Cerebrovascular Imaging Research Articles

A case of ischemic-hypoxic encephalopathy due to oral succinylcholine ingestion.

A case of ischemic-hypoxic encephalopathy due to oral succinylcholine ingestion.

Abstract WP171: Incidence And Outcomes Of Pseudoaneurysm In Pediatric Patients With Blunt Cerebrovascular Injury

Objective: Pseudoaneurysm is a rare manifestation of blunt cerebrovascular injury (BCVI) in pediatric patients and carries a high risk of both ischemic stroke and rupture. There is a paucity of data regarding the incidence, prognosis and best practice in management in children. The aim of this study is to describe the history and outcomes of children with traumatic cerebrovascular pseudoaneurysm. Methods: Patients between the ages of 0 and 18 years were identified from the prospectively enrolled trauma registry at a tertiary care pediatric hospital between January 1, 2011 and July 1, 2021 who presented with head and/or neck blunt trauma, had available cerebrovascular imaging and a diagnosis consistent with BCVI. Retrospective chart review was performed to identify patients with pseudoaneurysm formation. Results: Twenty patients were identified with diagnosis of BCVI and of those, six developed pseudoaneurysm. Twelve of the fourteen other BCVIs included the internal carotid artery, while two involved vertebral arteries. All pseudoaneurysms were of the internal carotid artery. Pseudoaneurysm was diagnosed at a median interval of 5 days from initial injury (range 1 day to 6 weeks). Other BCVIs were all diagnosed within the first 2 days of hospitalization. Treatment for pseudoaneurysm included a course of antiplatelet therapy in all. Three patients were initially treated with anticoagulation with subsequent transition to antiplatelet therapy. Endovascular intervention was performed in two patients. 2 patients suffered arterial ischemic stroke. All 6 patients were living and discharged home with favorable neurologic outcomes based on Glasgow Outcome Scale with median follow-up time of 7 months. Conclusions: In this retrospective cohort, pseudoaneurysm was observed in 30% of pediatric patients with BCVI, which is higher than previously reported. Treatment of pseudoaneurysm was variable, but all patients had favorable neurologic outcomes. Compared to other forms of BCVI, pseudoaneurysm was identified following a longer period of time from initial injury. Further studies are needed to identify risk factors for pseudoaneurysm and to inform the need and timing for serial imaging in identifying pseudoaneurysms given potential treatment implications.

Albumin-Consolidated AIEgens for Boosting Glioma and Cerebrovascular NIR-II Fluorescence Imaging.

The application of an exogenous polymer matrix to construct aggregation-induced emission (AIE) nanoprobes promotes the utility of AIE luminogens (AIEgens) in diagnosing brain diseases. However, the limited fluorescence (FL) and low active-targeting abilities of AIE-based nanoprobes impede their imaging application. Here, we employed endogenous albumin as an effective matrix to encapsulate AIEgens to enhance FL quantum yield (QY) and active-targeting ability. The albumin-consolidated strategy effectively inhibited the intramolecular vibration of AIEgens and enhanced endocytosis mediated by the gp60 receptor. The QYs of three kinds of albumin-based AIE nanoprobes with FL emissions ranging from the visible (400-650 nm) to the second near-infrared (NIR-II, 1000-1700 nm) region was at least 10% higher, and the tumor-targeting efficiency was ∼25% higher, compared with those of nanoprobes constructed by the exogenous polymer. Albumin-based AIE nanoprobes have achieved active-targeting NIR-II imaging of brain tumors and cerebrovascular imaging with a high signal-to-background ratio (SBR, ∼90) and high resolution (∼70 μm) in mouse models. Therefore, the albumin-based AIE nanoprobes will enable FL imaging-guided surgery of brain tumors and cerebral ischemia, which will improve surgical efficacy to prevent recurrence and side effects.

Clinical Implications of Focal Mineral Deposition in the Globus Pallidus on CT and Quantitative Susceptibility Mapping of MRI.

ObjectiveTo assess focal mineral deposition in the globus pallidus (GP) by CT and quantitative susceptibility mapping (QSM) of MRI scans and evaluate its clinical significance, particularly cerebrovascular degeneration.Materials and MethodsThis study included 105 patients (66.1 ± 13.7 years; 40 male and 65 female) who underwent both CT and MRI with available QSM data between January 2017 and December 2019. The presence of focal mineral deposition in the GP on QSM (GPQSM) and CT (GPCT) was assessed visually using a three-point scale. Cerebrovascular risk factors and small vessel disease (SVD) imaging markers were also assessed. The clinical and radiological findings were compared between the different grades of GPQSM and GPCT. The relationship between GP grades and cerebrovascular risk factors and SVD imaging markers was assessed using univariable and multivariable linear regression analyses.ResultsGPCT and GPQSM were significantly associated (p < 0.001) but were not identical. Higher GPCT and GPQSM grades showed smaller gray matter (p = 0.030 and p = 0.025, respectively) and white matter (p = 0.013 and p = 0.019, respectively) volumes, as well as larger GP volumes (p < 0.001 for both). Among SVD markers, white matter hyperintensity was significantly associated with GPCT (p = 0.006) and brain atrophy was significantly associated with GPQSM (p = 0.032) in at univariable analysis. In multivariable analysis, the normalized volume of the GP was independently positively associated with GPCT (p < 0.001) and GPQSM (p = 0.002), while the normalized volume of the GM was independently negatively associated with GPCT (p = 0.040) and GPQSM (p = 0.035).ConclusionFocal mineral deposition in the GP on CT and QSM might be a potential imaging marker of cerebral vascular degeneration. Both were associated with increased GP volume.

Fluorescently-tagged magnetic protein nanoparticles for high-resolution optical and ultra-high field magnetic resonance dual-modal cerebral angiography.

Extremely small paramagnetic iron oxide nanoparticles (FeMNPs) (<5 nm) can enhance positive magnetic resonance imaging (MRI) contrast by shortening the longitudinal relaxation time of water (T1), but these nanoparticles experience rapid renal clearance. Here, magnetic protein nanoparticles (MPNPs) are synthesized from protein-conjugated citric acid coated FeMNPs (c-FeMNPs) without loss of the T1 MRI properties and tagged with fluorescent dye (f-MPNPs) for optical cerebrovascular imaging. The c-FeMNPs shows average size 3.8 ± 0.7 nm with T1 relaxivity (r1) of 1.86 mM-1 s-1 and transverse/longitudinal relaxivity ratio (r2/r1) of 2.53 at 11.7 T. The f-MPNPs show a higher r1 value of 2.18 mM-1 s-1 and r2/r1 ratio of 2.88 at 11.7 T, which generates excellent positive MRI contrast. In vivo cerebral angiography with f-MPNPs enables detailed microvascular contrast enhancement for differentiation of major blood vessels of murine brain, which corresponds well with whole brain three-dimensional time-of-flight MRI angiograms (17 min imaging time with 60 ms repetition time and 40 μm isotropic voxels). The real-time fluorescence angiography enables unambiguous detection of brain capillaries with diameter < 40 μm. Biodistribution examination revealed that f-MPNPs were safely cleared by the organs like the liver, spleen, and kidneys within a day after injection. Blood biochemical assays demonstrated no risk of iron overload in both rats and mice. With hybrid neuroimaging technologies (e.g., MRI-optical) on the rise, f-MPNPs built on this platform can generate exciting neuroscience applications.

Cerebrovascular imaging in vivo by non-contact photoacoustic microscopy based on photoacoustic remote sensing with a laser diode for interrogation.

Photoacoustic microscopy (PAM) is a unique tool for biomedical applications because it can visualize optical absorption contrast in vivo. Recently, non-contact PAM based on non-interferometric photoacoustic remote sensing (PARS), termed PARS microscopy, has shown promise for selected imaging applications. A variety of superluminescent diodes (SLDs) have been employed in the PARS microscopy system as the interrogation light source. Here, we investigate the use of a low-cost laser diode (LD) as the interrogation light source in PARS microscopy, termed PARS-LD. A side-by-side comparison of PARS-LD and a PARS microscopy system using an SLD was conducted that showed comparable performance in terms of resolution and signal-to-noise ratio. More importantly, for the first time to our knowledge, in vivo PAM imaging of mouse brain vessels was conducted in a non-contact manner, and the results show that PARS-LD provides great performance.

Application of MAGnetic resonance imaging compilation in acute ischemic stroke.

BACKGROUNDSynthetic magnetic resonance imaging (MRI) MAGnetic resonance imaging compilation (MAGiC) is a new MRI technology. Conventional T1, T2, T2-fluid-attenuated inversion recovery (FLAIR) contrast images, quantitative images of T1 and T2 mapping, and MAGiC phase sensitive inversion recovery (PSIR) Vessel cerebrovascular images can be obtained simultaneously through post-processing at the same time after completing a scan. In recent years, studies have reported that MAGiC can be applied to patients with acute ischemic stroke. We hypothesized that the synthetic MRI vascular screening scheme can evaluate the degree of cerebral artery stenosis in patients with acute ischemic stroke.AIMTo explore the application value of vascular images obtained by synthetic MRI in diagnosing acute ischemic stroke.METHODSA total of 64 patients with acute ischemic stroke were selected and examined by MRI in the current retrospective cohort study. The scanning sequences included traditional T1, T2, and T2-FLAIR, three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), diffusion-weighted imaging (DWI), and synthetic MRI. Conventional contrast images (T1, T2, and T2-FLAIR) and intracranial vessel images (MAGiC PSIR Vessel] were automatically reconstructed using synthetic MRI raw data. The contrast-to-noise ratio (CNR) values of traditional T1, T2, and T2-FLAIR images and MAGiC reconstructed T1, T2, and T2-FLAIR images in DWI diffusion restriction areas were measured and compared. MAGiC PSIR Vessel and TOF MRA images were used to measure and calculate the stenosis degree of bilateral middle cerebral artery stenosis areas. The consistency of MAGiC PSIR Vessel and TOF MRA in displaying the degree of vascular stenosis with computed tomography angiography (CTA) was compared.RESULTSAmong the 64 patients with acute ischemic stroke, 79 vascular stenosis areas showed that the correlation between MAGiC PSIR Vessel and CTA (r = 0.90, P < 0.01) was higher than that between TOF MRA and CTA (r = 0.84, P < 0.01). With a degree of vascular stenosis > 50% assessed by CTA as a reference, the area under the receiver operating characteristic (ROC) curve of MAGiC PSIR Vessel [area under the curve (AUC) = 0.906, P < 0.01] was higher than that of TOF MRA (AUC = 0.790, P < 0.01). Among the 64 patients with acute ischemic stroke, 39 were scanned for traditional T1, T2, and T2-FLAIR images and MAGiC images simultaneously, and CNR values in DWI diffusion restriction areas were measured, which were: Traditional T2 = 21.2, traditional T1 = -6.7, and traditional T2-FLAIR = 11.9; and MAGiC T2 = 7.1, MAGiC T1 = -3.9, and MAGiC T2-FLAIR = 4.5.CONCLUSIONThe synthetic MRI vascular screening scheme for patients with acute ischemic stroke can accurately evaluate the degree of bilateral middle cerebral artery stenosis, which is of great significance to early thrombolytic interventional therapy and improving patients’ quality of life.

VBNet: An end-to-end 3D neural network for vessel bifurcation point detection in mesoscopic brain images

Background and objectiveAccurate detection of vessel bifurcation points from mesoscopic whole-brain images plays an important role in reconstructing cerebrovascular networks and understanding the pathogenesis of brain diseases. Existing detection methods are either less accurate or inefficient. In this paper, we propose VBNet, an end-to-end, one-stage neural network to detect vessel bifurcation points in 3D images. MethodsFirstly, we designed a 3D convolutional neural network (CNN), which input a 3D image and output the coordinates of bifurcation points in this image. The network contains a two-scale architecture to detect large bifurcation points and small bifurcation points, respectively, which takes into account the accuracy and efficiency of detection. Then, to solve the problem of low accuracy caused by the imbalance between the numbers of large bifurcations and small bifurcations, we designed a weighted loss function based on the radius distribution of blood vessels. Finally, we extended the method to detect bifurcation points in large-scale volumes. ResultsThe proposed method was tested on two mouse cerebral vascular datasets and a synthetic dataset. In the synthetic dataset, the F1-score of the proposed method reached 96.37%. In two real datasets, the F1-score was 92.35% and 86.18%, respectively. The detection effect of the proposed method reached the state-of-the-art level. ConclusionsWe proposed a novel method for detecting vessel bifurcation points in 3D images. It can be used to precisely locate vessel bifurcations from various cerebrovascular images. This method can be further used to reconstruct and analyze vascular networks, and also for researchers to design detection methods for other targets in 3D biomedical images.

Three-Dimensional Reconstruction of Cerebrovascular and Algorithm Realization.

Objective In the three-dimensional reconstruction of CT cerebrovascular medical image registration, a new optimization algorithm based on the relative position information between the contours of various blood vessels in the image is proposed. Methods Using the rule that the center of gravity of the vascular tissue structure on the series of slices has continuity, find the registration relationship between the contours of the vessels in the two adjacent slices. Because the shape of cerebrovascular contour is relatively symmetrical, its center of gravity is slightly away from its geometric center. Therefore, the geometric center is used to replace the center of gravity, and the “mass” of each contour is calculated according to the area of each contour to achieve the registration of the blood vessel contour. Results The method has the characteristics of global optimization and stronger robustness. Conclusion The cerebrovascular image obtained by this method is more realistic and can be used for the import of various software, simulation training, and later research, which provides an effective method for preoperative simulation of cerebrovascular intervention surgery.

Prognostic Scores for Large Vessel Occlusion Strokes.

Endovascular thrombectomy (EVT) for large vessel occlusion strokes (LVOS) presents several treatment challenges. We provide a summary of existing tools for patient selection (pre-EVT tools) and for prognostication of long-term outcomes following reperfusion therapy (post-EVT tools). Recently published randomized trials demonstrated superiority of EVT over medical therapy alone for LVOS. Uniform patient selection paradigms based on demographic, clinical, and radiographic variables are not completely standardized, leading to variability in patient selection for EVT for LVOS. Post-EVT, an accurate assessment of long-term prognosis is critical in the decision-making process. Prognostic scores can serve as useful adjuncts to facilitate clinical decision-making during early management of patients with ischemic stroke, particularly those with LVOS. The acute management of LVOS comprises rapid clinical assessment, triage, and cerebrovascular imaging, followed by evaluation for candidacy for thrombolysis and EVT. Pre-EVT prognostic tools that accurately predict the likelihood of benefit from EVT may guide reliable, efficient, and cost-effective patient selection. Following EVT, severe stroke deficits and subacute poststroke complications that portend a poor prognosis may warrant invasive therapies. Clinical decisions regarding these treatment options involve careful discussions between providers and patient families, and are also based on prognosis provided by the treating clinician. Reliable post-EVT prognostic tools can facilitate this by providing accurate and objective prognostic information. Several prognostic tools have been developed and validated in the literature, some of which may be applicable in the pre-EVT and post-EVT settings, although clinical utility and application varies. Validation in contemporary datasets as well as implementation and impact studies are needed before these scales can be used to guide clinical decisions for individual patients.

Carotid Artery Stenting: Applications and Technical Considerations.

To examine current understanding of diverse etiologies of extracranial carotid disease, including clinical and imaging manifestations as well as treatment approaches. Increasing availability of advanced cerebrovascular imaging modalities continues to elucidate atherosclerotic and nonatherosclerotic carotid steno-occlusive disease as a common culprit of cerebral ischemia. Individualized treatment strategies targeting each etiologic subset would optimize preventive measures and minimize recurrence of cerebral ischemia. Ischemic stroke is a prominent cause of mortality and long-term disability worldwide. The magnified effect of carotid disease warrants constant and close inspection.

Using Clinical and Echocardiographic Characteristics to Characterize the Risk of Ischemic Stroke in Patients with COVID-19

BackgroundCOVID-19 has been associated with an increased incidence of ischemic stroke. The use echocardiography to characterize the risk of ischemic stroke in patients hospitalized with COVID-19 has not been explored. MethodsWe conducted a retrospective study of 368 patients hospitalized between 3/1/2020 and 5/31/2020 who had laboratory-confirmed infection with SARS-CoV-2 and underwent transthoracic echocardiography during hospitalization. Patients were categorized according to the presence of ischemic stroke on cerebrovascular imaging following echocardiography. Ischemic stroke was identified in 49 patients (13.3%). We characterized the risk of ischemic stroke using a novel composite risk score of clinical and echocardiographic variables: age <55, systolic blood pressure >140 mmHg, anticoagulation prior to admission, left atrial dilation and left ventricular thrombus. ResultsPatients with ischemic stroke had no difference in biomarkers of inflammation and hypercoagulability compared to those without ischemic stroke. Patients with ischemic stroke had significantly more left atrial dilation and left ventricular thrombus (48.3% vs 27.9%, p = 0.04; 4.2% vs 0.7%, p = 0.03). The unadjusted odds ratio of the composite novel COVID-19 Ischemic Stroke Risk Score for the likelihood of ischemic stroke was 4.1 (95% confidence interval 1.4-16.1). The AUC for the risk score was 0.70. ConclusionsThe COVID-19 Ischemic Stroke Risk Score utilizes clinical and echocardiographic parameters to robustly estimate the risk of ischemic stroke in patients hospitalized with COVID-19 and supports the use of echocardiography to characterize the risk of ischemic stroke in patients hospitalized with COVID-19.

The unrealized promise of cerebrovascular magnetic resonance imaging in psychiatric research across the lifespan

The unrealized promise of cerebrovascular magnetic resonance imaging in psychiatric research across the lifespan

Combined Application of CT Perfusion Imaging and CT Angiography in Imaging Diagnosis of Acute Cerebrovascular Diseases.

The incidence rate of cerebrovascular diseases is increasing year by year, but the accuracy of clinical diagnosis is not high enough to cause disease. Many patients cannot effectively diagnose and treat the disease at the early stage. CT perfusion imaging (CTP) and CT angiography (CTA) were used to diagnose cerebrovascular diseases. In this paper, 26 cases of patients with acute cerebrovascular disease in our hospital from June to August 2020 were selected as the research objects. According to the diagnosis method voluntarily chosen by patients, 6 cases were only detected by CT perfusion imaging, 8 cases were only detected by CT angiography, and the remaining 12 cases were diagnosed by CT perfusion imaging and CT angiography. Then, according to the diagnosis results of the CT image of the patients with cerebrovascular disease, these samples were followed up after 3 months, 6 months, and 9 months, and more accurate diagnosis results were obtained. The study showed that, after 3 months of CT detection, the sensitivity of patients with CTP detection was 67%, that of patients with CTA detection was 72%, and that of patients with combined detection was 83%. After 6 months of CT detection, the sensitivity of patients with CTP detection was 75%, that of patients with CTA detection was 79%, and that of patients with combined detection was 93%. After 9 months of CT detection, the sensitivity of patients with CTP detection was 86%, that of patients with CTA detection was 89%, and that of patients with combined detection was 99%. Therefore, the use of CTA combined with CTP joint detection of acute cerebrovascular disease imaging technology can effectively improve the diagnostic accuracy of patients.

First Report: Rare RNF213 Variant Associated with Familial Moyamoya Disease in an African American Family

ObjectiveTo investigate potential genetic susceptibility for moyamoya disease (MMD) in an African American family. Materials and methodsNeurovascular imaging and analyses of MMD susceptibility genes RNF213 and/or ACTA2 in a young proband with MMD and two first-degree relatives. ResultsThe proband presented with pseudobulbar affect and chorea, then had a right hemispheric ischaemic stroke and rapidly fatal course. One relative had a mild haemorrhagic thalamic stroke and clinically silent ischaemic infarct. Despite evidence of slowly progressive disease, he remained clinically stable. Another relative was neurologically intact with normal cerebrovascular imaging to date. All three have the rare R4131C (p.Arg4131Cys or p.R4131C, c.12391C>T) variant of the RNF213 gene. They are the first Black people and only the 5th family worldwide known to harbour this variant. MMD was confirmed in both of the patients with neurological events. ConclusionsOur report provides compelling evidence that MMD is a clinically complex, heritable genetic disease. It supports the probable pathogenicity of R4131C. Furthermore, it illustrates the wide phenotypic spectrum of R4131C, from asymptomatic carrier to late presenting, mild disease to catastrophic, rapidly fatal childhood disease. To our knowledge, this is also the first report of heritable MMD in a Black family. Finally, this study highlights the importance of racially and ethnically diverse participants in biomedical research.

The role of noninvasive imaging in the diagnostic workup for pulsatile tinnitus.

We sought to assess the diagnostic yield of advanced noninvasive imaging in the evaluation of patients with pulsatile tinnitus. Pulsatile tinnitus can be caused by high-risk cerebrovascular pathologies such as arteriovenous fistulae. The role of advanced noninvasive imaging, including magnetic resonance angiography and magnetic resonance venography, in the diagnostic evaluation of pulsatile tinnitus is not well defined. We performed a retrospective cohort study of patients presenting for outpatient diagnostic evaluation of pulsatile tinnitus from January 2018 to March 2020 at Weill Cornell Medicine. Patients with non-pulsatile tinnitus and established etiologic diagnoses were excluded. Systematic chart abstraction was summarized using standard descriptive statistics. Univariate logistic regression was used to identify factors associated with nondiagnostic noninvasive imaging. A total of 187 patients (139 (74.3%) women) took part in this study, with a mean age of 48.6 years (standard deviation (SD) = 15.5 years) and a mean body mass index (BMI) of 26.9 kg/m2 (SD = 6.1 kg/m2). Of the 187 patients, 121 (64.7%) underwent exclusively noninvasive imaging, and 66 (35.3%) patients also had digital subtraction angiography (DSA). In patients who had exclusively noninvasive imaging, 62 (51.2%) patients received a diagnosis. In patients who underwent noninvasive and DSA imaging, 14 (21.2%) patients received a diagnosis based on DSA. Patients who were older at symptom onset (odds ratio (OR) = 1.05; 95% confidence interval (CI) 1.01-1.09) and those with a lower BMI (OR = 0.88, 95% CI 0.77-0.98) were more likely to have nondiagnostic noninvasive imaging. Noninvasive cerebrovascular imaging often uncovers the etiology of pulsatile tinnitus. DSA remains useful for additional evaluation for patients with specific associated features.

Hyperdense middle cerebral artery sign and response to combination of mechanical Thrombectomy plus intravenous thrombolysis in acute stroke patients

Background and purposeCombining intra-arterial mechanical thrombectomy (IAMT) and intravenous thrombolysis (IVT) has shown to have an excellent recanalization rate and better clinical outcome in acute ischemic stroke (AIS) patients. Hyperdense middle cerebral artery sign (HMCAS) on pretreatment non-contrast head CT scan of AIS patients is one of the early ischemic radiological findings in middle cerebral artery territory AIS. We aimed to evaluate whether the presence of HMCAS predicts the outcome of AIS patients receiving combination therapy with IAMT and IVT. MethodsWe retrospectively reviewed medical records and cerebrovascular images of the patients treated with IAMT and IVT for AIS in our center. Patients with occlusion in the terminal internal carotid artery or middle cerebral artery on pretreatment CT angiogram of the head were included. Clinical outcome was compared between subjects with HMCAS and those without. Modified Rankin Score (mRS) and symptomatic intracranial hemorrhage (sICH) were used as measures of efficacy and safety, respectively. ResultsOf 93 patients, 46 (49%) had HMCAS on their initial head CT scan. Both groups had comparable baseline characteristics and stroke severity. After adjusting for age, NIHSS score, time from symptom onset to starting IVT, and history of diabetes mellitus in multivariate logistic regression analysis, there was no difference in terms of a poor outcome (mRS >2) (OR = 0.5 [CI 0.2–1.4], p = 0.188) or rate of sICH (OR = 3.3 [CI 0.6–19.0], p = 0.190) between the two groups. ConclusionsHMCAS is not a predictor of poor outcome in AIS patients receiving combination therapy with IAMT and IVT and does not affect treatment safety.

Well‐Defined Segment of Carbon Nanotube with Bright Red Emission for Three‐Photon Fluorescence Cerebrovascular Imaging

AbstractAs the shortest segment of carbon nanotubes (CNTs), cycloparaphenylenes (CPPs) offer a well‐defined alternative for CNTs as the fluorophores in bioimaging. However, most of CPPs emit blue or yellow light, the bright red‐emitting CPP materials required by bioimaging, particularly in vivo imaging, are still lacking. Here, it is shown that a CPP (TB[9]CPP) with red emission up to 650 nm is successfully synthesized and characterized. The fluorescence quantum yields of TB[9]CPP are measured up to 44% in chloroform and 17% as nanodots in aqueous media. Meanwhile, the water‐soluble nanodots present outstanding three‐photon fluorescence performances, thereby are utilized for in vivo probing of brain vessels by three‐photon fluorescence microscopic imaging technique, exhibiting a high penetration depth, good resolution, and clear image contrast.

Urinary sodium and potassium excretion and cerebrovascular health: a multimodal imaging study.

Dietary sodium and potassium intake are associated with stroke, but the potential mechanisms are unclear. We aimed to study the association between sodium and potassium intake and subclinical cerebrovascular health in hypertensive older males using multimodal magnetic resonance imaging. A total of 189 hypertensive male subjects without previous cardiovascular or cerebrovascular disease were included. Daily urinary sodium and potassium excretion were estimated from a fasting spot urine sample using a formula approach. A dedicated cerebrovascular health imaging protocol including vessel wall imaging, angiography, arterial spin labeling imaging and T2-weighted fluid-attenuated inversion recovery imaging was performed to study intracranial atherosclerosis, vascular rarefaction (defined as fewer discernible vessels on angiography), brain perfusion and small vessel disease, respectively. The mean age was 64.9 (± 7.2) years. The average daily urinary and potassium excretion was 4.7 (± 1.4) g/L and 2.1 (± 0.5) g/L, respectively. Increased urinary sodium excretion was associated with decreased cerebral blood flow and elevated urinary potassium excretion was associated with reduced prevalence of intracranial plaque. The associations remained significant after adjusting for covariates, even including blood pressure control. Quadratic regression analysis indicated a marginally significant U-shaped association between urinary sodium intake and white matter hyperintensity, which lost significance in fully adjusted models. No significant association of urinary sodium and potassium excretion with other cerebrovascular health measures was noted. We concluded that in hypertensive older males without overt cardiovascular disease, increased sodium intake and reduced potassium intake are associated with impaired subclinical cerebrovascular health.

State of the Art: Venous Causes of Pulsatile Tinnitus and Diagnostic Considerations Guiding Endovascular Therapy.

Venous variants and pathologic abnormalities are the most common causes of pulsatile tinnitus. These conditions include causes of turbulence within normally located veins and sinuses, and abnormally enlarged or abnormally located veins in close transmissive proximity to the conductive auditory pathway. Such disorders include pathologic abnormalities of the lateral sinus (transverse sinus stenosis and sigmoid sinus wall anomalies), abnormalities and variants of the emissary veins, and anomalies of the jugular bulb and jugular vein. Despite being the most common causes for pulsatile tinnitus, venous variants and pathologic abnormalities are often overlooked in the workup of pulsatile tinnitus. Such oversights can result in delayed patient care and prolonged patient discomfort. Advances in both cerebrovascular imaging and endovascular techniques allow for improved diagnostic accuracy and an increasing range of endovascular therapeutic options to address pulsatile tinnitus. This review illustrates the venous causes of pulsatile tinnitus and demonstrates the associated endovascular treatment. © RSNA, 2021.