Cerebral Blood Flow Perfusion Research Articles

Unraveling the thrombin–Alzheimer’s connection: Oral anticoagulants as potential neuroprotective therapeutics

In Alzheimer’s disease (AD), toxic amyloids formed by amyloid-β (Aβ) proteins and tau are implicated in the development of inflammatory, vascular, and neurodegenerative brain disorders. Thrombin has also been recognized as a proteopathic factor involved in Aβ-induced neurovascular dysfunction. Vascular Aβ activates the contact system in the blood, stimulating the production of inflammatory bradykinin and procoagulant thrombin. Thrombin, in turn, triggers inflammation, platelet activation, and the formation of fibrinolysis-resistant, Aβ-containing fibrin clots, leading to Aß-type cerebral amyloid angiopathy and associated neuropathology. Targeting thrombin with oral anticoagulants can normalize proinflammatory and prothrombotic states, counteracting the neurovascular consequences of AD. Pre-clinical studies have shown that such interventions preserve vascular and blood–brain barrier integrity, improve cerebral blood flow and brain perfusion, and reduce parenchymal accumulations of toxic Aβ, tau, fibrin(ogen), and thrombin. These effects mitigate neuroinflammatory and neurodegenerative processes, ultimately preserving cognitive functions for a longer period. Recent observational clinical studies in patients with atrial fibrillation (AF) demonstrated that treatment with direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs) reduced the risk of dementia by up to 48% compared to non-users. The anti-dementia effects were most prominent in elderly patients but were also observed in individuals with low AF risk or newly diagnosed AF. In addition, DOACs reduced the risk of intracranial hemorrhage by approximately 50% compared to VKAs. The current review highlights the potential neuroprotective role of DOACs in AD. By preventing excessive thrombin generation caused by Aβ pathology, DOACs could protect vascular and neuronal functions, thereby slowing cognitive decline. DOACs, such as dabigatran, apixaban, and rivaroxaban, warrant further clinical investigation for their potential repurposing as disease-modifying therapeutics in AD.

Perfusion Abnormalities on 24-Hour Perfusion Imaging in Patients With Complete Endovascular Reperfusion.

Perfusion abnormalities in the infarct and salvaged penumbra have been proposed as a potential reason for poor clinical outcome (modified Rankin Scale score >2) despite complete angiographic reperfusion (Thrombolysis in Cerebral Infarction [TICI3]). In this study, we aimed to identify different microvascular perfusion patterns and their association with clinical outcomes among TICI3 patients. University Hospital Bern's stroke registry of all patients between February 2015 and December 2021. Macrovascular reperfusion was graded using the TICI scale. Microvascular reperfusion status was evaluated within the infarct area on cerebral blood volume and cerebral blood flow perfusion maps obtained 24-hour postintervention. Primary outcome was functional independence (90-day modified Rankin Scale score 0-2) evaluated with the logistic regression analysis adjusted for age, sex, and 24-hour infarct volume from follow-up imaging. Based on microvascular perfusion findings, the entire cohort (N=248) was stratified into one of the 4 clusters: (1) normoperfusion (no perfusion abnormalities; n=143/248); (2) hyperperfusion (hyperperfusion on both cerebral blood volume and cerebral blood flow; n=54/248); (3) hypoperfusion (hypoperfusion on both cerebral blood volume and cerebral blood flow; n=14/248); and (4) mixed (discrepant findings, eg, cerebral blood volume hypoperfusion and cerebral blood flow hyperperfusion; n=37/248). Compared with the normoperfusion cluster, patients in the hypoperfusion cluster were less likely to achieve functional independence (adjusted odds ratio, 0.3 [95% CI, 0.1-0.9]), while patients in the hyperperfusion cluster tended to have better outcomes (adjusted odds ratio, 3.3 [95% CI, 1.3-8.8]). In around half of TICI3 patients, perfusion abnormalities on the microvascular level can be observed. Microvascular hypoperfusion, despite complete macrovascular reperfusion, is rare but may explain the poor clinical course among some TICI3 patients, while a detrimental effect of hyperperfusion after reperfusion could not be confirmed.

Insomnia in patients with MRI-negative epilepsy: The associated factors and 3D-pCASL cerebral blood flow perfusion changes

ObjectiveThis study aimed to identify the factors associated with insomnia in MRI-negative epilepsy and uncover the underlying pathological mechanism driving insomnia within the context of epilepsy. MethodsWe conducted a retrospective study of patients with MRI-negative epilepsy recruited consecutively from December 2021 to December 2022. All subjects completed the Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Self-rating Anxiety Scale (SAS), and Self-rating Depression Scale (SDS). Additionally, some subjects underwent the three-dimensional pseudo continuous arterial spin labeling(3D-pCASL) imaging examination. Bilateral frontal lobe, temporal lobe, hippocampus, thalamus, amygdala, caudate nucleus and lenticular nucleus were selected as regions of interest(ROI) and cerebral blood flow(CBF) values were measured in these regions. Subjects were classified into insomnia (ISI ≥ 10) or non-insomnia (ISI < 10) groups, and univariate and stepwise logistic regression analyses were employed to identify the factors associated with insomnia. Furthermore, CBF values in each ROI were compared between the two groups to identify the brain regions potentially related to the underlying pathological mechanism of insomnia in epilepsy. ResultsA total of 73 patients with MRI-negative epilepsy were recruited in this study(men, 49.3 %). Among them, 14 patients(19.2 %) had insomnia. Univariate regression revealed that nocturnal seizures, number of anti-seizure medication(ASM), anxiety, use of valproic acid(VPA), depression, and excessive daytime sleepiness(EDS) may be associated with insomnia in MRI-negative epilepsy (all p＜0.05). Stepwise regression demonstrated that nocturnal seizures, anxiety, and EDS were independently associated with insomnia in MRI-negative epilepsy (OR[95 %CI]P: 14.64[2.02–106.27]0.008,49.35[3.06–796.61]0.006, 13.28[1.25–140.66]0.032, respectively). Furthermore, CBF values in the left amygdala were significantly lower in patients with MRI- negative epilepsy who had insomnia. ConclusionThe prevalence of insomnia in MRI-negative epilepsy is 19.2%. Nocturnal seizures, anxiety, and EDS were independently associated with insomnia in MRI-negative epilepsy. The noteworthy decrease in CBF values in the left amygdala might be connected to the underlying pathological mechanism of insomnia in epilepsy.

Salidroside promotes angiogenesis after cerebral ischemia in mice through Shh signaling pathway

AimsThe purpose of this study was to explore the impacts of salidroside on vascular regeneration, vascular structural changes and long-term neurological recuperation following cerebral ischemia and its possible mechanism. Main methodsFrom Day 1 to Day 28, young male mice with middle cerebral artery blockage received daily doses of salidroside and measured neurological deficits. On the 7th day after stroke, the volume of cerebral infarction was determined using TTC and HE staining. Microvascular density, astrocyte coverage, angiogenesis and the expression of the Shh signaling pathway were detected by IF, qRTPCR and WB at 7, 14 and 28 days after stroke. Changes in blood flow, blood vessel density and diameter from stroke to 28 days were measured by the LSCI and TPMI. Key findingsCompared with the dMACO group, the salidroside treatment group significantly promoted the recovery of neurological function. Salidroside was found to enhance cerebral blood flow perfusion and reduce the infarct on the 7th day after stroke. From the 7th to the 28th day after stroke, salidroside treatment boosted the expression of CD31, CD31+/BrdU+, and GFAP in the cortex around the infarction site. On the 14th day after stroke, salidroside significantly enhanced the width and density of blood vessels. Salidroside increased the expression of histones and genes in the Shh signaling pathway during treatment, and this effect was weakened by the Shh inhibitor Cyclopamine. SignificanceSalidroside can restore nerve function, improve cerebral blood flow, reduce cerebral infarction volume, increase microvessel density and promote angiogenesis via the Shh signaling pathway.

Deep Learning for Perfusion Cerebral Blood Flow (CBF) and Volume (CBV) Predictions and Diagnostics

Dynamic susceptibility contrast magnetic resonance perfusion (DSC-MRP) is a non-invasive imaging technique for hemodynamic measurements. Various perfusion parameters, such as cerebral blood volume (CBV) and cerebral blood flow (CBF), can be derived from DSC-MRP, hence this non-invasive imaging protocol is widely used clinically for the diagnosis and assessment of intracranial pathologies. Currently, most institutions use commercially available software to compute the perfusion parametric maps. However, these conventional methods often have limitations, such as being time-consuming and sensitive to user input, which can lead to inconsistent results; this highlights the need for a more robust and efficient approach like deep learning. Using the relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) perfusion maps generated by FDA-approved software, we trained a multistage deep learning model. The model, featuring a combination of a 1D convolutional neural network (CNN) and a 2D U-Net encoder-decoder network, processes each 4D MRP dataset by integrating temporal and spatial features of the brain for voxel-wise perfusion parameters prediction. An auxiliary model, with similar architecture, but trained with truncated datasets that had fewer time-points, was designed to explore the contribution of temporal features. Both qualitatively and quantitatively evaluated, deep learning-generated rCBV and rCBF maps showcased effective integration of temporal and spatial data, producing comprehensive predictions for the entire brain volume. Our deep learning model provides a robust and efficient approach for calculating perfusion parameters, demonstrating comparable performance to FDA-approved commercial software, and potentially mitigating the challenges inherent to traditional techniques.

Validation of a C57/BL6J mouse model of focal cerebral ischemia established by electrocoagulation of the middle cerebral artery

To modify the method for establishing mouse models of middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia using electrocoagulation. Forty-six C57/BL6J male mice were divided into MCAO model group (n=34) and sham-operated group (n=12). In the model group, MCAO was induced by permanent coagulation of the right middle cerebral artery (MCA) using a coagulator, and cerebral blood flow perfusion was monitored before and at 20 min and 1 day after modeling. Neurological deficits of the mice at 1, 7, and 14 days after modeling were evaluated using Longa score, mNSS score, beam walking test, cylinder test and corner test. TTC staining was used to measure the cerebral infarct size, and Western blotting was performed to detect the expressions of BDNF, GFAP and DCX proteins in the ischemic cortex. The mice in the model group showed significantly reduced cerebral blood flow in the MCA on the ischemic side and obvious neurological deficits with increased forelimb use asymmetry on days 1, 7 and 14 after modeling (P < 0.05). In the cerebral cortex on the ischemic side of the model mice, the expressions of GFAP and DCX increased significantly at 1, 7, and 14 days (P < 0.05) and the expression of BDNF increased at 1 day after modeling ischemia (P < 0.05). We successfully prepared mouse models of MCAO using a modified method by changing the electrocoagulation location from the distal location of the junction between the MCA and the inferior cerebral vein to a 2 mm segment medial to the junction between the MCA and the olfactory bundle.

Evidence-based evaluation of adjuvant therapy with Chinese medicine for cerebral small vessel disease: A systematic review and meta-analysis

Background: As the population ages, the prevalence of cerebral small vessel disease (CSVD) steadily increases, resulting in a significant economic burden on society. In East Asian nations, Chinese medicine has been used extensively to teat CSVD and has been reported to improve the cognitive function of patients. The present study aimed to comprehensively assess the efficacy and safety of Chinese medicine as adjuvant therapy for CSVD. Methods: A literature search of the CNKI, Wanfang, VIP, SinoMed, Medline, Cochrane Library, and ChiCTR databases were searched for RCTs investigating the use of TCM as an adjuvant in the treatment of CSVD, published up to July 27, 2023, was performed. Based on the Cochrane Collaboration Network bias risk assessment criteria, Review Manager version 5.3 was used to perform a meta-analysis. Results: Meta-analysis of 27 RCTs, including 2554 subjects, revealed that the majority of the RCTs exhibited risk for ambiguous bias. The findings demonstrated that the use of Chinese medicine as an adjuvant treatment for CSVD effectively enhanced the cognitive function, as evidenced by improvements in the MMSE score (mean difference (MD) = 2.42, 95% confidence interval (CI) [1.79,3.17], P &lt; .00001), MoCA score (MD = 2.39, 95% CI [1.78,2.99], P &lt; .00001) and ADL score (MD = 4.13, 95% CI [1.74,6.51], P = .0007). Furthermore, the study also demonstrated the advantages of Chinese medicine adjuvant therapy in enhancing the Chinese medicine syndrome score (MD = −2.57, 95% CI [−3.31, −1.83], P &lt; .00001), CRP (MD = −1.35, 95% CI [−2.27, −0.43], P = .004), Hcy (MD = −3.44,95% CI [−4.05, −2.83], P &lt; .00001), and blood flow velocity (CBV) (MD = 1.37,95% CI [0.24,2.50], P = .02). Moreover, there was no statistical difference in the incidence of adverse reactions between the 2 groups. Conclusion: Findings of the present study indicate that the Chinese medicine, as an adjuvant to conventional treatment, appeared to be efficacious in enhancing cognitive function, reducing Chinese medicine syndrome score, improving blood biochemical markers, and improving cerebral blood flow perfusion in patients with CSVD, without any notable adverse reactions. However, it is imperative to validate these conclusions in future high-quality investigations.

Hybrid Surgery for Revascularization of Chronic Occlusion of Internal Carotid Artery.

The aim of this study was to conclude the safety and effectiveness of hybrid surgery for revascularization of chronic occlusion of internal carotid artery (COICA). A total of 56 COCIA patients underwent hybrid surgery (carotid endarterectomy+carotid artery stenting) from September 2017 to September 2021 in our department. The clinical material and radiology data (preoperation and postoperation) were retrospectively analyzed to conclude the safety and effectiveness of hybrid surgery for revascularization of COICA. All 56 patients underwent hybrid surgery got revascularization successfully (with a successful rate of 100%) and improved intracranial blood flow. The computed tomography perfusion results indicate that the postoperative cerebral blood flow perfusion of the patient is significantly improved compared with before surgery. In 1 patient, postoperative brain magnetic resonance imaging within 24 hours showed spotted fresh infarction with head magnetic resonance imaging, without any clinical symptoms; 3 patients developing symptoms of ipsilateral neural-functional defect (hypoglossal nerve, superior laryngeal nerve, and mandibular branch of facial nerve, respectively), 2 weeks later the symptoms were disappeared. Imaging study at 3 and 6 months during the follow-up showed no abnormalities. Hybrid surgery is safe and effective for revascularization of COICA.

Cerebral perfusion in post-stroke aphasia and its relationship to residual language abilities.

Stroke alters blood flow to the brain resulting in damaged tissue and cell death. Moreover, the disruption of cerebral blood flow (perfusion) can be observed in areas surrounding and distal to the lesion. These structurally preserved but suboptimally perfused regions may also affect recovery. Thus, to better understand aphasia recovery, the relationship between cerebral perfusion and language needs to be systematically examined. In the current study, we aimed to evaluate (i) how stroke affects perfusion outside of lesioned areas in chronic aphasia and (ii) how perfusion in specific cortical areas and perilesional tissue relates to language outcomes in aphasia. We analysed perfusion data from a large sample of participants with chronic aphasia due to left hemisphere stroke (n = 43) and age-matched healthy controls (n = 25). We used anatomically defined regions of interest that covered the frontal, parietal, and temporal areas of the perisylvian cortex in both hemispheres, areas typically known to support language, along with several control regions not implicated in language processing. For the aphasia group, we also looked at three regions of interest in the perilesional tissue. We compared perfusion levels between the two groups and investigated the relationship between perfusion levels and language subtest scores while controlling for demographic and lesion variables. First, we observed that perfusion levels outside the lesioned areas were significantly reduced in frontal and parietal regions in the left hemisphere in people with aphasia compared to the control group, while no differences were observed for the right hemisphere regions. Second, we found that perfusion in the left temporal lobe (and most strongly in the posterior part of both superior and middle temporal gyri) and inferior parietal areas (supramarginal gyrus) was significantly related to residual expressive and receptive language abilities. In contrast, perfusion in the frontal regions did not show such a relationship; no relationship with language was also observed for perfusion levels in control areas and all right hemisphere regions. Third, perilesional perfusion was only marginally related to language production abilities. Cumulatively, the current findings demonstrate that blood flow is reduced beyond the lesion site in chronic aphasia and that hypoperfused neural tissue in critical temporoparietal language areas has a negative impact on behavioural outcomes. These results, using perfusion imaging, underscore the critical and general role that left hemisphere posterior temporal regions play in various expressive and receptive language abilities. Overall, the study highlights the importance of exploring perfusion measures in stroke.

Arterial spin labelling MRI for brain tumour surveillance: do we really need cerebral blood flow maps?

ObjectivesArterial spin labelling (ASL) perfusion MRI is one of the available advanced MRI techniques for brain tumour surveillance. The first aim of this study was to investigate the correlation between quantitative cerebral blood flow (CBF) and non-quantitative perfusion weighted imaging (ASL-PWI) measurements. The second aim was to investigate the diagnostic accuracy of ASL-CBF and ASL-PWI measurements as well as visual assessment for identifying tumour progression.MethodsA consecutive cohort of patients who underwent 3-T MRI surveillance containing ASL for treated brain tumours was used. ROIs were drawn in representative parts of tumours in the ASL-CBF maps and copied to the ASL-PWI. ASL-CBF ratios and ASL-PWI ratios of the tumour ROI versus normal appearing white matter (NAWM) were correlated (Pearson correlation) and AUCs were calculated to assess diagnostic accuracy. Additionally, lesions were visually classified as hypointense, isointense, or hyperintense. We calculated accuracy at two thresholds: low threshold (between hypointense-isointense) and high threshold (between isointense-hyperintense).ResultsA total of 173 lesions, both enhancing and non-enhancing, measured in 115 patients (93 glioma, 16 metastasis, and 6 lymphoma) showed a very high correlation of 0.96 (95% CI: 0.88–0.99) between ASL-CBF ratios and ASL-PWI ratios. AUC was 0.76 (95%CI: 0.65–0.88) for ASL-CBF ratios and 0.72 (95%CI: 0.58–0.85) for ASL-PWI ratios. Diagnostic accuracy of visual assessment for enhancing lesions was 0.72.ConclusionASL-PWI ratios and ASL-CBF ratios showed a high correlation and comparable AUCs; therefore, quantification of ASL-CBF could be omitted in these patients. Visual classification had comparable diagnostic accuracy to the ASL-PWI or ASL-CBF ratios.Clinical relevance statementThis study shows that CBF quantification of ASL perfusion MRI could be omitted for brain tumour surveillance and that visual assessment provides the same diagnostic accuracy. This greatly reduces the complexity of the use of ASL in routine clinical practice.Key Points• Arterial spin labelling MRI for clinical brain tumour surveillance is undervalued and underinvestigated.• Non-quantitative and quantitative arterial spin labelling assessments show high correlation and comparable diagnostic accuracy.• Quantification of arterial spin labelling MRI could be omitted to improve daily clinical workflow.

Predictability of inter-regional cerebral perfusion similarity on dopamine responsiveness and the moderation role of cognition in PD patients

BackgroundLarge heterogeneity can be found in dopamine responsiveness of patients with Parkinson's disease (PD). Instantly and objectively understanding dopamine responsiveness of patients may help clinical practice. PurposeThis PD study explored the predictability of off-state inter-regional cerebral blood flow (CBF) perfusion similarity on patient's dopamine responsiveness and tested whether the predictive power could be moderated by patient's cognitive status. Materials and methodThe PD cohort with 192 patients (containing off state and on state (PD-off and PD-on)) and the normal control (NC) cohort with 92 subjects were included. The intra-individual CBF relative variation networks were constructed and compared between PD-off and PD-on, PD-off and NC to identify the alterations caused by dopamine depletion. Based on that, regression analysis of off-state inter-regional CBF perfusion similarity on patient's dopamine responsiveness was performed. Finally, moderation analysis was conducted to test the moderation role of cognition on the regression model. ResultsIn the PD-off cohort, a total of 82 edges in the network were identified that affected by dopamine depletion. Off-state inter-regional CBF perfusion similarity was found that had a significant influence on patient's dopamine responsiveness. Cognitive status was validated that positively moderated the relationship between off-state inter-regional CBF perfusion similarity and dopamine responsiveness. ConclusionDopamine responsiveness of PD patient could be predicted by off-state inter-regional CBF perfusion similarity. Patient's cognitive status might have a positive moderation effect on his/her dopamine responsiveness.

Peri-therapeutic multi-modal hemodynamic assessment and detection of predictors for symptomatic in-stent restenosis after percutaneous transluminal angioplasty and stenting.

This study performed multi-modal hemodynamic analysis including quantitative color-coded digital subtraction angiography (QDSA) and computational fluid dynamics (CFD) to delineate peri-therapeutic hemodynamic changes and explore the risk factors for in-stent restenosis (ISR) and symptomatic ISR (sISR). Forty patients were retrospectively reviewed. Time to peak (TTP), full width at half maximum (FWHM), cerebral circulation time (CCT), angiographic mean transit time (aMTT), arterial stenosis index (ASI), wash-in gradient (WI), wash-out gradient (WO) and stasis index were calculated with QDSA and translesional pressure ratio (PR) and wall shear stress ratio (WSSR) were quantified from CFD analysis. These hemodynamic parameters were compared between before and after stent deployment and multivariate logistic regression model was established to detect predictors for ISR and sISR at follow-up. It was found that stenting generally reduced TTP, stasis index, CCT, aMTT and translesional WSSR while significantly increased translesional PR. ASI decreased after stenting, and during the mean follow-up time of 6.48 ± 2.86 months, lower ASI (<0.636) as well as larger stasis index were corroborated to be independently associated with sISR. aMTT showed a linear correlation with CCT before and after stenting. PTAS not only improved cerebral circulation and blood flow perfusion but also changed local hemodynamics significantly. ASI and stasis index derived from QDSA were proved to play a prominent role in risk stratification for sISR. Multi-modal hemodynamic analysis could facilitate intraoperative real-time hemodynamic monitoring and help the determination of the end point of intervention.

Efficacy of modified EDAS combined with a superficial temporal fascia attachment-dural reversal surgery for the precise treatment of ischemic cerebrovascular disease.

To investigate the potential therapeutic benefits of Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery for the treatment of ischemic cerebrovascular disease. Retrospective analysis was made on the clinical data of 33 patients with ischemic cerebrovascular disease, who were admitted to the Neurological Diagnosis and Treatment Center of the Second Affiliated Hospital of Xinjiang Medical University from December 2019 to June 2021. All patients were treated with Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery. At 3 months after operation, the outpatient department rechecked the patient's head CT perfusion imaging (CTP) to understand the intracranial cerebral blood flow perfusion. The DSA of the patient's head was re-examined 6 months after operation to observe the establishment of collateral circulation. The improved Rankin Rating Scale (mRS) score was used to evaluate the good prognosis rate of patients at 6 months after surgery. The mRS score ≤2 was defined as good prognosis. The preoperative cerebral blood flow (CBF), local blood flow peak time (rTTP), and local mean transit time (rMTT) of 33 patients were 28.235 ml/(100 g·min), 17.702 s, 9.796 s, respectively. At 3 months after surgery, CBF, rTTP, and rMTT were 33.743 ml/(100 g·min), 15.688, and 8.100 s, respectively, with significant differences (P < 0.05). At 6 months after operation, the establishment of extracranial and extracranial collateral circulation was observed in all patients by re-examination of head DSA. At 6 months after operation, the good prognosis rate was 81.8%. The Modified EDAS combined with superficial temporal fascia attachment-dural reversal surgery is safe and effective in the treatment of ischemic cerebrovascular disease, which can significantly increase the establishment of collateral circulation in the operation area and improve the prognosis of patients.

Subclinical liver traits are associated with structural and hemodynamic brain imaging markers.

Impaired liver function affects brain health and therefore understanding potential mechanisms for subclinical liver disease is essential. We assessed the liver-brain associations using liver measures with brain imaging markers, and cognitive measures in the general population. Within the population-based Rotterdam Study, liver serum and imaging measures (ultrasound and transient elastography), metabolic dysfunction-associated fatty liver disease (MAFLD), non-alcoholic fatty liver disease (NAFLD) and fibrosis phenotypes, and brain structure were determined in 3493 non-demented and stroke-free participants in 2009-2014. This resulted in subgroups of n=3493 for MAFLD (mean age 69 ± 9 years, 56% ♀), n=2938 for NAFLD (mean age 70 ± 9 years, 56% ♀) and n=2252 for fibrosis (mean age 65 ± 7 years, 54% ♀). Imaging markers of small vessel disease and neurodegeneration, cerebral blood flow (CBF) and brain perfusion (BP) were acquired from brain MRI (1.5-tesla). General cognitive function was assessed by Mini-Mental State Examination and the g-factor. Multiple linear and logistic regression models were used for liver-brain associations and adjusted for age, sex, intracranial volume, cardiovascular risk factors and alcohol use. Higher gamma-glutamyltransferase (GGT) levels were significantly associated with smaller total brain volume (TBV, standardized mean difference (SMD), -0.02, 95% confidence interval (CI) (-0.03 to -0.01); p=8.4·10-4 ), grey matter volumes, and lower CBF and BP. Liver serum measures were not related to small vessel disease markers, nor to white matter microstructural integrity or general cognition. Participants with ultrasound-based liver steatosis had a higher fractional anisotropy (FA, SMD 0.11, 95% CI (0.04 to 0.17), p=1.5·10-3 ) and lower CBF and BP. MAFLD and NAFLD phenotypes were associated with alterations in white matter microstructural integrity (NAFLD ~ FA, SMD 0.14, 95% CI (0.07 to 0.22), p=1.6·10-4 ; NAFLD ~ mean diffusivity, SMD -0.12, 95% CI (-0.18 to -0.05), p=4.7·10-4 ) and also with lower CBF and BP (MAFLD ~ CBF, SMD -0.13, 95% CI (-0.20 to -0.06), p=3.1·10-4 ; MAFLD ~ BP, SMD -0.12, 95% CI (-0.20 to -0.05), p=1.6·10-3 ). Furthermore, fibrosis phenotypes were related to TBV, grey and white matter volumes. Presence of liver steatosis, fibrosis and elevated serum GGT are associated with structural and hemodynamic brain markers in a population-based cross-sectional setting. Understanding the hepatic role in brain changes can target modifiable factors and prevent brain dysfunction.

Comparison of arterial spin labeling perfusion with dynamic susceptibility contrast perfusion in Moyamoya disease.

Moyamoya disease (MMD) leads to frequent ischemic/hemorrhagic manifestations. Our aim was to compare findings of arterial spin labeling (ASL) with dynamic susceptibility contrast (DSC) perfusion in patients of MMD. Patients diagnosed as MMD underwent magnetic resonance imaging with ASL and DSC perfusion sequences. Perfusion in bilateral anterior cerebral artery and middle cerebral artery territories at two levels (level of thalami and centrum semiovale) was graded as normal (score 1), or reduced (score 2) on DSC and ASL cerebral blood flow (CBF) maps by comparison with normal cerebellar perfusion. Time to peak (TTP) maps of DSC perfusion were also qualitatively scored as normal (score 1), or increased (score 2) similarly. Correlation between scores of ASL, CBF, DSC, CBF, and DSC, TTP maps was assessed by using Spearman's rank correlation. Among the 34 patients, we did not find any significant correlation between the ASL CBF maps and DSC CBF maps (r = -0.028, P = 0.878), mean matching index 0.39 ± 0.31, whereas significant correlation was noted between the ASL CBF maps and DSC TTP maps (r = 0.58, P = 0.0003), mean matching index 0.79 ± 0.26. ASL CBF underestimated the perfusion compared to DSC perfusion. ASL perfusion CBF maps do not match the DSC perfusion CBF maps and rather match the TTP maps of DSC perfusion. This is explained by inherent problems in estimation of CBF in these techniques because of delay in arrival of label (in ASL perfusion) or contrast bolus (in DSC perfusion) due to the presence of stenotic lesions.

Clinical efficacy analysis of butylphthalide combined with urinary kallidinogenase in treating chronic cerebral circulatory insufficiency.

To investigate the clinical effect of butylphthalide combined with urinary kallidinogenase in the treatment of chronic cerebral circulatory insufficiency (CCCI). A total of 102 CCCI patients admitted to our hospital from October 2020 to December 2021 were retrospectively enrolled in this study. According to the different therapeutic strategy, the patients were divided into combined group (treated with butylphthalide combined with urinary kallidinogenase, n=51) and butylphthalide group (treated with butylphthalide, n=51). Blood flow velocity and cerebral blood flow perfusion before and after treatment between the two groups were compared. The clinical efficacy and adverse events of the two groups were analyzed. After treatment, the effective rate of the combined group was significantly higher than the butylphthalide group (p=.015). Before treatment, the blood flow velocity of middle cerebral artery (MCA), vertebral artery (VA), basilar artery (BA) were comparable (p>.05, respectively), while after treatment, the blood flow velocity of MCA, VA, and BA in combined group were faster than those in butylphthalide group (p<.001, respectively). Before treatment, the relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), relative mean transmit time (rMTT) of the two groups were comparable (p>.05, respectively). After treatment, rCBF and rCBV in combined group were higher than those in butylphthalide group (p<.001, respectively), and rMTT in combined group was lower than that in butylphthalide group (p=.001). The rate of adverse events in the two groups were comparable (p=.558). Butylphthalide combined with urinary kallidinogenase can improve the clinical symptoms of CCCI patients, and the effect is promising, which is worthy of clinical application.

Quantitative IVIM parameters evaluating perfusion changes in brain parenchyma in patients newly diagnosed with acute leukemia: Compared with healthy participants.

To study the value of quantitative IVIM parameters in evaluating cerebral blood perfusion changes in patients newly diagnosed with acute leukemia (AL) by comparing them with healthy participants. This prospective study consecutively recruited 49 participants with newly diagnosed AL and 40 normal controls between July 2020 and September 2022. All participants underwent an MRI of the brain using an axial T1-weighted and an IVIM sequence. The IVIM parameters (water diffusion coefficient, sADC, pseudoperfusion fraction, f; diffusion coefficient, D, pseudodiffusion coefficient, D *, and perfusion-diffusion ratio, PDR) and peripheral white blood cell (WBC) counts were obtained. An unpaired t-test or the Mann-Whitney U-test was performed to compare the differences in gray matter (GM) and white matter (WM) of healthy participants and AL patients and the differences in IVIM parameters between healthy participants and patients with AL. In addition, multivariate (logistic regression) analyses were used to identify independent predictors and then, the receiver operating characteristic curve (ROC) analyses were performed. 40 healthy participants and 49 patients with newly diagnosed AL were evaluated. In healthy participants, sADC, PDR, D and f values of GM were significantly higher than those of WM (t = 5.844, t = 3.838, t = 7.711, z = -2.184, respectively, all P < 0.05). In AL patients, the D, f and sADC values of GM were significantly higher than those of WM (t = 3.450, t = 6.262, t = 4.053, respectively, all P < 0.05). The sADC and f value from AL patients were significantly lower than those from healthy participants in GM (z = -2.537, P = 0.011; and z = -2.583, P = 0.010, respectively) and WM (z = -2.969, P = 0.003; z = -2.923, P = 0.003, respectively). The WBC counts of AL patients were significantly higher than those of healthy participants (t = 3.147, P = 0.002). Multivariate analyses showed that the f values of GM and WM were independent predictors of AL (P = 0.030, and 0.010, respectively), with the optimal cut-off value at 7.08% (AUC ROC curve: 0.661, specificity: 11.4%, sensitivity: 98%) and 13.77% (AUC ROC curve: 0.682, specificity: 79.5%, sensitivity: 59.2%). The IVIM parameters of brain parenchyma in patients newly diagnosed with AL differed from those of the healthy participants. The changes of cerebral blood flow perfusion are expected to provide new ideas for studying central nervous system infiltration in AL.

Effect of Butylphthalide combined with Oxiracetam on cognitive function, Intellectual recovery and serum inflammatory factors in patients with cognitive impairment after cerebral infarction.

To evaluate the effect of butylphthalide combined with oxiracetam on cognitive function, intellectual recovery and serum inflammatory factors in patients with cognitive impairment after cerebral infarction. This is a Clinical comparative study. A total of 80 patients with cognitive impairment after cerebral infarction who visited Renmin Hospital, Hubei University of Medicine from January 2020 to January 2022 were enrolled and randomly divided into two groups. Patients in the control group were treated with oral oxiracetam combined with routine treatment. Patients in the study group were given butylphthalide combined with oxiracetam on the basis of routine treatment. Compare the clinical effect, cognitive function and intellectual recovery, inflammatory factor level changes, CBV, CBF, MTT and other cerebral blood flow perfusion indicators, as well as post-treatment incidence of adverse drug reactions in the two groups of patients. The efficacy of the study group was significantly higher than that of the control group (p=0.03). After treatment, the levels of CBV and CBF in the study group were higher than those in the control group, the levels of TNF-α, CRP and IL-6 were significantly lower than those of the control group, while MTT was shorter than that in the control group, with statistically significant difference (p=0.00). Furthermore, there was a statistically significant difference that the MMSE score and MOCA score of the study group were higher than those of the control group (p=0.00). Butylphthalide combined with oxiracetam has an obvious curative effect in the treatment of patients with cognitive impairment after cerebral infarction. It is a safe and effective therapeutic option that can significantly recover cognitive function and intelligence, improve cerebral blood flow perfusion and reduce inflammatory factors, without an obvious increase in adverse reactions.

Superficial temporal artery-middle cerebral artery bypass in combination with encephalo-myo-synangiosis in Chinese adult patients with moyamoya disease.

To evaluate the feasibility and safety of superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis in combination with encephalo-myo-synangiosis (EMS) in Chinese adult patients with moyamoya disease (MMD). A total of 65 patients with MMD who underwent combined STA-MCA bypass + EMS surgical revascularisation were included in this study. Each patient had a follow-up visit 6 months after discharge. Early bypass function was evaluated via computed tomography angiography and digital subtraction angiography, which were performed preoperatively and at 6 months after surgery. The perfusion parameters of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP) were obtained and analysed. The clinical status of each patient was evaluated using a modified Rankin scale (mRS) preoperatively and at 1 week and 6 months after surgery. Among the 65 enrolled patients, postoperative complications were observed in 5 (7.69%) patients, with 2 cases of dysphasia, 2 cases of new cerebral infarction and 1 case of seizure. Six months after surgery, 66 out of 68 hemispheres were found to have a functioning extra-intracranial bypass, and the patency rate was 97.06%. In terms of CBF perfusion, both the CBF and CBV increased significantly, while the MTT and TTP decreased after surgery. The mRS scores measured 1 week and 6months after surgery were much lower than those measured preoperatively. A direct STA-MCA bypass procedure in combination with indirect EMS bypass is feasible and safe for Chinese adult patients with MMD.

Three-dimensional pseudocontinuous arterial spin labeling perfusion imaging shows cerebral blood flow perfusion decline in attention-deficit/hyperactivity disorder children.

To investigate the feasibility of three-dimensional pseudocontinuous arterial spin labeling (3D-pcASL) perfusion imaging in the brain of children with Attention-deficit/hyperactivity disorder (ADHD). A total of 78 ADHD children aged 5-13 years were prospectively selected as the study group, and 89 healthy children matched in age and sex were selected as the control group. All children underwent MRI conventional sequence, 3D-pcASL, and 3D-T1 sequence scans. The brain gray and white matter volume and cerebral blood flow (CBF) perfusion values were obtained by software post-processing, and were compared and analyzed in the two groups to find out their characteristics in the brain of ADHD children. The total brain volume and total CBF values were lower in ADHD children than in healthy children (P < 0.05); the gray and white matter volumes in the frontal lobe, temporal lobe, hippocampus, caudate nucleus, putamen, globus pallidus and other brain regions were lower in ADHD children than in healthy children (P < 0.05); the gray matter CBF values in the frontal lobe, temporal lobe, hippocampus, caudate nucleus, putamen, globus pallidus and other brain regions were lower in ADHD children than in healthy children (P < 0.05); the differences between the white matter CBF values of white matter in the said brain regions of ADHD children and healthy children were not statistically significant (P > 0.05); and the CBF values in frontal lobe and caudate nuclei could distinguish ADHD children (AUC > 0.05, P < 0.05). The 3D-pcASL technique showed reduced cerebral perfusion in some brain regions of ADHD children.