Balloon neck-plasty to create a wide-necked aneurysm in the elastase-induced rabbit model.

PURPOSE: The elastase-induced aneurysm (EIA) model in rabbits has been proposed for translational research; however, the adjustment of aneurysm neck size remains challenging. In this study, the technical feasibility and safety of balloon neck-plasty to create a wide-necked aneurysm in rabbit EIA model were investigated. METHODS: Male New Zealand White rabbits (N = 15) were randomly assigned to three groups: group A, EIA creation without neck-plasty; group B, neck-plasty immediately after EIA creation; group C, neck-plasty 4 weeks after EIA creation. The diameter of balloon used for neck-plasty was determined 1 mm larger than origin carotid artery diameter. All rabbits were euthanized 4 weeks after their final surgery. Aneurysm neck, height, dome-to-neck (D/N) ratio, and histologic parameters were compared among the groups. RESULTS: Aneurysm creation was technically successful in 14 out of 15 rabbits (93.3%), with one rabbit experiencing mortality due to an adverse anesthetic event during the surgery. Saccular and wide-necked aneurysms were successfully created in all rabbits. Aneurysm neck was significantly greater in groups B and C compared to group A (all P < .05). D/N ratio was significantly lower in groups B and C compared to group A (all P < .05). Additionally, tunica media thickness, vessel area, and luminal area were significantly greater in groups B and C compared to group A (all P < .05). These variables were found to be significantly greater in group B compared to group C (all P < .05). CONCLUSION: The creation of a wide-necked aneurysm using balloon neck-plasty after elastase induction in rabbits has been determined to be technically feasible and safe.

Early Response to Endovascular Thrombectomy after Stroke: Early, Late, and Very Late Time Windows.

BACKGROUND AND PURPOSE: Endovascular thrombectomy (EVT) has benefits in selected patients 6-24 h after stroke onset. However, the response to EVT >24 h after stroke onset is still unclear. We compared the early response to EVT in patients with different time windows. METHODS: Patients who underwent EVT in an emergency setting were enrolled and categorized according to when EVT was performed: within 6 (early), 6-24 (late), and >24 h (very late) after stroke onset. Early neurological improvement (ENI) and deterioration (END) were defined as improvement and worsening, respectively, of National Institutes of Health Stroke Scale (NIHSS) score by ≥4 points after EVT. The three groups' clinical characteristics and response to EVT were compared. We also investigated factors associated with ENI and END. RESULTS: During study period, 274 patients underwent EVT (109 early, 104 late, and 61 very late). Patients who underwent EVT very late were younger (p = 0.007), had smaller ischemic cores, and had lower initial NIHSS scores (8 ± 5) than those who underwent EVT early (14 ± 6) and late (13 ± 7; p < 0.001). Stroke mechanisms also differed according to the time window (p < 0.001): cardioembolism was more common after early EVT, whereas large-artery atherosclerosis was more prevalent among patients who underwent EVT very late. ENI was significantly more common after early (60.6%) and late EVT (51.0%) than after very late EVT (29.5%; p = 0.001); however, rates of END did not differ (11.0%, 13.5%, and 4.9%, respectively). ENI was independently associated with male, higher NIHSS score, and early and late EVT. END was associated with failure of recanalization. CONCLUSIONS: ENI was more observed and associated with early and late EVT. Highly selected patients receiving very late EVT may not benefit from ENI but may still have a chance to prevent END. The occurrence of END was associated not with time window but with failure of recanalization.

In-stent restenosis and stented-territory infarction after carotid and vertebrobasilar artery stenting.

BACKGROUND: Prognosis after vertebrobasilar stenting (VBS) may differ from that after carotid artery stenting (CAS). Here, we directly compared the incidence and predictors of in-stent restenosis and stented-territory infarction after VBS and compared them with those of CAS. METHODS: We enrolled patients who underwent VBS or CAS. Clinical variables and procedure-related factors were obtained. During the 3 years of follow-up, in-stent restenosis and infarction were investigated in each group. In-stent restenosis was defined as reduction in the lumen diameter > 50% compared with that after stenting. Factors associated with the occurrence of in-stent restenosis and stented-territory infarction in VBS and CAS were compared. RESULTS: Among 417 stent insertions (93 VBS and 324 CAS), there was no statistical difference in in-stent restenosis between VBS and CAS (12.9% vs. 6.8%, P = 0.092). However, stented-territory infarction was more frequently observed in VBS than in CAS (22.6% vs. 10.8%; P = 0.006), especially a month after stent insertion. HbA1c level, clopidogrel resistance, and multiple stents in VBS and young age in CAS increased the risk of in-stent restenosis. Diabetes (3.82 [1.24-11.7]) and multiple stents (22.4 [2.4-206.4]) were associated with stented-territory infarction in VBS. However, in-stent restenosis (odds ratio: 15.1, 95% confidence interval: 3.17-72.2) was associated with stented-territory infarction in CAS. CONCLUSIONS: Stented-territory infarction occurred more frequently in VBS, especially after the periprocedural period. In-stent restenosis was associated with stented-territory infarction after CAS, but not in VBS. The mechanism of stented-territory infarction after VBS may be different from that after CAS.

Posttraumatic Growth Inventory-Expanded: Factor Structure, Test-Retest Reliability, and Validity in Trauma-Exposed and Bereaved Adults.

Posttraumatic growth (PTG) is a positive psychological change experienced after trauma and it has gained global recognition in recent years. The present study aimed to validate a South Korean version of the Posttraumatic Growth Inventory-Expanded (K-PTGI-X) for use with trauma-exposed and bereaved samples. A national sample comprising South Korean adults was used for the analysis. As a result, the 4-factor bi-factor model was best supported in both the trauma and bereaved groups in terms of personal strength, new possibilities, spiritual-existential change, and being able to relate to others. Additionally, the K-PTGI-X showed satisfying reliability, concurrent validity, and discriminant validity. Lastly, regarding the group differences, women showed higher rates of PTG than men and the bereaved group exhibited higher spiritual and existential growth in the PTG than the trauma group. Given these results, implications for adaptation in various fields when assessing and encouraging PTG in practical settings are discussed.

Clinical-Diffusion Mismatch Is Associated with Early Neurological Improvement after Late-Window Endovascular Treatment.

BACKGROUND: Clinical-diffusion mismatch (CDM) and perfusion-diffusion mismatch (PDM) are used to select patients for endovascular thrombectomy (EVT) in the late-window period. As CDM well reflects true penumbra, we hypothesized that patients with CDM and PDM would respond better to EVT than those with PDM only at the late-window period. METHODS: Acute ischemic stroke patients who received EVT 6-24 h after stroke onset were included. PDM (perfusion-/diffusion-weighted image (DWI) lesion volume >1.8) was used to select candidates for EVT in this time-period in our center. CDM was defined according to the DAWN trial criteria. Response to EVT was compared between patients with and without CDM. Early neurological improvement (ENI) was defined as improvement >4 points on National Institutes of Health Stroke Scale (NIHSS) score 1 day after EVT. Multivariable analysis was performed to investigate independent factors associated with ENI. The correlation between DWI lesion volume and NIHSS score was investigated in those with and without CDM. RESULTS: Among 94 patients enrolled, all patients had PDM and 44 (46.3%) had CDM. Forty-eight patients (51.1%) showed ENI. The prevalence of hypertension, initial NIHSS score, improvement in NIHSS score after EVT, and prevalence of ENI were greater in patients with CDM than those without. ENI was independently associated with onset-to-door time (odds ratio [95% confidence interval]: 0.998 [0.997-1.000]; p = 0.042), complete recanalization (23.912 [2.238-255.489]; p = 0.009), initial NIHSS score (1.180 [1.012-1.377]; p = 0.034), and the presence of CDM (5.160 [1.448-18.386]; p = 0.011). The correlation between DWI lesion volume and initial NIHSS score was strong in patients without CDM (r = 0.731) but only moderate in patients with CDM (r = 0.355). CONCLUSION: Patients with both CDM and PDM had a better response to late-window EVT than those with PDM only.

High serum total cholesterol associated with good outcome in endovascular thrombectomy for acute large artery occlusion.

BACKGROUND: The effect of cholesterol on the functional outcome after endovascular thrombectomy (EVT) is still controversial. This study aimed to investigate whether the lipid profile is associated with the EVT prognosis. METHODS: We retrospectively analyzed patients with emergent large vessel occlusion who underwent EVT. The blood lipid levels were measured in the fasting state, 1 day after admission. We divided patients into terciles of serum total cholesterol (TC) levels and compared the clinical characteristics among the groups. The factors associated with a good outcome at 3 months (modified Rankin scale 0-2) were investigated, considering the stroke mechanism and recanalization status. RESULTS: Among 274 patients, good outcomes were observed in 108 (39.4%) patients. Low initial severity (odds ratio (OR), 0.91, 95% confidence interval (CI), 0.858-0.954; p < 0.001) and high TC level (1.35, 1.034-1.758; p = 0.041) were associated with good outcomes. In patients with cardioembolism, young age (0.95, 0.915-0.991; p = 0.021), low initial severity (0.92, 0.857-0.988; p = 0.024), and high TC level (1.60, 1.019-2.499; p = 0.036) were associated with good outcomes. The lipid profile was not associated with a functional outcome in those with large artery atherosclerosis. In patients with complete recanalization, young age (0.97, 0.941-0.994; p = 0.016), low initial severity (0.91, 0.864-0.961; p = 0.001), absence of diabetes (0.45, 0.218-0.947; p = 0.035) or any hemorrhage (0.33, 0.142-0.760; p = 0.009), and high TC level (1.40, 1.031-1.879; p = 0.031) were associated with good outcomes. CONCLUSIONS: A high TC level was associated with favorable outcomes after EVT, especially in patients with cardioembolism and complete recanalization.

Development and Validation of the Self-Rating Suicide Risk Screening Questionnaire.

Since suicide is one of the major health problems worldwide, the goal of the present study is to develop a psychometrically sound suicide risk screening tool named Suicide Screening Questionnaire- Self-Rating (SSQ-SR) to quantify the risk of suicidal behavior. The development process includes item generation, item revision and refinement, and validation. A total sample of 2,238 adults in South Korea was used for analysis. The results of factor analysis showed that the SSQ-SR, containing 25 items, supported a three-factor model: "Situational factors," "Negative self-perceptions and mental health factors," and "Suicidal thoughts and behaviors." Also, SSQ-SR showed satisfying internal consistency, concurrent validity and discriminant validity. Lastly, the results of ROC analysis showed a cut-off point of 33.5 for the low-risk group and 36.5 for the high-risk group. Considering these results, the current results demonstrate the SSQ-SR is a valid scale and therefore can contribute to future suicide-related studies and prevention.

Feasibility of low-dose digital subtraction angiography protocols for the endovascular treatment of intracranial dural arteriovenous fistulas.

BACKGROUND: Among neurointerventional procedures, the embolization of complex shunt lesions usually requires more radiation dose. We aimed to evaluate the procedural outcome and safety in using low-dose DSA protocols for intracranial dural arteriovenous fistula (AVF) embolization treatment. METHODS: Between January 2014 and July 2018, 55 patients with dural AVFs who underwent endovascular treatment were included in the study. The low-dose group (n = 27) included from January 2016 used various low-dose DSA protocols made by modifying the thickness of the copper filter or the detector entrance dose. We compared radiation dose metrics, such as air-kerma, kerma-air product (KAP), and fluoroscopy time, as well as clinical and imaging outcomes with the conventional-dose group (n = 28) included before January 2016. RESULTS: The total KAP was 40.1% lower in the low-dose group (87.9 vs. 146.7 Gy cm2, p = 0.002). The average number of DSA runs (25.1 vs. 25.5, p = 0.86) and fluoroscopy times (77.4 vs. 69.7 min, p = 0.48) were similar between the groups. An immediate favorable occlusion rate (total or near total occlusion) was achieved in 41 (74.5%) patients. Ten patients (18.2%) underwent additional procedures due to residual (n = 6) and/or recurrent (n = 5) lesions. At a median of 10 months follow-up, 45 patients (86.5%) had achieved favorable occlusion. Treatment outcomes showed no significant between-group differences. There was one case (1.8%) of procedure-related complications in the low-dose group. All but one patient showed favorable clinical outcomes (modified Rankin score ≤ 2). CONCLUSION: The low-dose protocols were feasible by showing significant radiation dose reduction and acceptable procedural outcome.

Reliability of fast magnetic resonance imaging for acute ischemic stroke patients using a 1.5-T scanner.

OBJECTIVES: To determine whether fast scanned MRI using a 1.5-T scanner is a reliable method for the detection and characterization of acute ischemic stroke in comparison with conventional MRI. METHODS: From May 2015 to June 2016, 862 patients (FLAIR, n = 482; GRE, n = 380; MRA, n = 190) were prospectively enrolled in the study, with informed consent and under institutional review board approval. The patients underwent both fast (EPI-FLAIR, ETL-FLAIR, TR-FLAIR, EPI-GRE, parallel-GRE, fast CE-MRA) and conventional MRI (FLAIR, GRE, time-of-flight MRA, fast CE-MRA). Two neuroradiologists independently assessed agreements in acute and chronic ischemic hyperintensity, hyperintense vessels (FLAIR), microbleeds, susceptibility vessel signs, hemorrhagic transformation (GRE), stenosis (MRA), and image quality (all MRI), between fast and conventional MRI. Agreements between fast and conventional MRI were evaluated by generalized estimating equations. Z-scores were used for comparisons of the percentage agreement among fast FLAIR sequences and fast GRE sequences and between conventional and fast MRA. RESULTS: Agreements of more than 80% were achieved between fast and conventional MRI (ETL-FLAIR, 96%; TR-FLAIR, 97%; EPI-GRE, 96%; parallel-GRE, 98%; fast CE-MRA, 86%). ETL- and TR-FLAIR were significantly superior to EPI-FLAIR in the detection of acute ischemic hyperintensity and hyperintense vessels, while parallel-GRE was significantly superior to EPI-GRE in the detection of susceptibility vessel sign (p value < 0.05 for all). There were no significant differences in the other scores and image qualities (p value > 0.05). CONCLUSIONS: Fast MRI at 1.5 T is a reliable method for the detection and characterization of acute ischemic stroke in comparison with conventional MRI. KEY POINTS: • Fast MRI at 1.5 T may achieve a high intermethod reliability in the detection and characterization of acute ischemic stroke with a reduction in scan time in comparison with conventional MRI.

Estimated radiation dose according to the craniocaudal angle in cerebral digital subtraction angiography: Patient and phantom study.

BACKGROUND AND PURPOSE: Routine use of cranial angulation with 15-20 degrees, craniocaudal angled (CC) view, for cerebral digital subtraction angiography (DSA) helps minimize bone subtraction artifacts with less overlapping of the vessels, however, it may increase the radiation dose. We designed the phantom and patient studies to determine the effect of the angulation to the radiation dose and the feasibility of true posteroanterior angled (PA) view, in cerebral DSA. MATERIALS AND METHODS: In the phantom study, frontal DSA was simulated with variable angulations. In the patient study with thirty-one subjects, one internal carotid arteriogram was obtained with the CC view and the other, PA view in every patient. The dose-area product (DAP) and reference air-kerma (AK) were measured and compared between the angles. A qualitative analysis was performed to assess the diagnostic performance of the DSA over the angles. RESULTS: The phantom study confirmed that the greater craniocaudal angles caused higher radiation exposure. Especially, the radiation dose (AK) of the CC view was 5.4% higher than that of the PA view. In the patient study, the radiation dose of the PA view was significantly lower compared to the CC view (1.44 vs. 1.63 mGy, AK). In 4 patients, the dose particularly jumped when applying the CC view as the copper filter was automatically removed. The diagnostic ability of the DSA with the PA view tended to be higher without significance. CONCLUSIONS: In a daily routine cerebral angiography, a simple modification of the angle may help to minimize the radiation dose.

Comparison of 3D magnetic resonance imaging and digital subtraction angiography for intracranial artery stenosis.

OBJECTIVES: To compare three-dimensional high-resolution magnetic resonance imaging (3D HR-MRI) and digital subtraction angiography (DSA) for diagnosing and evaluating stenosis in the entire circle of Willis. METHODS: The study included 516 intracranial arteries from 43 patients with intracranial artery stenosis (ICAS) who underwent both 3D HR-MRI and DSA within 1 month. Two readers independently diagnosed atherosclerosis, dissection, moyamoya disease and vasculitis, rated their diagnostic confidence for each vessel and measured the luminal diameters. Reference standard was made from clinico-radiologic diagnosis. Diagnostic accuracy, diagnostic confidence, the degree of stenosis and luminal diameter were assessed and compared between both modalities. RESULTS: For atherosclerosis, 3D HR-MRI showed better diagnostic accuracy (P = .03-.003), sensitivity (P = .006-.01) and positive predictive value (P ≤ .001-.006) compared to DSA. Overall, the readers were more confident of their diagnosis of ICAS when using 3D HR-MRI (reader 1, P ≤ .001-.007; reader 2, P ≤ .001-.015). 3D HR-MRI showed similar degree of stenosis (P > .05) and higher luminal diameter (P < .05) compared to DSA. CONCLUSIONS: 3D HR-MRI might be useful to evaluate atherosclerosis, with better diagnostic confidence and comparable stenosis measurement compared to DSA in the entire circle of Willis. KEY POINTS: • 3D HR-MRI showed better diagnostic accuracy for atherosclerosiscompared to DSA • 3D HR-MRI showed better overall diagnostic confidence for stenosiscompared to DSA • 3D HR-MRI and DSA showed similar degree of stenosis.

Multi-Contrast High-Resolution Magnetic Resonance Findings of Spontaneous and Unruptured Intracranial Vertebral Artery Dissection: Qualitative and Quantitative Analysis According to Stages.

BACKGROUND: Although high-resolution magnetic resonance imaging (HR-MRI) has been used as a strong imaging method for diagnosing intracranial vertebral artery dissection (IVAD), the diagnosis is sometimes challenging because a dissection has geometric changes in the natural course. The radiologic features may change or disappear over time, which makes the diagnosis confusing. Our study was to present radiological findings according to the stages in spontaneous and unruptured, IVAD on 3T HR-MRI and to guide the age estimation of IVAD with the distinguishing findings according to the stages. METHODS: From January 2011 to July 2014, the 41 vertebral arteries (M:F = 18:12; age range 32-67 years) were retrospectively enrolled. Spontaneous, unruptured IVAD was diagnosed if it had a clear onset based on clinical and radiological findings. The stages were classified as acute (0-3 days), early subacute (3-10 days), late subacute (10-60 days) and chronic stage (>60 days; recovery and non-recovery groups) according to the time intervals from symptom onset, based on the prior published studies. HR-MR findings were assessed and compared in the intimal flap, double lumen, aneurysmal dilatation (maximal outer diameter, maximal wall thickness, wall thickness index and remodeling index), intramural hematoma (relative signal intensity) and vessel wall enhancement according to the stages with qualitative and quantitative methods. Two radiologists analyzed the HR-MR findings with consensus reading. RESULTS: IVAD was classified into acute (n = 6), early subacute (n = 8), late subacute (n = 16) and chronic (n = 11) stages. HR-MR dissection findings such as intimal flap, double lumen, aneurysmal dilatation and intramural hematoma significantly decreased from the earlier stages to the chronic stage (p < 0.05). The quantitative indices in aneurysmal dilatation and the relative signal intensity of intramural hematoma showed significant higher values in the earlier stages followed by a significant decrease in the chronic stage recovery group (p < 0.05). The degree of vessel wall enhancement was higher in the earlier stage and decreased in the chronic stage (p < 0.05), but mild vessel wall enhancement was identified 900 days after symptom onset. CONCLUSION: The 3T HR-MRI reveals the vessel wall characteristics and provides distinguishing findings between earlier stages and the chronic stage in spontaneous and unruptured IVAD. Characterization of these radiological findings according to stages may assist with the age estimation of the dissection and may help to understand IVAD as a whole.

Branching patterns determine the size of single subcortical infarctions.

BACKGROUND AND PURPOSE: The size variation of single subcortical infarcts (SSIs) may be because of differences in stroke mechanisms or branching patterns of perforators. We aim to investigate this issue using high-resolution MRI. METHODS: Patients with high-resolution MRI-identified SSI without significant (≥50%) middle cerebral artery stenosis were enrolled. Perforator stems were defined as perforators originating from the middle cerebral artery and perforator branches as linear structures inside the infarcted area, traceable from >2 adjacent slices. The branching index was calculated as the number of perforator branches divided by the number of perforator stems. Clinical and imaging characteristics were compared between large (≥20 mm in diameter) and small SSI groups. RESULTS: Forty-one patients (10 large and 31 small SSIs) were enrolled. Larger SSIs were more closely associated with diabetes mellitus and severe neurological dysfunction but not with the presence of middle cerebral artery plaque. Although there was no difference in the number of perforator stems, the number of perforator branches (4.8±2.2 versus 2.3±1.4; P=0.005) and branching index (2.9±1.0 versus 1.2±0.8; P<0.001) was higher in the large SSI group. SSI diameter showed a significant correlation with the number of perforator branches (r=0.630; P<0.001) and branching index (r=0.750; P<0.001). CONCLUSIONS: SSI diameter seems to be associated with anatomic branching variation rather than the mechanism of stroke. Definition of small vessel disease with lesion diameter criteria may not be appropriate.

Clinical outcomes of carotid endarterectomy in patients with carotid artery tandem lesions.

BACKGROUND AND PURPOSE: When carotid artery tandem lesions are present, the benefits of carotid endarterectomy (CEA) to reduce recurrent stroke remain uncertain. The present retrospective cohort study aimed to determine the clinical outcomes of CEA for carotid artery tandem stenosis that was diagnosed by contrast-enhanced magnetic resonance angiography. METHODS: Six hundred forty-seven consecutive patients underwent CEA between January 2001 and December 2010. Tandem stenosis, defined as a significant carotid bifurcation stenosis and identifiable stenosis of ≥50% of any downstream distal cerebral artery, was identified in 92 patients (14.2%) by contrast-enhanced magnetic resonance angiography. Patients with and without tandem stenosis were compared in terms of CEA outcomes. The primary end point was the composite of any stroke, myocardial infarction, or death during the periprocedural period or ipsilateral stroke within 4 years after CEA. RESULTS: Tandem stenosis did not associate with ipsilateral stroke during postoperative follow-up. The 2 groups did not differ in terms of estimated 4-year primary end point rates (8.7% versus 3.8%; P=0.07) or ipsilateral stroke-free (P=0.56), any stroke-free (P=0.89), or overall survival (P=0.41) rates. CONCLUSIONS: After diagnosis by contrast-enhanced magnetic resonance angiography, patients with and without tandem stenosis had similar rates of stroke and death.

Diffusion-weighted image and fluid-attenuated inversion recovery image mismatch: unclear-onset versus clear-onset stroke.

BACKGROUND AND PURPOSE: Mismatch in lesion visibility between diffusion-weighted image and fluid-attenuated inversion recovery image (DWI-FLAIR mismatch) has been proposed as a biomarker for the estimation of ischemic lesion age. The actual onset in some patients with unclear-onset stroke (UnCOS) may be close to the first-found abnormal time. We hypothesized that patients with UnCOS within a particular time window might have a similar DWI-FLAIR mismatch profile with patients with clear-onset stroke (COS). METHODS: Patients who underwent MRI within 6 hours from first-found abnormal time were recruited retrospectively. Clinical characteristics and the proportion of DWI-FLAIR and perfusion-weighted image-DWI mismatch in each time window were compared between UnCOS and COS. RESULTS: The final analysis included 259 patients (114 with UnCOS and 145 with COS). Patients with UnCOS were older and had more severe stroke at baseline. Risk factors, stroke subtypes, and perfusion-weighted image-DWI mismatch did not differ between the 2 groups. The proportion of patients with DWI-FLAIR mismatch in UnCOS did not differ from COS within 2 hours of first-found abnormal time (50.0% versus 51.5%; P=0.92), but it was significantly lower in UnCOS than in COS at 2 to 3 hours (16.1% versus 44.4%; P=0.02), 3 to 4 hours (13.8% versus 36.4%; P=0.04), and 4 to 5 hours (5.6% versus 29.6%; P=0.05). CONCLUSIONS: The proportion of DWI-FLAIR mismatch in UnCOS within the first 2 hours from first-found abnormal time was similar with COS, but it sharply decreased beyond 2 hours. These data suggest that patients with UnCOS within 2 hours of symptom detection may be good candidates for multimodal imaging-based thrombolysis.

Reperfusion injury on magnetic resonance imaging after carotid revascularization.

BACKGROUND AND PURPOSE: Reperfusion injury can be revealed as delayed gadolinium enhancement in the subarachnoid space on a fluid-attenuated inversion recovery image, which is designated as a hyperintense acute reperfusion marker (HARM). We sought to investigate the occurrence and predictors of HARM and its association with new ischemic infarcts after carotid revascularization. METHODS: Forty-five patients who underwent carotid endarterectomy or stenting were prospectively enrolled. Diffusion-weighted imaging and fluid-attenuated inversion recovery were performed before and 24 hours after the procedures. Postprocedural fluid-attenuated inversion recovery was done after intravenous gadolinium injection. RESULTS: HARM was observed in 8 (17.8%) patients. Of these, 4 patients showed neurological deterioration associated with HARM. These symptomatic HARMs disappeared on follow-up magnetic resonance imaging. Patients with symptomatic HARM were older (P=0.010) and had more frequent leukoaraiosis (P=0.012) and higher postprocedural systolic blood pressure (P=0.025) than those without. New brain infarcts on postprocedural diffusion-weighted imaging were identified in 13 (28.9%) patients. HARM was not associated with new infarcts. CONCLUSIONS: HARM after carotid revascularization is not uncommon. Symptomatic HARM was associated with old age, underlying leukoaraiosis, and postprocedural high blood pressure.

Color-coded fluid-attenuated inversion recovery images improve inter-rater reliability of fluid-attenuated inversion recovery signal changes within acute diffusion-weighted image lesions.

BACKGROUND AND PURPOSE: Diffusion-weighted image fluid-attenuated inversion recovery (FLAIR) mismatch has been considered to represent ischemic lesion age. However, the inter-rater agreement of diffusion-weighted image FLAIR mismatch is low. We hypothesized that color-coded images would increase its inter-rater agreement. METHODS: Patients with ischemic stroke <24 hours of a clear onset were retrospectively studied. FLAIR signal change was rated as negative, subtle, or obvious on conventional and color-coded FLAIR images based on visual inspection. Inter-rater agreement was evaluated using κ and percent agreement. The predictive value of diffusion-weighted image FLAIR mismatch for identification of patients <4.5 hours of symptom onset was evaluated. RESULTS: One hundred and thirteen patients were enrolled. The inter-rater agreement of FLAIR signal change improved from 69.9% (k=0.538) with conventional images to 85.8% (k=0.754) with color-coded images (P=0.004). Discrepantly rated patients on conventional, but not on color-coded images, had a higher prevalence of cardioembolic stroke (P=0.02) and cortical infarction (P=0.04). The positive predictive value for patients <4.5 hours of onset was 85.3% and 71.9% with conventional and 95.7% and 82.1% with color-coded images, by each rater. CONCLUSIONS: Color-coded FLAIR images increased the inter-rater agreement of diffusion-weighted image FLAIR recovery mismatch and may ultimately help identify unknown-onset stroke patients appropriate for thrombolysis.

Negative pressure pulmonary edema after general anesthesia using the i-gel.

Negative pressure pulmonary edema (NPPE) is a rare complication that occurs mainly after tracheal extubation. We report a case of postoperative NPPE associated with the use of the i-gel. A 28-year-old woman was scheduled for an emergency right axillary sentinel lymph node excision. During emergence, the patient experienced a sudden onset of airway obstruction, and spontaneous ventilation through the i-gel was impossible. Pink and frothy secretions were noted in the i-gel and the patient's oral cavity. Positive airway pressure with 100% oxygen was applied using a facemask, and the patient was subsequently treated with high-flow oxygen therapy. In this case, laryngospasm or displacement of the i-gel was believed to be the cause of airway obstruction. We recognized that NPPE is likely to occur regardless of the airway device, and the use of the i-gel cannot completely eliminate the possibility of NPPE occurrence.

Facilitated Retrograde Access via the Facial Vein for Transvenous Embolization of the Cavernous Sinus Dural Arteriovenous Fistula with Isolated Ophthalmic Venous Drainage.

Management of cavernous sinus dural arteriovenous fistula (CSDAVF) continues to present significant challenges, particularly when the inferior petrosal sinus is thrombosed, collapsed, or angiographically invisible. In this study, we introduce facilitated retrograde access via the facial vein, which is employed in the transvenous embolization of CSDAVF with isolated superior ophthalmic venous drainage. We also present illustrative cases and technical points.

In Vitro Head-to-Head Comparison of Flow Reduction between Fibered and Non-Fibered Pushable Coils.

PURPOSE: To compare the embolization effects of a non-fibered pushable coil with a conventional fibered pushable coil in an in vitro bench-top experiment. MATERIALS AND METHODS: A simplified vascular phantom with 4 channels (1 for the non-fibered coil, 1 for the fibered coil, and 2 for continuous circuit flow) was used. A single coil of the longest length was inserted to evaluate the effect of single-coil embolization, and 3 consecutive coils were inserted to assess the effect of multiple-coil embolization. Post-embolization angiography was performed to obtain flow variables (time to peak [TTP], relative peak intensity [rPI], and angiographic flow reduction score [AFRS]) from time density curves. The packing densities of the two coil types were calculated, and the AFRS of each channel was determined by dividing the TTP by the rPI. RESULTS: When inserting a single coil, the conventional fibered coil demonstrated better flow reduction, as indicated by a higher AFRS (25.6 vs. 17.4, P=0.034). However, the non-fibered coil exhibited a significantly higher packing density (12.9 vs. 2.4, P=0.001). Similar trends were observed with multiple coils. CONCLUSION: The conventional fibered pushable coil showed better flow reduction efficiency, while the non-fibered pushable coil had a higher packing density, likely due to the flexibility of the coil loops. A better understanding of the distinct characteristics of different pushable coils can enhance the outcomes of various vascular embolization.