Microstructural damage pattern of vascular cognitive impairment: a comparison between moyamoya disease and cerebrovascular atherosclerotic disease

Moyamoya disease and cerebrovascular atherosclerotic disease are both chronic ischemic diseases with similar presentations of vascular cognitive impairment. The aim of the present study was to investigate the patterns of microstructural damage associated with vascular cognitive impairment in the two diseases. The study recruited 34 patients with moyamoya disease(age 43.9 ± 9.2 years; 20 men and 14 women, 27 patients with cerebrovascular atherosclerotic disease(age: 44.6 ± 7.6 years; 17 men and 10 women), and 31 normal controls(age 43.6 ± 7.3 years; 18 men and 13 women) from Huashan Hospital of Fudan University in China. Cognitive function was assessed using the Mini-Mental State Examination, long-term delayed recall of Auditory Verbal Learning Test, Trail Making Test Part B, and the Symbol Digit Modalities Test. Single-photon emission-computed tomography was used to examine cerebral perfusion. Voxel-based morphometry and tract-based spatial statistics were performed to identify regions of gray matter atrophy and white matter deterioration in patients and normal controls. The results demonstrated that the severity of cognitive impairment was similar between the two diseases in all tested domains. Patients with moyamoya disease and those with cerebrovascular atherosclerotic disease suffered from disturbed supratentorial hemodynamics. Gray matter atrophy in bilateral middle cingulate cortex and parts of the frontal gyrus was prominent in both diseases, but in general, was more severe and more diffuse in those with moyamoya disease. White matter deterioration was significant for both diseases in the genu and body of corpus callosum, in the anterior and superior corona radiation, and in the posterior thalamic radiation, but in moyamoya disease, it was more diffuse and more severe. Vascular cognitive impairment was associated with regional microstructural damage, with a potential link between, gray and white matter damage. Overall, these results provide insight into the pathophysiological nature of vascular cognitive impairment. This study was approved by the Institutional Review Board in Huashan Hospital, China(approval No. 2014-278). This study was registered with ClinicalTrials.gov on December 2, 2014 with the identifier NCT02305407.

Computed tomography perfusion and computed tomography angiography for prediction of clinical outcomes in ischemic stroke patients after thrombolysis

Cerebral blood perfusion and cerebrovascular lesions are important factors that can affect the therapeutic efficacy of thrombolysis.At present,the majority of studies focus on assessing the accuracy of lesion location using imaging methods before treatment,with less attention to predictions of outcomes after thrombolysis.Thus,in the present study,we assessed the efficacy of combined computed tomography（CT） perfusion and CT angiography in predicting clinical outcomes after thrombolysis in ischemic stroke patients.The study included 52 patients who received both CT perfusion and CT angiography.Patients were grouped based on the following criteria to compare clinical outcomes：（1） thrombolytic and non-thrombolytic patients,（2） thrombolytic patients with CT angiography showing the presence or absence of a vascular stenosis,（3） thrombolytic patients with CT perfusion showing the presence or absence of hemodynamic mismatch,and（4） different CT angiography and CT perfusion results.Short-term outcome was assessed by the 24-hour National Institution of Health Stroke Scale score change.Long-term outcome was assessed by the 3-month modified Rankin Scale score.Of 52 ischemic stroke patients,29 were treated with thrombolysis and exhibited improved short-term outcomes compared with those without thrombolysis treatment（23 patients）.Patients with both vascular stenosis and blood flow mismatch（13 patients） exhibited the best short-term outcome,while there was no correlation of long-term outcome with CT angiography or CT perfusion findings.These data suggest that combined CT perfusion and CT angiography are useful for predicting short-term outcome,but not long-term outcome,after thrombolysis.

A simple image-based method for online moisture content estimation of iron ore green pellets

Moisture content(MC)is an important quality metric of iron ore green pellets in pelletizing process in ironmaking industry.Current image-based methods for MC estimation may result in big errors for gray-scale pellet images captured under various lighting conditions.We proposed a simple image-based method to improve the MC estimation accuracy by illumination correction and linear regression modeling.Firstly,the illumination of the pellet image was transformed into the reference illumination by use of a color checker chart and piecewise linear interpolation,so that the influence of different illuminations could be greatly reduced.By experimental analysis,it was found that MC is approximately adversely proportional to the average intensity of the transformed images.A simple model for MC prediction was then established by linear fitting.Experiments demonstrated that the proposed method has good robustness to different lighting conditions and achieves the best performance in metrics of mean square error,mean absolute error and maximum absolute error in comparison with five state-of-art MC estimating methods.Application on a working disk pelletizer shows that the proposed method can predict well the change of moisture content with time,and its computing efficiency can satisfy the requirement for online MC monitoring during the pelletizing process.