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1.
The authors discuss the potentialities of CT in the diagnosis of endophytic stomach cancer. They proposed a method for CT of the stomach based on a pneumatic study of its lumen via a nasogastric probe with graded inflation and repeated CT imaging. The major CT-semiotics of endophytic stomach cancer were obtained. This method should be employed in combination with the existing routine methods of stomach cancer diagnosis, and its efficacy is in direct relation to the quality of preliminary routine x-ray and endoscopic investigations.  相似文献   

2.
Multichannel data collection in the neurosciences is routine and has necessitated the development of methods to identify the direction of interactions among processes. The most widely used approach for detecting these interactions in such data is based on autoregressive models of stochastic processes, although some work has raised the possibility of serious difficulties with this approach. This article demonstrates that these difficulties are present and that they are intrinsic features of the autoregressive method. Here, we introduce a new method taking into account unobserved processes and based on coherence. Two examples of three-process networks are used to demonstrate that although coherence measures are intrinsically non-directional, a particular network configuration will be associated with a particular set of coherences. These coherences may not specify the network uniquely, but in principle will specify all network configurations consistent with their values and will also specify the relationships among the unobserved processes. Moreover, when new information becomes available, the values of the measures of association already in place do not change, but the relationships among the unobserved processes may become further resolved.  相似文献   

3.
Clinical and X-Ray studies were performed in 85 patients with disseminated pulmonary tuberculosis. All the patients underwent routine computerized tomography (CT) and high-resolution CT. According to the pathogenetic process, the authors identified hematogenic (n = 38), lymphogenic (n = 19), bronchogenic (n = 18) and mixed (n = 10) disseminations. High-resolution CT was found to have great advantages in detecting various types of tuberculous disseminations and in assessing the pattern of pulmonary abnormalities. Disseminated tuberculosis was revealed in 7 patients who had no pathological changes on routine lung X-ray films. The specific signs of hematogenic, lymphogenic disseminations and bronchgenic inoculations were identified in other forms of pulmonary tuberculosis. CT symptomatology is shown to be determined by the pathogenetic variant of its development and the stage of the process. Small focal changes in the lung were prevalent in patients with acute and subacute hematogenic forms of the disease. Infiltrates with decay cavities, thin-wall caverns, emphysema and bronchoectases were detected over the chronic course. Lymphogenic disseminations were characterized by the predominance of interstitial changes along with multiple minor foci. High-resolution CT had advantages in identifying decay cavities, signs of fibrosis and in evaluating mediastinal lymph nodes. CT data are of great significance for differential diagnosis of disseminated tuberculosis with lung metastases and diffuse interstitial diseases.  相似文献   

4.
Thirteen years ago, a 35-year-old woman was found on routine ocular examination to have a pigmented tumor in her right eye, adjacent to the optic nerve head. The appearance of her fundus was suggestive of a melanocytoma. Her visual acuities were RE: 1.0 and LE: 1.0. Ultrasound examination revealed that the tumor diameter was 4.4 mm on the base and the maximal thickness was 2.7 mm. Fluorescein angiography showed a persistent hypofluorescence of the lesion. There were several additional examinations (e.g. determination of the visual field, measurement of the intraocular pressure, detection of visually evoked potentials, CT scan and MRI examination) to exclude a benign tumor of similar appearance, The patient underwent ocular examination every year. During the observation period a minor tumor enlargement occurred but there were no changes in the visual acuities. In the last two years minor signs of malignant transformation were found. The findings documented and illustrated here suggest that our methods were useful to differentiate the melanocytoma from a malignant melanoma, and no surgical interventions were needed to characterize or to remove the tumor. In addition, our patient has had good vision during the past 13 years.  相似文献   

5.
The authors analyzed the results of complex radiation study of 1192 patients with various interstitial lung diseases (ILD). An algorithm of differential diagnosis of diffuse and disseminated lesions of the lung was derived by using the findings. The X-ray morphological principle underlies the algorithm. The level of structural lesions of the lung and tissue reactions and the presence of granuloma shadows are the governing criteria for evaluating the gross structure in the differential diagnostic complex. Great emphasis is laid on the significance of computed tomography (CT), high performance CT in particular, which is becoming the priority radiation diagnostic technique in pulmonology. Morphofunctional studies, 99mTc AMA and 67Ga citrate pulmonary scintigraphy in particular, specify the magnitude of changes in the microcirculatory bed and the activity of intrathoracic lymph nodes.  相似文献   

6.
The purpose of the paper was to present comparative laminar anatomy of human temporal bone on the basis of cross-sections of autopsy specimens and CT scans made in identical thin layers. The investigations were made on 20 temporal bones taken during anatomopathological dissections of cadavers of men and women (aged 40 to 60 a) without visible pathological changes in the skull. The CT examinations were made by means of a Siemens Somatom DR 2 apparatus, using high resolution programme, on 10 patients who had pathological changes in the ear. The obtained scans were compared with temporal bone cross-sections, schemas of regular anatomical relation of 8 layers corresponding to routine CT examinations were worked out.  相似文献   

7.
One hundred and ten consecutive patients and 130 SPECT/CT examinations were involved in this retrospective study that focused on the evaluation of the excess of dose contributed by the CT to the patient during the SPECT/CT explorations, for routine examinations in nuclear medicine. The average age of patients was 53 years. In this study, it appeared that irradiation induced by a low dose CT combined with a SPECT is low compared to that of a diagnostic CT. The main risk on patients is the occurrence of radiation-induced cancer. In our study, this increased risk induced by the additional CT with low dose settings in line with SPECT examination, is not significant and does not exceed 0.026%. By weighing the diagnostic value of SPECT/CT examination with that of a stand-alone SPECT examination dosimetric “incremental cost” is justified because of its direct clinical benefit conveyed to the patient.  相似文献   

8.
Ultrasonic (US) examinations of the urinary tract of 2384 patients have revealed pathologic shifts in 725 cases; x-ray examinations had to be carried out in 632 of these to specify the diagnosis. X-Ray and US-based radiodiagnosis of a wide spectrum of renal diseases, carried out at a common municipal hospital, promotes a better diagnosis. Employment of US examinations as a screening method helps recognize renal hypoplasia, cystic diseases, and an acute inflammatory process, renal carbuncle, fairly well. The diagnosis of other renal abnormalities, urolithiasis, hydronephrotic transformations, tumors and injuries still has to be specified by routine x-ray methods.  相似文献   

9.
Flow cytometric (FCM) DNA and S-Phase (S%) analyses were compared to computerized image analysis (SAMBA 2005) in 27 breast carcinomas (T3, N0-N1, M0) treated by 3 cycles of preoperative Adriamycin, vincristine, cyclophosphamide, methotrexate, 5-fluorouracil (AVCMF) chemotherapy (CT). Twelve carcinomas had shown objective regression and 15 no regression. Samples studied were obtained by sequential fine-needle cytopunctures. Comparing DNA profiles obtained by both methods before and after the first cycle, it appears that tumors can be divided into 3 groups. In the first group (10 cases), no changes were observed after the first cycle of CT. These tumors before treatment had either single DNA peak without cells in S% and G2M or a major peak with a small S% and G2M peak. The second group (9 cases) showed some changes in DNA profiles with an increased G2M peak but no additional values; these tumors before treatment had a small S% and a G2M peak. In the third group (8 cases), before treatment, all were non-diploid with high S% and high G2M. After the first cycle, all showed obvious changes in DNA profiles with a decrease of the G0/G1 peak and an increased S% and G2M with dispersed additional values along the scale in (G2M) x 2 and (G2M) x 4 regions. When changes were compared to tumor regression in the 1st and 2nd groups, 1/10 and 3/9 cases, respectively, were evaluated as objective regression. In the third group, all had objective regression (p less than 0.001). In most cases, a good correlation was observed with both methods.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
Experience in the use of CT in combined radiodiagnosis of pneumonia was analysed. It has been concluded that CT objectively reflects morphological inflammatory pulmonary changes and permits their all-round assessment over time. The diagnosis of pneumonia in CT is based on classical x-ray symptoms. As compared to survey radiography CT reveals symptoms of pneumonia to the full at earlier stages. CT is an important additional method of investigation of inflammatory pulmonary diseases, but it should not be used separately without survey radiography. In a majority of cases when CT is performed there is no need in x-ray tomography.  相似文献   

11.
The author presents the results of a CT use during combined investigation on 2500 patients and the wounded who were admitted to hospital on emergency as well as patients who developed serious complications during treatment, especially in the postoperative period. CT findings were verified during operation, at autopsy or during a follow-up. They were indicative of a high effectiveness of emergency CT of different organs and systems in the diagnosis of lesions, acute diseases and their complications. The use of CT permitted considerable reduction of a diagnostic (preoperative) period, a decrease in use of routine invasive x-ray and surgical methods, and the improvement of therapeutic results.  相似文献   

12.
Screening for Y chromosome microdeletions is recommended in cases of severe impaired spermatogenesis. Improvement of molecular biology techniques has made this diagnosis more accessible in routine practice when evaluation of male infertility is necessary. However, the diagnosis of Y chromosome microdeletions is not proposed by all IVF centres. The aim of the present study was to specify the prescribing conditions (indication, financing) and practical conduct (methods, billing) for this analysis in France. We observed that microdeletion screening is a rapidly expanding activity. The development of a consensus on the indications for this screening and a standardised technique, with a national quality control, appears to be necessary. The funding of this analysis by French Social Security appears to be an essential step to ensure widespread use in routine practice. Lastly, the answers to our questionnaire revealed a strong demand for information concerning this analysis.  相似文献   

13.
ObjectiveTo assess the added benefit of scanning lower limbs in addition to usual whole-body PET/CT scan in patients with no known or suspected primary or metastatic melanoma involving the lower limbs.Materials and methodsThis is a retrospective study of 133 consecutive patients (189 FDG PET/CT) who underwent FDG PET/CT for staging of melanoma at different time points in the course of disease from October 2005 to July 2009 at Brest University Hospital. Reports of whole-body PET/CT scans including lower limbs were reviewed. PET/CT abnormalities on the lower extremities were tabulated by location and correlated with pathology, other imaging studies and at least a 6-month clinical follow-up.ResultsAmong the 189 consecutive PET/CT scans performed in 133 patients, 34 scans in 29 patients highlighted abnormal FDG uptakes considered as equivocal or suggestive of malignancy on lower limbs. In 29 cases, uptakes were located both on lower limbs and on the rest of the body (lung, liver, mediastinal and sub-diaphragmatic lymph nodes, adrenal glands, bone) corresponding to disseminated disease. In five cases, PET/CT uptakes were located only on lower limbs; each pathological uptake corresponded to benign lesions. Lower limbs findings never impacted clinical and therapeutic decision.ConclusionLower limbs additional PET/CT acquisition appears to offer poor additional benefit with no unexpected solitary lesion detected and routine skull base to upper thigh images may be sufficient for this subset of patients.  相似文献   

14.
Gating is necessary in cardio-thoracic small-animal imaging because of the physiological motions that are present during scanning. In small-animal computed tomography (CT), gating is mainly performed on a projection base because full scans take much longer than the motion cycle. This paper presents and discusses various gating concepts of small-animal CT, and provides examples of concrete implementation. Since a wide variety of small-animal CT scanner systems exist, scanner systems are discussed with respect to the most suitable gating methods. Furthermore, an overview is given of cardio-thoracic imaging and gating applications. The necessary contrast media are discussed as well as gating limitations. Gating in small-animal imaging requires the acquisition of a gating signal during scanning. This can be done extrinsically (additional hardware, e.g. electrocardiogram) or intrinsically from the projection data itself. The gating signal is used retrospectively during CT reconstruction, or prospectively to trigger parts of the scan. Gating can be performed with respect to the phase or the amplitude of the gating signal, providing different advantages and challenges. Gating methods should be optimized with respect to the diagnostic question, scanner system, animal model, type of narcosis and actual setup. The software-based intrinsic gating approaches increasingly employed give the researcher independence from difficult and expensive hardware changes.  相似文献   

15.
刘琳  韩英  袁有法  张宝性  赵金彩 《生物磁学》2011,(12):2350-2352
目的:探讨多排螺旋CT(MSCT)高分辨薄层重组对体检中肺部疾病的诊断价值,以及MSCT薄层重组与常规CT扫描图像质量及诊断准确率对照。方法:搜集做64排常规CT扫描同时行薄层重组的2473例体检病例中筛选的97例患者进行回顾性分析。结果:97例患者在常规CT扫描中有80例可以显示病变,而在MSCT薄层重组中97例均有阳性发现;其中双肺弥漫性病变79例(两肺间质纤维化78例,肺内多发转移瘤1例),肺结核3例,肺内孤立结节12例,早期中央型肺癌1例,先天性支气管闭锁1例以及纵隔肿瘤1例;MSCT薄层重组图像可清晰显示肺内小叶间隔线增厚、弥漫分布的囊性病变、肺内结节的细微征象。结论:MSCT薄层重组在胸部体检中的诊断阳性率、细节分辨率、图像质量及确诊率均优于常规CT,可作为肺内病变尤其是早期肺癌筛查方法之首选。  相似文献   

16.

Background

Early signs of ischaemic stroke on computerised tomography (CT) scanning are subtle but CT is the most widely available diagnostic test for stroke. Scoring methods that code for the extent of brain ischaemia may improve stroke diagnosis and quantification of the impact of ischaemia.

Methodology and Principal Findings

We showed CT scans from patients with acute ischaemic stroke (n = 32, with different patient characteristics and ischaemia signs) to doctors in stroke-related specialties world-wide over the web. CT scans were shown twice, randomly and blindly. Observers entered their scan readings, including early ischaemic signs by three scoring methods, into the web database. We compared observers'' scorings to a reference standard neuroradiologist using area under receiver operator characteristic curve (AUC) analysis, Cronbach''s alpha and logistic regression to determine the effect of scales, patient, scan and observer variables on detection of early ischaemic changes. Amongst 258 readers representing 33 nationalities and six specialties, the AUCs comparing readers with the reference standard detection of ischaemic signs were similar for all scales and both occasions. Being a neuroradiologist, slower scan reading, more pronounced ischaemic signs and later time to CT all improved detection of early ischaemic signs and agreement on the rating scales. Scan quality, stroke severity and number of years of training did not affect agreement.

Conclusions

Large-scale observer reliability studies are possible using web-based tools and inform routine practice. Slower scan reading and use of CT infarct rating scales improve detection of acute ischaemic signs and should be encouraged to improve stroke diagnosis.  相似文献   

17.
Patients with an elevated erythrocyte sedimentation rate (ESR) and non-specific symptoms often pose a diagnostic dilemma. PET/CT visualises infection, inflammation and malignancy, all of which may cause elevated ESR. The objective of this study was to determine the contribution of 18F-fluorodeoxglucose positron emission tomography (PET/CT) in the diagnostic work-up of referred patients with an elevated ESR, in whom initial routine evaluation did not reveal a diagnosis. We conducted a combined retrospective (A) and prospective (B) study in elderly (>50 years) patients with a significantly elevated ESR of≥50 mm/h and non-specific complaints. In study A, 30 patients were included. Malignancy (8 patients), auto-inflammatory disease (8 patients, including 5 with large-vessel vasculitis) and infection (3 patients) were suggested by PET/CT. Two scans showed non-specific abnormalities and 9 scans were normal. Of the 21 abnormal PET/CT results, 12 diagnoses were independently confirmed and two alternative diagnosis were made. Two diagnoses were established in patients with a normal scan. In study B, 58 patients in whom a prior protocolised work-up was non-diagnostic, were included. Of these, 25 PET/CT-scans showed suspected auto-inflammatory disease, particularly large-vessel vasculitis (14 cases). Infection and malignancy was suspected in 5 and 3 cases, respectively. Seven scans demonstrated non-specific abnormalities, 20 were normal. Of the 40 abnormal PET/CT results, 22 diagnoses were confirmed, 3 alternative diagnoses were established. Only one diagnosis was established in the 20 patients with a normal scan. In both studies, the final diagnosis was based on histology, clinical follow-up, response to therapy or additional imaging. In conclusion, PET/CT may be of potential value in the diagnostic work-up of patients with elevated ESR if routine evaluation reveals no diagnosis. In particular, large-vessel vasculitis appears to be a common finding. A normal PET/CT scan in these patients suggests that it is safe to follow a wait-and-see policy.  相似文献   

18.
The results of routine roentgenotomography, CT and USI in the diagnosis of intrathoracic metastases of lung cancer were compared in 69 patients (central type--52, peripheral--17). These results were compared with operative findings in 45 patients. The sensitivity of USI in the diagnosis of enlarged paravasal lymph nodes exceeded that of roentgenotomography and was slightly inferior to CT. CT was informative for all mediastinal lymph nodes whereas tomography and USI were informative in certain areas only. The authors recommend to combine the use of routine and ultrasound tomography to assess the spreading of lung cancer to the mediastinum. The information obtained increases the accuracy of staging and specifying a process, slightly yielding CT results.  相似文献   

19.

Background

Despite several leprosy control measures in Nigeria, child proportion and disability grade 2 cases remain high while new cases have not significantly reduced, suggesting continuous spread of the disease. Hence, there is the need to review detection methods to enhance identification of early cases for effective control and prevention of permanent disability. This study evaluated the cost-effectiveness of three leprosy case detection methods in Northern Nigeria to identify the most cost-effective approach for detection of leprosy.

Methods

A cross-sectional study was carried out to evaluate the additional benefits of using several case detection methods in addition to routine practice in two north-eastern states of Nigeria. Primary and secondary data were collected from routine practice records and the Nigerian Tuberculosis and Leprosy Control Programme of 2009. The methods evaluated were Rapid Village Survey (RVS), Household Contact Examination (HCE) and Traditional Healers incentive method (TH). Effectiveness was measured as number of new leprosy cases detected and cost-effectiveness was expressed as cost per case detected. Costs were measured from both providers'' and patients'' perspectives. Additional costs and effects of each method were estimated by comparing each method against routine practise and expressed as incremental cost-effectiveness ratio (ICER). All costs were converted to the U.S. dollar at the 2010 exchange rate. Univariate sensitivity analysis was used to evaluate uncertainties around the ICER.

Results

The ICER for HCE was $142 per additional case detected at all contact levels and it was the most cost-effective method. At ICER of $194 per additional case detected, THs method detected more cases at a lower cost than the RVS, which was not cost-effective at $313 per additional case detected. Sensitivity analysis showed that varying the proportion of shared costs and subsistent wage for valuing unpaid time did not significantly change the results.

Conclusion

Complementing routine practice with household contact examination is the most cost-effective approach to identify new leprosy cases and we recommend that, depending on acceptability and feasibility, this intervention is introduced for improved case detection in Northern Nigeria.  相似文献   

20.
For many decades X-ray myelography has remained one of the major diagnostic methods for spinal pathology. With the advent of computed tomography (CT), CT myelography using water-soluble contrast agents has been developed. Visualization of the subarachnoidal spaces of the spinal cord and dural sac without an intrathecal contrast agent has become possible with the emergence of magnetic resonance imaging (MRI). Its further development and improvement has brought to existence the new noninvasive technique MR myelography based on the suppression of a signal from the medulla and its enhancement from the cerebrospinal fluid-containing spaces. This paper compares routine X-ray myelography, CT myelography, and MR myelography used in the diagnosis of lumbosacral intervertebral disk herniation and assesses the informative value and benefits of MR myelography as a noninvasive diagnostic method for this pathology.  相似文献   

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