Force Transmission Analysis and Optimization of Bowden Cable on Body in a Flexible Exoskeleton.

The Bowden cable is a significant force transmission equipment for a flexible exoskeleton. However, the previous researches of Bowden cable had emphasized on the data from experimenting test board, instead of on human body, which produced the inaccurate assisting analysis of the flexible exoskeleton. In this paper, a flexible exoskeleton for assisting knee extension was proposed, which provided an on-body condition. Then, the friction force and its influencing factors between the wire rope and sheath of the Bowden cable from the motor to the anchor of knee have been analyzed. The segment models of force transmission with the concern of three kinds of friction modes were established, and the relationship between various lengths and bending angles of Bowden cable was fitted to the equations of curve. Furthermore, the association rule between the force transmission and the lengths of Bowden cable was obtained, based on which, the optimal force transmission efficiency was 78.68% when the length value of the Bowden cable was 475 mm. A flexible exoskeleton prototype was assembled; then, the experiments with force transmission and metabolic cost have been developed. The results showed that the force transmission efficiency had strong association with the lengths of Bowden cable, instead of the transmission velocities. Furthermore, this knee assistance exoskeleton reduced the net metabolic cost of the testees during walking. These experiments results corroborated the force transmission modeling and simulation of the Bowden cable on body we proposed in this paper.

Human Motion Pattern Recognition and Feature Extraction: An Approach Using Multi-Information Fusion.

An exoskeleton is a kind of intelligent wearable device with bioelectronics and biomechanics. To realize its effective assistance to the human body, an exoskeleton needs to recognize the real time movement pattern of the human body in order to make corresponding movements at the right time. However, it is of great difficulty for an exoskeleton to fully identify human motion patterns, which are mainly manifested as incomplete acquisition of lower limb motion information, poor feature extraction ability, and complicated steps. Aiming at the above consideration, the motion mechanisms of human lower limbs have been analyzed in this paper, and a set of wearable bioelectronics devices are introduced based on an electromyography (EMG) sensor and inertial measurement unit (IMU), which help to obtain biological and kinematic information of the lower limb. Then, the Dual Stream convolutional neural network (CNN)-ReliefF was presented to extract features from the fusion sensors' data, which were input into four different classifiers to obtain the recognition accuracy of human motion patterns. Compared with a single sensor (EMG or IMU) and single stream CNN or manual designed feature extraction methods, the feature extraction based on Dual Stream CNN-ReliefF shows better performance in terms of visualization performance and recognition accuracy. This method was used to extract features from EMG and IMU data of six subjects and input these features into four different classifiers. The motion pattern recognition accuracy of each subject under the four classifiers is above 97%, with the highest average recognition accuracy reaching 99.12%. It can be concluded that the wearable bioelectronics device and Dual Stream CNN-ReliefF feature extraction method proposed in this paper enhanced an exoskeleton's ability to capture human movement patterns, thus providing optimal assistance to the human body at the appropriate time. Therefore, it can provide a novel approach for improving the human-machine interaction of exoskeletons.

Double-Layered Microcapsules Significantly Improve the Long-Term Effectiveness of Essential Oil.

In order to improve the long-term effectiveness of essential oil, a double-layered microcapsule was prepared using the inclusion encapsulation method in this study, with ß-cyclodextrin as its inner layer and chitosan and sodium alginate as its outer layer. The optimized preparation process was obtained through the response surface method. The morphology, particle size, encapsulation efficiency, thermal stability and sustained release effect of the double-layered microcapsules were characterized. The microcapsules were spherical, with a particle size distribution between 2-6 µm, and had good thermal stability within 250 °C. Their encapsulation efficiency can be up to 80%, and it can continuously release the active ingredients of the essential oil under normal temperature and high temperature conditions for a long time. In order to further examine the application effect of the double-layered microcapsule, it was loaded onto the cotton fabric by the soak-roll method. The finished cotton fabric showed excellent washability and rubbing fastness. They can still maintain a light fragrance naturally for two months. The microcapsules prepared in this study can be potentially applied in sleep aid, antibacterial, mosquito prevention, food science and other related products.

Imaging examination, diagnosis, and control and prevention of nosocomial infection for coronavirus disease 2019: Expert consensus of Hunan radiologist. / æ–°åž‹å† çŠ¶ç— æ¯’è‚ºç‚Žå½±åƒå­¦æ£€æŸ¥ã€ è¯Šæ–­åŠåŒ»é™¢å† æ„ŸæŸ“é¢„é˜²ä¸ŽæŽ§åˆ¶ï¼šæ¹–å—çœæ”¾å°„å­¦ä¸“å®¶å ±.

The outbreak of coronavirus disease 2019 (COVID-19) is a huge threat to global public health because it develops rapidly. There is no specific treatment so far. Chest imaging examination is an important auxiliary examination method in diagnosis of COVID-19. To further standardize the imaging examination and diagnosis of COVID-19, Hunan Society of Radiology together with Imaging Technology Professional Committee of Hunan Medical Association reach an expert consensus document on imaging examination, diagnosis, and control and prevention of nosocomial infection for COVID-19. This document summarizes the epidemiological characteristics, clinical features, imaging examination procedure, imaging findings, CT staging, the value of imaging examination, and the methods for control and prevention of nosocomial infection for COVID-19 during imaging examination. Furthermore, it extends the clinical characteristics and imaging manifestations of COVID-19 in children.

Design, validation, and clinical practice of standardized imaging diagnostic report for COVID-19. / COVID-19规范化影像学诊断报告的设计、验证与临床实践.

OBJECTIVES: To design a standardized imaging diagnostic reporting mode for screening coronavirus disease 2019 (COVID-19), and to prospectively verify its effectiveness in clinical practice. METHODS: A new classification and standardized imaging diagnosis report mode of viral pneumonia was established by studying and summarizing the imaging findings of various kinds of viral pneumonia, combining with lesion density, interstitial changes, pleural effusion, lymph nodes, and some special signs. After systematic training, the radiologist experienced clinical practice for screening CT features. COVID-19 cases were screened retrospectively in the single-center. The confirmed cases were verified, and the diagnostic efficacy of the standardized imaging reporting system in screening COVID-19 was tested. RESULTS: There were 912 patients in this stage receiving the screening imaging examination. Of them, 190 patients were screened in the report mode and 30 patients were diagnosed as COVID-19. The CT manifestation of COVID-19 was characterized by pure ground glass lesions or with a few solid components, predominant subpleural distribution, no lymph node enlargement and pleural effusion, and often with paving-way sign and air bronchus sign. In combination with the above signs, the diagnostic efficacy of COVID-19 was 0.942. CONCLUSIONS: The standardized imaging diagnosis report mode based on COVID-19 chest image features is effective and practical, which should be popularized.

Clinical and CT imaging features between the first nucleic acid-negative and first nucleic acid-positive COVID-19 patients. / 2019å† çŠ¶ç— æ¯’ç— é¦–æ¬¡æ ¸é ¸é˜´æ€§ä¸Žé¦–æ¬¡æ ¸é ¸é˜³æ€§æ‚£è€ ä¸´åºŠåŠCT影像学表现.

OBJECTIVES: To investigate the role of chest CT for the diagnostic work-up for patients with suspected infection of coronavirus disease 2019 (COVID-19). METHODS: The clinical data and imaging findings of the first nucleic acid-negative COVID-19 patients were analyzed and compared with the first nucleic acid-positive patients. RESULTS: Compared with the first nucleic acid-positive patients, the onset time of the first nucleic acid-negative patients was shorter [(3.58±2.94) d], but the diagnosis was longer [(3.92±3.66) d]. There were no significant differences in the characteristics of the clinical data and radiological findings between the 2 groups (P>0.05). CONCLUSION: Chest CT examination is important to avoid COVID-19 missed diagnosis due to false negative nucleic acid.

Value of CT application in the screening,diagnosis,and treatment of COVID-19. / CT检查在2019å† çŠ¶ç— æ¯’ç— ç­›æŸ¥ã€è¯Šæ–­åŠæ²»ç–—ä¸­çš„åº”ç”¨ä»·å€¼.

The coronavirus disease 2019 (COVID-19) has attracted extensive attention all around the world recently. Early screening, early diagnosis, early isolation, and early treatment remain the most effective prevention and control measures. Computed tomography (CT) plays a vital role in the screening, diagnosis, treatment, and follow-up of COVID-19, especially in the early screening, with a higher sensitivity than that of real-time fluorescence RT-PCR. The combination of CT and artificial intelligence has the potential to help clinicians in improving the diagnostic accuracy and working efficiency.

Structured reporting of cardiovascular magnetic resonance based on expert consensuses and guidelines.

BACKGROUND: There is a gap between China and developed countries in Europe and America as to the normalization of cardiac magnetic resonance (CMR) diagnostic reports. The aim of this study was to construct a structured CMR report template suitable for China's actual conditions. METHODS: Cardiac magnetic resonance standardized image interpretation and post-processing guidelines and CMR report guidelines are the consensus and recommendations of the Society for Cardiovascular Magnetic Resonance (SCMR) experts whose goal is to ensure the consistent quality and repeatability of CMR reports. This structured CMR report template was constructed based on the guidelines for standardized image interpretation, post processing and reporting of CMR examinations, combined with the experiences learned in Germany and the practical experiences in China. It consisted of three parts: Device and Methods, Findings (Structure and function, Tissue Characterization), Summary and Conclusion. Detailed directions were provided section by section. RESULTS: This structured CMR report template underlined the comprehensive analysis of the results of morphological, functional and tissue characteristics to provide conclusive opinions and answer the corresponding important questions raised by the clinicians. CONCLUSION: The standardization of qualitative and quantitative assessments of CMR results is the core of structured reporting of CMR.

Comparison and Correlation of Magnetic Resonance Imaging and Clinical Severity in Nonhuman Immunodeficiency Virus Patients with Cryptococcal Infection of Central Nervous System.

BACKGROUND: The incidence of cryptococcal meningitis among immunocompetent patients increases, especially in China and imaging plays an important role. The current study was to find the correlation between magnetic resonance imaging (MRI) manifestation and clinical severity in nonhuman immunodeficiency virus patients with cryptococcal infection of central nervous system (CNS). METHODS: A total of 65 patients with CNS cryptococcal infection from August 2014 to October 2016 were retrospectively included in this study. All the patients had MRI data and clinical data. The patients were divided into two groups according to whether the patients were confirmed with identifiable underlying disease. Comparison and correlation of MRI and clinical data in both groups were investigated using independent sample t- test, Chi-square test, Mann-Whitney test and Spearman rank correlation analysis. RESULTS: In all 65 patients, 41 cases (41/65, 63.1%; Group 1) had normal immunity and 24 cases (24/65, 36.9%; Group 2) had at least one identifiable underlying disease. Fever, higher percentage of neutrophil (NEUT) in white blood cell (WBC), and increased cell number of cerebral spinal fluid (CSF) were much common in patients with underlying disease (Group 1 vs. Group 2: Fever: 21/41 vs. 21/24, χ2 = 8.715, P = 0.003; NEUT in WBC: 73.15% vs. 79.60%, Z = -2.370, P = 0.018; cell number of CSF: 19 vs. 200, Z = -4.298, P < 0.001; respectively). Compared to the patients with normal immunity, the lesions are more common in the basal ganglia among patients with identifiable underlying disease (Group 1 vs. Group 2: 20/41 vs. 20/24, χ2 = 7.636, P = 0.006). The number of the involved brain areas in patients with identifiable underlying disease were well correlated with the number of cells and pressure of CSF (r = -0.472, P = 0.031; r = 0.779, P = 0.039; respectively). CONCLUSIONS: With the increased number of the involved brain areas in patients with identifiable underlying disease, the body has lower immunity against the organism which might result in higher intracranial pressure and more severe clinical status.

[Manifestations of the connective tissue associated interstitial lung disease under high resolution computed tomography].

OBJECTIVE: To analyze the features of the connective tissue associated interstitial lung disease (CTD-ILD) by high resolution computed tomography (HRCT).
 Methods: A total of 127 patients with CTD-ILD, who were diagnosed by clinic laboratory examination and pathology in Xiangya Hospital of Central South University form September 2013 to September 2015, were enrolled for this study. Their lung features of HRCT imaging were retrospectively analyzed.
 Results: The classifications for 127 patients were as follows: 36 cases of rheumatoid arthritis (28.3%), 34 cases of dermatomyositis and polymyositis (26.8%), 31 cases of systemic sclerosis (24.4%), 18 cases of Sjögren syndrome (14.2%), 7 cases of mixed connective tissue disease (5.5%), and 1 cases of systemic lupus erythematosus (0.8%). According to the features of HRCT imaging, the patients were divided as follows: 77 cases (60.6%) of nonspecific interstitial pneumonia (NSIP), 46 cases (36.2%) of usual interstitial pneumonia (UIP), 2 cases (1.6%) of lymphocytic interstitial pneumonia (LIP), 1 case (0.8%) of cryptogenic interstitial pneumonia (COP), and 1 case (0.8%) of acute interstitial pneumonia (AIP). The HRCT findings for 36 cases of rheumatoid arthritis associated interstitial lung disease were UIP (24 cases, 66.7%) and NSIP (12 cases, 33.3%); the HRCT findings for 34 cases of dermatomyositis and polymyositis associated interstitial lung disease were NSIP (32 cases, 94.1%), UIP (1 case, 2.9%) and COP (1 case, 2.9%); the HRCT findings for 31 cases of systemic sclerosis associated interstitial lung disease were NSIP (21 cases, 67.8%), UIP (9 cases, 29%), LIP(1 case, 3.2%); the HRCT findings for 18 cases of Sjögren syndrome associated interstitial lung disease were NSIP (9 cases, 50.0%), UIP (8 cases, 44.4%), LIP (1 case, 5.6%); the HRCT findings for 7 cases of mixed connective tissue disease associated interstitial lung disease were UIP (4 cases, 57.1%), NSIP (3 cases, 42.9%). SLE-ILD was rare, with only 1 case of AIP.
 Conclusion: Different types of CTD-ILD patients display relatively unique manifestation of HRCT.

[Quantitatively evaluating the evolution of the tumor perfusion in A549 lung adenocarcinoma transplantation model induced by antiangiogenic treatment].

OBJECTIVE: To quantitatively evaluate the evolution of the tumor perfusion in A549 lung adenocarcinoma transplantation model induced by antiangiogenic treatment. METHODS: To establish the preclinical transplantation model of lung adenocarcinoma, 60 BALB/c nu/nu mice was inoculated with A549 cell lines via axilla. Sixty mice were randomly divided into 2 groups. The treatment group was treated with intravenous Bevacizumab (10 mg/kg weight, in a single injection), and the control group received saline only in the same dose. Five times of volume perfusion CT (VPCT) scan was performed before treatment, and on the second, forth, sixth and tenth days of treatment, respectively. The values of blood flow (BF) in the A549 tumors were measured after scanning. The microvessel density (MVD), vessel maturity index (VMI) in the tumors were determined using multiplexed QDs-based immunohistochemical staining. RESULTS: Comparing the values of BF, VMI and MVD between the two groups on the same day before treatment, the values of BF, VMI and MVD of the treatment group were (13.5±1.5) ml·(100 ml)(-1)·min(-1,) 0.14±0.04, (45.7±16.5)/HPF, respectively, and those in the control group were (13.4±1.6) ml·(100 ml)(-1)·min(-1) , 0.14±0.05, (48.0±7.0) /HPF , respectively. There was no significant difference between the two groups (all P>0.05). And on the second, forth, sixth, tenth days of treatment, the values of BF of the treatment group were (17.9±7.3), (32.2±6.9), (18.5±2.4) and (13.8±1.8) ml·(100 ml)(-1)·min(-1,) respectively, and those in the control group were (10.5±0.6), (9.6±0.8), (5.7±1.2) and (1.9±1.0) ml·(100 ml)(-1)·min(-1,) respectively. The values of VMI of the treatment group were 1.17±0.22, 3.25±0.23, 2.94±0.31 and 1.07±0.18, respectively, and those in the control group were 0.12±0.03, 0.13±0.03, 0.15±0.03, and 0.13±0.03, respectively. The values of MVD of the treatment group were (38.0±6.3), (24.3±5.4), (15.2±3.4) and (13.5±4.7)/HPF, respectively, and those in the control group were (44.8±5.9), (48.0±12.8), (41.8±5.7) and (45.7±20.3)/HPF, respectively. In treated mice, BF and VMI were significantly higher than those in the control group (all P<0.01). BF and VMI increased from day2, and reached the peak at day4 (P<0.01), then decreased at day6, however the value of BF at day6 was still higher than that in the baseline (P<0.01) and decreased to the baseline level at day10; while the value of VMI was still higher than that in the baseline at day10. And on the forth, sixth, tenth days of treatment, in treated mice, the values of MVD were significantly lower than those in the control group and the baseline level before treatment (all P<0.01). In control mice, BF decreased (all P<0.01) with the time, while MVD and VMI had no changes. CONCLUSIONS: The tumor perfusion and vessel maturity are transiently increased in A549 lung adenocarcinoma transplantation model induced by antiangiogenic treatment. VPCT is helpful to quantify the evolution of the tumor perfusion and then evaluate the functional changes of tumor vessel maturity.

Optimal Blood Suppression Inversion Time Based on Breathing Rates and Heart Rates to Improve Renal Artery Visibility in Spatial Labeling with Multiple Inversion Pulses: A Preliminary Study.

OBJECTIVE: To determine whether an optimal blood suppression inversion time (BSP TI) can boost arterial visibility and whether the optimal BSP TI is related to breathing rate (BR) and heart rate (HR) for hypertension subjects in spatial labeling with multiple inversion pulses (SLEEK). MATERIALS AND METHODS: This prospective study included 10 volunteers and 93 consecutive hypertension patients who had undergone SLEEK at 1.5T MRI system. Firstly, suitable BSP TIs for displaying clearly renal artery were determined in 10 volunteers. Secondly, non-contrast enhanced magnetic resonance angiography with the suitable BSP TIs were performed on those hypertension patients. Then, renal artery was evaluated and an optimal BSP TI to increase arterial visibility was determined for each patient. Patients' BRs and HRs were recorded and their relationships with the optimal BSP TI were analyzed. RESULTS: The optimal BSP TI was negatively correlated with BR (r1 = -0.536, P1 < 0.001; and r2 = -0.535, P2 < 0.001) and HR (r1 = -0.432, P1 = 0.001; and r2 = -0.419, P2 = 0.001) for 2 readers (κ = 0.93). For improving renal arterial visibility, BSP TI = 800 ms could be applied as the optimal BSP TI when the 95% confidence interval were 17-19/min (BR1) and 74-82 bpm (HR1) for reader#1 and 17-19/min (BR2) and 74-83 bpm (HR2) for reader#2; BSP TI = 1100 ms while 14-15/min (BR1, 2) and 71-76 bpm (HR1, 2) for both readers; and BSP TI = 1400 ms when 13-16/min (BR1) and 63-68 bpm (HR1) for reader#1 and 14-15/min (BR2) and 64-70 bpm (HR2) for reader#2. CONCLUSION: In SLEEK, BSP TI is affected by patients' BRs and HRs. Adopting the optimal BSP TI based on BR and HR can improve the renal arterial visibility and consequently the working efficiency.

[Multi-slice CT angiography in the diagnosis of lesions of mesenteric artery and mesenteric vein].

OBJECTIVE: To evaluate the value of multi-slice CT angiography (MSCTA) in the diagnosis of super mesenteric artery (SMA) and super mesenteric vein (SMV), and discuss the 3D reconstruction method for detecting mesenteric vessel lesions. METHODS: Thirty-three patients suffering from mesenteric vessel diseases were analyzed. There were 14 SMA lesions, including 9 thromboses, 3 dissecting aneurysms, 1 pseudoaneurysm, and 1 malrotation. There were 19 SMV thromboses. The 3D reconstruction included volume rendering (VR), maximum intensity projection (MIP), and multi-planner reformation (MPR). RESULTS: The lesions appeared clear by MSCTA in the 33 patients. The SMA thrombosis was shown clear in the MIP in all 9 patients, and only 4 of them were detected in the VR. There was significant difference between MIP andVR in detecting SMA thrombosis (P=0.0294). Three dissecting aneurysms were best shown in the MPR; 1 pseudoaneurysm and 1 malrotation were clearly manifested in the VR. The thrombosis of SMV was clearly shown by both MIP and MPR in all 19 patients. Collateral vessels were clearly shown in the MIP in 12 patients; the collateral vessels were detected by VR only in 5, and the other 7 failed to show the collateral vessels. There was significant difference between the MIP and the VR in showing lateral collateral vessels (P=0.0046). CONCLUSION: Both lesions of SMA and SMV can be detected by MSCTA. MIP is an ideal reconstruction method for SMA thrombosis and collateral vessels around the SMV.

[Correlation of blood flow assessed by CT perfusion imaging and microvascular ultrastructure in non-small cell lung cancer: a preliminary study].

OBJECTIVE: To investigate the correlation between blood flow assessed by CT perfusion imaging and characteristics of microvascular ultrastructure in non-small cell lung cancer (NSCLC). METHODS: twenty-eight patients with non-small cell lung cancer proven surgically and pathologically underwent perfusion CT examination. The patients were divided into a hyper-perfusion group and a hypo-perfusion group by the median value of blood flow, and then the differences of microvascular ultrastructure in the two groups were analyzed. RESULTS: The median BF value of the 28 patients was 36.40 ml×100 g(-1)×min(-1). Take this median value as the boundary, the group with hypo-perfusion showed a significantly lower BF value than the group with hyper-perfusion [(30.84 ± 4.79) ml×100 g(-1)×min(-1) vs. (49.67 ± 10.89) ml×100 g(-1)×min(-1), t = -5.925, P < 0.001]. The group with lymph node metastasis showed a significantly lower BF value than the group without lymph node metastasis [(30.78 ± 5.24) ml×100 g(-1)×min(-1) vs. (50.73 ± 11.16) ml×100 g(-1)×min(-1), t = 3.490, P = 0.015]. The maturity of microvessels of the hyper-perfusion group was higher than that of the hypo-perfusion group. Under the electron microscope, the microvessels in the hypo-perfusion group showed a more narrow lumen, poorer integrity of basement membrane, a more close relationship between cancer cells and microvascular wall, and cancer cells were more easily seen in the microvascular lumen. CONCLUSION: The blood flow value of CT perfusion imaging may be related with the abnormal microvascular ultrastructure, and may be helpful to the prediction of metastasis risk in NSCLC.

Low tumor blood flow assessed with perfusion CT correlates with lymphatic involvement in patients with stage T1b non-small cell lung cancer.

BACKGROUND: To investigate the correlation of computed tomography (CT) perfusion parameters and lymphatic involvement in patients with stage T1b non-small cell lung cancer (NSCLC). METHODS: Forty-six patients (30 men and 16 women; age range, 36-73 years; mean age, 57 years), with stage T1b non-small cell lung cancer, underwent perfusion CT before surgery. The correlations between CT perfusion parameters (blood flow, blood volume, peak enhancement intensity), tumor angiogenesis (microvessel density and maturity of microvessels of surgical specimens) and lymphatic involvement were retrospectively investigated. Receiver operator curve (ROC) analysis was used to identify the parameter threshold at which tumors had or did not have lymph node metastasis, and the corresponding sensitivity and specificity were calculated. RESULTS: A significant tendency for tumors with low blood flow and high density of immature microvessels to show lymphatic involvement was found (all P < 0.001). High correlation (r =-0.769, P < 0.001) was observed between tumor blood flow and immature microvessels. The area under ROC curves (AUC) for blood flow to detect lymph node metastasis was 0.866 (95% confidence interval, 0.766-0.966). For blood flow, the sensitivity, specificity, and accuracy of predicting lymph node metastasis were 88.9, 64.3, and 73.9% respectively, if the cutoff point was set at 43.05 mL/100 g/minute. CONCLUSIONS: Blood flow may be useful to predict lymphatic involvement before surgery in stage T1b NSCLC.

[Correlation between computed tomographic vascular convergence sign and enhancement value in patients with pulmonary nodules].

OBJECTIVE: To explore the correlation between computed tomographic (CT) vascular convergence sign and enhancement value in patients with pulmonary nodules. METHODS: A total of 708 consecutive patients with pulmonary nodule received dual-source CT scan from January 2010 to January 2012. They were divided into vascular convergence sign group (including 4 subgroups) and non-vascular convergence sign group. Then the correlation between CT vascular convergence sign and enhancement values was analyzed. RESULTS: The enhancement values in vascular convergence sign group were significantly higher than those in non-vascular convergence sign group ((27.6 ± 10.5) vs (3.2 ± 2.8) HU, P = 0.000). The CT enhancement values in lesions tended to increase with the number of connecting blood vessels. However, no significant differences existed among the subgroups (P > 0.05). The accuracy of vascular convergence sign for detection of pulmonary malignant nodules was 84.9%, 70.6% and 60.3% according to the standards of CT enhancement values ≥ 15, 20, 25 HU respectively. The sensibility, specificity and accuracy of determining pulmonary malignant nodules were 97.2%, 68.8% and 93.7% according to the standard of vascular convergence sign. The accuracy of determining pulmonary nodules' CT enhancement values ≥ 15 HU was 88.1% according to the standard of vascular convergence sign. CONCLUSION: Vascular convergence sign may be used to indicate the enhancement of pulmonary nodules when CT enhancement images are not available.

[Evaluation of three-dimensional tumor microvascular architecture phenotype heterogeneity in non-small cell carcinoma and its significance].

OBJECTIVE: To explore the degree, mechanism and clinical significance of three-dimensional tumor microvascular architecture phenotype heterogeneity (3D-TMAPH) in non-small cell carcinoma (NSCLC). METHODS: Twenty-one samples of solitary pulmonary nodules were collected integrally. To establish two-dimensional tumor microvascular architecture phenotype (2D-TMAP) and three-dimensional tumor microvascular architecture phenotype (3D-TMAP), five layers of each nodule were selected and embedded in paraffin. Test indices included the expressions of vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), EphB4, ephfinB2 and microvascular density marked by anti-CD34 (CD34-MVD). The degrees of 3D-TMAPH were evaluated by the coefficient of variation and extend of heterogeneity. Spearman rank correlation analysis was used to investigate the relationships between 2D-TMAP, 3D-TMAP and clinicopathological features. RESULTS: 3D-TMAPH showed that 2D-TMAP heterogeneity was expressed in the tissues of NSCLC. The heterogeneities in the malignant nodules were significantly higher than those in the active inflammatory nodules and tubercular nodules. In addition, different degrees of heterogeneity of CD34-MVD and PCNA were found in NSCLC tissues. The coefficients of variation of CD34- MVD and PCNA were positively related to the degree of differentiation (all P<0.05), but not related to the P-TNM stages, histological type or lymphatic metastasis (all P>0.05). The level of heterogeneity of various expression indexes (ephrinB2, EphB4, VEGF) in NSCLC tissues were inconsistent, but there were no significant differences in heterogeneity in NSCLC tissues with different histological types (P>0.05). CONCLUSION: 3D-TMAPH exists widely in the microenvironment during the genesis and development of NSCLC and has a significant impact on its biological complexity.

Lymphatic microvessel density combined with CT used in the diagnosis of mediastinal and hilar lymph node metastasis of non-small cell lung cancer.

BACKGROUND AND AIMS: Lymphatic microvessel density (LMVD) has been demonstrated to correlate with tumor metastasis. The purpose of this study is to determine whether the criteria combining LMVD with computed tomography (CT) could improve the diagnostic accuracy of lymph node (LN) metastasis in non-small cell lung cancer (NSCLC). METHODS: Ninety four patients with NSCLC who had chest CT scans preoperatively and LMVD tested by immunohistochemistry postoperatively were randomized into two groups: the training set (n = 66) and the test set (n = 28). Cut-off point of LMVD was selected to separate the LN metastasis-predictive positive and negative groups. On the basis of LMVD levels, chest CTs of the training set were re-analyzed and hypothetical criteria for LN metastasis diagnosis were established. Diagnostic characteristics for LN metastasis were tested by using the combined criteria in the test set as compared to those of CT alone. RESULTS: There was a significantly positive correlation between LMVD and LN metastasis (p <0.01). For sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV), accuracy was 67, 81, 75, 81 and 79% for the combined criteria, respectively. Diagnostic efficacy of the combined criteria was significantly higher than that of CT only (p <0.05). CONCLUSIONS: Diagnosis of LN metastasis using a combination of LMVD and CT is superior to the CT-only diagnosis. In future clinical trials, it is necessary to evaluate the efficacy of adjuvant therapy for the selection of patients according to the combined criteria.

[Correlation between podoplanin-positive lymphatic microvessel density and CT characteristics of non-small cell lung cancer].

BACKGROUND AND OBJECTIVE: It has been proven that ymphatic microvessel density (LMVD) was closely correlated with the lymphatic metastasis of non-small cell lung cancer (NSCLC). The aim of the present study is to explore the relationship between podoplanin-LMVD and multi-slice spiral computed tomography (MSCT) characteristics of NSCLC. METHODS: MSCT scanning was performed on 34 cases of NSCLC (squamous carcinoma, 15 cases; adenocarcinoma, 15 cases; and adenosquamous carcinoma, 4 cases) prior to operation. Clinical pathology results, including lymph node metastasis, were obtained. CT characteristics, such as shape of the edge, internal structure, and adjacent structures, were described. LMVD in the central and peripheral areas examined respectively using SP immunohistochemical technique were analyzed. RESULTS: Lymph node metastasis was found to be associated with LMVD in the peripheral areas. LMVD in the peripheral areas of the resected lesions, the MSCT findings of which included spinous process, pleural indentation, and carcinomatous lymphangitis, was higher than that of the lesions without these MSCT characteristics (P<0.05). CONCLUSION: MSCT findings of spinous process, pleural indentation, or carcinomatous lymphangitis of NSCLC may suggest a higher level of tumor lymphangiogenesis with a higher risk of lymph node metastasis.

[Relationship between multi-slice spiral CT pulmonary perfusion imaging and the expression of EphB4 and ephrinB2 in non-small cell lung cancer].

OBJECTIVE: To investigate the role of the expression of ephrinB2 and EphB4 in non-small cell lung cancer (NSCLC), and their relationship with multi-slice spiral CT pulmonary perfusion imaging. METHODS: Thirty-one nodules with pathologically proven NSCLC underwent CT perfusion scan. The perfusion parameters including blood flow (BF), blood volume (BV), peak enhancement image (PEI) were collected. The expression of ephrinB2 and EphB4 in tumor cells and interstitial vasculature were detected by immunohistochemistry. Correlation analysis and trend test were used to assess the relationship between ephrinB2/EphB4 expression and clinicopathological features, and between ephrinB2/EphB4 expression and perfusion parameters. RESULTS: Positive expression of ephrinB2 and EphB4 in the NSCLC group was 83.9% and 71.0%, respectively, significantly higher than that in the internal control group (P < 0.01). The expression of ephrinB2 and EphB4 was consistently in tumor parenchyma but differently in tumor vessels. The expressions of ephrinB2 and EphB4 were positively correlated with lymphatic metastasis (P < 0.05). The expression of EphB4 was negatively correlated with blood flow (BF) and blood volume (BV), respectively (P < 0.05). There was a significant positive correlation between ephrinB2 expression and BF (r = 0.516, P = 0.003), and a positive correlation between ephrinB2 expression and BV (r = 0.448, P = 0.013). The expressions of ephrinB2 and EphB4 were not correlated with PEI (P > 0.05). The values of BF and BV in the high and moderate EphB4 expression groups were significantly decreased compared with that in the negative group (P < 0.01). The value of BF in the high ephrinB2 expression group was significantly increased compared with that in the moderately positive group and negative group (P < 0.01). The value of BV in the high ephrinB2 expression group was significantly increased compared with that in the negative group (P < 0.01). CONCLUSION: The CT pulmonary perfusion imaging reflects the density difference of blood vessels with functional lumen, and such difference also depends on the quantity and quality of vasculature with functional lumen.