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        west china medical publishers
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        find Keyword "computed tomography" 142 results
        • Research progress in CT study of lower esophageal varices with liver cirrhosis

          ObjectiveTo summarize the research progress of CT related to esophageal varices of cirrhotic patients complicated with portal hypertension.MethodsRelevant CT literatures of esophageal varices of cirrhotic patients complicated with portal hypertension were collected to make an review,then summarized the research status and progress of CT in the diagnosis and evaluation of lower esophageal varices.ResultCT had a good correlation with endoscopic diagnosis of esophageal varices, and CT was of great value in evaluating the presence, degree, and risk of esophageal varicose veins, especially in predicting the risk of esophageal varicose veins, which could be used as an effective modality to assist endoscopic examination to a certain extent.ConclusionsCT is an important examination method for esophageal varices, which has important value in diagnosis and evaluation. In the future, more further researches can be carried out to provide more strong and accurate support for the diagnosis and treatment of esophageal varices.

          Release date:2019-06-05 04:24 Export PDF Favorites Scan
        • Application of V/P SPECT/CT in quantitative assessment of lung function in patients with asthma

          ObjectiveTo explore the application of pulmonary ventilation and perfusion imaging (V/P SPECT/CT) in quantitative evaluation of ventilation and perfusion function and its potential value in guiding local treatment of lung in patients with asthma.MethodsA total of 20 patients with asthma were included in this study. All patients underwent V/P SPECT/CT and pulmonary function test, and symptoms were assessed by the ACT questionnaire. Patients were graded for degree of airway obstruction according to V/ P SPECT/CT image visual scoring criteria. The comprehensive lung function (%) of the patients was quantitatively evaluated by combining the ventilation and perfusion defect of each lung segment in V/P imaging. The correlation between the degree of airway obstruction, comprehensive lung function, pulmonary function test and ACT score was analyzed.ResultsV/P SPECT/CT imaging can be used to grade the degree of airway obstruction in asthma patients (0-3 grade). Airway obstruction grading by V/P SPECT/CT visual score was associated with predictive forced expiratory volume in one second (FEV1%pred) of patients (r=–0.74, P<0.001). V/P SPECT/CT can also comprehensively evaluate ventilation and perfusion function in patients with asthma, and comprehensive lung function measured by this method was also correlated with FEV1%pred (r=0.629, P=0.003). V/P SPECT/CT can be used to quantitatively analyze the percentage of ventilation and perfusion function in each lung lobe. Compared with V/P SPECT/CT results, the CT volume overestimates the contribution in the upper lobes, and underestimates the lower lobes contribution to overall function.ConclusionsV/P SPECT/CT can be used as a new method to directly reflect the degree of airway obstruction in patients with asthma. Moreover, it can comprehensively and quantitatively evaluate the ventilation and perfusion function of asthma patients. V/P SPECT/CT can also be used to evaluate lobe function in patients with asthma, helping to identify the heterogeneity of changes in pulmonary function in patients with asthma, and has potential value for future treatment targeting specific areas of the lung.

          Release date:2021-05-25 01:52 Export PDF Favorites Scan
        • The acceleration algorithm for projection decomposition of dual-energy computed tomography image reconstruction based on projection matching

          Dual-energy computed tomography (CT) reconstruction imaging technology is an important development direction in the field of CT imaging. The mainstream model of dual-energy CT reconstruction algorithm is the basis material decomposition model, and the projection decomposition is the crucial technique. The projection decomposition algorithm based on projection matching was a general method. With establishing the energy spectrum lookup table, we can obtain the stable solution by the least squares matching method. But the computation cost will increase dramatically when size of lookup table enlarges and it will slow down the computer. In this paper, an acceleration algorithm based on projection matching is proposed. The proposed algorithm makes use of linear equations and plane equations to fit the lookup table data, so that the projection value of the decomposition coefficients can be calculated quickly. As the result of simulation experiment, the acceleration algorithm can greatly shorten the running time of the program to get the stable and correct solution.

          Release date:2018-08-23 03:47 Export PDF Favorites Scan
        • Imaging features of hepatic epithelioid hemangioendothelioma

          Objective To evaluate the imaging features of hepatic epithelioid hemangioendothelioma (HEHE). Methods The imaging data of 15 patients with HEHE proved by surgery and pathology who reeived treatment in West China Hospital from Jul. 2012 to Aug. 2018, were retrospectively analyzed. The location, boundary, density/signal, and enhanced features of tumor were observed. Results Among 15 cases, there were 3 cases of single, 5 cases of multiple, and 6 cases of fusion. Thirteen cases were distributed under the capsular of liver, accompanied by the capsule retraction sign, 14 cases had lollipop sign, 7 cases had core pattern sign. On plain CT images, the lesions manifested as low density. On plain MR images, the lesions had hypointense on T1-weighted images and hyperintense on T2-weighted images. The enhanced scanning could be characterized by mild enhancement, rim-like enhancement at early phase, and progressive centripetal fill-in enhancement during dynamic phase imaging. Conclusions CT and MRI imagings of HEHE are different, and there are certain characteristics of capsule retraction sign, lollipop sign, and core pattern sign.

          Release date:2018-02-05 01:53 Export PDF Favorites Scan
        • The Role of Monitoring Procalcitonin in Comprehensive Evaluation during Diagnosis and Treatment of Community Acquired Pneumonia

          ObjectiveTo investigate the role of dynamic monitoring procalcitonin (PCT) in the comprehensive evaluation during the diagnosis and treatment of community acquired pneumonia (CAP). MethodsFour hundred and sixty-eight patients with CAP were randomly assigned to a PCT-guided group (the research group) and a standard guideline group (the control group). The clinical symptoms,CURB-65 grade,blood leucocyte count and classification,and C-reactive protein (CRP)were compared between two groups. The PCT-guided application time of antibiotics,the hospitalization time,chest CT examination rate,the cure or the improvement rate were also estimated and commpared. ResultsThe hospitalization time [(9.6±1.7)days vs. (10.9±1.6)days],hospitalization cost [(6 957.11±1 009.46) yuan vs. (8 011.35±1 049.77) yuan],chest CT examination rate (56.96% vs. 89.40%),the application time of antibiotics [(16.5±2.3)days vs. (20.0±1.2)days],and the rate of required antibiotics upgrade (6.96% vs. 11.06%) in the research group were all significantly lower than the control group (P<0.05). There was no significant difference between two groups in the ratio of the adverse reaction of antibiotics (14.78% vs. 15.20%),the rate of transfer into ICU (2.61% vs. 3.69%) or the mortality (1.74% vs. 2.30%)(P>0.05). ConclusionOn the basis of CAP guidelines,the dynamic monitoring of PCT may shorten the time of antibiotic use and the hospitalization,reduce the cost of hospitalization and the rate of chest CT scan in patients with CAP.

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        • Early radiological diagnostic value of closed chest trauma in rabbits

          Objective To explore the early diagnostic value of single photon emission computed tomography(SPECT), thoracic computed tomography(CT),and chest X-ray for closed chest trauma. Methods To establish the animal model of unilateral chest impact trauma,to adopt SPECT, thoracic CT, and chest X-ray for early diagnosis of closed chest trauma,and to compare these findings with postmortem examination. Results Thirty minutes after blunt chest trauma, the region of interesting (ROI) between traumatized lung and the heart (ROI2/ROI1) immediately increased to the peak six hours after trauma; on the contralateral lung, the ratio (ROI3/ROI1) increased slowly and reached the peak after six hours, these ratio was still smaller than that of the traumatized lung. These differences were significant (Plt;0.01). Conclusions Chest X-ray is still the most fundamental diagnostic method of chest trauma,but it was thought that the patients of severe chest trauma and multiple injuries should be examined early by thoracic CT. Radionuclide imaging have more diagnostic value than chest X-ray on pulmonary contusion. The diagnostic sensibility to pulmonary contusion of thoracic CT is superior to conventional radiograph,but thoracic CT is inferior to SPECT on exploring exudation and edema of pulmonary contusion. Thoracic CT is superior to conventional radiograph on diagnosis of chest trauma,therefore patients of severe chest trauma and multiple injuries should be adopted to thoracic CT examination at emergency room in order to be diagnosed as soon as possible.

          Release date:2016-08-30 06:28 Export PDF Favorites Scan
        • The CT Features of Gastric Bare Area under Pathological Conditions

          ObjectiveTo investigate the CT presenting rate and features of gastric bare area (GBA, including the area posterior to GBA and the adipose tissue in the gastrophrenic ligament) without pathologic changes.MethodsThirty cases with superior peritoneal ascites, but without pathological involvement of GBA were included into the study to show the normal condition of GBA, including the presenting rate and CT features. We selected some cases with GBA invasion by inflammation or neoplasm to observe their CT features. ResultsAll cases with superior peritoneal ascites showed the GBA against the contrast of ascites with the presenting rate of 100%. The GBA appeared at the level of gastricesophageal conjunction and completely disappeared at the level of hepatoduodenal ligament and Winslow’s foramen. The maximum scope of GBA presented at the level of the sagital part of the left portal vein with mean right to left distance of (4.39±0.08)cm (3.8~5.7 cm) (distance between the left and right layer of the gastrophrenic ligament). In acute pancreatitis, the width of GBA increased, in which local hypodensity area could be seen. In gastric leiomyosarcoma invading GBA, the mass could not separate from the crus of the diaphragm. In lymphoma and metastasis invading GBA, the thickness of GBA increased and the density was heterogeneous, in which lymph nodes presenting as small nodes or fused mass. ConclusionThe results of this study show that it is helpful to use contrast enhanced spiral CT scanning to observe the change of GBA and to diagnose retroperitoneal abnormalities that involving GBA comprehensively and accurately.

          Release date:2016-08-28 04:49 Export PDF Favorites Scan
        • CT signs and clinicopathological features of peripheral cavitary lung adenocarcinoma with the largest diameter less than or equal to 3 cm

          ObjectiveTo investigate the CT signs and clinicopathological features of peripheral cavitary lung adenocarcinoma with the largest diameter less than or equal to 3 cm.Methods From January 2015 to December 2017, the CT signs and clinicopathological fertures of 51 patients with ≤3 cm peripheral cavitary lung adenocarcinoma diagnosed by chest CT and surgical pathology were retrospectively analyzed. Furthermore, CT signs and clinicopathological features of thick-walled cavitary lung adenocarcinoma and thin-walled cavitary lung adenocarcinoma were compared. There were 29 males and 22 females at age of 62 (56, 67) years.ResultsThere were 27 thick-walled cavitary lung adenocarcinoma and 24 thin-walled cavitary lung adenocarcinoma. Thick-walled cavitary adenocarcinoma had greater SUVmax [6.5 (3.7, 9.7) vs. 2.2 (1.4, 3.8), P=0.019], larger cavity wall thickness (11.8±4.6 mm vs. 7.6±3.7 mm, P=0.001), larger tumor tissue size [2.1 (1.7, 2.8) cm vs. 1.6 (1.2, 2.0) cm, P=0.006], and more solid nodules (17 patients vs. 8 patients, P=0.035). Thin-walled cavitary adenocarcinoma had more smoking history (12 patients vs. 6 patients, P=0.038), larger cavity size [12.3 (9.2, 16.6) mm vs. 4.4 (2.8, 7.1) mm, P=0.000], and larger proportion of cavities [0.30 (0.19, 0.37) vs. 0.03 (0.01, 0.09), P=0.000]. On CT signs, there were more features of irregular inner wall (19 patients vs. 6 patients, P=0.000), intra-cystic separation (16 patients vs. 6 patients, P=0.001) and vessels through the cystic cavity (10 patients vs. 1 patient, P=0.001) in thin-walled caviraty lung adenocarcinoma.ConclusionPeripheral cavitary lung adenocarcinoma of ≤3 cm on chest CT has characteristic manifestations in clinical, imaging and pathology, and there is a statistical difference between thick-walled cavitary lung adenocarcinoma and thin-walled cavitary lung adenocarcinoma.

          Release date:2020-01-17 05:18 Export PDF Favorites Scan
        • Low Dose MSCT Diagnosis of Pulmonary Fungal Infection

          Objective To explore the diagnosis value of the low dose multi-slice spiral computed tomography (MSCT) imaging in pulmonary fungal infection in order to improve its diagnosis level. Methods CT manifestations of 106 cases of pulmonary fungal infection confirmed by operation, pathology, mycetes cultivation and follow-ups of clinical therapy were retrospectively analyzed. All cases underwent low dose MSCT examinations including CARE dose 4D and sinogram affirmed iterative reconstruction technology, and 6 cases underwent contrast-enhanced CT scanning. Results Among the basic MSCT findings of pulmonary fungal infection, they showed patch-nodular type in 54 cases, solid variant in 38 cases, and tumor type in 14 cases. In all cases, 91 cases displayed as mulifocality, 83 cases as polymorphism and 78 cases as polytropy. Among the 106 cases with comparative distinctive MSCT manifestations, bud of branch sign were showed in 39 cases, halo sign in 32 cases, wedge shape consolidation in 19 cases, ice needle sign in 15 cases, crescentic sign in 11 cases, air ring sign in 6 cases, and contra-halo sign in 4 cases. The nodules in the cavities were not enhanced in enhanced scan in 5 cases. Conclusions There are some distinctive MSCT findings in patients with pulmonary fungal infection. Pulmonary fungal infection can be diagnosed with typical MSCT findings in close combination with the clinical information.

          Release date:2016-10-02 04:56 Export PDF Favorites Scan
        • Imaging findings of pancreatic hematologic malignancies

          Objective To summarize the CT, MRI, and positron emission computed tomography (PET) imaging findings of hematologic malignancies of the pancreas, so as to improve the capacity of its diagnosis. Methods After searching articles concerning radiological research about hematologic malignancies of the pancreas, summarizing its imaging characteristics. Results Hematologic malignancies of the pancreas include pancreatic lymphoma, pancreatic multiple myeloma, myeloid sarcoma, posttransplantation lymphoproliferative disorder, and giant lymph node hyperplasia. ① Pancreatic lymphoma: imaging features of pancreatic lymphoma are segmental or diffuse homogeneous enlargement of the pancreas, diameter of mass >5 cm, adenopathy below the level of renal veins, and lack of pancreatic duct dilation. Blurred margins of pancreas by lymphadenopathy is highly suggestive of lymphoma. ② Pancreatic multiple myeloma: pancreatic multiple myeloma are hyperintense on both T1- and T2-weighted images. ③ Pancreatic granulocytic sarcoma: pancreatic granulocytic sarcoma present as homogeneous hypoenhancing mass on CT, usually without pancreatic duct dilation. On MRI, the lesions are isointense and mildly hyperintense on T1- and T2-weighted images respectively. ④ Posttransplantation lymphoproliferative disorder: diameter of leison of posttransplantation lymphoproliferative disorder usually is >5 cm with poor enhancement. Lesions are mildly hyperintense on T2-weighted images and extremely hypermetabolic on PET images. ⑤ Giant lymph node hyperplasia: it mainly appear as solitary noninvasive masses. Punctate calcification and surrounding supply vessels are observed in hyaline vascular type. Plasma cell type demonstrate unapparent enhancement and less calcification. Conclusions Hematologic malignancies of the pancreas manifest different imaging features on CT, MRI, and PET. Familiarity with such characteristics helps to early recognize diseases and determine next-step measures.

          Release date:2017-11-22 03:58 Export PDF Favorites Scan
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