Explore the correlation between cerebral vessel characteristics with cognitive impairment among elder individuals: a community study from China

Background Brain Magnetic Resonance Imaging (MRI) examination of cerebral small vessel disease (CSVD) may help screen vascular cognitive impairment. A recently estimated CSVD score system was suggested to capture the overall CSVD burden. The study aimed to detect the association between systemic evaluation score of cerebral vascular imaging parameters with cognitive functions. Methods This was a cross-sectional study in community settings. From October 2017 to September 2018, elder (≧60) residents were recruited through on-site visit in 6 communities from Shanghai, China. The participants underwent brain MRI, carotid ultrasound, laboratory tests of blood and urine samples. Cognitive function was evaluated using Mini-Mental State Examination (MMSE). MRI score of CSVD was calculated according to the 2012 standard for the evaluation of statistical changes in imaging. Results Total 171 subjects completed survey and examinations. There were 55 participants diagnosed with cognitive impairment, with a total percentage of 32.2%. Participants with and without cognitive impairment showed significant differences in age, BMI and education level. Cognitive impaired participant had more disease history/comorbidity of hypertension and chronic renal insufficiency, higher level of creatinine, as well as lower level of full blood count (FBC) and alanine aminotransferase (ALT). A significant difference was detected in CSVD score between participants with and without cognitive impairment. Results of linear regression analysis showed significant negative correlations between MMSE score and both left and right carotid artery peak systolic velocity (PSV), however the CSVD score was only borderline (P = 0.0566) positively correlated with MMSE. Multivariate linear correlation analysis including all collected risk factor data showed that left carotid artery PSV score was among the independent negative correlated factors of MMSE. Multivariate binary logistic analysis showed that age, education and history of hypertension were the only statistically associated factors of cognitive impairment. Conclusions The current study identified high prevalence of cognitive impairment in a Chinese community. In addition, correlations between cerebral vascular disease imaging status and cognitive functions were confirmed although the sample size limited the possibility of screening cognitive impairment with imaging technique.

Real-Time Cerebral Vessel Segmentation in Laser Speckle Contrast Image Based on Unsupervised Domain Adaptation

Laser speckle contrast imaging (LSCI) is a full-field, high spatiotemporal resolution and low-cost optical technique for measuring blood flow, which has been successfully used for neurovascular imaging. However, due to the low signal–noise ratio and the relatively small sizes, segmenting the cerebral vessels in LSCI has always been a technical challenge. Recently, deep learning has shown its advantages in vascular segmentation. Nonetheless, ground truth by manual labeling is usually required for training the network, which makes it difficult to implement in practice. In this manuscript, we proposed a deep learning-based method for real-time cerebral vessel segmentation of LSCI without ground truth labels, which could be further integrated into intraoperative blood vessel imaging system. Synthetic LSCI images were obtained with a synthesis network from LSCI images and public labeled dataset of Digital Retinal Images for Vessel Extraction, which were then used to train the segmentation network. Using matching strategies to reduce the size discrepancy between retinal images and laser speckle contrast images, we could further significantly improve image synthesis and segmentation performance. In the testing LSCI images of rodent cerebral vessels, the proposed method resulted in a dice similarity coefficient of over 75%.

Relationship between Circle of Willis Variations and Cerebral or Cervical Arteries Stenosis Investigated by Computer Tomography Angiography and Multitask Convolutional Neural Network

Circle of Willis (CoW) is the most critical collateral pathway that supports the redistribution of blood supply in the brain. The variation of CoW is closely correlated with cerebral hemodynamic and cerebral vessel-related diseases. But what is responsible for CoW variation remains unclear. Moreover, the visual evaluation for CoW variation is highly time-consuming. In the present study, based on the computer tomography angiography (CTA) dataset from 255 patients, the correlation between the CoW variations with age, gender, and cerebral or cervical artery stenosis was investigated. A multitask convolutional neural network (CNN) was used to segment cerebral arteries automatically. The results showed the prevalence of variation of the anterior communicating artery (Aco) was higher in the normal senior group than in the normal young group and in females than in males. The changes in the prevalence of variations of individual segments were not demonstrated in the population with stenosis of the afferent and efferent arteries, so the critical factors for variation are related to genetic or physiological factors rather than pathological lesions. Using the multitask CNN model, complete cerebral and cervical arteries could be segmented and reconstructed in 120 seconds, and an average Dice coefficient of 78.2% was achieved. The segmentation accuracy for precommunicating part of anterior cerebral artery and posterior cerebral artery, the posterior communicating arteries, and Aco in CoW was 100%, 99.2%, 94%, and 69%, respectively. Artificial intelligence (AI) can be considered as an adjunct tool for detecting the CoW, particularly related to reducing workload and improving the accuracy of the visual evaluation. The study will serve as a basis for the following research to determine an individual’s risk of stroke with the aid of AI.

A Nitric Oxide–Modulated Variable-Order Fractional Maxwell Viscoelastic Model of Cerebral Vascular Walls

It is well known that the mechanical behavior of arterial walls plays an important role in the pathogenesis of vascular diseases. Most studies existing in the literature focus on the mechanical interactions between the blood flow and wall’s deformations. However, in the brain, the smaller vessels experience not only oscillatory forces due to the pulsatile blood flow but also structural and morphological changes controlled by the surrounding brain cells. In this study, the mechanical deformation of the cerebral arterial wall caused by the pulsatile blood flow and the dynamics of the neuronal nitric oxide (NO) is investigated. NO is a small diffusive gaseous molecule produced by the endothelial cells and neurons, which is involved in the regulation of cerebral blood flow and pressure. The cerebral vessel is assumed to be a hollow axial symmetric cylinder whose wall thickness is much smaller than the cylinder’s radius and longitudinal length is much less than the propagating wavelength. The wall is an isotropic, homogeneous linear viscoelastic material described by an NO-modulated variable-order fractional Maxwell model. A fractional telegraph equation is obtained for the axial component of the displacement. Patterns of wall’s deformation are investigated through numerical simulations. The results suggest that a significantly decreased inactivation of the neuronal NO may cause a reduction in the shear stress at the blood-vessel interface, which could lead to a decrease in the production of shear-induced endothelial NO and neurovascular disease.

Mechanical Thrombectomy in Acute Terminal Internal Carotid Artery Occlusions Using a Large Manually Expandable Stentretriever (Tiger XL Device): Multicenter Initial Experience

Background: The recently introduced Tigertriever XL Device for treatment of cerebral vessel occlusions combines manual adjustability and maximum length in one device. In this study, we report our initial experience with the Tigertriever XL in terminal ICA occlusions. Methods: Retrospective multicenter analysis of acute terminal ICA occlusions treated by mechanical thrombectomy using the Tigertriever XL Device. Results: 23 patients were treated using the Tigetriever XL due to an acute occlusion of the terminal ICA. The overall successful reperfusion rate after a median of two maneuvers using the Tigertriever XL Device was 78.3% (mTICI 2b-3). In 43.5% (10/23) additional smaller devices were applied to treat remaining occlusions in downstream territories, which resulted in a final successful reperfusion rate of 95.7%. Device related complications did not occur. Two symptomatic intracerebral hemorrhages (sICH) were observed. Conclusions: The Tigertriever XL Device might be a helpful tool in the treatment of ICA terminus occlusions with large clot burden resulting in high reperfusion rates. This is mainly related to the manual adjustability of the device combined with the maximum length.

Progression of central nervous system disease from pediatric to young adulthood in sickle cell anemia

Silent cerebral infarcts and arteriopathy are common and progressive in individuals with sickle cell anemia. However, most data describing brain lesions in sickle cell anemia are cross-sectional or derive from pediatric cohorts with short follow-up. We investigated the progression of silent cerebral infarct and cerebral vessel stenosis on brain MRI and MRA, respectively, by describing the incidence of new or worsening lesions over a period of up to 25 years among young adults with sickle cell anemia and explored risk factors for progression. Forty-four adults with sickle cell anemia (HbSS or HbSβ0thalassemia), exposed to chronic transfusions ( n = 12) or hydroxyurea ( n = 32), median age 19.2 years (range 18.0–31.5), received a screening brain MRI/MRA and their results were compared with a clinical exam performed during childhood and adolescence. We used exact log-rank test to compare MRI and MRA progression among any two groups. The hazard ratio (HR) and 95% confidence interval (CI) were calculated from Cox regression analyses. Progression of MRI and MRA occurred in 12 (27%) and 4 (9%) young adults, respectively, relative to their pediatric exams. MRI progression risk was high among participants with abnormal pediatric exams (HR: 11.6, 95% CI: 2.5–54.7) and conditional or abnormal transcranial Doppler ultrasound velocities (HR: 3.9, 95% CI: 1.0–15.1). Among individuals treated with hydroxyurea, high fetal hemoglobin measured in childhood was associated with lower hazard of MRI progression (HR: 0.86, 95% CI: 0.76–0.98). MRA progression occurred more frequently among those with prior stroke (HR: 8.6, 95% CI: 1.2–64), abnormal pediatric exam ( P = 0.00084), and elevated transcranial Doppler ultrasound velocities ( P = 0.004). Brain MRI/MRA imaging in pediatrics can identify high-risk patients for CNS disease progression in young adulthood, prompting consideration for early aggressive treatments.

Serum glial fibrillary acidic protein and S100 calcium-binding protein B correlates cerebral vessel reactivity following carotid artery stenting

Using detection markers in serum has the advantages of simplicity, repeatability and the capability. This study combined the use of serum glial fibrillary acidic protein (GFAP) and S100B protein (S100B) with imaging tools to confirm the role of serum biomarkers in evaluating the cerebral vessel reactivity after carotid artery stenting (CAS). After CAS, the serum concentrations of GFAP and S100B increased to the peak at 24 h after operation, and then gradually decreased. The mean flow velocity (MFV) (pre-operation, post-operation, 30 days follow-up: 47.65 ± 17.24 cm/s, 62.37 ± 18.25 cm/s, 70.29 ± 16.89 cm/s; P < 0.05) and pulsatility index (PI) (pre-operation, post-operation, 30 days follow-up: 0.78 ± 0.21, 0.98 ± 0.19, 1.02 ± 0.20; P < 0.05) increased significantly in the ipsilateral middle cerebral artery after CAS. At the 30-day follow-up, the cerebrovascular reserve (CVR) (post-operation, 30 days follow-up: 27.47 ± 12.13 cm/s, 31.92 ± 10.94 cm/s; P < 0.05) improved significantly. In patients with different degrees of stenosis, the more severe the stenosis in the carotid artery, the more obvious the improvement of CVR at the 30 days of follow-up (CVR changes: 11.08 ± 7.95 cm/s, Kendall’s tau-b = 0.645, P < 0.001). And the serum concentrations of GFAP (r = − 0.629, P < 0.0001) and S100B (r = − 0.604, P < 0.0001) correlated negatively with CVR at 30 days after CAS. Therefore, we recommend using the biomarkers GFAP and S100B associated with imaging tools such as transcranial Doppler (TCD) and Magnetic resonance imaging (MRI) to evaluate the cerebral vessel reactivity following CAS.

An evaluation of performance measures for arterial brain vessel segmentation

Background Arterial brain vessel segmentation allows utilising clinically relevant information contained within the cerebral vascular tree. Currently, however, no standardised performance measure is available to evaluate the quality of cerebral vessel segmentations. Thus, we developed a performance measure selection framework based on manual visual scoring of simulated segmentation variations to find the most suitable measure for cerebral vessel segmentation. Methods To simulate segmentation variations, we manually created non-overlapping segmentation errors common in magnetic resonance angiography cerebral vessel segmentation. In 10 patients, we generated a set of approximately 300 simulated segmentation variations for each ground truth image. Each segmentation was visually scored based on a predefined scoring system and segmentations were ranked based on 22 performance measures common in the literature. The correlation of visual scores with performance measure rankings was calculated using the Spearman correlation coefficient. Results The distance-based performance measures balanced average Hausdorff distance (rank = 1) and average Hausdorff distance (rank = 2) provided the segmentation rankings with the highest average correlation with manual rankings. They were followed by overlap-based measures such as Dice coefficient (rank = 7), a standard performance measure in medical image segmentation. Conclusions Average Hausdorff distance-based measures should be used as a standard performance measure in evaluating cerebral vessel segmentation quality. They can identify more relevant segmentation errors, especially in high-quality segmentations. Our findings have the potential to accelerate the validation and development of novel vessel segmentation approaches.

Serum glial fibrillary acidic protein and S100 calcium-binding protein B correlates cerebral vessel reactivity following carotid artery stenting

Using detection markers in serum has the advantages of simplicity, repeatability and the capability. This study combined the use of serum glial fibrillary acidic protein (GFAP) and S100B protein (S100B) with imaging tools to confirm the role of serum biomarkers in evaluating the cerebral vessel reactivity after carotid artery stenting (CAS). After CAS, the serum concentrations of GFAP and S100B increased to the peak at 24 hours after operation, and then gradually decreased. The mean flow velocity (MFV) (pre-operation, post-operation, 30 days follow-up: 47.65 ± 17.24 cm/s, 62.37 ± 18.25 cm/s, 70.29 ± 16.89 cm/s; P < 0.05) and pulsatility index (PI) (pre-operation, post-operation, 30 days follow-up: 0.78 ± 0.21, 0.98 ± 0.19, 1.02 ± 0.20; P < 0.05) increased significantly in the ipsilateral middle cerebral artery after CAS. At the 30-day follow-up, the cerebrovascular reserve (CVR) (post-operation, 30 days follow-up: 27.47 ± 12.13 cm/s, 31.92 ± 10.94 cm/s; P < 0.05) improved significantly. In patients with different degrees of stenosis, the more severe the stenosis in the carotid artery, the more obvious the improvement of CVR at the 30 days of follow-up (CVR changes: 11.08 ± 7.95 cm/s, Kendall’s tau-b = 0.645, P < 0.001). And the serum concentrations of GFAP (r = – 0.629, P < 0.0001) and S100B (r = − 0.604, P < 0.0001) correlated negatively with CVR at 30 days after CAS. Therefore, we recommend using the biomarkers GFAP and S100B associated with imaging tools such as transcranial Doppler (TCD) and Magnetic resonance imaging (MRI) to evaluate the cerebral vessel reactivity following CAS.