steers an ultrasound beam to interrogate a 3D volume of tissue. The real-time nature of RT3D ultrasound differentiates it from reconstructed 3D ultrasound, in which a conventional ultrasound transducer is moved mechanically through the third dimension. RT3D ultrasound is considerably faster than reconstructed 3D ultrasound, making it suitable for capturing continuous rapid motion such as that of the beating heart. Although RT3D ultrasound has not yet found widespread clinical use, these scanners are presently employed in more than 20 locations worldwide, primarily for cardiac research. The author helped develop the RT3D ultrasound technology as well as specialized analysis and visualization methods for the resulting data. In developing such methods, it has been necessary to consider the physical and mathematical processes by which the ultrasound data are collected. Difficulties arise because of high noise, variation in contrast and intensity between scans, ultrasound's nonrectilinear coordinate system, and the anisotropic nature of the echoes themselves. This article reviews these specific difficulties and provides solutions that are applicable to generalized analysis and visualization of RT3D ultrasound data. Some of the methods presented can also be applied to other imaging modalities with nonrectilinear coordinates.  相似文献   

12.
Cerebral venous drainage in humans is thought to be ensured mainly via the internal jugular veins (IJVs). However, anatomic, angiographic, and ultrasound studies suggest that the vertebral venous system serves as an important alternative drainage route. We assessed venous blood volume flow in vertebral veins (VVs) and IJVs of 12 healthy volunteers using duplex ultrasound. Measurements were performed at rest and during a transient bilateral IJV and a circular neck compression. Total venous blood volume flow at rest was 766 +/- 226 ml/min (IJVs: 720 +/- 232, VVs: 47 +/- 33 ml/min). During bilateral IJV compression, VV flow increased to 128 +/- 64 ml/min. Circular neck compression, causing an additional deep cervical vein obstruction, led to a further rise in VV volume flow (186 +/- 70 ml/min). As the observed flow increase did not compensate for IJV flow cessation, other parts of the vertebral venous system, like the intraspinal epidural veins and the deep cervical veins, have to be considered as additional alternative drainage pathways.  相似文献   

13.
The aim of this randomized controlled study was to compare ultrasound-guided procedure with the Seldinger’s technique for placement of implantable venous ports. A total of 214 patients were randomized to receive TIAP placement by either ultrasound-guided procedure or the Seldinger’s technique. Complications and pain perception were compared between these two groups. No severe perioperative or periinterventional complication occurred. Significantly (P < 0.05) lower pain perception was observed in the ultrasound-guided group. Seldinger’s technique group showed higher rate in incidence of early and late complications including catheter dislocation, catheter occlusion, venous thrombosis, fever of unknown origin, skin necrosis, and sepsis. In conclusion, both techniques, the TIAP implantation via ultrasound-guided jugular vein puncture and via Seldinger’s technique subclavian vein puncture, are feasible and safe. Regarding intrainterventional pain perception and implantation-related complications, the jugular vein puncture under ultrasound guidance seems to be advantageous.  相似文献   

14.
Fetal ultrasound (FU) is used during almost all pregnancies and makes a large contribution to the identification of fetal malformation. It is particularly difficult to announce a malformation, particularly those affecting the brain, because there are often doubts concerning both the diagnosis and the prognosis. AIM: The aim of this study was to analyze how imaging for prenatal screening is organized and how couples are managed and supported. We concentrated on the procedures used to inform couples: content, method of delivery and consequences. METHOD: Study amongst large multidisciplinary centers in Paris and the Paris region, by semi-directed interviews using a questionnaire. RESULTS: We showed that it is difficult to standardize the way in which information is supplied before and after the examination, and that doctors tend to recommend abortion when the prognosis is uncertain. DISCUSSION: These results provide information that will help decision-making concerning a standardized procedure allowing couples to benefit from all the capacities of prenatal screening, particularly when the diagnosis and prognosis are uncertain. There is a need for multidisciplinary teams to support and to accompany the decision concerning whether to have an abortion or to continue the pregnancy.  相似文献   

15.
By using 237 verified cases of diffuse carcinoma and benign diseases of the stomach as an example, the authors assess the capacities of routine transabdominal ultrasound study (USS) of the stomach in the diagnosis of tumors and present their modification of the procedure facilitating the imaging of problem areas. In the authors' opinion, the symptoms of thickening of the wall of the stomach and abnormalities in its normal five-layered structure indicate diffuse gastric carcinoma. The authors consider USS to be a supplement to the basic diagnostic techniques--X-ray study and gastroscopy.  相似文献   

16.
The main purpose of the authors is to present their view of a place of present-day ultrasonography in the diagnosis of acute small and large intestinal obstruction. A comparatively sizable material covering 218 verified cases of acute ileus, including 77 patients with large intestinal obstruction and 141 patients with impaired passage of the intestinal contents along the small bowel was used to outline the aspects of ultrasound techniques and the symptomatology of ileus, by differentiating its some types. Along with the general assessment of the methodological and semiotic aspects of ultrasound diagnosis of acute uleus, the authors emphasizes a role of sonography in the detection of large intestinal obstruction by outlining their modified procedure of ultrasound irrigoscopy. For greater objectivization of their positive assessment of the place of ultrasound in the diagnosis of acute ileus and large intestinal obstruction, the authors comparatively studied X-ray and ultrasound studies to reveal this pathology. In addition to their purely personal assessment of a role of ultrasound in the diagnosis of large intestinal obstruction, the lecture also shows its authors' opinion as to the organizational issues associated with the necessity of correcting the existing diagnostic algorithm to detect large intestinal obstruction.  相似文献   

17.
目的:探讨盆腔瘀血综合征患者彩色多普勒超声的影像学特征及与临床因素的相关性。方法:对112例盆腔瘀血综合征患者行彩色多普勒超声检查,按超声诊断分级Ⅰ级、Ⅱ级、Ⅲ级分为62例、27例、23例,观察彩色多普勒超声的影像学特征,分析静脉内径与病程的相关性,并分析超声诊断分级与临床症状积分、体质量指数(BMI)、妊娠次数、既往工作站立时间的相关性。结果:不同超声诊断分级患者的静脉内径、静脉丛范围和静脉流速差异具有统计学意义(P<0.05)。静脉内径与病程呈正相关(P<0.05),超声诊断分级与临床症状积分、妊娠次数、既往工作站立时间呈显著正相关(P<0.05),与BMI呈负相关(P<0.05)。结论:彩色多普勒超声对盆腔瘀血综合征具有特异性的诊断价值,超声诊断分级、静脉内径与临床因素存在一定的的关联性。  相似文献   

18.
Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking.  相似文献   

19.
Inversion of venous flow is well visualized by colour duplex ultrasound and is the basic haemodynamic feature of varicocele. We tried to assess the value of dissection of branches of the spermatic vein in the internal inguinal ring using an operating microscope with a magnification of 4.5x. 16 patients were operated according to the ultrasound classification proposed by Hirsh et al. [8]. Varicocele was grade III in 2 cases, grade IV in 11 cases and grade V in 3 cases and was situated on the left in 13 patients and on the right in 3 patients. The diagnosis was based on clinical examination and colour duplex ultrasound. The operating time was 25–35 min. The incision was 1.5 to 2 cm long. No short-term complications or long-term hydrocele were observed. No reno-spermatic flow was observed on colour duplex ultrasound after six months. The mean testicular volume was 22 ml before surgery and did not change after the operation. This surgical technique is less invasive than the conventional retroperitoneal or laparoscopic procedures, and the incision is smaller than with the percutaneous technique. It is less radical than conventional microsurgery, but the operating time is shorter, and the surgical wound is smaller, sparing the artery and lymphatic vessels. In conclusion, this operation can be considered to be a good option in the surgical treatment of varicocele in view of its low complication rate, the absence of hydrocele, a minimally invasive procedure and the good haemodynamic results.  相似文献   

20.
With ESSA, we propose an approach of RNA secondary structure analysis based on extensive viewing within a friendly graphical interface. This computer program is organized around the display of folding models produced by two complementary methods suitable to draw long RNA molecules. Any feature of interest can be managed directly on the display and highlighted by a rich combination of colours and symbols with emphasis given to structural probe accessibilities. ESSA also includes a word searching procedure allowing easy visual identification of structural features even complex and degenerated. Analysis functions make it possible to calculate the thermodynamic stability of any part of a folding using several models and compare homologous aligned RNA both in primary and secondary structure. The predictive capacities of ESSA which brings together the experimental, thermodynamic and comparative methods, are increased by coupling it with a program dedicated to RNA folding prediction based on constraints management and propagation. The potentialities of ESSA are illustrated by the identification of a possible tertiary motif in the LSU rRNA and the visualization of a pseudoknot in S15 mRNA.  相似文献   

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