Retrograde perfusion and filling of mouse coronary vasculature as preparation for micro computed tomography imaging

Visualization of the vasculature is becoming increasingly important for understanding many different disease states. While several techniques exist for imaging vasculature, few are able to visualize the vascular network as a whole while extending to a resolution that includes the smaller vessels. Additionally, many vascular casting techniques destroy the surrounding tissue, preventing further analysis of the sample. One method which circumvents these issues is micro-Computed Tomography (μCT). μCT imaging can scan at resolutions <10 microns, is capable of producing 3D reconstructions of the vascular network, and leaves the tissue intact for subsequent analysis (e.g., histology and morphometry). However, imaging vessels by ex vivo μCT methods requires that the vessels be filled with a radiopaque compound. As such, the accurate representation of vasculature produced by μCT imaging is contingent upon reliable and complete filling of the vessels. In this protocol, we describe a technique for filling mouse coronary vessels in preparation for μCT imaging. Two predominate techniques exist for filling the coronary vasculature: in vivo via cannulation and retrograde perfusion of the aorta (or a branch off the aortic arch), or ex vivo via a Langendorff perfusion system. Here we describe an in vivo aortic cannulation method which has been specifically designed to ensure filling of all vessels. We use a low viscosity radiopaque compound called Microfil which can perfuse through the smallest vessels to fill all the capillaries, as well as both the arterial and venous sides of the vascular network. Vessels are perfused with buffer using a pressurized perfusion system, and then filled with Microfil. To ensure that Microfil fills the small higher resistance vessels, we ligate the large branches emanating from the aorta, which diverts the Microfil into the coronaries. Once filling is complete, to prevent the elastic nature of cardiac tissue from squeezing Microfil out of some vessels, we ligate accessible major vascular exit points immediately after filling. Therefore, our technique is optimized for complete filling and maximum retention of the filling agent, enabling visualization of the complete coronary vascular network--arteries, capillaries, and veins alike.     

Construction of healthy arteries using computed tomography and virtual histology intravascular ultrasound

Vessel geometry for numerical analysis is generally obtained by computed tomography (CT) or magnetic resonance imaging (MRI) and intravascular ultrasound (IVUS). Most medical imaging is obtained from patients for hemodynamic analysis due to the properties of vascular disease and the difficulties in angiography. To predict the site where plaque occurs and understand the progression of the lesion, however, it is necessary to take into consideration not only the diseased artery, but also the blood flow characteristics of healthy artery. In order to simulate healthy vessels prior to lesion formation, we performed CT and virtual histology intravascular ultrasound (VH-IVUS) on three actual patients and this data was used to develop criteria for healthy vessel construction, a method that virtually removes all intravascular plaque. The lumen of a vessel generated by CT and the lumen from VH-IVUS were compared, and the cross-sectional areas of plaque components (fibrous, fibrofatty, dense calcium, and necrotic) and the lumen from VH-IVUS were analyzed. Geometric differences in the healthy vessel and diseased vessel were analyzed, and flow characteristics of the healthy vessel and diseased vessel were compared through computational fluid dynamics simulation. Low average wall shear stress (AWSS) was distributed in the site where plaque was removed from the healthy vessel, and a high oscillatory shear index (OSI) was observed in the region proximal to the site where plaque previously existed. Low AWSS and high OSI are widely accepted indicators of plaque formation or the direction of plaque progression. A numerical model that effectively predicts lesion forming sites was also generated based on the healthy vessel construction method presented in this study.     

256层螺旋CT前瞻性心电门控冠状动脉成像的临床应用价值及其对比剂浓度研究

目的:探讨256层螺旋CT前瞻性心电门控冠状动脉成像的临床应用价值及不同浓度对比剂对其成像质量、碘用量以及有效辐射剂量的影响。方法:对120例疑似冠心病患者行256层螺旋CT成像扫描,将患者随机分为前瞻性心电门控组和回顾性心电门控组;出院前再将前瞻性心电门控组患者按数表法随机分为低浓度对比剂组、中浓度对比剂组和高浓度对比剂组。比较各组成像质量、碘用量、有效辐射剂量。结果:前瞻性心电门控组与回顾性心电门控组图像质量主观评分分布、可评价节段率、优良率、有效碘用量、信噪比(SNR)、载噪比(CNR)、主动脉CT值(CT主)、主动脉噪声值(SD主)比较无统计学差异(P0.05)。前瞻性心电门控组有效辐射剂量显著低于回顾性心电门控组(P0.05)。高浓度对比剂组可评价节段率、优良率、有效碘用量、SNR、CNR、CT主显著高于低浓度对比剂组和中浓度对比剂组(P0.05),中浓度对比剂组CNR显著高于低浓度对比剂组(P0.05)。结论:前瞻性心电门控技术用于冠心病诊断的图像质量与回顾性心电门控技术无明显差异,但是前瞻性心电门控技术辐射剂量更低。前瞻性心电门控使用低浓度对比剂可以获得满足临床诊断需要的图像质量,且碘用量更少。     

TEMP/TDM et TEP/TDM en cardiologie : quel avenir ?

Over the recent years, clinical cardiology has witnessed a rapid evolution of multi-slice computed tomography (CT), starting with 4-slice CT developing into the current state of the heart 64-slice CT technology. This technology permits non-invasive visualization of the coronaries with high precision. CT coronary angiography will likely play an important role in the diagnosis of coronary artery disease. Because not all coronary stenoses detected by CT angiography are flow limiting, the stress myocardial perfusion imaging data complement the CT information. The integration of nuclear imaging (SPECT or PET) and CT data provides a potential opportunity to delineate the anatomic extent and the physiologic severity of coronary artery disease. The objective of this article is to provide a critical view of the relative strengths and weaknesses of myocardial perfusion imaging and CT coronary angiography, which we hope will help elucidate the potential role of these modalities in the diagnosis and management algorithms of patients with known or suspected coronary artery disease.     

The role of magnetic resonance imaging in the management of vascular malformations of the trunk and extremities

Vascular malformations can usually be diagnosed on clinical grounds. They have a well-defined appearance on magnetic resonance imaging, which can effectively determine their tissue and flow characteristics. However, the role of cross-sectional imaging in the management of vascular malformations is not well defined. Most reviews suggest that magnetic resonance imaging should be reserved for cases in which the extent of the lesion cannot be estimated on physical examination. However, to date no group has compared the accuracy of physical examination alone to that of magnetic resonance imaging in determining this extent. A review was performed of all the patients evaluated for vascular malformations at the New York University Trunk and Extremity Vascular Anomalies Conference between July of 1994 and August of 1999. Patients who underwent magnetic resonance evaluation at other institutions and whose images were not available for review were excluded. All study patients either underwent magnetic resonance imaging examination at New York University Medical Center or had outside films reviewed at the center. The physical examination findings were compared with the magnetic resonance findings and the surgeon and radiologist made a joint decision about whether there was a correlation between the magnetic resonance and physical examination findings. Fifty-eight patients met the study criteria, 44 (76 percent) of whom were found to have more extensive disease on magnetic resonance examination than appreciated on physical examination. Of the 51 patients with low-flow vascular malformations (venous vascular malformations, lymphatic malformations, and capillary malformations), 39 (76 percent) had more extensive disease on magnetic resonance examination than on physical examination. Of the seven patients with high-flow arteriovenous malformations, five had more extensive disease on magnetic resonance. In all of the 44 patients whose magnetic resonance imaging findings did not correlate with those of the physical examination, therapeutic decision making was affected. Contrary to the conventional wisdom of published reviews, physical examination findings significantly underestimated the extent of vascular malformations in the majority of cases. Magnetic resonance imaging should be performed in all patients with vascular malformations of the trunk and extremities before therapy is planned. In an age when physicians are asked to justify their decisions, especially where the use of expensive diagnostic modalities is concerned, the situations in which these tests are indispensable must be clearly defined or else patients will be denied access to them.     

磁共振扩散加权成像在肺癌中的临床应用

影像学检查在肺癌的诊断和分期中起到了至关重要的作用,目前电子计算机体层成像(CT)和正电子发射断层成像技术以及磁共振成像(MRI)已经被广泛的应用于肺癌的分期和疗效评估。其中MRI不仅能提供形态学信息,近年来发展起来的磁共振功能成像能提供更多的功能信息。磁共振扩散加权成像(Diffusion-weighted imaging,DWI)是最常应用于临床的磁共振功能成像序列。最初主要应用在神经系统,随着磁共振成像序列的不断发展以及软硬件的开发应用,其在腹部和盆腔的应用也日趋广泛,然而胸部DWI成像仍待普及和更多认识。本文就肺部DWI成像在良恶性病变鉴别、恶性肿瘤的筛查、分期、以及治疗疗效评估方面进行综述。     

Blood supply of the main vessels in laboratory rats and rabbits

The vascular bed in 25 rabbits and 25 white rats has been revealed by means of vital injection of Indian ink into the intraorganic vessels, staining of erythrocytes (benzidine reaction) and silver impregnation. In preparations of the aorta, inferior and superior vena cava diameter of the vessels, the wall and middle membrane thickness, amount of elastic membranes have been measured. Ramification of small vessels and capillaries are revealed only in the paravasal tissues, surrounding the aorta and veins. In serial sections it has been stated that at their greatest extent vasa vasorum has no walls and only in places, where the intercostal (or others) vessels get out of the aorta in its middle or external tunics, a limited, as to its spread, network of intramural vessels exists. The morphometrical analysis does not show any regular connection between the vascular diameter, wall thickness, or middle membrane thickness, amount of elastic membranes in it with presence or peculiarities in distribution of the intramural vessels.     

宝石能谱CT的功能特点及心血管检查的临床应用

宝石能谱CT拥有一系列独特的技术,包括宝石探测器、高压发射器、ASIR重组技术、能谱栅技术等,使其具有低剂量高清成像、能谱成像和动态500排成像特点,实现了全身0.23mm的极限空间分辨率和类MRI的软组织低密度分辨率,为心脏能量成像、斑块性质的鉴别及金属伪影的消除提供了全新有效的手段。其特有的高纯度和高通透性的物理学特性,再加上影像链中采样率的增高,专有的高清算法,使得宝石能谱CT能够在更低的剂量下,获得更为清晰的图像质量,达到目前业内最高的空间分辨率和密度分辨率;同时,其独有的能谱栅成像技术,将CT诊断从形态学带入功能学领域,因此也被称为"显微CT,病理CT,绿色CT",宝石能谱CT代表了目前CT发展的趋势,它用准确的绝对CT值的单能量成像(keV)诊断和基物质成像诊断来取代传统的相对CT值的混合能量(kVp)成像诊断,用多参数CT成像诊断来代替传统的单参数CT成像诊断,而"三同"(同时、同源、同向)的物理基础保证了其能谱成像的准确性,使CT能谱成像真正走入了临床诊断的第一线,从而提高了心血管疾病诊断的准确性和安全性。为CT在心脏疾病的诊断方面开拓了新领域和新方法。     

Optimization of FDG-PET/CT imaging protocol for evaluation of patients with primary and metastatic liver disease

Background

Accurate determination of the extrahepatic extent and intrahepatic distribution of disease is very important in patients with primary and metastatic liver disease for deciding whether a patient receives potentially curable surgery or palliative treatment. Our objective was to evaluate the efficacy of delayed phase FDG-PET/CT imaging in lesion detection and to define its clinical impact compared to triple-phase contrast enhanced CT (CECT).

Methods

30 patients underwent delayed phase FDG-PET/CT imaging (90 min whole body scan followed by a delayed abdominal scan at 120 min). Maximum standard uptake values (SUVs) and SUV ratios between tumor and normal liver parenchyma (T/N) were evaluated. In addition, comparison was made to CECT obtained within 10 days of the FDG-PET/CT to evaluate for lesion concordance within individual liver segments (Couinaud designation).

Results

Sites of primary malignancies included: colorectal (19), breast (3), pancreas (2), lung (2), carcinoid (2), cholangiocarcinoma (1), and hepatocellular carcinoma (1). There was a significant increase in SUV value of liver lesions between early and delayed acquisition (P < 0.001). Although there was not a significant reduction in liver background activity between the two studies, there was a strong increase in T/N ratio (P < 0.001) allowing better lesion detection by visual inspection. New lesions were identified in 5 of the 30 patients, which were not appreciated on the early scan. Delayed phase FDG-PET/CT identified one lesion which was not present on the corresponding CECT. Delayed phase FDG-PET/CT revealed extrahepatic sites of metastases not appreciated on CECT in 6 patients.

Conclusion

Delayed phase FDG-PET/CT protocol improved lesion detectability in primary and metastatic liver disease, revealing new lesions in 17% of the patients. Moreover, FDG-PET/CT identified extrahepatic disease not seen on CECT in 20% of the patients.

     

Experimental Actinobacillus pleuropneumoniae challenge in swine: Comparison of computed tomographic and radiographic findings during disease

ABSTRACT: BACKGROUND: In pigs, diseases of the respiratory tract like pleuropneumonia due to Actinobacillus pleuropneumoniae (App) infection have led to high economic losses for decades. Further research on disease pathogenesis, pathogen-host-interactions and new prophylactic and therapeutic approaches are needed. In most studies, a large number of experimental animals are required to assess lung alterations at different stages of the disease. In order to reduce the required number of animals but nevertheless gather information on the nature and extent of lung alterations in living pigs, a computed tomographic scoring system for quantifying gross pathological findings was developed. In this study, five healthy pigs served as control animals while 24 pigs were infected with App, the causative agent of pleuropneumonia in pigs, in an established model for respiratory tract disease. RESULTS: Computed tomographic (CT) findings during the course of App challenge were verified by radiological imaging, clinical, serological, gross pathology and histological examinations. Findings from clinical examinations and both CT and radiological imaging, were recorded on day 7 and day 21 after challenge. Clinical signs after experimental App challenge were indicative of acute to chronic disease. Lung CT findings of infected pigs comprised ground-glass opacities and consolidation. On day 7 and 21 the clinical scores significantly correlated with the scores of both imaging techniques. At day 21, significant correlations were found between clinical scores, CT scores and lung lesion scores. In 19 out of 22 challenged pigs the determined disease grades (not affected, slightly affected, moderately affected, severely affected) from CT and gross pathological examination were in accordance. Disease classification by radiography and gross pathology agreed in 11 out of 24 pigs. CONCLUSIONS: High-resolution, high-contrast CT examination with no overlapping of organs is superior to radiography in the assessment of pneumonic lung lesions after App challenge. The new CT scoring system allows for quantification of gross pathological lung alterations in living pigs. However, computed tomographic findings are not informative of the etiology of respiratory disease.     

Unsteady and three-dimensional simulation of blood flow in the human aortic arch

A three-dimensional and pulsatile blood flow in a human aortic arch and its three major branches has been studied numerically for a peak Reynolds number of 2500 and a frequency (or Womersley) parameter of 10. The simulation geometry was derived from the three-dimensional reconstruction of a series of two-dimensional slices obtained in vivo using CAT scan imaging on a human aorta. The numerical simulations were obtained using a projection method, and a finite-volume formulation of the Navier-Stokes equations was used on a system of overset grids. Our results demonstrate that the primary flow velocity is skewed towards the inner aortic wall in the ascending aorta, but this skewness shifts to the outer wall in the descending thoracic aorta. Within the arch branches, the flow velocities were skewed to the distal walls with flow reversal along the proximal walls. Extensive secondary flow motion was observed in the aorta, and the structure of these secondary flows was influenced considerably by the presence of the branches. Within the aorta, wall shear stresses were highly dynamic, but were generally high along the outer wall in the vicinity of the branches and low along the inner wall, particularly in the descending thoracic aorta. Within the branches, the shear stresses were considerably higher along the distal walls than along the proximal walls. Wall pressure was low along the inner aortic wall and high around the branches and along the outer wall in the ascending thoracic aorta. Comparison of our numerical results with the localization of early atherosclerotic lesions broadly suggests preferential development of these lesions in regions of extrema (either maxima or minima) in wall shear stress and pressure.     

多种无创检查组合在冠心病诊断中的价值

目的：评价多种无创辅助检查组合对冠状动脉粥样硬化性心脏病（冠心病）辅助诊断价值,筛选有效的冠心病确诊和排除指标,初步确定优化的冠心病早期诊断策略。方法：回顾性分析6419例冠心病患者多项无创辅助检查结果（包括静息心电图、24小时动态心电图、负荷心电图、负荷核素心肌显像、16或64排CT冠状动脉成像）,以冠状动脉造影阳性（至少一支主要冠状动脉或其主要分支的内径有≥50％的狭窄）为金标准,观察各种无创辅助检查组合对冠心病诊断的特异性、敏感性、误诊率、漏诊率、阳性预测值和阴性预测值。结果：多项无创辅助检查组合在冠心病的诊断中敏感性56．02-87．43％,特异36．13-87．61％,阳性预测值58．83．97．16％,阴性预测值30．21．73．36％,非介入手段中,敏感性和阴性预测值以动态心电图联合核素心肌灌注显像组最高,特异性和阳性预测值以动态心电图联合冠脉CT成像组最高。结论：辅助检查组合可作为无创性诊断、评价冠心病的重要方法,动态心电图可作为各级别医院冠心病筛查的基本及重要手段。     

Distribution of stress and strain along the porcine aorta and coronary arterial tree

The existence of a homeostatic state of stresses and strains has been axiomatic in the cardiovascular system. The objective of this study was to determine the distribution of circumferential stress and strain along the aorta and throughout the coronary arterial tree to test this hypothesis. Silicone elastomer was perfused through the porcine aorta and coronary arterial tree to cast the arteries at physiological pressure. The loaded and zero-stress dimensions of the vessels were measured. The aorta (1.8 cm) and its secondary branches were considered down to 1.5 mm diameter. The left anterior descending artery (4.5 mm) and its branches down to 10 microm were also measured. The Cauchy mean circumferential stress and midwall stretch ratio were calculated. Our results show that the stretch ratio and Cauchy stress were lower in the thoracic than in the abdominal aorta and its secondary branches. The opening angle (theta) and midwall stretch ratio (lambda) showed a linear variation with order number (n) as follows: theta = 10.2n + 63.4 (R(2) = 0.989) and lambda = 4.47 x 10(-2)n + 1.1 (R(2) = 0.995). Finally, the stretch ratio and stress varied between 1.2 and 1.6 and between 10 and 150 kPa, respectively, along the aorta and left anterior descending arterial tree. The relative uniformity of strain (50% variation) from the proximal aorta to a 10-microm arteriole implies that the vascular system closely regulates the degree of deformation. This suggests a homeostasis of strain in the cardiovascular system, which has important implications for mechanotransduction and for vascular growth and remodeling.     

Arterial imaging with computerized fluoroscopy

Computerized fluoroscopy (CF) allows visualization of any segment of the arterial vascular system with intravenous injection of small volumes of standard iodinated contrast media. Because it avoids the risk of arterial puncture and the need for hospitalization, this technique is safer and more economical than standard arteriography. Because of these advantages, CF is likely to expand the role of arteriography in the clinical management of vascular disease. Computerized arteriographic imaging requires an intravenous power injection of 40 to 60 cc of iodinated contrast media. Immediately after injection, six to ten fluoroscopic images (1/15 sec duration) are obtained at 1.5-sec intervals. The first image serves as a mask from which subsequent images are serially subtracted by means of a digital video image processor. The sequence of different images is contrast enhanced and stored on a video disk. Video images are converted to hard copy arteriography with a standard multiformat camera. Technical failures (<5%) may result from patient motion, inadequate peripheral venous access, or extravasation of contrast media. Nearly 600 computerized intravenous arteriograms have been performed in 240 patients with peripheral vascular disease. Qualitative com-parisons with standard arteriograms suggest a close correlation between these two imaging techniques. Computerized fluoroscopy allows the identification of atheromatous plaque ulceration, stenoses, occlusions, and aneurysms. This method has been used to visualize the aortic arch and its branches, the cervical and intracranial vessels, the abdominal aorta, and arteries of the extremities. Computerized fluoroscopy has great potential as a method for safe, simple diagnostic screening and assessment of the postoperative patient.     

Patterns of disease activity in multiple sclerosis: clinical and magnetic resonance imaging study.

OBJECTIVE--To compare the abnormalities shown by magnetic resonance imaging of the brain in three clinically distinct groups of patients with multiple sclerosis, and to correlate the extent of abnormality with the degree of clinical disability in the three groups. DESIGN--All patients underwent magnetic resonance imaging and full neurological examination, and their disability was scored according to the expanded Kurtzke disability state scale. SETTING--National Hospital for Nervous Diseases (Multiple Sclerosis NMR Research Group). PATIENTS--Three groups of patients with confirmed multiple sclerosis were studied: 12 patients with minimal disability despite a long (greater than 10 years) duration of illness (benign multiple sclerosis), 16 who had developed progressive disability after a relapsing and remitting course (secondary progressive multiple sclerosis), and 13 who had had progressive disability from the onset of the disease (primary progressive multiple sclerosis). MAIN OUTCOME MEASURES--Number and size of lesions in 17 anatomically defined sites; total lesion load, estimated with an arbitrary scoring system weighted for the size of lesions; and disability score. RESULTS--Magnetic resonance imaging showed that all 41 patients had abnormalities. These were extensive in the groups with secondary progressive and benign disease compared with the group with primary progressive disease. The lesions in the patients with secondary progressive disease were larger and more confluent than those in the two other groups (p = 0.007). Most lesions (85%) in the patients with primary progressive disease were under 5 mm in diameter; this percentage was higher than that in the two other groups (p = 0.032). Consequently the patients with primary progressive disease had the lowest mean lesion load (36.7); that in the patients with benign disease was 52.7 and that in the patients with secondary progressive disease 64.6 (p = 0.05). No correlation existed between disability and total lesion load. The distribution of brain lesions and of detectable lesions of the spinal cord, and the frequency of cortical atrophy, were similar in all groups. CONCLUSIONS--No relation was found between the degree of clinical disability and the extent of abnormality shown by magnetic resonance imaging: patients with clinically benign disease often had extensive abnormalities and those with primary progressive disease had surprisingly few lesions. Though magnetic resonance imaging increases knowledge of the disease process in multiple sclerosis and is invaluable in diagnosis, it is not helpful in predicting disability in individual patients.     

Cancer of the upper stomach: current problems of its diagnosis

Data on 1248 cases of stomaches radically operated on for cancer at the surgical departments of the Moscow Regional Research Clinical Institute in 1971 to 2000 were used to study a number of problems associated with cancer of the upper stomach, by regarding the present-day role of radiation diagnosis as of paramount importance. The following radiation diagnostic techniques were assessed. Among them there were traditional X-ray studies (in each case), the new radiation diagnostic techniques: ultrasound study and computed tomography (CT) (750 studies), magnetic resonance imaging (MRI) (120 studies). The potentialities of radiation diagnosis and endoscopy performed in all cases are compared. A specially developed procedure for exploring endophytic forms of gastric cancer was employed in the morphological studies of the material. The incidence of cancer of the upper stomach and its association with the esophagus are presented; some aspects of the morphogenesis of cancer of this site are discussed. The relationship of its clinical symptoms and its radiation image has been studied. In the authors' opinion, the past two decades' rise in the incidence of proximal gastric cancer is one of the main problems in diagnosing gastric cancer that continues holding its stand in the general structure of cancer morbidity. The tendency for diffuse and mixed forms to increase in the morphogenesis of gastric cancer provides evidence that radiation techniques should be actively used in its diagnosis. It is necessary to apply classical double-contrasting X-ray study and endoscopy on equal grounds as basic diagnostic methods at early stages. Only their concord use may change the poor situation associated with the diagnosis of cancer at this site. CT and MRI as additional techniques may substantially provide more required diagnostic information. This is first and foremost associated with difficulties in gastric endoscopic study when esophageal cancer is apparently proved.     

Cerebrovascular casting of the adult mouse for 3D imaging and morphological analysis

Vascular imaging is crucial in the clinical diagnosis and management of cerebrovascular diseases, such as brain arteriovenous malformations (BAVMs). Animal models are necessary for studying the etiopathology and potential therapies of cerebrovascular diseases. Imaging the vasculature in large animals is relatively easy. However, developing vessel imaging methods of murine brain disease models is desirable due to the cost and availability of genetically-modified mouse lines. Imaging the murine cerebral vascular tree is a challenge. In humans and larger animals, the gold standard for assessing the angioarchitecture at the macrovascular (conductance) level is x-ray catheter contrast-based angiography, a method not suited for small rodents. In this article, we present a method of cerebrovascular casting that produces a durable skeleton of the entire vascular bed, including arteries, veins, and capillaries that may be analyzed using many different modalities. Complete casting of the microvessels of the mouse cerebrovasculature can be difficult; however, these challenges are addressed in this step-by-step protocol. Through intracardial perfusion of the vascular casting material, all vessels of the body are casted. The brain can then be removed and clarified using the organic solvent methyl salicylate. Three dimensional imaging of the brain blood vessels can be visualized simply and inexpensively with any conventional brightfield microscope or dissecting microscope. The casted cerebrovasculature can also be imaged and quantified using micro-computed tomography (micro-CT)(1). In addition, after being imaged, the casted brain can be embedded in paraffin for histological analysis. The benefit of this vascular casting method as compared to other techniques is its broad adaptation to various analytic tools, including brightfield microscopic analysis, CT scanning due to the radiopaque characteristic of the material, as well as histological and immunohistochemical analysis. This efficient use of tissue can save animal usage and reduce costs. We have recently demonstrated application of this method to visualize the irregular blood vessels in a mouse model of adult BAVM at a microscopic level(2), and provide additional images of the malformed vessels imaged by micro-CT scan. Although this method has drawbacks and may not be ideal for all types of analyses, it is a simple, practical technique that can be easily learned and widely applied to vascular casting of blood vessels throughout the body.     

头颅CT、头颅MRI 在结核性脑膜炎诊断中应用

结核性脑膜炎是中枢神经系统感染性疾病中常见病,且致死率、致残率都很高.结核性脑膜炎的临床表现具有非特异性性,因此临床上容易引起误诊、漏诊.目前结核性脑膜炎的诊断主要是依据临床资料,脑脊液检查、生化及病原学和影像学检查等综合诊断方法.早期诊断及治疗和结核性脑膜炎的预后有着密切的关系,提高早期诊断是改善结核性脑膜炎顸后关键.头颅CT、头颅MR在结核性脑膜炎诊断中有着重要的作用,对结核性脑膜炎的诊断可提供重要的价值.本文就头颅CT及头颅MR在结核性脑膜炎中的作用做一综述.     

脑发育性静脉畸形9例临床影像特征分析及文献复习

目的:研究脑发育性静脉畸形(Cerebral Developmental Venous Anomalies,CDVA)临床及影像学特征及复习CDVA文献。方法:回顾性收集了自2011年11月至2014年3月我科确诊的9例CDVA的病人,对其临床特征、影像学检查方法包括电子计算机断层扫描(Computed Tomography,CT)、核磁共振成像(Magnetic Resonance Imaging,MRI)、数字减影血管造影(Digital Subtraction Angiography,DSA)及特征进行分析并对相关文献进行复习。结果:(1)临床症状:9例病人的临床症状包括头晕4例(4/9)、头痛4例(4/9)、恶心不适2例(2/9)、站立不稳1例((1/9)、小脑出血史1例(1/9)、眼部症状行眼科检查偶然发现小脑CDVA1例(1/9);(2)病变部位:病变位于幕上4例(4/9);幕下5例(5/9);(3)影像学检查:9例病人中,6例行CT平扫或增强扫描(3例平扫,3例平扫+增强);4例行MRI(1例平扫,3例平扫+增强);3例行DSA检查;(4)影像学特点:CT增强及重建、MRI的T1WI增强、SWI、MRA及DSA静脉期像均可显示出髓静脉及其形成的特征性"海蛇头"征象和其引流静脉。结论:CT、MRI、DSA影像学方法均可用于CDVA的诊断,在临床实践中需根据需要优化选择联合应用。     

腰椎峡部裂诊治的研究进展

腰椎峡部裂和峡部裂型腰椎滑脱症是临床上腰痛症状的常见原因,越来越多的患者饱受其困扰。随着对疾病认识的加深和医学技术的不断发展,因本病临床表现的特异性及敏感性较低,影像学主要依赖于X线片、CT、MRI、SPECT等诊断。治疗方式包括保守治疗和手术治疗(包括峡部裂修复术和不同方式的融合术等),其影像学诊断及治疗方式的选择尚未达成统一的认识,其诊断和治疗方式仍在争论和探索中。本文将对该病的诊断和治疗的选择进行总结。