Counter-flow gas contrast in the differential diagnosis of formation of the cardiodiaphragmatic angle

X-ray examination using counter-flow gas contrast study was performed in 30 patients for differential diagnosis of cardiodiaphragmatic angular formations. Approximately 700 ml of gas was administered in to the mediastinum, 1500 ml into the abdominal cavity, followed by x-ray examination (roentgenoscopy, roentgenography and tomography) in 30 min. It made it possible to determine an accurate site of the formation and to make correct diagnosis in 28 cases. This method is highly informative and considerably reduces the diagnostic period, decreasing radiation exposure of a patient.     

X-ray and computed tomographic diagnosis of aneurysm of the thoracic aorta

The paper is concerned with the results of x-ray and CT investigations conducted in 62 patients with suspected aneurysm of the thoracic aorta. The diagnosis was confirmed in 56. Of them 38 patients were operated on, 2 died without surgical intervention. X-ray investigations permitted differential diagnosis of mediastinal formations in 91.5% of cases. However in 2 cases when the combined method of intravenous administration of a contrast medium by means of a syringe was not used, aneurysmal aortic dilatation was not detected by CT. This method was found to be effective for diagnosis of complications of aneurysms of the thoracic aorta (calcinosis, aortic wall stratification and thrombosis of aneurysmal cavity).     

Diagnosis of remote metastases of rectal cancer with the aid of minimally invasive diagnostic procedures under computerized tomography control

At 124 patients who have rectum cancer made computer tomography of a abdominal cavity, retroperitoneal space and small pelvis with the purpose of definition of prevalence of a tumour. Was used computer tomograph "Somatom CRX", "Siemens". Remote metastasis are revealed at 26 patients, their most often localization--liver (45.8%). Are described CT-attributes of organs remote metastasis: hypodense spherical formation from 1.0 up to 4.0 CM in a diameter. Pathology changed lymph nodes were characterized by increase of a diameter more 1.5 CM, illegibility of contours, merge in a conglomerate. This changes have not specific character and also can be in case of hyperplasia of lymph nodes. At 14 patients is made puncture biopsy of focal formations under the CT-control. Diagnostic efficiency CT with puncture biopsy have made: accuracy--0.92, sensitivity--0.77, specificity--0.96. Is judged high efficiency of a method.     

Ultra-low field magnetic resonance tomography in the diagnosis of diseases of the spine and spinal cord]

A total of 309 investigated cases was analyzed with the help of the Magnaview apparatus with field intensity of 0.04 T. The method included obtaining both T1- and T2-suspended tomograms in the sagittal and, if necessary, transverse planes. MRT was shown to be an effective method of diagnosis and differential diagnosis of the compression syndrome of osteochondrosis, the effects of a "spinal" trauma, extra- and intramedullary tumors, metastatic vertebral involvement, postoperative changes, and syringomyelia.     

Nondestructive tree-ring measurements for Japanese oak and Japanese beech using micro-focus X-ray computed tomography

The purpose of this study is to establish technology for utilizing images taken by micro-focus X-ray computed tomography (CT) to perform nondestructive tree-ring measurement of wooden cultural properties. This paper covers two experiments conducted using Japanese oak as a typical example of ring-porous wood and Japanese beech as a representative example of diffuse-porous wood. In the first experiment, images of thin strip specimens of Japanese oak and Japanese beech taken by micro-focus X-ray CT are compared against those taken by soft X-ray radiography, the method conventionally used in dendrodensitometry. A discussion then follows in regard to image quality and tree-ring width measurement resulting from the two methods. In the second experiment, tomograms are taken of folk art articles made of Japanese oak and Japanese beech, demonstrating that it is possible to use nondestructive means to visualize the tree-rings of three-dimensional objects. The results show that micro-focus X-ray CT offers much promise of widespread utilization in the tree-ring dating of wooden cultural properties.     

Current complex noninvasive diagnosis of parathyroid tumors

The diagnosis of bulky formations of the parathyroid glands (PTG) has become possible since current high-resolution techniques of visualization, such as ultrasound study (USS), computed tomography (CT), magnetic resonance imaging (MRI), were introduced into practice. The presence of clinical and/or laboratory signs of hyperparathyroidism (HPT) is a signal to initiate a goal-oriented search for abnormal PTG formations. The complex diagnosis of HPT involves the methods of detecting osteoporosis ranging from routine X-ray study of the hand and foot to more in-depth techniques: dichromatic X-ray absorptiometry (DXA) and quantitative CT (QCT). USS is an excellent method for screening if abnormal PTC changes are suspected; however, negative USS results in the presence of clinical and/or laboratory signs of HPT should not stop a diagnostic search. CT with intravenous contrast bolus specifies the site and structure of an formation, has some advantage in detecting retrosternal tumors. Due to its high tissue contrast, three-dimensional images, none ionizing radiation and osseous structural artefacts, MRI becomes a preferable tool for studying PTG when they are typically or atypically located. Needle biopsy is required when noninvasive methods cannot characterize the pattern of an abnormal PTG formation properly or their results are contradictory.     

Computed tomography in the evaluation of tumor regression after neoadjuvant therapy: X-ray surgery and X-ray morphological comparisons

An analysis was made of chest computed tomograms of 38 small-cell lung cancer patients subjected to radical surgical treatment after neoadjuvant therapy. CT data were compared with the findings of macro- and microscopic examination of surgical specimens. In 24 (63.2%) patients, computed tomograms made before surgery showed complete tumor response confirmed by gross examination in 22 (96.1%) of them. However, microscopic examination found cancer cells in 8 (33.3%) patients. In 2 (8.3%) patients, small residual tumors could be detected by sight, which was confirmed by pathological examination. In 14 (36.8%) patients with partial response, radiological and gross examination findings fully coincided. Nevertheless, in 2 (14.3%) cases the "residual tumor" appeared to be a segment of fibrocicatrical tissue under pathological examination. On the basis of the CT findings the values of diagnostic sensitivity, accuracy and specificity in tumor response evaluation were calculated which made up 87.5%, 68.4% and 54.5% respectively. With sufficiently high sensitivity, CT specificity is low. CT makes it possible to objectively define the response of small-cell lung cancer to neoadjuvant therapy. However, the conclusion about complete response to the treatment can be made only on the basis of a comprehensive evaluation of the results of all available investigation methods and pathological examination.     

Relationship between the physiological cross-section of the human jaw muscles and their cross-sectional area in computer tomograms

Physiological cross-section (PCS) and cross-sectional area in computer tomograms made at right angles to the mean fibre direction were compared in the masseter, temporalis and pterygoid muscles of six human cadavers. PCS was determined as (1) total cross-section of teased fibre bundles (2) total fibre weight divided by mean fibre length. The two measures correlated strongly, but the first was always 25% lower than the second, irrespective of the muscle concerned. The cross-sections in the tomograms (SCS) were smaller than the PCS, except in the lateral pterygoid. In all muscles, a statistically significant correlation was found between SCS and PCS. The SCS can be used to predict PCS, with an error of 0.3-1.0 cm2. In our material, cross-sections were about 20% higher than reported in the literature. It is suggested, that this discrepancy is caused by the loss of natural teeth.     

The localization and distribution of the antigen of the fixed rabies virus in the central nervous system of animals studied by the fluorescent antibody method]

The immunofluorescent study of cryostatic sections of the main structures of the brain of animals infected with fixed rabies virus, strain CVS, was carried out by the direct modification of the fluorescent antibody method. Definite regularities in the distribution of rabies virus antigen after the intracerebral distribution of rabies virus were established. The antigen could be detected mainly in neurons of the cortex, the hippocampus major, subcortical formations and was absent in the truncal formations of the brain and the cerebellum. After the peripheral inoculation of the virus the maximum accumulation of the antigen was noted in the truncal and cerebellar structures, less antigen could be detected in subcortical and other formations of the brain. These features should be taken into account in the laboratory rapid diagnosis of rabies. The advantages of the method of cryostatic tissue sections over traditional imprints on glass slides give ground to recommend the method of cryostatic sections for the rapid diagnosis of rabies.     

Structure and flexibility of individual immunoglobulin G molecules in solution

In contrast to averaging methods of determining structure, such as X-ray diffraction, NMR, and single-particle tomography, cryo-electron tomography allows three-dimensional imaging of an individual object in solution. The method has previously been used to study cells and very large macromolecules. We have used cryo-electron tomography to analyze a monoclonal IgG, with a molecular weight of only 150 kDa. Tomograms reveal y-shaped IgG molecules with three protruding subunits. Docking X-ray structures enabled us to recognize the three subunits as two ellipsoidal Fab arms and a heart-shaped Fc stem. Each subunit has a similar structure in the tomograms and in the X-ray map. Notably, the positions of the Fab arms relative to the Fc stem differed greatly from one molecule to another. The large flexibility of IgG in solution is most likely of functional significance in antigen recognition. This distribution of individual structures provides a qualitative insight into the system dynamics.     

Optimization of computed tomographic studies during the diagnosis of chronic nonspecific lung diseases

A comparative study was made of computerized tomograms of 115 patients, of them 78 suffered from nonspecific chronic pulmonary diseases (chronic bronchitis, bullous emphysema, spontaneous pneumothorax, and fibrosing alveolitis), and 37 patients were healthy. Of all transverse sections the most informative ones were defined, and anatomical reference points were determined for. A conclusion was made that computerized tomograms at 5 most informative levels were sufficient to diagnose changes in each of the lung segments in their diffuse affection. CT standardization was shown to have the same advantages as standardization of layins in routine tomography of the lungs, facilitating comparison over time and reducing radiation exposure of a patient.     

Structural transformation of collagen fibrils in corneal stroma during drying. An x-ray scattering study.

X-ray scattering experiments were performed on human corneas during drying. In a first stage the collagen interfibrillar distance decreased considerably. Then, at a critical point of dehydration, a structural transformation of the collagen fibrils was observed. This finding leads to a two-stage drying model, which explains the discrepancy between the collagen fibril diameters determined by x-ray scattering and by electron microscopy. Our results strongly suggest that the collagen fibrils in the corneal stroma are surrounded by a cylindrical coating made mainly of proteoglycans. The coating appears as a three-dimensional fractal network with fractal dimension of 2.7 +/- 0.1.     

Ununited lower limb fractures.

Nonunion is a fairly common complication of fracture management, with an overall rate of about 3% for the skeleton as a whole and 9% for the tibia. High-energy injury fractures have a nonunion rate as high as 75%. Other factors that may lead to nonunion are inappropriate treatment, infection, and preexisting disease. The diagnosis of nonunion is based largely on clinical examination. Plain radiographs and tomograms, computed tomograms, and contrast imaging may be used to confirm nonhealing. Radionuclide imaging can help determine the presence of infection, an impaired blood supply, or impaired osteogenic activity at the fracture site. The treatment of ununited fractures is based on the principles of good fracture management: adequate immobilization, asepsis and soft tissue cover, osteoconduction (bone contact), osteoinduction (stimulation of bone growth), and metabolic well-being. New modalities for osteoinduction are promising adjuncts to standard treatment, the autogenous bone graft, but conclusive proof of efficacy in humans does not yet exist.     

The Spatial Variation of Membrane Potential Near a Small Source of Current in a Spherical Cell

A theoretical analysis is presented of the change in membrane potential produced by current supplied by a microelectrode inserted just under the membrane of a spherical cell. The results of the analysis are presented in tabular and graphic form for three wave forms of current: steady, step function, and sinusoidal. As expected from physical reasoning, we find that the membrane potential is nonuniform, that there is a steep rise in membrane potential near the current microelectrode, and that this rise is of particular importance when the membrane resistance is low, or the membrane potential is changing rapidly. The effect of this steep rise in potential on the interpretation of voltage measurements from spherical cells is discussed and practical suggestions for minimizing these effects are made: in particular, it is pointed out that if the current and voltage electrodes are separated by 60°, the change in membrane potential produced by application of current is close to that which would occur if there were no spatial variation of potential. We thus suggest that investigations of the electrical properties of spherical cells using two microelectrodes can best be made when the electrodes are separated by 60°.     

Morphogenesis and significance of fibrous bodies in human pituitary adenomas

In the course of light and electron microscopic studies of 142 surgically-removed human pituitary adenomas, 28 tumors were found containing fibrous bodies composed of type II microfilaments with an average width of 115A. These spherical structures, measuring up to 4-5 micrometer occur exclusively in sparsely granulated growth hormone cells and acidophil stem cells, but as revealed by the immunoperoxidase technique, contain no growth hormone. Fibrous bodies are located in the Golgi region and are consistently associated with Golgi membranes and smooth-surfaced endoplasmic reticulum. Their association with centrioles is thought to be anatomical rather than functional. Several adenoma cells possess spherical formations composed entirely of smooth-walled membranes or transitional forms between smooth tubules and type II microfilaments, suggesting that smooth membranes may play a key role in the production of fibrillar substance. Fibrous bodies appear to be reliable morphologic markers and are valuable in the differential diagnosis of pituitary adenomas.     

Fifth dimension of life and the 4/5 allometric scaling law for human brain

Brain cells are not spherical. The basal metabolic rate (B) of a spherical cell scales as B approximately r2, where r is the radius of the cell; that of a brain cell scales as B approximately r(d), where r is the characteristic radius of the cell and d is the fractal dimensionality of its contour. The fractal geometry of the cell leads to a 4/5 allometric scaling law for human brain, uniquely endowing humans with a 5th dimension and successfully explains why the scaling exponent varies during rest and exercise. A striking analogy between Kleiber's 3/4 law and Newton's second law is heuristically illustrated. A physical explanation is given for the 4th dimension of life for three-dimensional organisms and the 5th dimension for human brain.     

A class of flow bifurcation models with lognormal distribution and fractal dispersion

We report a quantitative analysis of a simple dichotomous branching tree model for blood flow in vascular networks. Using the method of moment-generating function and geometric Brownian motion from stochastic mathematics, our analysis shows that a vascular network with asymmetric branching and random variation at each bifurcating point gives rise to an asymptotic lognormal flow distribution with a positive skewness. The model exhibits a fractal scaling in the dispersion of the regional flow in the branches. Experimentally measurable fractal dimension of the relative dispersion in regional flow is analytically calculated in terms of the asymmetry and the variance at local bifurcation; hence the model suggests a powerful method to obtain the physiological information on local flow bifurcation in terms of flow dispersion analysis. Both the fractal behavior and the lognormal distribution are intimately related to the fact that it is the logarithm of flow, rather than flow itself, which is the natural variable in the tree models. The kinetics of tracer washout is also discussed in terms of the lognormal distribution.     

CT与X线诊断肠梗阻的临床价值探讨

目的：探讨腹部X线与CT扫描鉴别急性肠梗阻的准确性,为临床诊断提供参考。方法：选取2011年8月-2013年8月我院收治的66例急性肠梗阻患者的临床资料进行回顾分析。所有患者均经手术活检或病理诊断证实为急性肠梗阻。术后患者均行腹部X线及CT扫描检查,对两种方法判断肠梗阻的发生、梗阻部位、类型及病因与手术病理结果进行比较,评价并分析两种检查方法的准确率。结果：66例肠梗阻患者中,X线检出率为89．39％,CT检出率为95．45％。X线诊断小肠梗阻准确率为72．10％,CT为86．05％;X线诊断结肠梗阻准确率为69．57％,CT为86．96％。X线诊断肿瘤准确率为69．57％,CT为86．96％;X线诊断肠粘连准确率为67．86％,CT为82．14％;X线诊断肠套叠准确率为60．00％,CT为80．00％;X线诊断单纯性机械性肠梗阻准确率为78．72％,CT为82．98％;X线诊断绞窄性肠梗准确率为73．68％,CT为78．95％。CT对肠梗阻部位、病因及类型的诊断准确率高于腹部X线片,差异具有统计学意义（P〈0．05）。结论：腹部X线与CT用于诊断急性肠梗阻具有较高的准确率,但CT对于肠梗阻部位、梗阻类型及梗阻病因的诊断优于X线片。     

CT 与X线诊断肠梗阻的临床价值探讨

目的：探讨腹部X 线与CT 扫描鉴别急性肠梗阻的准确性,为临床诊断提供参考。方法：选取2011年8 月-2013 年8 月我院 收治的66 例急性肠梗阻患者的临床资料进行回顾分析。所有患者均经手术活检或病理诊断证实为急性肠梗阻。术后患者均行腹 部X 线及CT扫描检查,对两种方法判断肠梗阻的发生、梗阻部位、类型及病因与手术病理结果进行比较,评价并分析两种检查 方法的准确率。结果：66 例肠梗阻患者中,X线检出率为89.39%,CT 检出率为95.45%。X 线诊断小肠梗阻准确率为72.10%,CT 为86.05%;X线诊断结肠梗阻准确率为69.57%,CT 为86.96%。X线诊断肿瘤准确率为69.57%,CT 为86.96%;X线诊断肠粘连 准确率为67.86%,CT 为82.14%;X 线诊断肠套叠准确率为60.00%,CT 为80.00%;X线诊断单纯性机械性肠梗阻准确率为78.72%,CT为82.98%;X线诊断绞窄性肠梗准确率为73.68%,CT 为78.95 %。CT 对肠梗阻部位、病因及类型的诊断准确率高于腹部X 线片,差异具有统计学意义(P<0.05)。结论：腹部X 线与CT 用于诊断急性肠梗阻具有较高的准确率,但CT 对于肠梗阻部位、梗阻类型及梗阻病因的诊断优于X线片。