Objective To evaluate the accuracy of presurgically resting-state fMRI(rs-fMRI) with subject order-independent group independent component analysis(ICA), compared to electric cortical stimulations. Methods Twenty-three patients with the lesion in motor area, which were recorded by our hospital from Jan, 2014 to Dec, 2015, were collected as the study sample. The data of 9 patients were excluded because of excessive head motion. As a result, 14 patients were included in this study. Rs-fMRI data before the surgery and the results of electric cortical stimulations were collected. Results All of this 14 patients were preoperatively located by rs-fMRI with SOI-GICA, including all the SMA and the ipsilesional primary motor area. On the side with lesion, the number of functional location of motor area was decreased compared with healthy side. Evaluate the accuracy of ICA by comparing the coincidence rate of these two techniques, based on the standardized electrical cortical stimulation in operation. The completely concordance between rs-fMRI with the SOI-GICA and electrical cortical stimulation in operation was 11 (11/14). Meanwhile the basically concordance of corresponded case was 3(3/14). Conclusions Rs-fMRI with the ICA has a relatively high accuracy rate in localizing motor area. Rs-fMRI has a remarkably referential contribution to the presurgically function assessment and surgical planning in implementation.

Objective:To explore the characteristics of cortical activation during the stimulation-assisted walking of hemiplegic stroke survivors using functional near-infrared spectroscopy (fNIRS).Methods:Eight stroke survivors with right hemiplegia (average age 44.4±7.2 years) in a self-controlled study each walked at 2km/h on a treadmill, alone and assisted by functional electronic stimulation (FES). Real-time near-infrared spectroscopic images were recorded. The Matlab NIRS-SPM toolkit was employed to calculate the changes in oxyhemoglobin concentration in different cortical regions. A general linear model was evaluated which integrated the task effects, and version 20.0 of the SPSS statistical software was used to perform single sample or paired sample t-tests of the beta values so as to produce activation hot maps of the significant differences.Results:During unassisted walking channels 8, 10, 11, 13-20, 23-28, 30 and 32-37 were significantly activated. During FES-assisted walking it was the same channels plus channels 9 and 22, 31. The results suggest that in walking the cortical regions activated are mainly located in M1 of the unaffected hemisphere, supplemented by M1 and SMA, PMC and S1 in the affected hemisphere. There were significant differences in the activation of channels 9, 24, 27, 32, 33 between the two walking tasks. FES-assistance enhances S1 activation on the unaffected side, as well as the SMA and PMC of the affected side more significantly.Conclusions:Bilateral asymmetrical activation is found mostly in M1 during walking with or without FES assistance. FES assistance significantly strengthens the compensatory activation of the PMC and SMA of the affected hemisphere while walking for those with hemiplegia.

Objective: To compare and quantify the differences in size-specific dose estimates (SSDE) obtained by effective diameter and water-equivalent diameter from the central slice of the scan range in head CT examination. Methods: A total of 111 consecutive adult patients who underwent head CT examination were enrolled in this study. All of CTDI_vol values in the dose report were documented. The dataset was assigned into group A and group B, based on the individual size-dependent conversion factors (f) of effective diameter (d_eff) and water-equivalent diameter (d_w) at the central slice multiplied by normalized volume computed tomography dose index (CTDI_vol ) respectively. Body size, f and SSDE were calculated. With SSDE_gross served as the reference level, the performance of SSDE_deff and SSDE_dw was evaluated. Results: Statistically significant differences were found in body size (t=47.587, P<0.05) and f(z=-9.242, P<0.05) between group A and group B. Statistically significant difference also existed in SSDE (t=-46.687, P<0.05), (56.20±2.66) and (53.49±2.48) mGy for group A and group B respectively. Strongly positive correlation was shown in body size (r=0.873, R² =0.761) and SSDE (r=0.974, R² =0.949) between group A and group B(all P<0.05). Positive correlation was also found between SSDE_deff and SSDE_gross(r=0.900, R² =0.809), SSDE_dw and SSDE_gross (r=0.904, R² =0.817, all P<0.05). Mean absolute difference was 2.34 and 0.78 mGy, for SSDE_deff vs. SSDE_gross and SSDE_dw vs. SSDE_gross respectively; mean absolute relative difference was 4.38%, 1.40%; root mean square difference was 1.17 mGy (2.17%), 1.06 mGy (1.91%). Interquartile range and full range of SSDE_deff and SSDE_dw were 3.22 vs. 2.39 mGy, 13.65 vs. 12.48mGy, respectively. A less degree of variation was observed in SSDE_dw than that in SSDE_deff. Conclusions SSDE_dw values based on the water-equivalent diameter at the central slice of the scan range got better agreement with those derived from all slices, which could serve as a simpler and more valid indicator to represent the average value of size-specific dose estimates of the whole scan range in head CT examination.

BACKGROUND:The incidence of high lumbar disc herniation in elderly patients with osteoporosis is increasing.The changes in lumbar overall mechanical strength and biomechanical properties of adjacent vertebrae after conventional posterior approach decompression and interbody fusion have not been clarified.Finite element analysis has great value in the field of biomechanics because of its advantages of non-invasiveness,high repeatability and accuracy. OBJECTIVE:To explore the establishment of a finite element model of senile osteoporotic L3/4 lamina decompression using finite element analysis and intervertebral fusion spine,and to evaluate the biomechanical status of the internal fixation complex of bones under bending motion in elderly patients with osteoporosis. METHODS:Mimics 21.0 was used to extract the DICOM data of the spine CT to establish the 3D bony structure of the lumbar spine(T12-L5),which was imported into Geomagic wrap 2017.The L3/4 full lamina decompression model was established after redrawing the mesh,deleting the nails,cutting the model,filling the cavity,detecting and editing the contour line,constructing curved surfaces and grids,fitting curved surfaces and other operations.Solidworks 2017 was used to construct pedicle screws,connecting rods,and intervertebral fusion cages,which were assembled into the L3/4 full lamina decompression model.Intervertebral discs and articular process cartilage and other structures were established through operations such as stretching,isometric surfaces,moving and copying entities.ANSYS Workbench 17.0 was utilized for material assignment,simulating spinal ligaments,meshing,applying force and limiting boundary conditions.A complete osteoporotic L3/4 laminar decompression and intervertebral fusion spine finite element model was established.The stress,strain and displacement cloud diagram of the L3/4 lamina decompression and intervertebral fusion full lumbar spine finite element model were observed under simulated bending conditions. RESULTS AND CONCLUSION:(1)In terms of the stress cloud diagram:The T12-L1 vertebra had the highest average stress value;L2 dropped by 24%;L3 dropped by 55%,and L4-5 dropped by about 80%.The stress concentration in the L4/5 articular process area was the highest,followed by L2/3,and lighter in L1/2 and T12/L1.The stress concentration at the junction of the screw and the connecting rod was obvious,followed by the screw at the entrance and exit of the pedicle.(2)In terms of strain and displacement cloud map:The strain degree of L4/5 and L2/3 articular process was the highest;the strain degree of T12/L1 and L1/2 was the second,and the L3/4 segmental fusion cage,pedicle screw and connecting rod had no any visible deformation.The intervertebral discs of all segments showed great deformation.(3)It is concluded that the cooperative operation of multiple software can successfully construct a finite element model of the spine with L3/4 lamina decompression and intervertebral fusion in elderly patients with osteoporosis.Elderly patients after lumbar spine surgery can tolerate forward flexion,confirming that L3/4 laminar decompression and intervertebral fusion can maintain the shape of the spine and ensure the stability of the spine,but it is necessary to be alert to the occurrence of thoracolumbar stress fractures and adjacent spondylopathy.

Objective To explore the validity of the size-specific dose estimate (SSDE) derived from the water-equivalent diameter (Dw)value of the slice located in the middle of the scan range in the head CT examination. Methods A total of 197 patients underwent head CT nonenhanced scan were enrolled in this retrospective study. The Dw, size-dependent conversion factor (f), normalized volume CT dose index (CTDIvol) and SSDE values of all slices were calculated. Two sets of SSDE, SSDEgroand SSDEcenbased on the Dwvalues slice by slice (Dw-gro) and the Dwvalues of the slices in the middle of the scan range (Dw-cen), were obtained across all patients. Pearson correlation analysis and linear regression analysis were performed for Dw-grovs Dw-cen, Spearman correlation analysis and linear regression analysis for SSDEgrovs SSDEcen, SSDE vs Dw, CTDIvolvs Dw. With the reference of SSDEgrovalue, mean absolute relative difference (MARD) of SSDEcen values were calculated to assess its accuracy and the correlated factors of MARD was analyzed with multivariate linear stepwise regression analysis. Results The minimal Dwvalue close to the roof of the skull corresponded to the maximal value of f and SSDE, which was the minimal value of CTDIvol. The significant positive correlation was showed between Dw-grovs Dw-cen, SSDEgrovs SSDEcen, SSDE vs Dw, CTDIvolvs Dw(r=0.947, 0.931, 0.416, 0.626;P＜0.05). The values of Dw,groand Dw-cenwere (16.94±0.69) and (18.50±0.62) cm respectively. The values of SSDEgroand SSDEcenwere [54.10 (52.29, 56.39)] mGy and [53.77 (51.85, 55.25)] mGy respectively. An approximation of SSDEcenvalues with an average of 1.62% of the gross MARD was found to match the reference value. Multivariate linear stepwise regression analysis indicated that MARD had negative correlation with Dw(β=–1.319,P＜0.05), positive correlation with CTDIvol(β=0.202,P＜0.05), and f was not included in the multivariate regression equation. Conclusion SSDEcenbased on the Dwvalue of the slice located at the center of the scan range yields small MARD value and can represent a reliable SSDE estimation in the head CT examination.

Objective To explore the clinical feasibility of predicting synchronous liver metastases based on MRI radiomics nomogram based on T2WI in rectal cancer. Methods The imaging and clinical data of 261 patients with primary rectal cancer admitted to Zhejiang People′s Hospital from April 2012 to May 2018 were retrospectively analyzed. 101 patients were accompanied by synchronous liver metastasis All cases were divided into training group (n=182) and verification group (n=79). T2WI image of each patient was selected to extract texture features by AK analysis software of GE company. A radiomics signature was constructed after reduction of dimension in training group by the least absolute shrinkage and selection operator (LASSO). Univariate logistic regression was used to select for independent clinical risk factors and multivariate logistic regression along with imaging omics tags were used to construct predictive models and nomogram. ROC was used to assess the accuracy of the nomogram in the training group and to verify them by the validation group. Finally, the clinical efficacy of each patient′s synchronized liver metastasis risk factor was calculated based on the nomogram. Results A total of 328 texture features were extracted from the T2WI. Seven most valuable features were selected after reducing the dimension by LASSO algorithm, including 3 co-occurrence matrices (GLCM) and 4 run-length matrices(RLM). Tumor staging and radiomic signatures were included in the Multifactor logistic regression to build the prediction model and nomogram. The accuracy of predicting SRLM was 0.862 and 0.844 in the training and the verification group, respectively. To evaluate the accuracy of the nomogram, radiomics signature and the tumor staging in all cases were 0.857, 0.832 and 0.663, respectively. There was no significant difference in the number of SRLM cases between the high risk group and the low risk group based on nomogram (P>0.05). Conclusion The radiomics nomogram based on T2WI can be used as a quantitative tool to predict synchronous liver metastases of rectal cancer.

BACKGROUND: The 2019 novel coronavirus disease (COVID-19) has had a massive impact on public health, resulting in sudden dietary and behavioral habit changes. Frontline epidemic prevention workers play a pivotal role against COVID-19. They must face high-risk infection conditions, insufficient anti-epidemic material supplies, mental pressure, and so on. COVID-19 seriously affects their dietary and behavioral habits, and poor habits make them more susceptible to COVID-19. However, their baseline dietary and behavioral habits before COVID-19 and their willingness to change these habits after the outbreak of COVID-19 remain unclear for these workers in China. This study aimed to explore the baseline dietary and behavioral habits of frontline workers and their willingness to change these habits after the outbreak of the epidemic; in addition, susceptible subgroups were identified by stratified analyses as targets of protective measures to keep them from being infected with COVID-19. METHODS: A cross-sectional study was conducted through an online questionnaire using a sample of 22,459 valid individuals living in China, including 9402 frontline epidemic prevention workers. RESULTS: Before COVID-19, 23.9% of the frontline epidemic prevention workers reported a high-salt diet, 46.9% of them reported a high frequency of fried foods intake, and 50.9% of them smoked cigarettes. After the outbreak of COVID-19, 34.6% of them expressed a willingness to reduce salt intake, and 43.7% of them wanted to reduce the frequency of pickled vegetables intake. A total of 37.9% of them expressed a willingness to decrease or quit smoking, and 44.5% of them wanted to increase sleep duration. Significant differences in the baseline dietary and behavioral habits and the willingness to change their habits were observed between frontline epidemic prevention workers and other participants. Among the frontline epidemic prevention workers with poor dietary and behavioral habits before COVID-19, frontline epidemic prevention experience was a promoting factor for adopting worse dietary and behavioral habits, including those in the high-salt intake subgroup (OR, 2.824; 95% CI, 2.341-3.405) and the 11-20 cigarettes/day subgroup (OR, 2.067; 95% CI, 1.359-3.143). CONCLUSIONS The dietary and behavioral habits of frontline epidemic prevention workers were worse than that those of other participants before COVID-19. They had a greater willingness to adopt healthy dietary and behavioral habits after experiencing the outbreak of COVID-19. However, frontline epidemic prevention workers with poor dietary and behavioral habits before COVID-19 continued in engage in these poor habits. Dietary and behavioral intervention policies should be drafted to protect their health, especially frontline epidemic prevention workers with poor habits at baseline.
Adult ; COVID-19/psychology* ; China/epidemiology* ; Cross-Sectional Studies ; Diet/standards* ; Female ; Health Behavior ; Health Knowledge, Attitudes, Practice ; Health Personnel/psychology* ; Humans ; Male ; Risk Reduction Behavior ; SARS-CoV-2 ; Surveys and Questionnaires