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find Keyword "电子计算机断层扫描" 21 results
  • Diagnosis and Treatment of Descending Necrotizing Mediastinitis

    Descending necrotizing mediastinitis (DNM)is a severe infection spreading from the cervical or odontoiatric region to the mediastinum through the anatomic cervical spaces. DNM is very rare but fatal. The course of the illness proceeds rapidly and the mortality rate is high. The pathogenic process is closely related to anatomical and physiological characteristic of cervix and mediastinum. The most valuable way for decreasing its high mortality rate is to give early diagnosis and treatments. Computed tomography(CT) scan is especially important method in early diagnosis.The early and enough use of broad spectrum antibiotics, individual surgical management based on neck and chest CT, such as clearing necrotic tissues,drainage and flushing are all effective methods to decrease mortality rate. Related management , such as department of stomatology, head and neck surgery, thoracic surgery,intensive care unit, and infectious department,should give cooperative therapy when necessary. At the same time, more attention should be paid to the patients who have some systemic disease such as diabetes mellitus and whose physical constitutions are very poor, which could lead to DNM and worsening. It can help to decrease the incidence rate of fatal complications and to increase cure rate.

    Release date:2016-08-30 06:06 Export PDF Favorites Scan
  • Computed tomography in diagnosis of pulmonary embolism

    肺栓塞( PE) 的确诊依赖于肺动脉的影像学检查。电子计算机断层扫描肺动脉造影( CTPA) 诊断PE 的敏感性和特异性高[ 1] , 而且该项检查是无创技术, 患者痛苦小, 并发症少, 已成为诊断PE 的一线技术[ 2,3] 。随着CT 仪器的不断升级和改进以及检查技术的不断研究, CT 在PE 中的应用不再仅限于PE 的定性诊断, 还用于肺动脉栓塞程度的量化、右心室改变的诊断、患者预后判断以及下肢深静脉血栓形成( DVT) 的诊断等。

    Release date:2016-08-30 11:52 Export PDF Favorites Scan
  • Corona virus disease 2019 lesion segmentation network based on an adaptive joint loss function

    Corona virus disease 2019 (COVID-19) is an acute respiratory infectious disease with strong contagiousness, strong variability, and long incubation period. The probability of misdiagnosis and missed diagnosis can be significantly decreased with the use of automatic segmentation of COVID-19 lesions based on computed tomography images, which helps doctors in rapid diagnosis and precise treatment. This paper introduced the level set generalized Dice loss function (LGDL) in conjunction with the level set segmentation method based on COVID-19 lesion segmentation network and proposed a dual-path COVID-19 lesion segmentation network (Dual-SAUNet++) to address the pain points such as the complex symptoms of COVID-19 and the blurred boundaries that are challenging to segment. LGDL is an adaptive weight joint loss obtained by combining the generalized Dice loss of the mask path and the mean square error of the level set path. On the test set, the model achieved Dice similarity coefficient of (87.81 ± 10.86)%, intersection over union of (79.20 ± 14.58)%, sensitivity of (94.18 ± 13.56)%, specificity of (99.83 ± 0.43)% and Hausdorff distance of 18.29 ± 31.48 mm. Studies indicated that Dual-SAUNet++ has a great anti-noise capability and it can segment multi-scale lesions while simultaneously focusing on their area and border information. The method proposed in this paper assists doctors in judging the severity of COVID-19 infection by accurately segmenting the lesion, and provides a reliable basis for subsequent clinical treatment.

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  • Research progress in lung parenchyma segmentation based on computed tomography

    Lung diseases such as lung cancer and COVID-19 seriously endanger human health and life safety, so early screening and diagnosis are particularly important. computed tomography (CT) technology is one of the important ways to screen lung diseases, among which lung parenchyma segmentation based on CT images is the key step in screening lung diseases, and high-quality lung parenchyma segmentation can effectively improve the level of early diagnosis and treatment of lung diseases. Automatic, fast and accurate segmentation of lung parenchyma based on CT images can effectively compensate for the shortcomings of low efficiency and strong subjectivity of manual segmentation, and has become one of the research hotspots in this field. In this paper, the research progress in lung parenchyma segmentation is reviewed based on the related literatures published at domestic and abroad in recent years. The traditional machine learning methods and deep learning methods are compared and analyzed, and the research progress of improving the network structure of deep learning model is emphatically introduced. Some unsolved problems in lung parenchyma segmentation were discussed, and the development prospect was prospected, providing reference for researchers in related fields.

    Release date:2021-06-18 04:50 Export PDF Favorites Scan
  • 胸部电子计算机断层扫描对肺癌外科治疗的临床意义

    目的 探讨胸部电子计算机断层扫描(CT)检查对肺癌外科治疗的临床意义. 方法 选择380例经手术治疗的肺癌患者,将胸部X线片和胸部CT检查结果与手术和病理检查结果作对照分析. 结果 胸部CT对病变定位准确性优于胸部X线片,但定性诊断仍有一定限制.对纵隔淋巴结转移的诊断准确性为84%,特异性为59%,敏感性为97%,阳性预测率为82%,阴性预测率为90%. 结论 胸部CT检查对纵隔淋巴结转移的评估优于胸部X线片,但对病灶定性仍有一定的局限性.

    Release date:2016-08-30 06:34 Export PDF Favorites Scan
  • Pancreatic neuroendocrine neoplasm: current status and advancement in imaging

    ObjectiveTo summarize the status and progress of imaging studies of pancreatic neuroendocrine neoplasms (pNENs).MethodThe relevant literatures published recently at domestic and abroad about the imaging of pNENs were collected and reviewed.ResultsDue to poor visibility of pancreatic body and tail, the application of ultrasound (US) was limited. Compared with US, endoscopic ultrasound (EUS) and contrast-enhanced ultrasound (CEUS) could improve the detection rate of pNENs. The ability of plain CT scans to differentiate pathological grades was still controversial, but the value of enhanced scan was higher. CT texture analysis was feasible in the discrimination of nonhypervascular pNENs and pancreatic ductal adenocarcinoma (PDAC). Teta2 was the parameter with the highest diagnostic performance. The enhanced features of MRI were similar to CT. Combined with the apparent diffusion coefficient (ADC) value, the diagnostic and classification capabilities of MRI were improved, and the sensitivity and specificity of different ADC thresholds were also different. 68Ga-tetraazacyclododecane tetraacetic acid (68Ga-DOTA) peptide PET-CT had good preliminary diagnostic value for well-differentiated pNENs, and 18Fluoro-fluorodeoxyglucose (18F-FDG) PET-CT had limited diagnostic value.ConclusionsSomatostatin receptor imaging is of high diagnostic value and can guide clinical treatment and predict prognosis, but it has not been widely used in China. Conventional morphological images have advantages in the diagnosis and classification of pNENs. Therefore, it is important to choose a proper image inspection method.

    Release date:2020-04-28 02:46 Export PDF Favorites Scan
  • Diagnosis and Therapy of Patients with Descending Necrotizing Mediastinitis

    Abstract: Objective To explore the diagnosis and treatment of descending necrotizing mediastinitis (DNM). Methods We retrospectively analyzed the records of eight DNM patients treated at Tangdu Hospital between 2006 and 2009 year. There were 7 males and 1 female aged from 21-98 years with a median age of 49.5 years. The diagnostic criteria included clinical manifestations, neck and chest CT scans, and bacteriological culture. Six of the patients had odontogenic infections and six had diabetes. Antibiotic treatment, incision drainage, and other symptomatic treatments were applied. Two patients received cervical incision drainage, five received thoracotomy, and one received video-assisted thoracoscopic surgery (VATS). Results After treatment, six patients recovered and two died of heart failure and neck vessel rupture. According to the bacterial culture, six patients presented mixed infections, and four of these presented mixed aerobic and anaerobic infections. The mean operation time was 75.6 minutes, the average volume of pus removed during the operation was 318.7 ml, and the average inpatient stay was 18 days. At six months follow-up, all six surviving patients showed improvements in quality of life. Conclusion The valid diagnosed criteria of DNM include history, sign, symptom, neck and chest CT scanning, and secretion culture.DNM mortality can be reduced by employing broad spectrum antibiotics early in treatment, individual surgical managements, and effective treatments for complicating illnesses.

    Release date:2016-08-30 05:48 Export PDF Favorites Scan
  • Radiomics model based on CT images for distinguishing invasive lung adenocarcinoma with micropapillary or solid structure

    ObjectiveTo investigate the radiomics features to distinguish invasive lung adenocarcinoma with micropapillary or solid structure. MethodsA retrospective analysis was conducted on patients who received surgeries and pathologically confirmed invasive lung adenocarcinoma in our hospital from April 2016 to August 2019. The dataset was randomly divided into a training set [including a micropapillary/solid structure positive group (positive group) and a micropapillary/solid structure negative group (negative group)] and a testing set (including a positive group and a negative group) with a ratio of 7∶3. Two radiologists drew regions of interest on preoperative high-resolution CT images to extract radiomics features. Before analysis, the intraclass correlation coefficient was used to determine the stable features, and the training set data were balanced using synthetic minority oversampling technique. After mean normalization processing, further radiomics features selection was conducted using the least absolute shrinkage and selection operator algorithm, and a 5-fold cross validation was performed. Receiver operating characteristic (ROC) curves were depicted on the training and testing sets to evaluate the diagnostic performance of the radiomics model. ResultsA total of 340 patients were enrolled, including 178 males and 162 females with an average age of 60.31±6.69 years. There were 238 patients in the training set, including 120 patients in the positive group and 118 patients in the negative group. There were 102 patients in the testing set, including 52 patients in the positive group and 50 patients in the negative group. The radiomics model contained 107 features, with the final 2 features selected for the radiomics model, that is, Original_ glszm_ SizeZoneNonUniformityNormalized and Original_ shape_ SurfaceVolumeRatio. The areas under the ROC curve of the training and the testing sets of the radiomics model were 0.863 (95%CI 0.815-0.912) and 0.857 (95%CI 0.783-0.932), respectively. The sensitivity was 91.7% and 73.7%, the specificity was 78.8% and 84.0%, and the accuracy was 85.3% and 78.4%, respectively. ConclusionThere are differences in radiomics features between invasive pulmonary adenocarcinoma with or without micropapillary and solid structures, and the radiomics model is demonstrated to be with good diagnostic value.

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  • 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
  • Short-term efficacy of CT-guided microwave ablation for solitary pulmonary nodules

    ObjectiveTo evaluate the clinical feasibility and safety of CT-guided percutaneous microwave ablation for peripheral solitary pulmonary nodules.MethodsThe imaging and clinical data of 33 patients with pulmonary nodule less than 3 cm in diameter treated by CT-guided microwave ablation treatment (PMAT) in our hospital from July 2018 to December 2019 were retrospectively analyzed. There were 21 males and 12 females aged 38-90 (67.6±13.4) years. Among them, 26 patients were confirmed with lung cancer by biopsy and 7 patients were clinically considered as partial malignant lesions. The average diameter of 33 nodules was 0.6-3.0 (1.8±0.6) cm. The 3- and 6-month follow-up CT was performed to evaluate the therapy method by comparing the diameter and enhancement degree of lesions with 1-month CT manifestation. Short-term treatment analysis including complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) was calculated according to the WHO modified response evaluation criteria in solid tumor (mRECIST) for short-term efficacy evaluation. Eventually the result of response rate (RR) was calculated. Progression-free survival was obtained by Kaplan–Meier analysis.ResultsCT-guided percutaneous microwave ablation was successfully conducted in all patients. Three patients suffered slight pneumothorax. There were 18 (54.5%) patients who achieved CR, 9 (27.3%) patients PR, 4 (12.1%) patients SD and 2 (6.1%) patients PD. The short-term follow-up effective rate was 81.8%. Logistic analysis demonstrated that primary and metastatic pulmonary nodules had no difference in progression-free time (log-rank P=0.624).ConclusionPMAT is of high success rate for the treatment of solitary pulmonary nodules without severe complications, which can be used as an effective alternative treatment for nonsurgical candidates.

    Release date:2021-07-28 10:22 Export PDF Favorites Scan
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