基于描述的微血管网络图象压缩

微血管网络图象已日渐成为临床诊断和科学研究的重要依据，为了压缩无用数据，保留已有测量结果，本文提出了基于描述的微血管网络图象压缩技术。通过血管提取、细化等步骤，最后建立了相应于原血管图的数学描述结构，这种方法使数据达到了极高的压缩比。借助于生成的描述结构，可以方便地获得已有的测量结果而无需对图象作恢复和再测量。由于描述保留了足够充分的网络构造信息，因此使网络重构成为可能。     

The Poggendorff illusion explained by natural scene geometry

One of the most intriguing of the many discrepancies between perceived spatial relationships and the physical structure of visual stimuli is the Poggendorff illusion, when an obliquely oriented line that is interrupted no longer appears collinear. Although many different theories have been proposed to explain this effect, there has been no consensus about its cause. Here, we use a database of range images (i.e., images that include the distance from the image plane of every pixel in the scene) to show that the probability distribution of the possible locations of line segments across an interval in natural environments can fully account for all of the behavior of this otherwise puzzling phenomenon.     

Endovascular occlusion of direct carotid cavernous fistula with detachable balloons: usefulness of 3D angiography

The objective of this study is to show rotational 3D angiography findings and their usefulness in the occlusion of carotid cavernous fistulas (CCFs) using detachable balloons. Five patients with direct CCF were retrospectively reviewed for details of interventional procedures and 2D and 3D angiography findings. Pretherapeutic 2D and 3D angiograms (n=2) were compared to evaluate the size of the fistula and the relative size of the cavernous sinus with respect to the fistula. Postinflation-predetachment (n=3) and postdetachment (n=4) 2D and 3D angiograms were compared in each stage to evaluate the relative location of the balloon to the internal carotid artery (ICA), presence of a pseudoaneurysm, and relative size of the balloon to the fistula. Pretherapeutic 2D and 3D angiograms were equally effective in showing the fistula and relative size of the cavernous sinus. But, 3D angiography with cut images at arbitrary viewing angles clearly visualized the 3D relations between the ICA, fistula, and cavernous sinus. Both postinflation-predetachment 2D and 3D images in two patients equally showed a contrast-filled pseudoaneurysm outside the ICA and intraluminal location of the balloon. However, only the 3D images showed no difference in size of the balloon compared with the fistula, which was relevant to traction-induced instability in the remaining one patient. Both postdetachment 2D and 3D angiograms were equal in terms of showing ICA compromise (60%) in one patient and an extraluminal balloon location with complete fistular occlusion in two patients. In the remainder, a small pseudoaneurysm was identified only on 3D images. Three-dimensional angiography is a useful imaging tool for capturing the complex perifistular anatomy in the pretherapeutic stage, and for providing detailed information about the degree of balloon inflation and its location, the presence of a pseudoaneurysm, and the expected traction-induced instability in the predetachment stage. Postinflation-predetachment 3D angiography may therefore offer a chance to correct an erroneous manipulation that would otherwise lead to an incomplete procedural outcome and disastrous balloon migration.     

Dopaminergic receptors in rat dura mater: pharmacological characteristics

1. The location and distribution of dopaminergic receptors in rat dura mater was studied by examining several dural zones (vascular, perivascular, intervascular) in different cranial and spinal regions. 2. The pharmacological characteristics and anatomical distribution of dopamine D1- and D2-like receptors sites were investigated using combined pharmacological techniques and immunofluorescent microscopy. 3. Samples of rat dura mater were obtained from 10 adult Wistar rats. On frozen slices, dopaminergic D1 and D2 receptors were stained immunohistochemically using monoclonal antibodies. 4. Inhibition studies were performed using fluorescent and non-fluorescent agonists or antagonists to define the pharmacological specificity of the immunostaining. 5. The greater sensitivity to displacement by amisulpride, bromocryptine, domperidone, haloperidol, raclopride and l-sulpiride than to displacement by N-propyl-nor-apomorphine, quinpirole and clozapine suggests that the immunofluorescent sites observed in these experiments are likely to belong to the dopamine D2 receptor subtype. 6. Our observations provide evidence of the presence of D1 and D2 receptors in the wall of meningeal vessels. The dopaminergic receptors are located in the adventitia, media and intima of dural arteries. Furthermore, the density of receptors is higher in close proximity to arteries and decreases passing from the vascular to the perivascular and intervascular zones. 7. In the rat dura mater, dopamine regulates the meningeal blood vessels and, through this action, dopamine and its receptors can play an important role in the pathogenesis of cephalalgia.     

Unveiling the foveal blue scotoma through an afterimage

The absence of short-wave-sensitive (S-) cones in the human foveola normally goes unnoticed, but the resulting foveal S-cone, or blue, scotoma can be visualized as the negative afterimage of a short-wavelength adapting field on a larger white background. The afterimage has an annular shape with a lighter inner region that corresponds to Maxwell's spot, and a small bright spot in the center corresponding to the foveal blue scotoma. We have shown that the visibility of the center spot in the afterimage approximately follows the spectral sensitivity curve of the S-cones. We further demonstrate that the central bright spot subtends a retinal area that is coincident with the tritanopic region of the foveola. The macular pigment distribution measured for the same observers also peaks in the central fovea, but has a relatively high density over a broader retinal region than the bright spot in the negative afterimage, and more closely corresponds to the lighter annular region of the afterimage. The results support the hypothesis of an active post-receptoral process for filling-in of chromatic scotomas.     

Self-enhancing effects of exposure to thin-body images

OBJECTIVE: This study examines the effect of thin-body media images on mood, self-esteem, and self-image ratings of restrained and unrestrained eaters. A secondary purpose was to examine whether these effects were influenced by exposure duration. METHOD: Under the guise of a perception study, participants were exposed to thin-body or control advertisements (e.g., perfume bottles) for either 7 or 150 ms and then completed a questionnaire packet. RESULTS: Restrained eaters reported more favorable self-image and social self-esteem (but not appearance self-esteem) scores after exposure to thin-body images than after exposure to control advertisements. The self-image and social self-esteem scores of unrestrained eaters were unaffected by advertisement type, but their appearance self-esteem scores were lower after exposure to thin-body advertisements. No differences were found for mood ratings and total self-esteem. DISCUSSION: We discuss restraint status as a moderator of the effects of thin-body images on women's body image.     

Confidential storage and transmission of medical image data

We discuss computationally efficient techniques for confidential storage and transmission of medical image data. Two types of partial encryption techniques based on AES are proposed. The first encrypts a subset of bitplanes of plain image data whereas the second encrypts parts of the JPEG2000 bitstream. We find that encrypting between 20% and 50% of the visual data is sufficient to provide high confidentiality.     

Property analysis of ectopic calcification in the carpal tunnel identification of apatite crystals: a case report

Introduction A 64-year-old woman presented with symptoms of subacute exacerbation of a year-long carpal tunnel syndrome that was caused by a large calcified mass in the tunnel.Conclusion The resected mass consisted of very tiny rods, and x-ray diffraction analysis, as well as the component analysis using energy dispersive x-ray microanalysis, revealed the mass to be most compatible with apatite. The back-scattered electron images suggested that precipitation might be a mechanism for development of the calcified mass.     

FliMax,a novel stimulus device for panoramic and highspeed presentation of behaviourally generated optic flow

A high-speed panoramic visual stimulation device is introduced which is suitable to analyse visual interneurons during stimulation with rapid image displacements as experienced by fast moving animals. The responses of an identified motion sensitive neuron in the visual system of the blowfly to behaviourally generated image sequences are very complex and hard to predict from the established input circuitry of the neuron. This finding suggests that the computational significance of visual interneurons can only be assessed if they are characterised not only by conventional stimuli as are often used for systems analysis, but also by behaviourally relevant input.     

3-D Visualization of Medical Images with Arbitrary Sections

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