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find Keyword "tomography" 349 results
  • Predictive Value of Preoperative 64 MDCT for Stage Ⅳ Gastric Cancer

    Objective  To evaluate the accuracy of preoperative 64 multidetector spiral computed tomography (MDCT) in the diagnosis of stage Ⅳ gastric cancer. Methods The data of patients with stage Ⅳ gastric cancer between July 2007 and April 2008 were collected. Twenty-nine patients underwent preoperative 64 MDCT were retrospectively analyzed. All computed tomography scans were prospectly analyzed by 2 abdominal radiologists separately. Pathological tumor stage was based on TNM stage according to the revised Japanese Classification of Gastric Carcinoma from the Japanese Gastric Cancer Association. All CT results were compared with clinical, surgical and histopathologic results. Results The 65.2% (15/23), 47.8% (11/23) and 70.8% (17/24) of the stage Ⅳ patients were accurately predicted of T, N and M stage, respectively. Moreover, 58.6% (17/29) of the stage Ⅳ patients were accurately predicted of TNM stage. But 6/9 cases with peritoneal metastases were not detected by preoperative 64 MDCT. Conclusion The 64 MDCT is a promising technique for detection and preoperative staging of stage Ⅳ gastric cancer. It was difficult to detect peritoneal metastases, but it may not increase the rate of exploratory laparotomy.

    Release date:2016-09-08 11:47 Export PDF Favorites Scan
  • Automatic Segmentation of Four Dimensional Computed Tomography of Lung Tumor Based on Star Shape Prior and Graph Cuts

    Lung four dimensional computed tomography (4D-CT) is of great value in tumor target localization and precise cancer radiotherapy. However, it is hard to segment tumors in 4D-CT data manually, since the data may contain a great number of slices with tumor. Meanwhile, auto-segmentation does not certainly guarantee the accuracy due to the complexity of images. Therefore, a new automatic segmentation technique based on Graph Cuts with star shape prior was proposed to increase automation and guarantee the accuracy of segmentation in our laboratory. Firstly, an object seed was selected in the image of initial phase and an initial target block was formed centering the selected seed. Then, the full search block-matching algorithm was adopted to obtain the most similar target block in the next phase and compute the motion field between them, and so on. Afterwards, the center seeds of each phase were obtained according to the motion fields, which would be set to the center point of star shape prior. Finally, tumors could be automatically segmented with Graph Cuts algorithm and star shape prior. Both qualitative and quantitative evaluation results showed that our approach could not only guarantee the accuracy of segmentation but also increase automation, compared with the traditional Graph Cuts algorithm.

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  • Distribution of choroidal thickness and its influencing factors in undergraduate students of Tianjin Medical University

    ObjectiveTo explore the distribution of choroidal thickness and its influence factors in university students.MethodsA cross-sectional study. A total of 896 eyes of 896 college students were included in the study. Among them, there were 350 males (350 eyes) and 546 females (546 eyes). All the eyes were right eyes. The average age was 19.18 ± 1.36 years old. According to the spherical equivalent refraction (SER), the eyes were divided into non-myopia group, low myopia group, moderate myopia group and high myopia group, which were 59, 251, 356 and 230 eyes, respectively. The subfoveal ChT (SFCT) was measured using a swept-frequency source optical coherence tomography scanner. According to the ETDRS, the choroid within 6 mm of the fovea was divided into three concentric circles centered on the fovea of the macula, which were the central area with a diameter of 1 mm, the inner ring area of 1-3 mm and the outer ring area of 3-6 mm. The outer ring area of 3-6 mm has a total of 9 zones. The inner ring and outer ring 4 regions were superior, inferior, nasal and temporal, respectively. The distribution characteristics of ChT in different regions, genders and diopter groups were observed. Bivariate correlation analysis were used to analyze the correlation of ChT and SER, axial length (AL).ResultsThe average SFCT of 896 eyes was 221.28±67.35 μm. The mean SFCT of males and females were 227.20±69.38 and 217.50±65.80 μm, respectively. The difference of SFCT between different genders was statistically significant (t=2.075, P=0.038). Compared with the central region ChT, there was no significant difference in ChT between the outer ring and the outer region (t=0.086, P=0.932). The difference of ChT in other regions was statistically significant (t=-21.973, -5.818, 36.328, -3.065, -18.017, -10.595, 57.007; P<0.001, <0.001, <0.001, <0.002, <0.001, <0.001, <0.001). In the horizontal direction, ChT gradually thickens from nasal to temporal (F=2 251.558, P<0.001); in the vertical direction, ChT gradually decreases from superior to the central, but have a little increased from central to inner inferior, then decreased to outer inferior again (F=45.425, P<0.05). Correlation analysis showed that SFCT was negatively correlated with AL (r=0.478, P<0.01) and a negative correlation with axial length (r=−0.395, P<0.01), and positively correlated with SER (r=0.478, P<0.01). SFCT decreased by 12.29 μm for every in myopic refractive error of 1 D, or by 20.14 μm for every increase in AL of 1 mm.ConclusionsChT is changed by different location. The horizontal direction is gradually thickened from nasal to temporal. The vertical direction is thicker than the center. The inferior inner ring area is thicker than the outer ring area. Gender, SER and AL are the influencing factors of SFCT.

    Release date:2018-07-23 04:02 Export PDF Favorites Scan
  • Randomized Controlled Trial of Combining Multi-Slice Spiral Computed Tomography with Inflammatory Biomarkers on Rectal Cancer Surgical Decision Making

    Objective To determine the influence and significance of combinative assessment of 64 multi-slice spiral computed tomography (MSCT) with serum amyloid A protein (SAA) or C-reactive protein (CRP) on the selection of operative procedures of rectal cancer under the multi-disciplinary team. Methods Prospectively enrolled patients diagnosed definitely as rectal cancer at West China Hospital of Sichuan University from February to August 2009 were randomly assigned into two groups. In one group named MSCT+SAA group, both 64 MSCT and SAA combinative assessment were made for the preoperative evaluation. In another group named MSCT+CRP group, both MSCT and CRP combinative assessment were made for preoperative evaluation. Furthermore, the preoperative staging and predicted operation procedures were compared with postoperative pathologic staging and practical operation procedures, respectively, and the relationship between the choice of operation procedures and clinicopathologic factors was analyzed. Results All 165 patients were randomly assigned into MSCT+SAA group (n=83) and MSCT+CRP group (n=82). The baseline characteristics of two groups were statistically similar (Pgt;0.05). For MSCT+SAA group, the accuracies of preoperative staging T, N, M and TNM were 74.7%, 68.7%, 100% and 66.3%, respectively. For MSCT+CRP group, the accuracies of preoperative staging T, N, M and TNM were 72.0%, 86.6%, 100% and 81.7%, respectively. There were statistically significant differences in the accuracies of N staging and TNM staging between two groups (P<0.05). However, there was no statistically significant difference of the accuracy of prediction to operative procedures between two groups (90.4% vs. 95.1%, Pgt;0.05). The pathological T staging (P<0.001), N staging (P<0.001), TNM staging (P<0.001), preoperative serum level of SAA (P=0.010), serum level of CRP (P=0.042), and distance of tumor to the dentate line (P=0.011) were associated with the operative procedures. Conclusion Combinative assessment of MSCT+CRP could improve the accuracy of preoperative staging and operative procedures prediction, which may be superior to MSCT+SAA.

    Release date:2016-09-08 10:56 Export PDF Favorites Scan
  • Relationship between retinal thickness at the macular area and axial length in myopia

    Objective To evaluate the correlation between retinal thickness (RT) at the macular area and the axial length (AL) in myopia. Mehtods Optical coherence tomography (OCT) was used to detect the RT at the macular fovea, and at the superior, nasal, inferior, and temporal side of the fovea and parafovea area. The AL of the examined eye was measured by IOL master measuring machine, and the correlation between RT at the macular area and the Al was evaluated. Results The minimum RT in the macular area in the eyes with myopia was (150.90plusmn;22.10)mu;m.The retina at the temporal side of parafovea was the thinnest. The average RT in the areas around the fovea was negatively correlated with the AL, and there was no correlation among the minimum RT, the mean RT at the fovea, and the AL of eye. Conclusions As the AL of eye increases, the RT at the parafovea decreases, while the minimum and the average RT at the fovea remain unchanged.  (Chin J Ocul Fundus Dis, 2006, 22: 397-399)

    Release date:2016-09-02 05:51 Export PDF Favorites Scan
  • 18F-FDG PET/CT combined with CT three-dimensional reconstruction in the differentiation of benign and malignant pulmonary nodules: A retrospective cohort study

    Objective To investigate the accuracy of 18F-FDG positron emission tomography/computed tomography (PET/CT) combined with CT three-dimensional reconstruction (CT-3D) in the differential diagnosis of benign and malignant pulmonary nodules. Methods The clinical data of patients who underwent pulmonary nodule surgery in the Department of Thoracic Surgery, Northern Jiangsu People's Hospital from July 2020 to August 2021 were retrospectively analyzed. The preoperative 18F-FDG PET/CT and chest enhanced CT-3D and other imaging data were extracted. The parameters with diagnostic significance were screened by the area under the receiver operating characteristic (ROC) curve (AUC). Three prediction models, including PET/CT prediction model (MOD PET), CT-3D prediction model (MOD CT-3D), and PET/CT combined CT-3D prediction model (MOD combination), were established through binary logistic regression, and the diagnostic performance of the models were validated by ROC curve. Results A total of 125 patients were enrolled, including 57 males and 68 females, with an average age of 61.16±8.57 years. There were 46 patients with benign nodules, and 79 patients with malignant nodules. A total of 2 PET/CT parameters and 5 CT-3D parameters were extracted. Two PET/CT parameters, SUVmax≥1.5 (AUC=0.688) and abnormal uptake of hilar/mediastinal lymph node metabolism (AUC=0.671), were included in the regression model. Among the CT-3D parameters, CT value histogram peaks (AUC=0.694) and CT-3D morphology (AUC=0.652) were included in the regression model. Finally, the AUC of the MOD PET was verified to be 0.738 [95%CI (0.651, 0.824)], the sensitivity was 74.7%, and the specificity was 60.9%; the AUC of the MOD CT-3D was 0.762 [95%CI (0.677, 0.848)], the sensitivity was 51.9%, and the specificity was 87.0%; the AUC of the MOD combination was 0.857 [95%CI (0.789, 0.925)], the sensitivity was 77.2%, the specificity was 82.6%, and the differences were statistically significant (P<0.001). Conclusion 18F-FDG PET/CT combined with CT-3D can improve the diagnostic performance of pulmonary nodules, and its specificity and sensitivity are better than those of single imaging diagnosis method. The combined prediction model is of great significance for the selection of surgical timing and surgical methods for pulmonary nodules, and provides a theoretical basis for the application of artificial intelligence in the pulmonary nodule diagnosis.

    Release date:2024-02-20 04:11 Export PDF Favorites Scan
  • Progress in the clinical application and correlation between glucose transporter-1 and 18F-FDG PET/CT imaging for non-small cell lung cancer

    Because of the unobvious early symptoms and low 5-year survival rate, the early diagnosis and treatment is of great significance for patients with non-small cell lung cancer. Glucose transporter-1 is the most widely distributed glucose transporters in various tissue cells in the human body, whose expression in non-small cell lung cancer is closely related to the histological types, lymph node metastasis, degree of differentiation, progression and prognosis.18F-FDG PET/CT imaging, a molecular imaging diagnostic method, is based on the characteristics of glucose metabolism in malignant tumors, which has been widely applied in the cancer diagnosis, stage division, evaluation of therapeutic effects and prognosis evaluation. Glucose transporter-1 is regulated and influenced by many factors, and it is closely related to 18F-FDG PET/CT imaging. This article briefly reviews the progress in the clinical application and correlation between glucose transporter-1 and 18F-FDG PET/CT imaging for non-small cell lung cancer, in order to improve the diagnosis and treatment of lung cancer.

    Release date:2021-06-18 04:50 Export PDF Favorites Scan
  • Assessing Liver Fibrosis with Non-Invasive Methods

    Objective To assess value and limitations of non-invasive methods in assessing liver fibrosis.Methods By summarized current situation and advancement of serum fibrotic markers, ultrasound, CT and MRI in assessing liver fibrosis, we investigated their value and limitations. Results In addition to diagnosis, non-invasive methods of assessing liver fibrosis assess severity of liver fibrosis. For liver fibrosis, however, non-invasive methods can not monitor effectively reaction to therapy and progression. Conclusion Non-invasive methods play important roles in diagnosis and assessing severity of liver fibrosis, and reduce the need of liver biopsy.

    Release date:2016-09-08 10:58 Export PDF Favorites Scan
  • CT texture analysis in gastric cancers

    CT texture analysis (CTTA) can objectively evaluate the heterogeneity of tissues and their lesions beyond the ability of subjective visual interpretation by extracting the texture features of CT images, then performing analysis and quantitative and objective evaluation, reflecting the tissue micro environmental information. This article reviews the recent studies on the applications of CTTA in gastric cancers, in the aspects of identification of gastric tumors, prediction of stage, correlation with Lauren classification, prediction of occult peritoneal carcinomatosis, evaluation of efficacy and prognosis, and prediction of biomarkers. It is regarded that CTTA has a good application prospect in gastric cancers.

    Release date:2020-12-28 09:30 Export PDF Favorites Scan
  • Optical coherence tomography of choroidal neovascularization of exudative age-related macular degeneration and central exudative chorioretinopathy

    Objective To investigate the characteristics and analyze the differences of choroidal neovascularization (CNV) image between exudative age-related macular degeneration (AMD) and central exudative chorioretinopathy (CEC) using optical coherence tomography (OCT). Methods Twenty-three eyes of 22 patients with exudative AMD and 20 eyes of 19 patients with CEC, which were diagnosed as CNV using fundus fluorescein angiograph (FFA) or indocyanine green angiograph ( ICGA), were examined by OCT.The size of CNV and the thickness of retinal neurosen sory layer in foveola were measured by OCT software. Results On OCT image, CNV had three main types of morphological features including simple CNV, CNV with serous retinal neurosensory layer detachment and CNV with choroidoretinal exudation. Exudative AMD mainly showed CNV with choroidoretinal exudation (56.52%) and CEC showed simple CNV (90.0%). The thickness of retinal neurosensory layer in foveola of patients with exudative AMD was thicker than that of patients with CEC and the size of CNV of patients with exudative AMD was larger than that of patients with CEC. Negative correlation was found between retinal neurosensory layer thickness in foveola and vision in both groups (gamma;=-0.521, P=0.001). Conclusions There were certain discrepancy in morphology and area in volved of CNV between exudative AMD and CEC on OCT images.  (Chin J Ocul Fundus Dis, 2001,17:299-302)

    Release date:2016-09-02 06:03 Export PDF Favorites Scan
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