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.
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.
【摘要】 目的 研究急性主动脉夹层时间分布规律。 方法 回顾性研究我院2000年1月-2010年12月所有急性主动脉夹层患者的时间资料，分析其月份、季节、周以及时刻分布特点。 结果 急性主动脉夹层月份分布高峰点为1月4日，高峰段为9月21日～次年4月19日（Plt;0.05）；季节分布以冬春季较多（Plt;0.05）；周分布无高峰点及高峰段（Pgt;0.05）；时刻分布高峰点为上午10点及下午4点。 结论 急性主动脉夹层具有明显的时间分布规律，我们应该在该病的高峰时间更加重视其发生的可能，从而减少误诊，改善预后。【Abstract】 Objective To investigate the features of time distribution in the occurrence of acute aortic dissection (AAD). Methods We retrospectively analyzed all the databases of AAD in our hospital between January 1, 2000 and December 31, 2010, and studied the monthly, seasonal, weekly, and circadian distribution of the cases. Results In terms of monthly distribution, the occurrence of AAD peaked at January 4th with the high frequency in the period of September 21st to April 19th of the next year (Plt;0.05). According to the seasonal distribution, the occurrence of AAD peaked in winter and spring (Plt;0.05). There was no peak time in weekly distribution (Pgt;0.05). In accordance with circadian distribution, the occurrence of AAD peaked at 10 and 16 o’clock (Plt;0.05). Conclusion Because of the obvious rhythm of time distribution of AAD, We can pay more attention to the diagnosis of AAD especially in the peak time, thus reducing the mistakes in diagnosis and improving the prognosis.
ObjectiveTo exclusively compare the short-and long-term outcomes of hepatic resection (HR) patients with multifocal tumors meeting the Milan criteria between locating in same and different sections. MethodsA total of 219 consecutive HR patients with multifocal tumors meeting the Milan criteria were divided into group SS (n=97, same section) and group DS (n=122, different sections) according to their anatomical location (Couinaud's segmentation). ResultsThe 1-, 3-, and 5-year overall survival (OS) and recurrence-free survival (RFS) rates were significantly higher in the group SS than those in the group DS (P < 0.05). The subgroup analysis showed that patients with 2 tumors and those undergoing en bloc resection were associated with better OS and RFS (P < 0.05). ConclusionsFor HCC patients with multifocal tumors meeting the Milan criteria, those with tumors locating in same hepatic section may have better longterm survival and lower HCC recurrence rates than those locating in different sections after HR.
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.
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.
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.
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.
Three dimensional (3D) printing is considered as an advanced manufacturing technology because of its additive nature. Electron beam melting (EBM) is a widely used 3D printing processes for the manufacturing of metal components. However, the products printed via this process generally contain micro porosities which affect mechanical properties, especially the fatigue property. In this paper, two types of EBM printed samples of the Ti-6Al-4V alloy, one with a round cross section and the other with a triangle cross section, were employed to investigate the existence of porosities using computed tomography (CT). Statistical analyses were conducted on the number, volume, shape, and distribution of pores. The results show that small pores (less than 0.000 2 mm3) account for 80% of all pores in each type of samples. Additionally, to some extent, the shape of sample has influence on the number of micro porosities in EBM made Ti-6Al-4V. The sphericity of the pores is relatively low and is inversely proportional to pore volume. It is found that re-melting on the free surface effectively reduce pore density near the surface. This study may help produce a medical implant with better fatigue resistance.