Arterial stiffness and atherosclerosis and incident cardiovascular events and all-cause mortality in individuals with manifest cardiovascular disease with and without type 2 diabetes.

Background: It is unclear if arterial stiffness and atherosclerosis are differentially related to cardiovascular events and mortality in individuals with manifest cardiovascular disease with and without type 2 diabetes (T2DM) and to what extent they mediate the relation between T2DM and these outcomes.

Methods: Prospective data were used from the UCC-SMART cohort, including individuals with manifest cardiovascular disease (n = 9465). Arterial stiffness (brachial pulse pressure and carotid artery distensibility coefficient (DC)) and atherosclerosis (presence of carotid plaque and ankle-brachial index <0.

Evaluating the Performance and Repeatability of Poroelastic and Poroviscoelastic Models in Intrinsic MR Elastography.

Intrinsic MR elastography (iMRE) leverages brain pulsations that arise from cerebral arterial pulsations to reconstruct the mechanical properties of the brain. While iMRE has shown much potential recently, the technique was demonstrated for a viscoelastic brain model only, which suffered from data-model mismatch at the low actuation frequencies of the arterial pulsations. This work aims to address those limitations by considering the porous nature of brain tissue, where both a poroelastic and a poroviscoelastic model are assessed and compared.

The relation between cerebral small vessel function and white matter microstructure in monogenic and sporadic small vessel disease - the ZOOM@SVDs study.

In cerebral small vessel disease (cSVD), vascular dysfunction has been associated with cSVD-lesions across the brain. Here we further explore the relation between vascular dysfunction and cSVD-related brain injury. We tested two hypotheses: (1) that complementary measures of abnormal small vessel function relate to decreased white matter integrity, and (2) that local variance in vascular dysfunction relates to local variance in white matter integrity within individual patients.

CO as an engine for neurofluid flow: Exploring the coupling between vascular reactivity, brain clearance, and changes in tissue properties.

The brain relies on an effective clearance mechanism to remove metabolic waste products for the maintenance of homeostasis. Recent studies have focused on elucidating the forces that drive the motion of cerebrospinal fluid (CSF), responsible for removal of these waste products. We demonstrate that vascular responses evoked using controlled manipulations of partial pressure of carbon dioxide (PaCO) levels, serve as an endogenous driver of CSF clearance from the brain.

Detectability and accuracy of computational measurements of in-silico and physical representations of enlarged perivascular spaces from magnetic resonance images.

Background: Magnetic Resonance Imaging (MRI) visible perivascular spaces (PVS) have been associated with age, decline in cognitive abilities, interrupted sleep, and markers of small vessel disease. But the limits of validity of their quantification have not been established.

New Method: We use a purpose-built digital reference object to construct an in-silico phantom for addressing this need, and validate it using a physical phantom.

Estimating the viscoelastic properties of the human brain at 7 T MRI using intrinsic MRE and nonlinear inversion.

Intrinsic actuation magnetic resonance elastography (MRE) is a phase-contrast MRI technique that allows for in vivo quantification of mechanical properties of the brain by exploiting brain motion that arise naturally due to the cardiac pulse. The mechanical properties of the brain reflect its tissue microstructure, making it a potentially valuable parameter in studying brain disease. The main purpose of this study was to assess the feasibility of reconstructing the viscoelastic properties of the brain using high-quality 7 T MRI displacement measurements, obtained using displacement encoding with stimulated echoes (DENSE) and intrinsic actuation.

Assessment of aortic and cerebral haemodynamics and vascular brain injury with 3 and 7 T magnetic resonance imaging in patients with aortic coarctation.

Aims: Coarctation of the aorta (CoA) is characterized by a central arteriopathy resulting in increased arterial stiffness. The condition is associated with an increased risk of stroke. We aimed to assess the aortic and cerebral haemodynamics and the presence of vascular brain injury in patients with previous surgical CoA repair.

Abnormalities in cardiac-induced brain tissue deformations are now detectable with MRI: A case-report of a patient who underwent craniotomy after trauma.

Background: Heartbeat and respiration induce cyclic brain tissue deformations, which receive increasing attention as potential driving force for brain clearance. These deformations can now be assessed using a novel 3D strain tensor imaging (STI) method at 7 T MRI.

Methods: An 18-year-old man had suffered a traumatic brain injury and was treated with a craniotomy with a maximal diameter of 12 cm.

Theory for a non-invasive diagnostic biomarker for craniospinal diseases.

Monitoring intracranial pressure (ICP) and craniospinal compliance (CC) is frequently required in the treatment of patients suffering from craniospinal diseases. However, current approaches are invasive and cannot provide continuous monitoring of CC. Dynamic exchange of blood and cerebrospinal fluid (CSF) between cranial and spinal compartments due to cardiac action transiently modulates the geometry and dielectric properties of the brain.

CADASIL Affects Multiple Aspects of Cerebral Small Vessel Function on 7T-MRI.

Objective: Cerebral small vessel diseases (cSVDs) are a major cause of stroke and dementia. We used cutting-edge 7T-MRI techniques in patients with Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL), to establish which aspects of cerebral small vessel function are affected by this monogenic form of cSVD.

Methods: We recruited 23 CADASIL patients (age 51.

Reliability of velocity pulsatility in small vessels on 3Tesla MRI in the basal ganglia: a test-retest study.

Objective: Recent work showed the feasibility of measuring velocity pulsatility in the perforating arteries at the level of the BG using 3T MRI. However, test-retest measurements have not been performed, yet. This study assessed the test-retest reliability of 3T MRI blood flow velocity measurements in perforating arteries in the BG.

Histopathology of Cerebral Microinfarcts and Microbleeds in Spontaneous Intracerebral Hemorrhage.

In patients with spontaneous intracerebral hemorrhage caused by different vasculopathies, cerebral microinfarcts have the same aspect on MRI and the same applies to cerebral microbleeds. It is unclear what pathological changes underlie these cerebral microinfarcts and cerebral microbleeds. In the current study, we explored the histopathological substrate of these lesions by investigating the brain tissue of 20 patients (median age at death 77 years) who died from ICH (9 lobar, 11 non-lobar) with a combination of post-mortem 7-T MRI and histopathological analysis.

Dynamic brain ADC variations over the cardiac cycle and their relation to tissue strain assessed with DENSE at high-field MRI.

Purpose: The ADC of brain tissue slightly varies over the cardiac cycle. This variation could reflect physiology, including mixing of the interstitial fluid, relevant for brain waste clearance. However, it is known from cardiac diffusion imaging that tissue deformation by itself affects the magnitude of the MRI signal, leading to artificial ADC variations as well.

Does the Internal Carotid Artery Attenuate Blood-Flow Pulsatility in Small Vessel Disease? A 7 T 4D-Flow MRI Study.

Background: Increased cerebral blood-flow pulsatility is associated with cerebral small vessel disease (cSVD). Reduced pulsatility attenuation over the internal carotid artery (ICA) could be a contributing factor to the development of cSVD and could be associated with intracranial ICA calcification (iICAC).

Purpose: To compare pulsatility, pulsatility attenuation, and distensibility along the ICA between patients with cSVD and controls and to assess the association between iICAC and pulsatility and distensibility.

Detecting low blood concentrations in joints using T1 and T2 mapping at 1.5, 3, and 7 T: an in vitro study.

Background: Intra-articular blood causes irreversible joint damage, whilst clinical differentiation between haemorrhagic joint effusion and other effusions can be challenging. An accurate non-invasive method for the detection of joint bleeds is lacking. The aims of this phantom study were to investigate whether magnetic resonance imaging (MRI) T1 and T2 mapping allows for differentiation between simple and haemorrhagic joint effusion and to determine the lowest blood concentration that can be detected.

Non-Invasive Assessment of Damping of Blood Flow Velocity Pulsatility in Cerebral Arteries With MRI.

Background: Damping of heartbeat-induced pressure pulsations occurs in large arteries such as the aorta and extends to the small arteries and microcirculation. Since recently, 7 T MRI enables investigation of damping in the small cerebral arteries.

Purpose: To investigate flow pulsatility damping between the first segment of the middle cerebral artery (M1) and the small perforating arteries using magnetic resonance imaging.

Double delay alternating with nutation for tailored excitation facilitates banding-free isotropic high-resolution intracranial vessel wall imaging.

The purpose of this study was to evaluate the use of a double delay alternating with nutation for tailored excitation (D-DANTE)-prepared sequence for banding-free isotropic high-resolution intracranial vessel wall imaging (IC-VWI) and to compare its performance with regular DANTE in terms of signal-to-noise ratio (SNR) as well as cerebrospinal fluid (CSF) and blood suppression efficiency. To this end, a D-DANTE-prepared 3D turbo spin echo sequence was implemented by interleaving two separate DANTE pulse trains with different RF phase-cycling schemes, but keeping all other DANTE parameters unchanged, including the total number of pulses and total preparation time. This achieved a reduction of the banding distance compared with regular DANTE enabling banding-free imaging up to higher resolutions.

Blood Flow Velocity Pulsatility and Arterial Diameter Pulsatility Measurements of the Intracranial Arteries Using 4D PC-MRI.

4D phase contrast magnetic resonance imaging (PC-MRI) allows for the visualization and quantification of the cerebral blood flow. A drawback of software that is used to quantify the cerebral blood flow is that it oftentimes assumes a static arterial luminal area over the cardiac cycle. Quantifying the lumen area pulsatility index (aPI), i.

Zooming in on cerebral small vessel function in small vessel diseases with 7T MRI: Rationale and design of the "ZOOM@SVDs" study.

Background: Cerebral small vessel diseases (SVDs) are a major cause of stroke and dementia. Yet, specific treatment strategies are lacking in part because of a limited understanding of the underlying disease processes. There is therefore an urgent need to study SVDs at their core, the small vessels themselves.

Strain Tensor Imaging: Cardiac-induced brain tissue deformation in humans quantified with high-field MRI.

The cardiac cycle induces blood volume pulsations in the cerebral microvasculature that cause subtle deformation of the surrounding tissue. These tissue deformations are highly relevant as a potential source of information on the brain's microvasculature as well as of tissue condition. Besides, cyclic brain tissue deformations may be a driving force in clearance of brain waste products.

An anomaly detection approach to identify chronic brain infarcts on MRI.

The performance of current machine learning methods to detect heterogeneous pathology is limited by the quantity and quality of pathology in medical images. A possible solution is anomaly detection; an approach that can detect all abnormalities by learning how 'normal' tissue looks like. In this work, we propose an anomaly detection method using a neural network architecture for the detection of chronic brain infarcts on brain MR images.

Arterial Remodeling of the Intracranial Arteries in Patients With Hypertension and Controls: A Postmortem Study.

The intracranial arteries play a major role in cerebrovascular disease, but arterial remodeling due to hypertension has not been well described in humans. We aimed to quantify this remodeling for: the basilar artery, the vertebral, internal carotid, middle/anterior (inferior)/posterior cerebral, posterior communicating, and superior cerebellar arteries of the circle of Willis. Ex vivo circle of Willis specimens, selected from individuals with (n=24) and without (n=25) a history of hypertension, were imaged at 7T magnetic resonance imaging using a 3-dimensional gradient-echo sequence.

Subvoxel vessel wall thickness measurements of the intracranial arteries using a convolutional neural network.

Vessel wall thickening of the intracranial arteries has been associated with cerebrovascular disease and atherosclerotic plaque development. Visualization of the vessel wall has been enabled by recent advancements in vessel wall MRI. However, quantifying early wall thickening from these MR images is difficult and prone to severe overestimation, because the voxel size of clinically used acquisitions exceeds the wall thickness of the intracranial arteries.