Abstract Objective Lacunar stroke is common (25% of ischemic strokes) and mostly because an intrinsic cerebral microvascular disease unknown cause. Although considered primarily to be process, the vessel tissue damage could also explained by dysfunctional endothelium or blood–brain barrier (BBB) leak, not just ischemia. We tested for subtle generalized BBB leakiness in patients with lacunar control cortical stroke. Methods recruited mild assessed leak gray matter, white cerebrospinal fluid,...

Background and Purpose— Several methods are available to assess the magnetic resonance perfusion lesion in acute ischemic stroke. We tested 10 of these compare sizes relation clinical scores final infarct extent. Methods— recruited patients with stroke, performed diffusion- perfusion-weighted imaging, recorded stroke severity at baseline, size on T2-weighted imaging ≥1 month, Rankin Scale score 3 months. calculated parameters (6 mean transit time, MTT; cerebral blood flow; 1 volume; 7...

Over the last 15 years, basic thresholding techniques in combination with standard statistical correlation-based data analysis tools have been widely used to investigate different aspects of evolution acute or subacute late stage ischemic stroke both human and animal data. Yet, a wave biology-dependent imaging-dependent issues is still untackled pointing towards key question: "how does an evolve?" Paving way for potential answers this question, magnetic resonance (MRI) CT (computed...

Background and Purpose— An acute mismatch on diffusion-weighted MRI (DWI) perfusion-weighted (PWI) may represent the “tissue-at-risk.” It is unclear which “semiquantitative” perfusion parameter most closely identifies final infarct volume. Methods— Acute stroke patients underwent DWI PWI (dynamic-susceptibility contrast imaging) admission (baseline), T 2 -weighted imaging (T WI) at 1 or 3 months after stroke. “Semiquantitative” mean transit time (MTT sq =first moment of concentration/time...

Background and Purpose— Lacunar stroke is associated with endothelial dysfunction histologically intrinsic cerebral microvascular disease of unknown cause. Endothelial could impair blood–brain barrier integrity. We assessed background leakage in patients lacunar ischemic compared cortical controls. Methods— recruited or mild generalized leak MRI intravenous gadolinium at least 1 month after stroke. used detailed image processing to compare signal change before for 30 minutes postcontrast...

There is growing interest in investigating the role of subtle changes blood-brain barrier (BBB) function common neurological disorders and possible use imaging techniques to assess these abnormalities. Some studies have used dynamic contrast-enhanced MR (DCE-MRI) demonstrated much smaller signal than obtained from more traditional applications technique, such as intracranial tumors multiple sclerosis. In this work, preliminary results are presented a DCE-MRI study patients with mild stroke...

Brain perfusion weighted images acquired using dynamic contrast studies have an important clinical role in acute stroke diagnosis and treatment decisions. However, computed tomography (CT) suffer from low contrast-to-noise ratios (CNR) as a consequence of the limitation exposure to radiation patient. As consequence, developments methods for improving CNR are valuable. The majority existing approaches denoising CT optimized 3D (spatial) information, including spatial decimation (spatially...

Pyrexia soon after stroke is associated with severe and poor functional outcome. Few studies have assessed brain temperature in patients, so little known of its associations body temperature, severity, or We measured temperatures ischemic normal-appearing using 1 H-magnetic resonance spectroscopy correlations (tympanic) four-hourly, infarct growth by 5 days, early neurologic (National Institute Health Stroke Scale, NIHSS) late outcome (death dependency). Among 40 patients (mean age 73 years,...

Some infarcts have persistently hyperintense areas on diffusion-weighted MRI (DWI) even at 1 month after stroke, whereas others become isointense to normal brain. We hypothesized that late DWI hyperintensity reflected different infarct evolution compared with were by month.We recruited patients prospectively ischemic performed and perfusion-weighted (PWI) admission, 5 days, 14 assessed functional outcome 3 months (Rankin Scale). Patient characteristics DWI/PWI values for or without "still...

Background and Purpose— In acute ischemic stroke, the amount of neuronal damage in hyperintense areas on MR diffusion imaging (DWI) is unclear. We used spectroscopic to measure N -acetyl aspartate (NAA, a marker normal neurons) lactate (a ischemia) compare with perfusion values lesion stroke. Methods— recruited patients stroke prospectively performed weighted (DWI), perfusion, imaging. coregistered images, outlined visible lesion, extracted metabolite, apparent coefficient (ADC) from lesion....

<h3>Background</h3> Magnetic resonance (MR) diffusion and perfusion imaging are used to identify ischaemic penumbra, but there few comparisons with neuronal loss ischaemia in vivo. The authors compared N-acetyl aspartate (NAA, found intact neurons) lactate (anaerobic metabolism) diffusion/perfusion parameters. <h3>Methods</h3> prospectively recruited patients acute stroke performed MR tensor, (PWI) proton chemical shift spectroscopic (CSI). We superimposed a 0.5 cm voxel grid on the...

Rationale Intravenous thrombolysis with recombinant tissue Plasminogen Activator improves outcomes in patients treated early after stroke but at the risk of causing intracranial hemorrhage. Restricting use to evidence still salvageable tissue, or definite arterial occlusion, might help reduce risk, increase benefit and identify for treatment late time windows. Aims To determine if perfusion angiographic imaging computed tomography magnetic resonance who are more likely from context a large...

Abstract Dynamic susceptibility contrast (DSC)‐MRI is commonly used to measure cerebral perfusion in acute ischemic stroke. Quantification of parameters involves deconvolution the tissue concentration‐time curves with an arterial input function (AIF), typically use singular value decomposition (SVD). To mitigate effects noise on estimated blood flow (CBF), a regularization parameter or threshold used. Often single global applied every voxel, and its has dramatic effect CBF values obtained....

Better prediction of tissue prognosis in acute stroke might improve treatment decisions. We hypothesized that there are metabolic ischemic disturbances measurable noninvasively by proton magnetic resonance spectroscopy ((1)H MRS) occur earlier than any structural changes visible on diffusion-tensor imaging (DTI), which may therefore serve for territorial identification at risk.We performed multivoxel (1)H MRS plus DTI within a maximum 26 hours, and 3-7 days, after stroke. compared choline,...

<h3>Background</h3> In randomised trials testing treatments for acute ischaemic stroke, imaging markers of tissue reperfusion and arterial recanalisation may provide early response indicators. <h3>Objective</h3> To determine the predictive value structural, perfusion angiographic late clinical outcomes assess practicalities in three comprehensive stroke centres. <h3>Methods</h3> We recruited patients with potentially disabling centres, performed magnetic resonance (MR) or CT, including...

We extend the image-to-image metamorphosis into constrained longitudinal metamorphosis. apply it to estimate an evolution scenario, in patients with acute ischemic stroke, of both scattered and solitary lesions visible on serial MR perfusion weighted imaging from subacute stages. then a patient-specific residual map that enables us capture most relevant shape intensity changes, continuously, as lesion evolves through chronic timepoints until merging final image. detect areas high residuals...

Background Intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) improves outcome after an ischaemic stroke but increases the risk of intracranial haemorrhage. Restricting rt-PA to patients salvageable tissue, or arterial occlusion, might reduce risk, increase benefit and enable treatment at late time windows. Objectives To determine if computed tomography (CT) magnetic resonance (MR) perfusion angiography (CTP/CTA; MRP/MRA) imaging provide important information...