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find Keyword "computed tomography" 142 results
  • Imaging manifestations and differential diagnosis of ectopic pancreas

    Objective To summarize the imaging manifestation and identification of ectopic pancreas (EP), so as to improve clinicians and radiologists’ knowledge of EP and aid in accurate preoperative diagnosis, thereby reducing the misdiagnosis rate and avoiding unnecessary surgery. Methods Combined with clinical experience and relevant literatures in recent years, the histopathology, common imaging manifestations and main differential diagnosis of ectopic pancreas were summarized. Results EP is a rare congenital developmental anomaly of pancreas, the most common location is the upper digestive system. At present, the commonly used imaging technology is computed tomography. The imaging findings of ectopic pancreas were similar to those of normal pancreas, and its density and enhancement characteristics were related to its histopathological composition. The specific signs of ectopic pancreas include “central umbilical sign” “ductal structure” and “flat/adherent sign”. Heterotopic pancreas should be differentiated from submucosal tumor of gastrointestinal tract. Conclusions The imaging findings of EP have certain characteristics. For some cases with atypical imaging findings, imaging diagnosis is difficult.

    Release date:2023-02-02 08:55 Export PDF Favorites Scan
  • Clinical application of three-dimensional technique in segmentectomy

    More and more relevant research results show that anatomical segmentectomy has the same effect as traditional lobectomy in the surgical treatment of early-stage non-small cell lung cancer (diameter<2.0 cm). Segmentectomy is more difficult than lobotomy. Nowadays, with the promotion of personalization medicine and precision medicine, three-dimensional technique has been widely applied in the medical field. It has advantages such as preoperative simulation, intraoperative positioning, intraoperative navigation, clinical teaching and so on. It plays a key role in the discovery of local anatomical variation of pulmonary segment. This paper reviewed the clinical application of three-dimensional technique and briefly described the clinical application value of this technique in segmentectomy.

    Release date:2021-06-07 02:03 Export PDF Favorites Scan
  • 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
  • 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
  • The significance of serum sRAGE combined with lung function and lung HRCT in predicting risk of COPD with NSCLC

    Objective To observe the value of serum soluble receptor of advanced glycation endproducts (sRAGE) combined with lung function and high resolution lung CT (HRCT) in predicting the risk of chronic obstructive pulmonary disease (COPD) developing non-small cell lung cancer (NSCLC). Methods From January 2019 to June 2021, 140 patients with COPD combined with NSCLC, 137 patients with COPD, and 133 patients with NSCLC were enrolled in the study from the People's Hospital of Ningxia Hui Autonomous Region. General data, clinical symptoms, pulmonary function indexes and HRCT emphysema indexes (EI) were collected. Serum sRAGE levels of these patients were measured by enzyme linked immunosorbent assay. Clinical characteristics of patients with COPD complicated with NSCLC were analyzed. Serum sRAGE, lung function and lung HRCT were combined to evaluate the correlation between the degree of emphysema and the occurrence of NSCLC in COPD, and receiver operator characteristic (ROC) curve analysis was performed for diagnostic efficiency. Results Compared with NSCLC group, COPD combined with NSCLC group had higher proportion of male patients, higher proportion of elderly patients, higher smoking index, and higher proportion of squamous cell carcinoma (P<0.05). FEV1 and FEV1%pred in COPD combined with NSCLC group were significantly lower than those in COPD group and NSCLC group. The Goddard score and EI values of emphysema were significantly increased (P<0.05). Serum sRAGE was significantly lower than that of COPD group and NSCLC group (P<0.05). Serum sRAGE level was positively correlated with FEV1%pred (r=0.366, P<0.001) and FEV1/FVC (r=0.419, P<0.001), and negatively correlated with Goddard score (r=–0.710, P=0.001) and EI value (r=–0.515, P<0.001). Binary multi-factor logistic regression analysis showed that age, smoking index, EI, Goddard score, RV/TLC were positively correlated with the risk of COPD developing NSCLC, while FEV1%pred, FVC, FEV1/FVC and serum sRAGE were negatively correlated with the risk of COPD developing NSCLC. ROC curve results showed that the area under the curve (AUC) of single diagnosis of sRAGE was 0.990, and the optimal cut-off value of 391.98 pg/mL with sensitivity of 93.3% and specificity of 89.7%. The AUC of sRAGE combined with age, smoking index, EI, Goddard score, FEV1%pred, FVC, FEV1/FVC, RV/TLC was 1.000 with sensitivity of 96.7%, specificity of 96.6%, and Yoden index of 0.933. Conclusion The combination of serum sRAGE, lung function and HRCT emphysema score can improve prediction of NSCLC occurrence in COPD.

    Release date:2023-10-18 09:49 Export PDF Favorites Scan
  • Texture filtering based unsupervised registration methods and its application in liver computed tomography images

    Image registration is of great clinical importance in computer aided diagnosis and surgical planning of liver diseases. Deep learning-based registration methods endow liver computed tomography (CT) image registration with characteristics of real-time and high accuracy. However, existing methods in registering images with large displacement and deformation are faced with the challenge of the texture information variation of the registered image, resulting in subsequent erroneous image processing and clinical diagnosis. To this end, a novel unsupervised registration method based on the texture filtering is proposed in this paper to realize liver CT image registration. Firstly, the texture filtering algorithm based on L0 gradient minimization eliminates the texture information of liver surface in CT images, so that the registration process can only refer to the spatial structure information of two images for registration, thus solving the problem of texture variation. Then, we adopt the cascaded network to register images with large displacement and large deformation, and progressively align the fixed image with the moving one in the spatial structure. In addition, a new registration metric, the histogram correlation coefficient, is proposed to measure the degree of texture variation after registration. Experimental results show that our proposed method achieves high registration accuracy, effectively solves the problem of texture variation in the cascaded network, and improves the registration performance in terms of spatial structure correspondence and anti-folding capability. Therefore, our method helps to improve the performance of medical image registration, and make the registration safely and reliably applied in the computer-aided diagnosis and surgical planning of liver diseases.

    Release date:2021-12-24 04:01 Export PDF Favorites Scan
  • A Denoising Method for Low-dose Small-animal Computed Tomography Image Based on Globe Dictionary Learning

    Considering the survival rate of small animals and the continuity of the experiments, high-dose X-ray shooting process is not suitable for the small animals in computed tomography (CT) experiments. But the low-dose process results with images might be polluted by noises which are not conducive for the experiments. In order to solve this problem, we in this paper introduce a global dictionary learning based denoising method to apply the promotion of the low dose CT image. We at first adopted the K-means singular value decomposition (K-SVD) algorithm to train a global dictionary based on the high dose CT image. Then, the noise image could be decomposed into sparse component which was free from noise through the orthogonal matching pursuit (OMP) algorithm. Finally, the noise-free image could be achieved by reconstructing the image only with its sparse components. The experiments results showed that the method we proposed here could decrease the noise efficiently and remain the details, and it would help promote the low dose image quality and increase the survival rate of the small animals.

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  • Assessment of Short Term Therapeutic Response to Radiofrequency Ablation by Contrast Enhanced Ultrasound in Hepatocellular Carcinoma

    Objective To investigate the value of contrast enhanced ultrasound (CEUS) in evaluating the short term therapeutic response to radiofrequency ablation (RFA) of primary hepatocellular carcinoma. Methods One hundred and ten lesions were studied in 96 patients. Each patient underwent CEUS within a week before RFA, the number, size, border, inner echo and perfusion pattern of lesions were observed. One month after ultrasound-guided RFA, color Doppler flow imaging, CEUS and contrast enhanced computed tomography (CECT, reference standard) were performed to assess the therapeutic response. Results Before RFA, in 96 cases with 110 lesions, 83 lesions showed homogeneous hyper-enhancement and the other 27 heterogeneous hyper-enhancement in arterial phase, and 98 lesions were hypo-enhanced in portal venous phase and late phase and the other 12 iso-enhanced. One month after RFA, 99 of 110 lesions were found no-enhancement in entire CEUS procedure, while 11 lesions showed local enhancement on the edge of lesion. Ninety-six of 110 lesions showed no-enhancement and other 14 with irregular enhancement by CECT. There was no statistical significance between CEUS and CECT (χ2=0.406, Pgt;0.05). Fourteen lesions as tumor residual by CECT were underwent RFA again, and then 1 month after RFA no-enhancement was showed by both CECT and CEUS. Conclusion CEUS can play a role in assessing the short term therapeutic response to RFA of hepatocellular carcinoma.

    Release date:2016-09-08 10:57 Export PDF Favorites Scan
  • Imaging features of ectopic pancreas in gastrointestinal tract

    ObjectiveTo analyze and conclude CT and MRI imaging features of ectopic pancreas in gastrointestinal tract so as to improve the understanding of the features.MethodsThe clinical, imaging, and pathological data of 12 patients with ectopic pancreas in the gastrointestinal tract confirmed by the pathology in the Sichuan Provincial People’s Hospital from November 2016 to June 2019 were retrospectively analyzed. The characteristics of image presentation were summarized.Results① The anatomical distribution: all patients had a single lesion. Of the 12 cases, 6 cases located in the gastric body lesser curvature, 3 cases located in the gastric angle, 1 case located in the posterior wall of gastric antrum, 1 case occurred in the upper jejunum, and 1 case occurred in the terminal ileum; 8 cases located in the submucosa, 2 cases located in the submucosa and muscular layer simultaneously, 1 case located in the submucosa, muscular and serous layer simultaneously, and 1 case located in the muscular layer. ② Size of the lesions: the maxium dimensions of the lesions were all 3 cm or less, and the long axes of the lesions were parallel to the gastrointestinal tract wall in 10 cases. ③ The internal characteristics: the results of 9 of 11 cases showed the isodensity compared to main pancreas on the plain CT scan. The results of 8 patients with enhanced CT showed the moderate to obvious enhancement, with 2 cases showed the slightly enhanced flaky or tube-like foci. In the arterial phase and portal venous phase, 6 cases showed the isodensity compared to main pancreas respectively. The result of MRI in 1 patient showed the isointensity compared to main pancreas on the plain scan and obviously heterogeneous enhancement.ConclusionCT and MRI could provide some information about location, size, and internal density or intensity of ectopic pancreas, and could be helpful for diagnosis.

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  • 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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