Hyperintense Vessel Research Articles

Collateral assessment on magnetic resonance imaging/angiography up to 30 hours after stroke onset.

We aimed to validate hyperintense vessel sign (HVS) on FLAIR imaging or posterior cerebral artery (PCA) laterality on MR angiography beyond 4.5 hours after stroke onset. Data from acute ischemic stroke patients with internal carotid or middle cerebral artery occlusion who underwent CT perfusion imaging at baseline, follow-up MR perfusion imaging and angiography within 30 hours after stroke, without effective recanalization on follow-up imaging, were analysed retrospectively. Patients were separately classified as high or low HVS (>5 or ≤5 slices of HVS), and PCA laterality positive or negative group. We compared core and penumbra volumes at follow-up imaging and neurological outcomes between high or low HVS group, and between PCA laterality positive or negative group. Of 49 patients analyzed, four patients with artifacts were excluded and 45 were classified into high (n = 23) or low (n = 22) HVS group. High group had a smaller core volume (median 32 ml versus 109 ml, p = 0.004), larger penumbra volume at follow-up (68 ml versus 0 ml, p = 0.001), and better outcomes (modified Rankin Scale at three months, 3 versus 5, p = 0.03). For PCA laterality analysis, 1 patient with previously occluded PCA was excluded and 48 patients were classified as positive (n = 22) or negative (n = 26). Positive group had larger core volume (116 ml versus 37 ml), and no significant differences in penumbral volumes or outcomes. Prominent HVS in later time was associated with small core volume, persistent penumbra volume and favorable outcomes.

Abstract TMP70: Association of Distal Hyperintense Vessel Sign and Outcomes in Patients With Symptomatic Posterior Circulation Intracranial Atherosclerotic Disease

Objectives: The Distal Hyperintense Vessel (DHV) sign on FLAIR imaging is a radiographic marker of inadequate blood flow due to poor collateral flow distal to the stenotic artery. Previous studies suggest that the DHV sign was associated with early recurrent ischemic stroke in the anterior circulation secondary to intracranial atherosclerotic disease (ICAD). However, its significance in ischemic stroke in the posterior circulation is unknown. Here, we investigate the association of DHV sign in the basilar artery and outcomes at discharge in patients with posterior circulation stroke or TIA secondary to ICAD. Methods: We retrospectively reviewed patients with ischemic strokes or TIA attributed to ICAD of the basilar or vertebral arteries admitted to two comprehensive stroke centers affiliated with UTSW Medical Center from 2010 to 2022. Patients were included if they met VERiTAS criteria (≥50% vertebrobasilar stenosis). The DHV sign was defined as positive when the increased intensity in the basilar artery distal to stenosis was higher than the surrounding CSF signal. The DHV sign was evaluated by blinded vascular neurologists and neuro-radiologists. The primary outcome was mRS at discharge. The secondary outcome was the incidence of clinical deterioration during admission, defined as any worsened neurological exam with associated new infarct or infarct expansion in the posterior circulation. Results: A total of 135 patients were included in the study. A total of 33 (24%) patients had the presence of the DHV sign on admission MRI. Compared to patients without DHV sign, patients with DHV sign had higher NIHSS scores on admission (median 7 vs 2, p<0.001), higher risk of clinical deterioration during hospitalization (27% vs 2%, p<0.001), higher mRS scores at discharge (median 3.45 vs 1.8, p<0.001) and higher mortality rate (24% vs 0%, p<0.001). In multivariate analysis, the DHV sign was an independent predictor of higher mRS scores at discharge. Conclusions: In patients with ischemic stroke or TIA secondary to basilar or vertebral artery atherosclerotic stenosis, the presence of the DHV sign in the basilar artery is associated with more severe disease and poorer outcomes at discharge compared to patients without DHV sign.

Stroke in a young adult: looking beyond the diffusion-weighted imaging sequence.

A 37-year-old migrainous woman was referred several hours after a sudden dysarthria lasting less than 1min. Brain MRI undertaken a few hours later showed no acute cerebral infarction on the diffusion-weighted imaging (DWI) sequence. However, an intraluminal thrombus within a distal branch of the middle cerebral artery (MCA) was seen on the T2*-weighted gradient echo images as well as hyperintense vessels related to slow flow beyond the occlusion's site. Control MRI 24h later confirmed the presence of a small infarct affecting the distal portion of the MCA territory but the thrombus was no longer visible. A comprehensive etiologic workup revealed the presence of a patent foramen ovale, as the underlying cause of the patient's stroke. Though the sensitivity of DWI sequence for acute ischemia is high, false negative exist particularly in cases of transient ischemic attack, brainstem or lacunar strokes. A careful brain MRI examination or the use of perfusion weighted imaging sequences are useful to avoid misdiagnosis particularly in young patients.

Location of Hyperintense Vessels on FLAIR Associated with the Location of Perfusion Deficits in PWI.

Perfusion imaging is preferred for identifying hypoperfusion in the management of acute ischemic stroke, but it is not always feasible/available. An alternative method for quantifying hypoperfusion, using FLAIR-hyperintense vessels (FHVs) in various vascular regions, has been proposed, with evidence of a statistical relationship with perfusion-weighted imaging (PWI) deficits and behavior. However, additional validation is needed to confirm that areas of suspected hypoperfusion (per the location of FHVs) correspond to the location of perfusion deficits in PWI. We examined the association between the location of FHVs and perfusion deficits in PWI in 101 individuals with acute ischemic stroke, prior to the receipt of reperfusion therapies. FHVs and PWI lesions were scored as present/absent in six vascular regions (i.e., the ACA, PCA, and (four sub-regions of) the MCA territories). Chi-square analyses showed a significant relationship between the two imaging techniques for five vascular regions (the relationship in the ACA territory was underpowered). These results suggest that for most areas of the brain, the general location of FHVs corresponds to hypoperfusion in those same vascular territories in PWI. In conjunction with prior work, results support the use of estimating the amount and location of hypoperfusion using FLAIR imaging when perfusion imaging is not available.

FLAIR hyperintense vessels on MRI post brain arteriovenous malformation embolization: A novel finding associated with post-procedure intraparenchymal hemorrhage.

Brain arteriovenous malformations (BAVMs) are frequently managed by endovascular embolization with a growing number of centers embolizing with intent to cure. Hemorrhage post-embolization is a severe and poorly understood complication. We present a novel imaging finding associated with post-embolization hemorrhage that has significantly impacted the management of patients at our institution. A retrospective review of all patients undergoing embolization of BAVM at a single center was performed. Post-embolization magnetic resonance imaging (MRI) was reviewed for the presence of T2 fluid-attenuated inversion recovery (FLAIR) hyperintense vessels (FHVs). Bivariate analysis was performed to determine associations between patient characteristics and risk of hemorrhage. A total of 50 patients underwent 75 embolization procedures. Forty-six post-embolization MRIs were available for review. There were four hemorrhages and 100% of those presented with FHV. In contrast, only 11.9% of embolization procedures without post-procedural hemorrhage had FHVs on MRI. In total, 18.7% of embolizations led to some morbidity or mortality, with only 6.7% leading to permanent morbidity or mortality. In bivariate analysis, only the presence of FHVs was correlated with the risk of hemorrhage (p < 0.05). This is the first series to describe the finding of hyperintense blood vessels on FLAIR imaging after embolization of BAVMs and correlate it with hemorrhage post embolization. This finding can help guide practitioners and potentially identify patients at risk of delayed hemorrhage post embolization.

The contribution of white matter pathology, hypoperfusion, lesion load, and stroke recurrence to language deficits following acute subcortical left hemisphere stroke.

Aphasia, the loss of language ability following damage to the brain, is among the most disabling and common consequences of stroke. Subcortical stroke, occurring in the basal ganglia, thalamus, and/or deep white matter can result in aphasia, often characterized by word fluency, motor speech output, or sentence generation impairments. The link between greater lesion volume and acute aphasia is well documented, but the independent contributions of lesion location, cortical hypoperfusion, prior stroke, and white matter degeneration (leukoaraiosis) remain unclear, particularly in subcortical aphasia. Thus, we aimed to disentangle the contributions of each factor on language impairments in left hemisphere acute subcortical stroke survivors. Eighty patients with acute ischemic left hemisphere subcortical stroke (less than 10 days post-onset) participated. We manually traced acute lesions on diffusion-weighted scans and prior lesions on T2-weighted scans. Leukoaraiosis was rated on T2-weighted scans using the Fazekas et al. (1987) scale. Fluid-attenuated inversion recovery (FLAIR) scans were evaluated for hyperintense vessels in each vascular territory, providing an indirect measure of hypoperfusion in lieu of perfusion-weighted imaging. We found that language performance was negatively correlated with acute/total lesion volumes and greater damage to substructures of the deep white matter and basal ganglia. We conducted a LASSO regression that included all variables for which we found significant univariate relationships to language performance, plus nuisance regressors. Only total lesion volume was a significant predictor of global language impairment severity. Further examination of three participants with severe language impairments suggests that their deficits result from impairment in domain-general, rather than linguistic, processes. Given the variability in language deficits and imaging markers associated with such deficits, it seems likely that subcortical aphasia is a heterogeneous clinical syndrome with distinct causes across individuals.

Plaque modification and stabilization after drug-coated balloon angioplasty for intracranial atherosclerotic lesions.

A drug-coated balloon (DCB) has potential applications in the treatment of intracranial atherosclerotic disease (ICAD). We aimed to evaluate changes of vessel wall features of ICAD lesions after DCB treatment by using vessel wall MRI (VWMRI). We retrospectively included patients with symptomatic ICAD who underwent DCB angioplasty alone. The incidences of stenosis of the lumen area, vessel wall thickening, hyperintense plaques, and prominent wall enhancement were compared between the baseline and follow-up VWMRI. There were 29 ICAD lesions from 29 patients, of which 22 were stenosis and 7 were occlusion. The median interval between DCB treatment and follow-up VWMRI was 4.1 [3.3, 6.7] months. After DCB treatment, follow-up VWMRI showed a significant decrease in the stenosis degree of the lumen area (83% [71%, 96%] vs 15% [3%, 41%], p < 0.001). Thirty-eight percent (11/29) of the patients observed normal appearance of the target vessel wall on follow-up VWMRI. In the stenosis group, the prevalence of hyperintense plaques decreased from 66.7% (14/21) at baseline to 23.8% (5/21) at follow-up, and prominent wall enhancement decreased from 66.7% (14/21) at baseline to 19.0%(4/21) at follow-up. The incidence of hyperintense plaques (p = 0.028) and vessel wall thickening (p = 0.018) tended to decrease with follow-up time. Although not significant (p = 0.106), a similar trend was observed between the incidence of prominent wall enhancement and follow-up time. Vascular healing with plaque modification and stabilization occurred following DCB treatment of ICAD lesions. • A drug-coated balloon (DCB) has potential applications in the treatment of intracranial atherosclerotic disease (ICAD). • Vascular healing with plaque modification and stabilization occurred following DCB treatment of ICAD lesions.

Estimating Perfusion Deficits in Acute Stroke Patients Without Perfusion Imaging.

Perfusion weighted imaging (PWI) is critical for determining whether stroke patients presenting in an extended time window are candidates for mechanical thrombectomy. However, PWI is not always available. Fluid-attenuated inversion recovery hyperintense vessels (FHVs) are seen in patients with a PWI lesion. We investigated whether a scale measuring the extent FHV could serve as a surrogate for PWI to determine eligibility for thrombectomy. The National Institutes of Health (NIH) FHV score was developed to quantify the burden of FHV and applied to magnetic resonance imaging scans of stroke patients with fluid-attenuated inversion recovery and perfusion imaging. The NIH-FHV was combined with the diffusion weighted image volume to estimate the diffusion-perfusion mismatch ratio. Linear regression was used to compare PWI volumes and mismatch ratios with estimates from the NIH-FHV score. Receiver operating characteristic analysis was used to test the ability of the NIH-FHV score to identify a significant mismatch. There were 101 patients included in the analysis, of whom 78% had a perfusion deficit detected on PWI with a mean lesion volume of 47 (±59) mL. The NIH-FHV score was strongly associated with the PWI lesion volume (P<0.001; R2=0.32; β-coefficient, 0.57). When combined with diffusion weighted image lesion volume, receiver operating characteristic analysis testing the ability to detect a mismatch ratio ≥1.8 using the NIH-FHV score resulted in an area under the curve of 0.94. The NIH-FHV score provides an estimate of the PWI lesion volume and, when combined with diffusion weighted imaging, may be helpful when trying to determine whether there is a clinically relevant diffusion-perfusion mismatch in situations where perfusion imaging is not available. Further studies are needed to validate this approach.

Association of distal hyperintense vessel sign and recurrent stroke in patients with symptomatic intracranial stenosis

ObjectiveThe distal hyperintense vessel sign (DHV) on fluid-attenuated inversion recovery magnetic resonance image (MRI) is an imaging biomarker of slow leptomeningeal collateral flow in the presence of large artery stenosis or occlusion reflecting impaired cerebral hemodynamics. In this study, we aim to investigate the significance of the DHV sign in patients with symptomatic ≥ 70% intracranial atherosclerotic stenosis. MethodsWe retrospectively reviewed patients with ischemic stroke or transient ischemic attack admitted to a single center from January 2010 to December 2017. Patients were included if they had symptomatic ≥ 70% atherosclerotic stenosis of the intracranial internal carotid artery or middle cerebral artery. The presence of the DHV sign was evaluated by blinded neuroradiologist and vascular neurologists. Recurrent ischemic stroke in the vascular territory of symptomatic intracranial artery was defined as new neurological deficits with associated neuroimaging findings during the follow up period. ResultsA total of 109 patients were included in the study, of which 55 had DHV sign. Average duration of follow up was 297 ± 326 days. Four patients were lost during follow up. Patients with the DHV sign had a higher rate of recurrent ischemic stroke (38%), compared to patients without the DHV sign (17%; p=0.018). In multivariate regression analysis, the presence of DHV sign was an independent predictor of recurrent ischemic stroke. A DHV score of ≥ 2 had a 63% sensitivity and 69% specificity for recurrent ischemic stroke. InterpretationIn patients with severe symptomatic intracranial atherosclerotic stenosis, those with a DHV sign on MRI are at higher risk of recurrent ischemic stroke.

Multiple hypointense veins on susceptibility weighted imaging as a promising biomarker of impaired cerebral hemodynamics in chronic steno-occlusive disease: a multiparametric MRI study.

Patients with steno-occlusive arterial disease may develop cerebral hypoperfusion with possible neurologic sequelae. The aim of the study is to verify the possible role of SWI, as a marker of cerebral hypoperfusion, in the identification of patient subgroups with significant chronic occlusions/stenoses at risk of critical cerebral hypoperfusion. We retrospectively identified 37 asymptomatic patients with chronic intra-extracranial occlusion/stenosis of the anterior circulation from a prospective brain MRI register between 2016 and 2020. All patients underwent 3 Tesla MRI. The imaging protocol included the following: SWI, 3D-FLAIR, DWI sequences, and 3D-TOF MRA. SWI findings were graded for the presence of asymmetric intracranial cortical veins (grades 1 to 4). The presence of collateralization was assessed with concomitant multiphase-CTA. FLAIR was evaluated for the presence of distal hyperintense vessels (DHVs), a described marker of flow impairment, and possible collateralization. Cerebral blood flow and arterial transit artifacts (ATAs) were evaluated at pCASL in 29 patients. SWI showed multiple hypointense vessels (MHVs) in 22/37 patients in the cerebral hemisphere ipsilateral to vessel occlusion/stenosis. SWI-MHV grade 1 was found in 15 patients (40.5%), grade 2 in 18 patients (48.7%), and grade 3 in 3 patients (8.1%); in one patient, SWI was graded as 4 (2.7%). A significant relationship was found among MHV, DHV, collaterals, ATAs, and hypoperfused areas on pCASL and with patients' previous neurological symptoms. SWI-MVH correlates with chronic cerebral flow impairment and is related to hypoperfusion and collateralization. It may help identify a subgroup of patients benefitting from revascularization.

Evaluation of T2-FLAIR combined with ASL on the collateral circulation of acute ischemic stroke.

Using magnetic resonance fluid-attenuated inversion recovery sequence (FLAIR) combined with three-dimensional arterial spin labeling (3D-ASL) cerebral perfusion imaging to explore the effect of collateral circulation on acute ischemic stroke (AIS). Eighty patients with AIS who had severe stenosis or occlusion at the end of the unilateral middle cerebral artery (MCA) were collected for the study on admission. Arterial transit artifact (ATA) was observed and graded for hyperintense vessel sign (HVS). CBF values were measured and recorded in the ischemic penumbra (IP) area and contralateral to it. The National Institutes of Health Stroke Scale (NIHSS) scores on the day of admission and discharge were recorded, and reductions in relative cerebral blood flow (rCBF) and discharge NIHSS scores were calculated. The rCBF and decrease in NIHSS scores were statistically significant (p < 0.05) between all levels of HVS, the groups of ATA, and the combination of the two. Correlation analysis results indicate that both HVS and ATA are positively correlated with rCBF and NIHSS score degradation. The receiver operating characteristic (ROC) curves showed that the sensitivity of HVS and ATA for evaluating cerebral blood flow (CBF) changes was 92.0% and 76.0%, and the specificity was 41.8% and 52.7%, respectively. The combined sensitivity of the two was 68.0%, and the specificity was 65.5%. The T2-FLAIR sequence combined with ASL can more accurately assess the blood flow changes in the IP area, the open state of collateral circulation, and the clinical prognosis.

Various tests of left neglect are associated with distinct territories of hypoperfusion in acute stroke.

Hemispatial neglect is among the most disabling consequences of right hemisphere stroke. However, there is no consensus on the optimal assessments to identify neglect. We hypothesized that different tests for neglect given the same day (i) detect distinct aspects and types of neglect, (ii) are sensitive to different cognitive functions (beyond spatially specific processing) and (iii) are associated with distinct regions of hypoperfusion. We examined data from 135 participants with acute, right-hemispheric ischaemic stroke who received an MRI and neglect testing within 48 h of acute infarct in a cross-sectional study. The volume of infarct was calculated on diffusion-weighted imaging. We also scored severity and location of fluid-attenuated inversion recovery hyperintense vessels in six areas (anterior cerebral artery territory, posterior cerebral artery territory and four within the middle cerebral artery territory) to estimate the volume and location of hypoperfusion in acute stroke. Neglect tests included gap detection, scene copy, line bisection, line cancellation, oral reading and picture description. We found strong correlations between tests that evaluated viewer-centred processing, as well as strong correlations between tests that evaluated stimulus-centred processing. The error rate on different tests was associated with hypoperfusion in different vascular territories, even after controlling for the volume of an infarct. Our results confirm that it is essential to administer a battery of different tests of hemispatial neglect to capture various deficits in attention and spatially specific processing that underlies neglect. Our results also show the potential usefulness of hyperintense vessel ratings as an indication of dysfunction beyond the infarct, as the ratings (and not infarct volume) were highly associated with many clinical deficits. Finally, results underscore that diverse types of neglect are clinically important in acute stroke, as they reflect different areas of hypoperfused tissue, which may be salvageable in the absence of infarct in those areas. As such, neglect batteries may be useful for detecting patients with cortical hypoperfusion who are candidates for reperfusion therapies.

Arterial spin labeling signal ratio between the lesion and contralateral sides for evaluation of acute middle cerebral artery infarct.

The purpose of our study was to differentiate arterial transit artifact from post-recanalization luxury perfusion on arterial spin labeling (ASL) image, and obtain the relationship between ASL signal intensity and clinical outcomes in patients with acute ischemic stroke.Thirty-five subjects with an acute middle cerebral artery (MCA) infarct were enrolled (18 with recanalized and 17 with non-recanalized MCAs). ASL images were obtained using pseudo-continuous ASL technique with 1600 ms (millisecond) of post-label delay within 3 days from symptom onset. Signal intensities on color ASL images were classified as high, intermediate, and poor grade visually. The ratio of maximum ASL signal between the ischemic area and contralateral side was calculated and compared between patients with and without MCA recanalization. Among patients with non-recanalized MCA, ASL signal ratios were compared between patients with and without hyperintense vessel sign on fluid attenuated inversion recovery (FLAIR). Also, correlation between the ASL signal ratio and National Institutes of Health Stroke Scale (NIHSS) score was evaluated.High or intermediate grade on color ASL images were more frequently found in patients with recanalized MCA (P < .01). Patients with non-recanalized MCA had higher ASL signal ratio in overall ASL signal grade (P = .010) and intermediate grade (P = .011). Among patients with non-recanalized MCA, those with hyperintense vessel sign on FLAIR had higher ASL signal ratios (P = .049). ASL signal ratio was negatively correlated with both initial (P = .023) and final (P = .003) NIHSS scores.The ASL signal ratio could help to differentiate between the pial collaterals and post-recanalization luxury perfusion. A higher ASL ratio was related with the hyperintense vessel sign on FLAIR and lower NIHSS score.

Hyperintense vessels on imaging account for neurological function independent of lesion volume in acute ischemic stroke

In acute ischemic stroke, reported relationships between lesion metrics and behavior have largely focused on lesion volume and location. However, hypoperfusion has been shown to correlate with deficits in the acute stage. Hypoperfusion is typically identified using perfusion imaging in clinical settings, which requires contrast. Unfortunately, contrast is contraindicated for some individuals. An alternative method has been proposed to identify hypoperfusion using hyperintense vessels on fluid-attenuated inversion recovery (FLAIR) imaging. This study aimed to validate the clinical importance of considering hypoperfusion when accounting for behavior in acute stroke and demonstrate the clinical utility of scoring the presence of hyperintense vessels to quantify it.One hundred and fifty-three participants with acute ischemic stroke completed a battery of commonly-used neurological and behavioral measures. Clinical MRIs were used to determine lesion volume and to score the presence of hyperintense vessels seen on FLAIR images to estimate severity of hypoperfusion in six different vascular regions. National Institutes of Health Stroke Scale (NIHSS) scores, naming accuracy (left hemisphere strokes), and language content produced during picture description were examined in relation to lesion volume, hypoperfusion, and demographic variables using correlational analyses and multivariable linear regression.Results showed that lesion volume and hypoperfusion, in addition to demographic variables, were independently associated with performance on NIHSS, naming, and content production. Specifically, hypoperfusion in the frontal lobe independently correlated with NIHSS scores, while hypoperfusion in parietal areas independently correlated with naming accuracy and content production.These results correspond to previous reports associating hypoperfusion with function, confirming that hypoperfusion is an important consideration—beyond lesion volume—when accounting for behavior in acute ischemic stroke. Quantifying hypoperfusion using FLAIR hyperintense vessels can be an essential clinical tool when other methods of identifying hypoperfusion are unavailable or time prohibitive.

Hyperintense posterior cerebral artery sign in patients with reversible cerebral vasoconstriction syndrome.

Background: This study investigated hyperintense vessel signs (HVS) on fluid-attenuated inversion recovery imaging in the P1–2 portions of posterior cerebral arteries (PCAs) as a “hyperintense PCA sign” and HVS of cortical arteries. We retrospectively examined whether these signs would be useful in diagnosing reversible cerebral vasoconstriction syndrome (RCVS) in the acute phase.Methods: Eighty patients with RCVS who underwent initial magnetic resonance imaging (MRI) within 7 days of onset were included in this study. HVS and related clinical factors were examined.Results: On initial MRI of RCVS patients, hyperintense PCA sign and HVS of cortical arteries were seen in 21 cases (26%) and 38 cases (48%), respectively. In patients showing hyperintense PCA sign, vasoconstriction of the A2–3 portion was a significant clinical factor. Conversely, vasoconstriction of the M1 and P1 portions and the presence of white matter hyperintensity on initial and chronic-stage MRI were significantly associated with the presence of HVS in cortical arteries.Conclusion: Because rich collateral flow exists around PCAs, the frequency of hyperintense PCA sign is not high. However, hyperintense PCA sign findings in patients with suspected RCVS offer credible evidence of extreme flow decreases due to vasoconstriction in peripheral PCAs and other arteries associated with the collateral circulation of PCAs. Conversely, HVS in cortical arteries tend to reflect slow antegrade circulation due to vasoconstriction of peripheral vessel and major trunks. Both signs appear useful for auxiliary diagnosis of acute-phase RCVS.

Diffusion- and Susceptibility Weighted Imaging Mismatch Correlates With Collateral Circulation and Prognosis After Middle Cerebral Artery M1-Segment Occlusion.

Objective: To explore the relation between diffusion-weighted and susceptibility weighted imaging (DWI-SWI) mismatch and collateral circulation or prognosis in patients with occluded M1 segments of middle cerebral artery (MCA).Methods: We enrolled 59 patients with MCA M1-segment occlusion for a retrospective review of baseline clinical and imaging data. As markers of circulatory collaterals, prominent laterality of posterior (PLPCA) and anterior (PLACA) cerebral arteries on magnetic resonance angiography (MRA) studies and a hyperintense vessel sign (HVS) on T2 fluid-attenuated inversion recovery (FLAIR) images were collectively scored. The extent of acute cerebral infarction was then quantified on DWI, using the Alberta Stroke Program Early CT Score (DWI-ASPECTS). Hypointensity vessel sign prominence (PVS) was also evaluated by SWI and similarly scored (SWI-ASPECT) to calculate DWI-SWI mismatch [(DWI-ASPECTS) – (SWI-ASPECTS)], ranging from −10 to 10 points.Results: DWI-SWI mismatch showed significant associations with PLPCA, PLACA, HVS prominence, and collective collateral scores (all, p < 0.05). National Institutes of Health Stroke Scale (NIHSS), DWI-SWI mismatch, and DWI-ASPECTS also differed significantly according to patient prognosis (good vs. poor) after MCA M1-segment occlusion (p < 0.05). In binary logistic regression analyses, NIHSS and DWI-SWI mismatch emerged as independent prognostic factors (p < 0.05).Conclusions: Collateral circulation may be an important aspect of DWI-SWI mismatch, which in this study correlated with prognostic outcomes of MCA M1-segment occlusion.

Hyperintense Vessels on Magnetic Resonance Imaging Correlate with Arteries in the Delayed Phase of Multiphase Computed Tomography Angiography

Hyperintense Vessels on Magnetic Resonance Imaging Correlate with Arteries in the Delayed Phase of Multiphase Computed Tomography Angiography

Flow-void and hyperintense vessel sign are unsuitable to characterise a non-vascular stroke-like lesion

With interest we read the article by Chong et al. about a study of 13 patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and 20 patients with acute ischemic stroke (AIS) for the sensitivity/specificity of the flow-void sign (FVS) and hyperintense vessel sign (HVS) on MRI [1].

Characterizing subtypes and neural correlates of receptive aprosodia in acute right hemisphere stroke

IntroductionSpeakers naturally produce prosodic variations depending on their emotional state. Receptive prosody has several processing stages. We aimed to conduct lesion-symptom mapping to determine whether damage (core infarct or hypoperfusion) to specific brain areas was associated with receptive aprosodia or with impairment at different processing stages in individuals with acute right hemisphere stroke. We also aimed to determine whether different subtypes of receptive aprosodia exist that are characterized by distinctive behavioral performance patterns. MethodsTwenty patients with receptive aprosodia following right hemisphere ischemic stroke were enrolled within five days of stroke; clinical imaging was acquired. Participants completed tests of receptive emotional prosody, and tests of each stage of prosodic processing (Stage 1: acoustic analysis; Stage 2: analyzing abstract representations of acoustic characteristics that convey emotion; Stage 3: semantic processing). Emotional facial recognition was also assessed. LASSO regression was used to identify predictors of performance on each behavioral task. Predictors entered into each model included 14 right hemisphere regions, hypoperfusion in four vascular territories as measured using FLAIR hyperintense vessel ratings, lesion volume, age, and education. A k-medoid cluster analysis was used to identify different subtypes of receptive aprosodia based on performance on the behavioral tasks. ResultsImpaired receptive emotional prosody and impaired emotional facial expression recognition were both predicted by greater percent damage to the caudate. The k-medoid cluster analysis identified three different subtypes of aprosodia. One group was primarily impaired on Stage 1 processing and primarily had frontotemporal lesions. The second group had a domain-general emotion recognition impairment and maximal lesion overlap in subcortical areas. Finally, the third group was characterized by a Stage 2 processing deficit and had lesion overlap in posterior regions. ConclusionsSubcortical structures, particularly the caudate, play an important role in emotional prosody comprehension. Receptive aprosodia can result from impairments at different processing stages.

Vessel flow void sign and hyperintense vessel sign on FLAIR images distinguish between MELAS and AIS

ObjectiveThis study aimed to evaluate the sensitivity and specificity of the vessel signs, including the Vessel Flow Void Sign (VFVS) and the Hyperintense Vessel Sign (HVS) in Fluid Attenuated Inversion Recovery (FLAIR) images during the differentiation of Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like Episodes (MELAS) in Acute Ischemic Stroke (AIS). MethodsMagnetic Resonance Imaging (MRI) scans of 13 MELAS and 20 AIS patients were obtained during the acute stage of the diseases (median time to scan <1 day from symptom onset). To evaluate VFVS and HVS on the FLAIR images, Logistic Regression was used to analyze their correlation with MELAS. Then, a new scale of scoring, involving two aspects (VFVS and HVS) on FLAIR images was established. Receiver operating characteristic (ROC) curves were used to evaluate the efficacy of the developed criterion. ResultsFLAIR images from 12 of the 13 MELAS patients exhibited VFVS while none exhibited HVS. Moreover, FLAIR images from 3 of the 20 AIS patients exhibited VFVS while 17 exhibited HVS. Logistic Regression showed that VFVS and the absence of HVS (NoHVS) were independent MELAS predictors. If there were VFVS, the patient scored 2 points, while there were NoHVS, the patient scored 1 point. Patients with >1.5 scores were prone to be MELAS, while patients with <1.5 scores were prone to be AIS. Sensitivity was found to be 92.3%, specificity was 85%, with an AUC of 0.94. ConclusionWe have established a new scoring criterion, with a high sensitivity and specificity, for differentiating between MELAS and AIS in patients during the acute stage.