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find Keyword "distribution" 62 results
  • Effects of different puncture levels in bilateral percutaneous vertebroplasty on distribution of bone cement and effectiveness of osteoporotic thoracolumbar compression fractures

    Objective To investigate the effects of different puncture levels on bone cement distribution and effectiveness in bilateral percutaneous vertebroplasty for osteoporotic thoracolumbar compression fractures. Methods A clinical data of 274 patients with osteoporotic thoracolumbar compression fractures who met the selection criteria between December 2017 and December 2020 was retrospectively analyzed. All patients underwent bilateral percutaneous vertebroplasty. During operation, the final position of the puncture needle tip reached was observed by C-arm X-ray machine. And 118 cases of bilateral puncture needle tips were at the same level (group A); 156 cases of bilateral puncture needle tips were at different levels (group B), of which 87 cases were at the upper 1/3 layer and the lower 1/3 layer respectively (group B1), and 69 cases were at the adjacent levels (group B2). There was no significant difference in gender, age, fracture segment, degree of osteoporosis, disease duration, and preoperative visual analogue scale (VAS) score, and Oswestry disability index (ODI) between groups A and B and among groups A, B1, and B2 (P>0.05). The operation time, bone cement injection volume, postoperative VAS score, ODI, and bone cement distribution were compared among the groups. Results All operations were successfully completed without pulmonary embolism, needle tract infection, or nerve compression caused by bone cement leakage. There was no significant difference in operation time and bone cement injection volume between groups A and B or among groups A, B1, and B2 (P>0.05). All patients were followed up 3-32 months, with an average of 7.8 months. There was no significant difference in follow-up time between groups A and B and among groups A, B1, and B2 (P>0.05). At 3 days after operation and last follow-up, VAS score and ODI were significantly lower in group B than in group A (P<0.05), in groups B1 and B2 than in group A (P<0.05), and in group B1 than in group B2 (P<0.05). Imaging review showed that the distribution of bone cement in the coronal midline of injured vertebrae was significantly better in group B than in group A (P<0.05), in groups B1 and B2 than in group A (P<0.05), and in group B1 than in group B2 (P<0.05). In group A, 7 cases had postoperative vertebral collapse and 8 cases had other vertebral fractures. In group B, only 1 case had postoperative vertebral collapse during follow-up. ConclusionBilateral percutaneous vertebroplasty in the treatment of osteoporotic thoracolumbar compression fractures can obtain good bone cement distribution and effectiveness when the puncture needle tips locate at different levels during operation. When the puncture needle tips locate at the upper 1/3 layer and the lower 1/3 layer of the vertebral body, respectively, the puncture sites are closer to the upper and lower endplates, and the injected bone cement is easier to connect with the upper and lower endplates.

    Release date:2023-03-13 08:33 Export PDF Favorites Scan
  • Nonparametric Method of Estimating Survival Functions Containing Right-censored and Interval-censored Data

    Missing data represent a general problem in many scientific fields, especially in medical survival analysis. Dealing with censored data, interpolation method is one of important methods. However, most of the interpolation methods replace the censored data with the exact data, which will distort the real distribution of the censored data and reduce the probability of the real data falling into the interpolation data. In order to solve this problem, we in this paper propose a nonparametric method of estimating the survival function of right-censored and interval-censored data and compare its performance to SC (self-consistent) algorithm. Comparing to the average interpolation and the nearest neighbor interpolation method, the proposed method in this paper replaces the right-censored data with the interval-censored data, and greatly improves the probability of the real data falling into imputation interval. Then it bases on the empirical distribution theory to estimate the survival function of right-censored and interval-censored data. The results of numerical examples and a real breast cancer data set demonstrated that the proposed method had higher accuracy and better robustness for the different proportion of the censored data. This paper provides a good method to compare the clinical treatments performance with estimation of the survival data of the patients. This provides some help to the medical survival data analysis.

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  • Current research status of blood routine indexes in predicting severity of acute pancreatitis

    ObjectiveTo summarize the blood routine indexes and predictive systems that can predict the severity of acute pancreatitis (AP). MethodThe recent domestic and foreign literatures on the predictive value of blood routine indexes for the severity of AP were reviewed.ResultsFrom the current research results at domestic and foreign, independent blood routine indexes such as red blood cell distribution width, average platelet volume, hematocrit (TCT), platelet (PLT) count, platelet distribution width, percentage of immature granulocytes (IG%), and some blood routine calculation indexes such as neutrophil to lymphocyte ratio (NLR), PLT to lymphocyte ratio (PLR), red blood cell distribution width to PLT ratio (RPR), neutrophil-monocyte product, and so on, all had different predictive value for the severity of AP. In addition, multiple prediction modes such as blood routine indexes combined with some serological indexes or other scoring systems could also be used to predict the severity of AP. In general, the predictive value of the NLR, IG%, and HCT on the severity of AP had been unanimously recognized by researchers. However, the conclusions of related studies on the predictive values of PLT, PLR, and RPR on the severity of AP were still controversial. ConclusionsAt present, there are a variety of blood routine indexes can be used to predict severity of AP, but their predictive values are different. Further researches are still needed.

    Release date:2022-03-01 03:44 Export PDF Favorites Scan
  • Research progress on the correlation between parameters related to blood routine examination and acute cerebral infarction

    Acute cerebral infarction is characterized by high incidence rate, high recurrence rate, high disability rate and multiple complications. Early evaluation and treatment of acute cerebral infarction is particularly important to improve the survival rate and prognosis of patients. As an easily available clinical laboratory indicator, blood routine test can reflect the pathological changes in the body to a certain extent. In recent years, many studies have shown that the indicators such as red cell volume distribution width, mean platelet volume, neutrophil to lymphocyte ratio and platelet to lymphocyte ratio in blood routine examination have important values in the onset, severity and prognosis of acute cerebral infarction. This article reviews the correlations of the above parameters and ratio parameters with acute cerebral infarction, in order to provide some reference and basis for clinical diagnosis, treatment and prognosis evaluation of acute cerebral infarction.

    Release date:2022-12-23 09:29 Export PDF Favorites Scan
  • Application of electrical impedance tomography in diagnosis and monitoring of pulmonary diseases

    Electrical impedance tomography (EIT) is a new non-invasive functional imaging technology, which has the advantages of non-invasion, non-radiation, low cost, fast response, portability and visualization. In recent years, more and more studies have shown that EIT has great potential in the detection of lung diseases and has been applied to early diagnosis and treatment of some diseases. This paper introduced the basic principle of EIT, discussed the research and clinical application of EIT in the detection of acute respiratory distress syndrome, chronic obstructive pulmonary disease, pneumothorax and pulmonary embolism, and focused on the summary and introduction of indicators and functional images of EIT related to the detection of lung diseases. This review will help medical workers understand and use EIT, and promote the further development of EIT in lung diseases as well as other fields.

    Release date:2025-04-24 04:31 Export PDF Favorites Scan
  • Numerical simulation of the focal region modulation to realize uniform temperature distribution during high-intensity focused ultrasound brain tumor therapy

    The temperature during the brain tumor therapy using high-intensity focused ultrasound (HIFU) should be controlled strictly. This research aimed at realizing uniform temperature distribution in the focal region by adjusting driving signals of phased array transducer. The three-dimensional simulation model imitating craniotomy HIFU brain tumor treatment was established based on an 82-element transducer and the computed tomography (CT) data of a volunteer's head was used to calculate and modulate the temperature distributions using the finite difference in time domain (FDTD) method. Two signals which focus at two preset targets with a certain distance were superimposed to emit each transducer element. Then the temperature distribution was modulated by changing the triggering time delay and amplitudes of the two signals. The results showed that when the distance between the two targets was within a certain range, a focal region with uniform temperature distribution could be created. And also the volume of focal region formed by one irradiation could be adjusted. The simulation results would provide theoretical method and reference for HIFU applying in clinical brain tumor treatment safely and effectively.

    Release date:2019-02-18 02:31 Export PDF Favorites Scan
  • Association between preoperative red cell distribution width and prognosis in esophageal cancer: A systematic review and meta-analysis

    ObjectiveTo explore the relation of preoperative red blood cell distribution width (RDW) with prognosis in esophageal cancer.MethodsThe PubMed, EMbase, Web of Science, Cochrane Library, VIP, Wanfang, CNKI and SinoMed databases were searched to identify potential studies assessing the correlation between preoperative RDW and prognosis of esophageal cancer patients from establishment of databases to February 2019. The endpoint events included the overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS). The Stata 12.0 software was applied for the meta-analysis and the hazard ratio (HR) and 95% confidence interval (CI) were calculated.ResultsA total of 10 retrospective studies involving 4 260 esophageal cancer patients from China or Japan were included. The score of Newcastle-Ottawa scale (NOS) of the included studies was more than 6 points. The results demonstrated that elevated preoperative RDW was significantly associated with poor CSS (HR=1.50, 95% CI 1.14 to 1.99, P=0.004) and DFS (HR=1.45, 95% CI 1.14 to 1.85, P=0.002), while no significant association between preoperative RDW and OS in esophageal cancer was observed (HR=1.17, 95% CI 0.95 to 1.45, P=0.143). Subgroup analysis based on the pathology revealed that preoperative RDW had high prognostic value in esophageal squamous carcinoma (ESCC) (HR=1.37, 95% CI 1.05 to 1.77, P=0.018).ConclusionPreoperative RDW may be an independent prognostic factor for Chinese and Japanese esophageal cancer patients, especially for ESCC patients. However, more prospective studies with bigger sample sizes from other countries are still needed to verify our findings.

    Release date:2019-12-13 03:50 Export PDF Favorites Scan
  • Correlation analysis of red blood cell distribution width and disease severity of acute exacerbation of bronchiectasis in the elderly patients

    ObjectiveTo investigate the relationship between the red blood cell distribution width (RDW) and the severity of acute exacerbation of bronchiectasis in elderly patients.MethodsThe clinical data of 216 elderly patients with acute exacerbation of bronchiectasis admitted from January 2015 to October of 2018 were analyzed retrospectively. The severity of acute exacerbation of bronchiectasis in the elderly was evaluated by bronchiectasis severity index (BSI) score. Meanwhile, 50 elderly people receiving qualified medical examination were collected as a healthy control group in the same period. The distributions of BSI score, RDW, procalcitonin (PCT), neutrophil percentage (NEU%) and C-reactive protein (CRP) were described in the patients with different risk degree. The severity of acute exacerbation of bronchiectasis in the elderly was evaluated by BSI. The patients were divided into three groups by BSI score: a low risk group, a middle risk group, and a high risk group. The indexes were described including the distribution of stratified BSI score, RDW, PCT, NEU%, CRP at different risk levels. The correlation of each index was analyzed by Spearman correlation. The threshold value of RDW was calculated by general linear regression, and the influencing factors of BSI score were analyzed by multivariate linear regression analysis.ResultsThe higher the risk stratification, the higher the BSI score, RDW, PCT, NEU% and CRP were. RDW was positively correlated with PCT, NEU% and CRP (r values were 0.425, 0.311, 0.177, respectively, P<0.05). BSI score was positively correlated with RDW, PCT, NEU%, and CRP (r values were 0.425, 0.394, 0.650, 0.578, respectively, P<0.05). RDW was positively correlated with PSI score (r=0.425, P<0.05). The thresholds of RDW were 11.45% and 14.03%. Multiple linear regression showed that RDW, PCT, NEU% and CRP were all influential factors of BSI score and explained 52.3% of the total mutation rate.ConclusionRDW is related to the severity of acute exacerbation of bronchiectasis in the elderly, and can predict the severity of acute exacerbation of bronchiectasis in the elderly.

    Release date:2019-07-19 02:21 Export PDF Favorites Scan
  • Research on Numerical Simulation of Temperature Distribution during Transcranial Tumor Therapy with High Intensity Focused Ultrasound

    Numerical simulation is one of the most significant methods to predict the temperature distribution in high-intensity focused ultrasound (HIFU) therapy. In this study, the adopted numerical simulation was used based on a transcranial ultrasound therapy model taking a human skull as a reference. The approximation of the Westervelt formula and the Pennes bio-heat conduction equation were applied to the simulation of the transcranial temperature distribution. According to the temperature distribution and the Time Reversal theory, the position of the treatable focal region was corrected and the hot spot existing in the skull was eliminated. Furthermore, the influence of the exposure time, input power and the distance between transducer and skull on the temperature distribution was analyzed. The results showed that the position of the focal region could be corrected and the hot spot was eliminated using the Time Reversal theory without affecting the focus. The focal region above 60℃ could be formed at the superficial tissue located from the skull of 20 mm using the hot spot elimination method and the volume of the focal region increases with the exposure time and the input power in a nonlinear form. When the same volume of the focal region was obtained, the more power was inputted, the less the exposure time was needed. Moreover, the volume of the focal region was influenced by the distance between the transducer and the skull.

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  • The value of platelet volume indices in early period as prognostic indicators of sepsis

    ObjectiveTo investigate the prognostic value of platelet volume indices [mean platelet volume (MPV) and platelet distribution width (PDW)] in early period for patients with sepsis .MethodsThis retrospective study was conducted in a general ICU at a University Hospital from January 2015 to January 2017. Patients with sepsis were divided into a survival group and a death group according to 28-day prognosis. The demographic and clinical data were recorded and analyzed, including platelet indices, Charlson comorbidity index, Glasgow Coma Scale (GCS) score and Acute Physiology and Chronic Health Evaluation Ⅱ (APACHEⅡ) score. Multivariable COX proportional hazard ratio model was used to evaluate the 28-day mortality risk, and receiver operating characteristic (ROC) curve were used to evaluate the value of platelet volume indices.ResultsA total of 209 patients were enrolled in this study. Mean arterial pressure, pH, platelet count, serum creatinine, bilirubin, troponin I, prothrombin time, GCS score and platelet volume indices showed significant differences between the survival group (n=137) and the death group (n=72) (all P<0.05). Multivariable COX regression analysis revealed that the PDW was independently associated with 28-day mortality in sepsis (HR=1.068, 95%CI 1.002-1.139, P=0.043). The area under the ROC curve of PDW was 0.762 (95%CI 0.694 - 0.831), with a sensitivity of 86% and a specificity of 63% at a cut-off value of 18.65%.ConclusionPDW can be used as a powerful prognostic indicator in patients with sepsis following 28-day.

    Release date:2019-07-19 02:21 Export PDF Favorites Scan
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