Hyperintense Acute Reperfusion Marker Research Articles

Poor venous outflow is associated with hyperintense acute reperfusion marker on follow-up MRI in patients with acute ischemic stroke with a large vessel occlusion

BackgroundHyperintense acute reperfusion marker (HARM) refers to delayed enhancement in the subarachnoid or subpial space on post-contrast fluid attenuated inversion recovery (FLAIR) images. HARM is a measure of blood–brain barrier...

The value of hyperintense acute reperfusion marker sign for evaluation of subacute cerebral infarction

The value of hyperintense acute reperfusion marker sign for evaluation of subacute cerebral infarction

Teaching Neuro Images : Hyperintense acute reperfusion marker in ischemic stroke with transient symptoms

A 67-year-old man with 45-minute onset left hemiparesis underwent 3.0T gadolinium-enhanced MRI (reported iodine contrast allergy) with right frontoparietal small infarcts on diffusion-weighted images without vascular obstruction. No reperfusion therapy was given due to complete spontaneous symptoms regression. Twenty-four hours later, a second MRI showed right parietal CSF space enhancement on fluid-attenuated inversion recovery. Neither MRI nor CT had sign of hemorrhage (figure).

Abstract TMP90: The Harm Sign As A Trial Biomarker Of Reperfusion Injury: Frequency, Determinants, And Outcomes In EVT Patients With Successful Reperfusion

Introduction: With successful reperfusion (SR, mTICI 2b-3) now being achieved in the great preponderance of patients undergoing endovascular thrombectomy (EVT), prevention of blood-brain barrier disruption and reperfusion injury is an emerging therapeutic target. For trials of agents to reduce BBB injury, the hyperintense acute reperfusion marker (HARM) sign is a potentially useful physiologic biomarker. However, past studies of HARM have generally failed to disaggregate non-EVT patients, EVT patients without SR, and EVT patients with SR. Methods: In a prospectively maintained database, we analyzed consecutive patients with SR (mTICI 2b-3) after EVT for anterior circulation large vessel occlusion undergoing post-gadolinium MRI scans at 3-6h and 24h after thrombectomy. Results: Among 48 SR patients meeting study entry criteria, the HARM sign was present in 65%. Patients with HARM sign, compared to those without, did not differ in age or NIHSS, but were more often female (54% vs 10%), more often had history of hypertension (65% vs 47%), and had higher initial SBP (156 vs 144). Patients with HARM sign more often received IV TPA (39% vs 29%), had longer time from onset to achievement of SR (median 352 vs 264 mins), underwent more passes (2.5 vs 1.9), and less often had complete (mTICI 3) reperfusion (13% vs 41%). With regard to outcomes, HARM patients more often had radiologic hemorrhage (75% vs 24%), less often were ambulatory at discharge (23% vs 59%), had less functional independence (mRS 0-2) at 90d (33% vs 59%), and had higher in-hospital mortality (16% vs 0%). Conclusion: The HARM sign is present in two-thirds of EVT patients with successful reperfusion; is associated with higher blood pressure, IV lytic therapy, longer time to reperfusion, more procedure manipulations, and less than complete macro-reperfusion; and is strongly associated with hemorrhagic transformation and worse clinical outcomes. The HARM sign is a promising biomarker for use in trials of treatments to avert reperfusion injury.

Good outcome associated with blood-brain barrier disruption and lower blood pressure after endovascular therapy

ObjectivesTo evaluate the association between post-endovascular thrombectomy (EVT) blood-brain barrier (BBB) disruption on MRI or CT and average systolic blood pressure (SBP) with favorable 90-day functional outcome. Observational studies have found elevated SBP associated with worse outcomes post-EVT, while recent randomized trials found no difference in targeted BP reduction. There may be a subgroup of patients who benefit from targeted BP reduction post-EVT. MethodsThis is a single-center study of 1) anterior large vessel occlusion stroke patients treated with EVT from 2015 to 2021, 2) achieved mTICI grade 2b or 3. Hyperintense acute reperfusion marker (HARM), hemorrhagic transformation (HT), and midline shift at 3 h post-EVT and 24 h imaging were assessed independently by multiple raters. Binary logistic regression models were used to determine the association of post-EVT SBP with outcomes. BBB disruption was defined as HT or HARM on 3h post-EVT imaging. ResultsOf 103 patients, those with SBP 100-129 versus SBP 130-160 found no significant difference in favorable 90-day outcome (64% vs. 46%, OR 2.11, 95% CI 0.78-5.76, p=0.143). However, among 71 patients with BBB disruption, a significant difference in favorable outcome of 64% in SBP 100-129 vs. 39% in SBP 130-160 group (OR 5.93, 95% CI 1.50-23.45, p=0.011) was found. There was no difference in symptomatic ICH, 90-day mortality, midline shift (≥5 mm), and hemicraniectomy, between BP or BBB groups. ConclusionsBBB disruption on 3h post-EVT imaging and lower SBP was associated with favorable outcome. This imaging finding may guide targeted BP therapy and suggests need for a randomized control trial.

Ipsilateral blooming of microbleeds after Hyperintense Acute Reperfusion Marker sign in an ischemic Stroke patient, a case report

BackgroundHyperintense Acute Reperfusion Marker (HARM) is a hyperintense subarachnoid signal on FLAIR MRI sequence caused by gadolinium contrast leakage into the subpial space. While, on FLAIR, HARM may mimic subarachnoid hemorrhage, it is differentiated from it on computed tomography (CT) and SWAN MRI sequences. Cerebral microbleeds are black, rounded spots on SWAN caused by blood-products deposition following red blood cell leakage from small cerebral vessels brain. Both microbleeds and HARM carry important prognostic implication as they are associated with blood-brain barrier disruption and an increased risk of intracerebral hemorrhage.Case presentationA 79-year-old man presented with aphasia and right hemiparesis due to ischemic stroke with left middle cerebral artery occlusion. Admission NIHSS score was 7, and he was successfully treated by intravenous thrombolysis and mechanical thrombectomy. On day 1, his clinical condition worsened, and he had an urgent gadolinium-enhanced MRI. There was no evidence of early recurrence, nor of hemorrhage on SWAN or on FLAIR. Left middle cerebral artery was permeable. The patient was anticoagulated for newly diagnosed atrial fibrillation, and a second MRI following a generalized tonic-clonic seizure showed multiple left hemispheric diffusion-weighted imaging (DWI) hyperintense spots and a left hemispheric sub-arachnoid hyperintensity on FLAIR, compatible with a subarachnoid hemorrhage. This diagnosis was excluded by SWAN MRI sequence and a normal cerebral CT the same day. The diagnosis of HARM was retained. At day 9, patient’s condition improved, and a control MRI did not show evidence of HARM. However, numerous microbleeds were detected in the left hemisphere only (ipsilateral with HARM and stroke).ConclusionsThis case highlights first of all the importance of differentiating HARM and subarachnoid hemorrhage, especially in an anticoagulated patient with clinical aggravation. Secondly, it is crucial to identify microbleeds and understand their pathophysiology, as they are associated with higher risk of hemorrhage and stroke recurrence in ischemic stroke patients. Finally, the mono-hemispheric appearance of microbleeds in this case suggests for the first time that, in some acute ischemic stroke patients, a relationship between HARM and cerebral microbleeds may exist.

The Clinical Significance of the Hyperintense Acute Reperfusion Marker Sign in Subacute Infarction Patients

Purpose: The hyperintense acute reperfusion marker (HARM) is characterized by the delayed enhancement of the subarachnoid or subpial space observed on postcontrast fluid-attenuated inversion recovery (FLAIR) images, and is considered a cerebral reperfusion marker for various brain disorders, including infarction. In this study, we evaluated the cerebral distribution patterns of HARM for discriminating between an enhancing subacute infarction and an enhancing mass located in the cortex and subcortical white matter. Materials and methods: We analyzed consecutive patients who experienced a subacute ischemic stroke, were hospitalized, and underwent conventional brain magnetic resonance imaging including postcontrast FLAIR within 14 days from symptom onset, as well as those who had lesions corresponding to a clinical sign detected by diffusion-weighted imaging and postcontrast T1-weighted imaging between May 2019 and May 2021. A total of 199 patients were included in the study. Of them, 94 were finally included in the subacute infarction group. During the same period, 76 enhancing masses located in the cortex or subcortical white matter, which were subcategorized as metastasis, malignant glioma, and lymphoma, were analyzed. We analyzed the overall incidence of HARM in subacute ischemic stroke cases, and compared the enhancement patterns between cortical infarctions and cortical masses. Results: Among 94 patients with subacute stroke, 78 patients (83%) presented HARM, and among 76 patients with subcortical masses, 48 patients (63%) presented peripheral rim enhancement. Of 170 subcortical enhancing lesions, 88 (51.8%) showed HARM, and 78 (88.6%) were determined to be subacute infarction. Among 94 patients with subacute stroke, 48 patients (51%) had diffusion restrictions, and HARM was found in 39 patients (81.2%). Of the 46 patients (49%) without diffusion restriction, 39 patients (84.8%) showed HARM. Conclusions: The presence of HARM was significantly associated with subacute infarctions. For the masses, a peripheral rim enhancement pattern was observed around the mass rather than the cerebral sulci on postcontrast FLAIR.

Abstract 1122‐000167: Hyperintense Acute Reperfusion Marker and Hemorrhagic Conversion in Stroke Patients Undergoing Mechanical Reperfusion

This meeting abstract was removed due to the OA licensing requirements of this journal. The full abstract is listed here : https://www.svin.org/files/SVIN_2021_Abstracts_for_Web.pdf

Hyperintense acute reperfusion marker associated with hemorrhagic transformation in the WAKE-UP trial.

Hyperintense acute reperfusion marker (HARM) is an indicator of early disruption of the blood-brain-barrier. Our aim was to investigate the incidence of HARM in patients with a diffusion weighted imaging (DWI) - fluid attenuated inversion recovery (FLAIR) mismatch and determine the association between this marker and hemorrhagic complications as well as clinical outcome. We included patients from the Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) trial who underwent baseline perfusion weighted imaging (PWI). HARM was defined as a hyperintense signal in the cerebrospinal fluid space on FLAIR imaging at 24 h after baseline imaging. We compared baseline characteristics in patients with and without HARM and investigated the association between HARM and any hemorrhagic transformation (HT) and parenchymal hematoma (PH) in a multivariate logistic regression. We also explored HARM as an independent predictor of poor outcome, defined as a modified Rankin Scale of 3-6 at 90 days. HARM was present in 14 of 223 (6%) patients with a DWI-FLAIR mismatch and baseline characteristics were similar in patients with vs without HARM. HARM showed an independent relationship with any HT (OR 6.67; 95%CI 1.72-26.58) and any PH (OR 6.92; 95%CI 1.34-29.49). The rate of HARM was similar in patients with good and poor outcome (5%, p = 0.90). In the WAKE-UP trial, the incidence of HARM was only 6% at 24 h. An association was present between HARM and hemorrhagic complications, but no relationship with functional outcome was observed.

GLOS and HARM in patients with transient neurovascular symptoms with and without ischemic infarction

Background and purposeGadolinium leakage in ocular structures (GLOS) on fluid attenuated inversion recovery images (FLAIR) is a novel imaging marker in acute ischemic stroke and other neurological disorders. MethodsIn patients with transient neurovascular symptoms who underwent repeated MRI with intravenous contrast agent administration, the presence of acute ischemic lesions on diffusion-weighted images (DWI) as well as the frequency and pattern of blood-brain barrier and blood-retina barrier impairment as demonstrated by the hyperintense acute reperfusion marker (HARM) and GLOS respectively on postcontrast FLAIR were evaluated. ResultsOverall 28 patients with transient neurovascular symptoms (median age 70.5 years; 18 (64.3%) male) were included. Follow-up MRI was performed within 35 (IQR 21–47) hours after the initial MRI. On DWI, acute ischemic lesions were observed in 22 (78.6%). On contrast-enhanced FLAIR, GLOS was observed in 12 (42.9%) patients: in 1 (3.6%) only in the anterior chamber, and in 11 (39.3%) in the anterior chamber and vitreous body. HARM was observed in 3 (10.7%) patients. In one patient without ischemic lesion on DWI or HARM on FLAIR, GLOS was observed in the anterior chamber and vitreous body. Presence of GLOS was associated with higher age (p = 0.04) and detection of HARM (p = 0.03). ConclusionsIn patients with transient neurovascular symptoms, GLOS is a frequent finding and associated with HARM on contrast-enhanced FLAIR. As GLOS was observed in one patient without an ischemic lesion or HARM, it might be useful as an additional imaging marker.

Abstract P327: Utilizing Iodine Contrast Extravasation Post Reperfusion and Dual Energy Ct Imaging to Predict Risk of Hemorrhagic Conversion in Acute Stroke Patients

Introduction: Hyperintense acute reperfusion marker (HARM) has been identified on post-contrast magnetic resonance imaging (MRI) to be a marker of hemorrhagic conversion (HC) post reperfusion therapy in acute stroke patients. We have previously described a case where MRI HARM was mimicked on post contrast computed topography (CT) imaging in an acute stroke patient post reperfusion. Dual-Energy (DECT) allows for differentiation between acute blood and iodine contrast extravasation (ICE), and thus can have utility when ICE is present. Here we sought to validate whether post-intervention ICE/CT hyperdensity reperfusion maker (CT HARM), and contrast subtracted on DECT is associated with HC in acute stroke patients. Method: Data was obtained from our Institutional Review Board approved stroke admission database from January 2017 to November 2019, including ischemic stroke patients that received thrombolysis or thrombectomy, had evaluable images within 24 hours of admission, and received a DECT. Ischemic volumes of the stroke was measured on diffusion-weighted image (DWI). ICE was measured on CT head and DECT using the freehand 3D region of interest tool on the Visage Imaging PACS System. Susceptibility weighted MRI sequences were used to grade HC. Data analysis was conducted with regression modeling. Results: A total of 82 patients were included, 49% women, median age 73 (interquartile range (IQR), 61- 77), admission NIHSS 12 (IQR, 7 - 21), 24 hour change in NIHSS 4 (IQR, 0 -13), glucose 125 (IQR, 106 -158), creatinine 1.0 (IQR, 0.8 - 1.2), infarct volume 50.6 ± 7.1 mL, 48% treated with thrombectomy, 7% with PH-1 or PH-2 identified on MRI, and 56% with MCA infarcts. ICE volume was 2.6 ± 1.0 mL and DECT volume was 2.2 ± 1.1mL. ICE increased the likelihood of MRI confirmed PH-1 or PH-2 hemorrhagic conversion (odds ratio (OR) 14.34, 95% confidence interval (CI) 5.74 - 22.94) and decreased likelihood of increase in NIHSS at 24 hours (OR 0.20, 95% CI 0.01 to 0.40). There were no other significant associations with ICE or DECT volumes. Conclusion: Our results are supportive of our proposed association between CT HARM and risk of HC. More studies are needed to study whether quantitative of DECT can be predictive of stroke outcomes post reperfusion therapy.

Hyperintense Acute Reperfusion Marker on FLAIR in Patient with Possible Contrast-Induced Encephalopathy Following Cerebral Angiography

Contrast-induced encephalopathy (CIE) is a rare complication of angiography and endovascular intervention following administration of iodinated intravenous contrast agents. Neuroimaging findings of CIE usually show cerebral edema, leptomeningeal enhancement, and parenchymal signal abnormality on fluid-attenuated inverse recovery (FLAIR). Hyperintense acute reperfusion marker (HARM) generally implies an enhancement of the subarachnoid cerebrospinal fluid space on brain FLAIR imaging in cases of acute ischemic stroke or hyperperfusion syndrome. We report a case of possible CIE following cerebral angiography, accompanied by HARM sign.

Gadolinium leakage in ocular structures: A novel MRI finding in transient global amnesia

Background and purposeWe investigated the frequency and pattern of blood-brain barrier as well as blood-retina barrier impairment in transient global amnesia (TGA) as demonstrated by hyperintense acute reperfusion marker (HARM) and gadolinium leakage in ocular structures (GLOS) respectively on fluid attenuated inversion recovery images (FLAIR). MethodsPatients with TGA who underwent repeated MRI after intravenous contrast agent administration were identified and the presence of GLOS in the anterior chamber and vitreous body and HARM noted on FLAIR. ResultsOverall 10 patients (IQR 64.25–71.75 years; 4 (40%) patients were male) were included. On contrast-enhanced FLAIR, GLOS was observed in 3 (30%) patients; in all of these in the anterior chamber and vitreous body as well as bilateral and symmetrical. HARM was observed in none of the patients. Frequency of hippocampal DWI lesions, as well as extent of age related white matter lesions did not differ significantly between patients with and without GLOS. ConclusionsIn contrast to HARM, GLOS is a relatively common finding in TGA patients. As GLOS is thought to share its pathophysiology at least to some extent with HARM and is associated with HARM in ischemic stroke, it might be used as surrogate marker for blood-brain barrier impairment in TGA.

Frequency of Blood-Brain Barrier Disruption Post-Endovascular Therapy and Multiple Thrombectomy Passes in Acute Ischemic Stroke Patients.

Background and Purpose- The high prevalence of hyperintense acute reperfusion marker (HARM) seen after endovascular therapy is suggestive of blood-brain barrier disruption and hemorrhage risk and may be attributable to multiple thrombectomy passes needed to achieve recanalization. Methods- Patients with acute stroke were included if they were screened from January 2015 through February 2019, received an acute ischemic stroke diagnosis involving the anterior circulation, treated with or without IV tPA (intravenous tissue-type plasminogen activator), consented to the NINDS Natural History Study, and imaged with a baseline magnetic resonance imaging before receiving endovascular therapy. Consensus image reads for HARM and hemorrhagic transformation were performed. Good clinical outcome was defined as 0-2 using the latest available modified Rankin Scale score. Results- Eighty patients met all study criteria and were included in the analyses. Median age was 65 years, 64% female, 51% black/African American, median admit National Institutes of Health Stroke Scale=19, 56% treated with IV tPA, and 84% achieved Thrombolysis in Cerebral Infarction score of 2b/3. Multiple-pass patients had significantly higher rates of severe HARM at 24 hours (67% versus 29%; P=0.001), any hemorrhagic transformation (60% versus 36%; P=0.04) and poor clinical outcome (67% versus 36%; P=0.008). Only age (odds ratio, 1.1; 95% CI, 1.01-1.12; P=0.022) and severe HARM at 24 hours post-endovascular therapy were significantly associated with multiple passes (odds ratio, 7.2; 95% CI, 1.93-26.92; P=0.003). Conclusions- In this exploratory study, multiple thrombectomy passes are independently associated with a significant increase in blood-brain barrier disruption detected at 24 hours. Patients with HARM post-endovascular therapy had a >7-fold increase in the odds of having multiple- versus single-pass thrombectomy. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00009243.

Usefulness of hyperintense acute reperfusion marker sign in patients with transient neurologic symptom.

It aimed to investigate the incidence and final diagnosis of hyperintense acute reperfusion marker (HARM) signs in patients initially suspected of having a transient ischemic attack (TIA).In retrospective manner, a series of consecutive series of patients who arrived at the emergency department and was initially assessed as TIA within 12 hours of symptom onset between July 2015 and December 2016 were enrolled. Conventional magnetic resonance imaging protocol including diffusion-weighted imaging (DWI) and pre- and post-contrast fluid attenuation inversion recovery imaging (FLAIR) was conducted to evaluate the ischemic lesion and prognosis. Through the review of medical records and imaging studies, their final diagnosis and its association with HARM signs on post-contrast FLAIR were investigated.A total of 174 subjects were enrolled (mean age, 64.0 ± 12.9 years old; male, 54.6%; DWI lesion, 17.8%). HARM signs were observed in 18 (10%) patients, and their final diagnoses were classified as true TIA (n = 11, 61%), seizure (2, 11%), posterior reversible encephalopathy (2, 11%), reversible cerebral vascular constriction (1, 6%) and unclassified encephalopathy (2, 11%). The co-occurrence of HARM and DWI lesions were observed in 7 subjects which were 6 subjects of true TIA (ischemic stroke) and 1 subject with RCVS related ischemic stroke.The observation of HARM sign would be helpful to confirm the ischemic insult and distinguish the other disease.

Gadolinium Leakage in Ocular Structures Is Common in Lacunar Infarction.

Background and Purpose- We investigated the frequency and pattern of blood-brain barrier, as well as blood-retina barrier, impairment in acute lacunar infarction as demonstrated by hyperintense acute reperfusion marker and gadolinium leakage in ocular structures (GLOS), respectively, on fluid-attenuated inversion recovery images. Methods- Acute lacunar infarction patients who underwent repeated magnetic resonance imaging after intravenous contrast agent administration were identified and the presence of GLOS in the anterior chamber and vitreous body and hyperintense acute reperfusion marker noted on fluid-attenuated inversion recovery. Results- Overall, 24 acute lacunar infarction patients (median age 64.5 years; interquartile range, 54-78 years) were included. On contrast-enhanced fluid-attenuated inversion recovery, GLOS was observed in 11 (45.8%) patients: in 4 (16.7%) in the anterior chamber only and in 7 (29.2%) in the anterior chamber and vitreous body. In all patients, GLOS was bilateral and symmetrical. In patients with GLOS in the anterior chamber only, the time between initial and follow-up magnetic resonance imaging was significantly shorter (7.5 [interquartile range, 4.25-11.5] hours) compared with patients with GLOS in the anterior chamber and vitreous body (28 [interquartile range, 10-43] hours; P=0.047). Hyperintense acute reperfusion marker could not be demonstrated in any of the patients. Conclusions- In acute lacunar infarction patients, unlike hyperintense acute reperfusion marker, GLOS is a frequent finding and shows a similar temporal evolution like in larger ischemic stroke.

Hyperintense Acute Reperfusion Marker after Intravenous Thrombolysisin a Patient with Hyperacute Ischemic Stroke

Hyperintense Acute Reperfusion Marker after Intravenous Thrombolysisin a Patient with Hyperacute Ischemic Stroke

Targeting Reperfusion Injury in the Age of Mechanical Thrombectomy.

Pharmacological recanalization with r-tPA (recombinant tissue-type plasminogen activator) has been the mainstay for acute ischemic stroke (IS) treatment.1 Recent randomized controlled trials have additionally demonstrated the efficacy of mechanical thrombectomy (MT).2–4 Although the restoration of blood flow is a major goal in acute treatment, if this occurs too late, worse damage can ensue, compared with no revascularization.5 This worsening results because of the generation of excess reactive oxygen species (ROS) which leads to direct cellular damage and indirect damage through the triggering of inflammation. Inflammation causes the generation of damaging immune mediators, effector molecules, and more ROS.6 ROS can also lead to apoptosis/necrosis via DNA/RNA damage and lipid peroxidation. This cycle is known as reperfusion injury (R/I; Figure). Experimental studies have shown that durations of >2- to 3-hours transient middle cerebral artery occlusion (tMCAO) lead to worsened injury compared with permanent MCAO.7 At the clinical level, delayed revascularization can sometimes lead to worsened outcomes.8 Hyperintense acute reperfusion marker seen on magnetic resonance imaging in some patients with stroke has been associated with hemorrhagic transformation (HTf) and clinical worsening, suggesting the existence of R/I in humans.9 Hence, adjunctive treatments to recanalization to target R/I has the potential to improve current outcomes while reducing complications of r-tPA. Figure. Reperfusion injury is thought to occur when a sudden influx of oxygenated blood introduces reactive oxygen species (ROS) into critically damaged ischemic brain. Ischemically damaged mitochondria become unable to efficiently neutralize ROS. Elevated ROS can directly damage DNA, RNA, and cause lipid peroxidation. ROS lead to immune cell activation, including brain resident microglia. Ischemic brain may also elaborate damage-associated molecular patterns (DAMPs) that act on Toll-like receptors (TLR) present on the surface of microglia. TLR activation triggers immune …

Role of Hyperintense Acute Reperfusion Marker for Classifying the Stroke Etiology.

The hyperintense acute reperfusion marker (HARM) is a delayed enhancement of the subarachnoid or subpial space observed on post-contrast fluid-attenuated inversion recovery (FLAIR) images and is associated with permeability changes to the blood-brain barrier in acute stroke. We investigated the relationship between HARM and stroke etiology based on the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification. In addition, we evaluated the relationship between HARM and stroke locations with respect to vascular territories and anatomic compartments. We recruited 264 consecutive patients (109 women; mean age 68.63 years) who were diagnosed with acute ischemic stroke and underwent brain magnetic resonance imaging (MRI) including post-contrast FLAIR and DWI within 7 days of symptom onset from May 2015 to March 2016 for this retrospective study. Post-contrast FLAIR images were obtained 5 min after gadolinium administration. The mean time interval between the onset of stroke symptoms and MRI acquisition in total included patients was 18 h and 7 min (median 12 h and 57 min, range 2-127 h). We analyzed the overall incidence and distribution patterns of HARM in acute ischemic stroke cases and compared the relative incidence and distribution patterns of HARM between the subgroups of stroke etiology based on conventional TOAST classification. We obtained odds ratio (OR) of HARM in different stroke locations based on vascular territories and anatomical compartments. This study was approved by our institutional review board. Among the 264 patients, 67 (25.38%) patients were HARM positive and 197 (74.62%) patients were HARM negative. There was significant difference in HARM incidence among the stroke subgroups (p < 0.001). Small vessel occlusion (SVO) was associated with the HARM-negative group (p < 0.001), while large artery atherosclerosis (LAA) and cardioembolism (CE) were associated with the HARM-positive group (p = 0.001). Also, regional pattern of HARM on the same vascular territory as the acute infarction was dominantly demonstrated regardless of stroke etiology. The OR for HARM from middle cerebral artery (MCA) infarction was 1.868 [95% confidence interval (CI): 1.025-3.401]. The OR for HARM from cortical infarction was 9.475 (95% CI: 4.754-18.883) compared to other anatomic compartments. The presence of the HARM was significantly associated with embolic infarctions including LAA and CE. Conversely, SVO was exclusively associated with the absence of the HARM. Second, MCA and cortical infarction showed a more pronounced HARM compared to infarctions at other vascular territories and anatomic compartments. According to the results in the current study, we speculate that the presence of HARM on post-contrast FLAIR images was associated with specific stroke causes especially in embolic causes.

Subacute endovascular recanalization of symptomatic cerebral artery occlusion: a propensity score-matched analysis

BackgroundThe interval between the onset of cerebral vessel occlusion and recanalization has been shown to be an independent predictor of poor outcomes. However, endovascular recanalization of symptomatic cerebral vessel occlusion...