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1.
We investigate a concept for making a large area, flat-panel detector for digital radiology. It employs an x-ray sensitive photoconductor to convert incident x-radiation to a charge image which is then electronically read out with a large area integrated circuit. The large area integrated circuit, also called an active matrix, consists of a two-dimensional array of thin film transistors (TFTs). The potential advantages of the flat-panel detector for digital radiography include: instantaneous digital radiographs without operator intervention; compact size approaching that of a screen-film cassette and thus compatibility with existing x-ray equipment; high quantum efficiency combined with high resolution. Its potential advantages over the x-ray image intensifier (XRII)/video systems for fluoroscopy include: compactness; geometric accuracy; high resolution, and absence of veiling glare. The feasibility of the detector for digital radiology was investigated using the properties of a particular photoconductor (amorphous selenium) and active matrix array (with cadmium selenide TFTs). The results showed that it can potentially satisfy the detector design requirements for radiography (e.g., chest radiography and mammography). For fluoroscopy, the images can be obtained in real-time but the detector is not quantum noise limited below the mean exposure rate typically used in fluoroscopy. Possible improvements in x-ray sensitivity and noise performance for the application in fluoroscopy are discussed.  相似文献   

2.
Graded manual compression therapy under ultrasound guidance has become the standard first line treatment of post-catheterization femoral pseudoaneurysms. Although effective, this treatment is often poorly tolerated by both patient and operator. We describe a new mechanical technique which has proven successful in our department, and is well tolerated by both patients and staff.  相似文献   

3.
The author introduces a photopenic marker that was used to delineate better anatomic mapping in a double-phase technetium-99m-sestamibi parathyroid imaging. This home-marker was placed on a patient within the imaging field to increase reproducibility of the images: early versus delayed images.  相似文献   

4.
Progress in the care of the critically ill patient with life-threatening infection has been hampered by inconsistent, often confusing terminology. The clinical syndrome of sepsis-familiar to all yet definable by none-describes a highly heterogeneous group of disorders with different causes and differing prognoses. The imminent availability of mediator-directed therapy has created a sense of urgency to develop better methods for delineating discrete clinical syndromes and to modulate the host response, which may bring both benefit and harm, depending on the clinical circumstances. The term systemic inflammatory response syndrome (SIRS) was introduced several years ago to describe the familiar clinical syndrome of sepsis, independent of its cause. SIRS can result from trauma, pancreatitis, drug reactions, autoimmune disease, and a host of other disorders; when it arises in response to infection, sepsis is said to be present. SIRS describes a dynamic process that has adaptive survival value for the host. The maladaptive consequence of this process in the critically ill patient is the development of progressive but potentially reversible remote organ dysfunction-the multiple organ dysfunction syndrome. The development of cogent conceptual frameworks for classification of the septic response in critically ill patients is more than a question of linguistic pedantry. Optimal therapy presupposes identification of an homogeneous patient population with a characteristic disease process and a predictable response to an intervention. Although progress has been made in identifying such groups of critically ill patients, the disappointing results of clinical trials of agents that so clearly demonstrate efficacy in animal models indicates that considerable work remains.  相似文献   

5.
Replacement of a long segment of esophagus for esophageal atresia or severe stenosis remains a special problem in children. The following studies were designed to test the hypothesis that a section of small bowel without serosa could survive as a free autologous transplant to replace part of the mediastinal esophagus. Laparotomy was performed in 20 adult cats, a loop of small bowel was resected and an end-to-end jejunojejunostomy was completed. The serosa of the resected bowel was removed and the mucosa-muscularis graft was used to replace a segment of the middle esophagus that was resected via a right thoracotomy. The interposed graft was entirely wrapped with adjacent skeletal muscle flaps. Postoperative studies include barium swallow and cine esophagograms, histology and blood vessel casts. Results are presented which show anatomical and functional survival of 16 grafts without blood vessel anastomoses or intrinsic vascular pedicles.  相似文献   

6.
This paper argues that we should understand the process of IT design as the development of sociotechnical configurations. Drawing upon our experiences with an electronic patient record (EPR) on an Intensive Care Unit (ICU), we depict medical work practices as natural systems. Several considerations for design are developed. First, the EPR should not be overly structured with rationalistic and prefixed notions of the organization and content of medical work. Implementing structure is crucial, however, this should be derived from detailed, empirical knowledge of the practice involved. Second, it is crucial to ensure that the usage of the system will yield immediate benefits for primary users: the systems should support work, not generate it. Third, designing IT should include being aware of the socio political nature of seemingly 'neutral' tools as EPRs.  相似文献   

7.
8.
RATIONALE AND OBJECTIVES: To introduce routine bilaterally antegrade selective stationary digital subtraction angiography (DSA), and prospectively compare it with unselective stationary DSA in the detection of calf arteries and assess additional time and complication rate. METHODS: Twenty-five patients received one unselective and two separate antegrade selective studies of each calf. Images were evaluated for image quality, number of depicted run-off vessels, and potential crural bypass recipient arteries. RESULTS: Bilaterally antegrade selective DSA was significantly superior in image quality and motion artifacts (P < 0.01). The number of adequately depicted run-off arteries per calf increased from 79% (2.37 of 3) to 96% (2.89 of 3) for legs with advanced peripheral vascular disease (PVD). Seventy-nine instead of 62 potential bypass recipients were identified (P = 0.002). Mean procedure time needed for selective catheterizations was 7 minutes. No adverse events were seen. CONCLUSIONS: Bilaterally antegrade selective DSA clearly is superior to aortic run-off DSA depicting tibial arteries. It requires comparatively small additional effort. Outflow vessel detection essentially is independent of advanced PVD.  相似文献   

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10.
Amelogenesis imperfecta is a rare developmental abnormality of enamel, the main clinical problems of which are extensive loss of tooth tissue, poor aesthetics and tooth sensitivity. Management often involves complex and long-term treatment but is usually successful if patients are well motivated. This case report outlines the management of a teenager with amelogenesis imperfecta (hypocalcified type) who had requested a dental clearance at an early age.  相似文献   

11.
A rare autopsy case of mediastinal bronchogenic cyst with malignant transformation is presented. The cyst had been located in the anterior mediastinum for at least 28 years in a 52 year old male. Chest X-ray findings showing rapid enlargement of the cyst and biopsy of the spine for lumbago made a clinical diagnosis as suspicious mediastinal cystic teratoma with malignant transformation metastasizing to the spine. Postmortem examination revealed that the cyst was located in the anterior mediastinum extending to the left pulmonary hilum and had no connection with the tracheobronchial tree. The cyst wall consisted of bronchus-like tissue including ciliated epithelium, hyaline cartilage, smooth muscle and mucoserous glands. There were no teratomatous components in the wall. Malignant tumor predominantly consisting of round cells occurred in the thickened cyst wall and grew into the cyst cavity with direct invasion of the lung and metastases to the liver, adrenal glands, bone marrow of the lumbar spine and lymph nodes. An immunohistochemical study showed that the tumor cells frequently expressed cytokeratin, epithelial membrane antigen and carcino-embryonic antigen, occasionally CA19-9, vimentin and neuron-specific enolase. From these findings, the tumor was diagnosed as undifferentiated carcinoma arising in the mediastinal bronchogenic cyst.  相似文献   

12.
AIM: To establish whether infection with Epstein-Barr virus (EBV) contributed to the development of coronary artery lesions in a six year old child with an aneurysm and stenoses of the coronary arteries and suspected Kawasaki disease. METHODS: Postmortem paraffin wax sections of the coronary artery and myocardium were examined by in situ hybridisation for expression of EBER-1 (EBV-encoded RNA-1). Positive controls consisted of an EBV positive case of Hodgkin disease and a case of posttransplantation lymphoma. RESULTS: No EBER-1 positive cells were identified in either myocardium or walls of the coronary artery. CONCLUSIONS: Although EBV has been implicated in the aetiology of Kawasaki disease and development of coronary artery lesions, this process was not confirmed in this patient. It is likely that an unusual immunological reaction to a primary EBV infection with suspected deregulation of T helper cell activity leads to severe coronary artery damage in early childhood.  相似文献   

13.
Objective: As cognitive dissonance is theorized to contribute to the effects of dissonance-based eating disorder prevention programs, we evaluated a high-dissonance version of this program against a low-dissonance version and a wait-list control condition to provide an experimental test of the mechanism of intervention effects. Method: Female college students (N = 124, mean age = 20.9 years, SD = 3.9) with body image concerns were randomized to the 3 conditions. The high-dissonance program was designed to maximize dissonance induction, and the low-dissonance program was designed to minimize it; the substantive content of the 2 programs was matched. Results: Relative to controls, those in the high-dissonance condition showed significantly greater reductions in thin-ideal internalization, body dissatisfaction, dieting, and eating disorder symptoms by posttest, and those in the low-dissonance condition showed significantly greater reductions in the first 3 outcomes by posttest, with most of these effects persisting to 3-month follow-up. High-dissonance participants showed significantly greater reductions in eating disorder symptoms than low-dissonance participants did by posttest, but this effect was nonsignificant by 3-month follow-up. Conclusions: Results suggest that dissonance induction contributes to intervention effects but imply that the intervention content, nonspecific factors, and demand characteristics play a much more potent role in producing effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

14.
The purpose of this investigation was to apply the recently developed CAMPI (computer analysis of mammography phantom images) method to a Fischer Mammotest Stereotactic Digital Biopsy machine. Another aim was to further elucidate the nature of the empirically introduced CAMPI measures. Images of an American College of Radiology (ACR) accreditation phantom centered on the largest two speck groups were obtained on this machine under a variety of x-ray conditions. An additional measure, alternative SNR (ASNR) is introduced which is complementary to the SNR measure. Analyses of the Mammotest images revealed that the mAs and kVp dependencies of the CAMPI measures could be understood from basic imaging physics principles. It is shown that: (1) the measures reflect the expected linearity of the digital detector and Poisson photon statistics; (2) under automatic exposure control (AEC) conditions the signal (SIG) measure is proportional to subject contrast; and (3) under AEC conditions the noise (NOI) measure is proportional to the square root of the average absorbed photon energy. Correspondence with basic imaging physics principles shows that the measures are significantly free of artifacts. Precision of the CAMPI measures exceeds that of human observers by orders of magnitude. CAMPI measures are expected to be more relevant to clinical mammography than Fourier metrics as the measurements are done on objects of arbitrary shape and size that were designed by the manufacturer to resemble various detection tasks in mammography. It is concluded that CAMPI can perform objective and highly precise evaluations of phantom image quality in mammography. It could be used as a sophisticated quality control tool, as a replacement for the current ACR/MQSA phantom evaluation program, and to evaluate the rapidly evolving digital mammography technology.  相似文献   

15.
A newborn presented with a cerebral ganglioglioma. This is a rare diagnosis in a neonate. The imaging appearance (hyperdense on CT, hyperintense on T1-weighted and hypointense on T2-weighted MRI) is very unusual for this type of tumor.  相似文献   

16.
Terminolateral neurorrhaphies were used up to the beginning of this century. After that, they were no longer reported. We tested the efficacy of a new type of end-to-side neurorrhaphy. A group of 20 rats had the peroneal nerve sectioned, and the distal ending was sutured to the lateral face of the tibial nerve after removing a small epineural window. All experiments were made on the right side, the left one remaining untouched in half the animals of each group. The other half was denervated by sectioning and inverting the endings of the peroneal nerves. In this way, tibial cranial muscles were either normal or denervated on the left side and reinnervated through end-to-side neurorrhaphies on the right side. After 7.8 months, the animals were subjected to electrophysiologic tests, sacrificed, and the nerves and muscles were taken for histologic examination. A response of the tibial cranial muscle was obtained in 90 percent of the animals. The distal ending of the peroneal nerve showed an average of 861 nerve fibers. The average areas of the reinnervated tibial cranial muscles were (microns 2) 1617.81 for M2n (when the contralateral side was normal) and 1579.19 for M2d (when the contralateral was denervated). We conclude that the terminolateral neurorrhaphy is functional, conducting electrical stimuli and allowing the passage of axons from the lateral surface of a healthy nerve, to reconstitute the distal segment of a sectioned nerve. The absence of an incision on the axons of the donor nerve was no impediment to axonal regeneration or to the passage of electrical stimuli. The results demonstrate the possibility of using end-to-side and terminolateral neurorrhaphies for reconstituting neural lesions when only a distal end is available; the reinnervation can be obtained from the lateral face of a healthy nerve.  相似文献   

17.
Clinical reports have suggested an unusual frequency in the number of patients with food allergy to snails who are also allergic to the house-dust mite (HDM). As allergy to HDM is one of the most frequent sensitizations in atopic patients of Western countries, evaluation of the relevance of the concomitant sensitization to Dermatophagoides pteronyssinus and to snails is an important consideration. To evaluate the responsibility of different snail components and of snail mites for inducing in vivo hypersensitivity in patients allergic to HDM, the in vivo reactivity of patients with clinical symptoms after ingestion of snails was assessed by skin prick tests with extracts and hemolymph from four different Helix species snails, and extracts from the snail parasitic mite, Riccardoella limacum. In addition, to obtain epidemiologic data on cosensitization to HDM and snails in allergic patients, the frequency of snail sensitization and its relationship to HDM sensitization were determined in a population of 169 allergic children. All patients allergic to snails had positive skin prick tests to the snail extracts and none to R. limacum extract. The number of positive skin reactions did not significantly differ whatever the species, snail part, or heating procedure used. The strongest reactions were obtained with Helix pomatia (Burgundy snail). Among the 169 prospectively tested children, 38 had a positive prick test to snail extracts; 79% of the snail-sensitized children had sensitization to HDM; and 31% of the children allergic to HDM were found to be sensitized to snails. These results show that snail components, and not the mite R. limacum, were responsible for the in vivo hypersensitivity. These snail components reacting in vivo are present in different parts of snails, including the hemolymph. One-third of the children allergic to HDM were sensitized to snails without any previous ingestion of snails: this observation suggests that HDM was the sensitizing agent and that the cross-reaction could be clinically relevant in countries where eating snails is common.  相似文献   

18.
A 65-year-old female with congenital giant, hairy and pigmented nevus developed sudden onset of headache and consciousness disturbance. CT scan revealed a high density mass in the right temporal subcortical region. The high density area suggested hematoma. A right temporal craniotomy was performed. Hemorrhage was observed in a black colored tumor. Histologically, the tumor was malignant melanoma, while the skin tumor was benign intradermal nevi. This patient was diagnosed as neurocutaneous melanosis. Neurocutaneous melanosis belongs to unusual congenital syndrome, and an adult case is very rare. To our knowledge this is the oldest patient to be reported with this disease.  相似文献   

19.
Gallstone ileus is a rare complication of cholecystolithiasis with a high mortality because of the advanced age of the patients and the often delayed diagnosis. Signs of a cholecystoduodenal fistula are often absent in conventional ultrasonic and radiological methods. Treatment options are: 1. Enterolithotomy, 2. One stage procedure or 3. Two stage procedure consisting of enterolithotomy and the surgery of the biliary tract. In the case of our patient we performed a conventional cholecystectomy and the closure of the cholecystoduodenal fistula, which was found accidentally. When the gallstone ileus appeared 6 days later the enterolithotomy was performed. Thus in case of accidentally found cholecystoduodenal fistula an exploration of the abdominal cavity and the small intestine to find the gallstone should be performed on principle. Gallstones with a diameter of more than 2-3 cm should be removed by enterolithotomy to prevent the gallstone ileus.  相似文献   

20.
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