Purpose
Intracranial hemorrhage (ICH) is a potentially severe complication after mechanical thrombectomy (MT). Here, we investigated risk factors for the occurrence of any and symptomatic ICH after ...MT due to large-vessel occlusion of the anterior circulation.
Methods
Consecutive patients with acute ischemic anterior circulation stroke with large-vessel occlusion undergoing MT were analyzed. ICH was categorized according to the Heidelberg Bleeding Classification. Forty-three procedural and clinical parameters were analyzed using univariate tests and multivariate logistic regressions.
Results
Of 612 patients, any ICH was detected in 195 (31.9%), while 27 (4.4%) developed a symptomatic ICH. Infarct size > 1/3 of vascular territory in control imaging (OR 2.18, 95% CI 1.45–3.21), higher serum glucose levels (OR 1.23 for change of 15 units mg/dL, 95% CI 1.10–1.39), and higher thrombectomy maneuver count (OR 1.21, 95% CI 1.11–1.32) were significantly associated with a higher risk of developing any ICH compared to no ICH. Wake-up strokes (OR 3.99, 95% CI 1.38–11.60), transfer from an external clinic (OR 3.04, 95% CI 1.24–7.48), and higher serum glucose levels (OR 1.22 for change of 15 units mg/dL, 95% CI 1.05–1.42) were revealed as independent risk factors for development of symptomatic ICH compared to no symptomatic ICH. Patients with no infarct demarcation (OR 0.10, 95% CI 0.01–0.80) and complete recanalization (OR 0.57, 95% CI 0.37–0.86) showed a lower risk of developing any ICH.
Conclusion
Wake-up strokes and patients who are treated within a drip-and-ship concept are especially vulnerable for symptomatic ICH, while complete recanalization, contrary to subtotal recanalization only, was revealed as a protective factor against ICH.
Background:
There is little evidence of endovascular therapy (EVT) being performed in acute ischemic stroke beyond 24 h, and that evidence is limited to anterior circulation stroke.
Objective:
To ...extend evidence of efficacy and safety of EVT after more than 24 h in both anterior and posterior circulation stroke.
Methods:
Local, prospectively collected registries were screened for patients with acute ischemic stroke and large-vessel occlusion who had received either EVT > 24 h after last-seen-well but <24 h after symptom recognition (EVT>24LSW) or EVT > 24 h since first (definitive) symptom recognition (EVT>24DEF). Patients treated <24 h served as a group for comparison. Favorable outcome was defined as modified Rankin scale (mRS) 0–2 or return to prestroke mRS at 3 months.
Results:
Between January 2014 and August 2021, N = 2347 were treated with EVT at our comprehensive stroke center, of whom n = 43 met the inclusion criteria (EVT>24LSW, n = 16, EVT>24DEF, n = 27). EVT>24LSW patients were treated at a median of 28.7 h interquartile range (IQR) = 27.3–32.8 after last-seen-well and 7.3 h (IQR = 2.8–14.3) after symptom recognition; EVT>24DEF patients were treated 52.5 h (IQR = 26.5–94.2) after first symptoms. Favorable outcome was achieved by 23.3% (10/43) in the EVT > 24 compared with 39.4% (886/2250) in the EVT < 24 group (p = 0.04). Bleeding rates were similar across groups. Mortality was also similar EVT > 24, 27.9% (12/43) versus EVT < 24, 25.7% (584/2264), p = 0.727; posterior circulation, EVT > 24, 41.7% (5/12) versus EVT < 24, 36.5% (92/252) p = 0.764.
Conclusion:
In selected patients, EVT seems effective and safe beyond 24 h for both anterior and posterior circulation stroke.
Objectives
Patients with multiple sclerosis (MS) regularly undergo MRI for assessment of disease burden. However, interpretation may be time consuming and prone to intra- and interobserver ...variability. Here, we evaluate the potential of artificial neural networks (ANN) for automated volumetric assessment of MS disease burden and activity on MRI.
Methods
A single-institutional dataset with 334 MS patients (334 MRI exams) was used to develop and train an ANN for automated identification and volumetric segmentation of T2/FLAIR-hyperintense and contrast-enhancing (CE) lesions. Independent testing was performed in a single-institutional longitudinal dataset with 82 patients (266 MRI exams). We evaluated lesion detection performance (F1 scores), lesion segmentation agreement (DICE coefficients), and lesion volume agreement (concordance correlation coefficients CCC). Independent evaluation was performed on the public ISBI-2015 challenge dataset.
Results
The F1 score was maximized in the training set at a detection threshold of 7 mm
3
for T2/FLAIR lesions and 14 mm
3
for CE lesions. In the training set, mean F1 scores were 0.867 for T2/FLAIR lesions and 0.636 for CE lesions, as compared to 0.878 for T2/FLAIR lesions and 0.715 for CE lesions in the test set. Using these thresholds, the ANN yielded mean DICE coefficients of 0.834 and 0.878 for segmentation of T2/FLAIR and CE lesions in the training set (fivefold cross-validation). Corresponding DICE coefficients in the test set were 0.846 for T2/FLAIR lesions and 0.908 for CE lesions, and the CCC was ≥ 0.960 in each dataset.
Conclusions
Our results highlight the capability of ANN for quantitative state-of-the-art assessment of volumetric lesion load on MRI and potentially enable a more accurate assessment of disease burden in patients with MS.
Key Points
• Artificial neural networks (ANN) can accurately detect and segment both T2/FLAIR and contrast-enhancing MS lesions in MRI data.
• Performance of the ANN was consistent in a clinically derived dataset, with patients presenting all possible disease stages in MRI scans acquired from standard clinical routine rather than with high-quality research sequences.
• Computer-aided evaluation of MS with ANN could streamline both clinical and research procedures in the volumetric assessment of MS disease burden as well as in lesion detection
.
Objectives
The clinical utility of electronically derived ASPECTS (e-ASPECTS) to quantify signs of acute ischemic infarction could be demonstrated in multiple studies. Here, we aim to clinically ...validate the impact of CT slice thickness (ST) on the performance of e-ASPECTS software.
Methods
A consecutive series of
n
= 258 patients (06/2016 and 01/2019) with middle cerebral artery occlusion and subsequent treatment with mechanical thrombectomy was analyzed. The e-ASPECTS score and acute infarct volumes were calculated from baseline non-contrast CT with a software using 1-mm slice thickness (ST) (defined as ground truth) and axial reconstructions with 2–10-mm ST and correlated with baseline stroke severity (NIHSS) as well as clinical outcome (mRS) using logistic regressions.
Results
In comparison with the ground truth, significant differences were seen in e-ASPECTS scores with ST > 6 mm (
p
≤ 0.031) and infarct volumes with ST > 4 mm (
p
≤ 0.001). There was a significant correlation of lower e-ASPECTS and higher acute infarct volumes with increasing baseline NIHSS values for all ST (
p
≤ 0.001, respectively), with values derived from 1 mm yielding the highest correlation for both parameters (rho, − 0.38 and 0.31, respectively). Similarly, lower e-ASPECTS and higher acute infarct volumes from all ST were significantly associated with poor outcome after 90 days (
p
≤ 0.05, respectively) with values derived from 1-mm ST yielding the highest effects for both parameters (OR, 0.69 95% CI 0.50–0.88 and 1.27 95% CI 1.10–1.50, respectively).
Conclusions
The e-ASPECTS software generates robust values for e-ASPECTS and acute infarct volumes when using ST ≤ 4 mm with ST = 1 mm yielding the best performance for predicting baseline stroke severity and clinical outcome after 90 days.
Key Points
•
Clinical utility of automatically derived ASPECTS from computed tomography scans was shown in patients with acute ischemic stroke and treatment with mechanical thrombectomy.
•
Thin slices (= 1 mm) had the highest clinical utility in comparison with thicker slices (2–10 mm) by having the strongest correlation with baseline stroke severity and independent effects on clinical outcome after 90 days.
•
Automatically calculated acute infarct volumes possess clinical utility beyond ASPECTS and should be considered in future studies.
Abstract
Swift diagnosis and treatment play a decisive role in the clinical outcome of patients with acute ischemic stroke (AIS), and computer-aided diagnosis (CAD) systems can accelerate the ...underlying diagnostic processes. Here, we developed an artificial neural network (ANN) which allows automated detection of abnormal vessel findings without any a-priori restrictions and in <2 minutes. Pseudo-prospective external validation was performed in consecutive patients with suspected AIS from 4 different hospitals during a 6-month timeframe and demonstrated high sensitivity (≥87%) and negative predictive value (≥93%). Benchmarking against two CE- and FDA-approved software solutions showed significantly higher performance for our ANN with improvements of 25–45% for sensitivity and 4–11% for NPV (
p
≤ 0.003 each). We provide an imaging platform (
https://stroke.neuroAI-HD.org
) for online processing of medical imaging data with the developed ANN, including provisions for data crowdsourcing, which will allow continuous refinements and serve as a blueprint to build robust and generalizable AI algorithms.
Purpose
To determine the radiation exposure in endovascular stroke treatment (EST) of acute basilar artery occlusions (BAO) and compare it with radiation exposure of EST for embolic middle cerebral ...artery occlusions (MCAO).
Methods
In this retrospective analysis of an institutional review board−approved prospective stroke database of a comprehensive stroke center, we focused on radiation exposure (as per dose area product in Gy × cm
2
, median (IQR)), procedure time, and fluoroscopy time (in minutes, median IQR) in patients receiving EST for BAO. Patients who received EST for BAO were matched case by case with patients who received EST for MCAO according to number of thrombectomy attempts, target vessel reperfusion result, and thrombectomy technique.
Results
Overall 180 patients (
n
= 90 in each group) were included in this analysis. General anesthesia was conducted more often during EST of BAO (BAO: 75 (83.3%); MCAO: 18 (31.1%),
p
< 0.001). Procedure time (BAO: 31 (20–43); MCAO: 27 (18–38);
p
value 0.226) and fluoroscopy time (BAO: 29 (20–59); MCAO: 29 (17–49),
p
value 0.317) were comparable. Radiation exposure was significantly higher in patients receiving EST for BAO (BAO: 123.4 (78.7–204.2); MCAO: 94.3 (65.5–163.7),
p
value 0.046), which represents an increase by 23.7%.
Conclusion
Endovascular stroke treatment of basilar artery occlusions is associated with a higher radiation exposure compared with treatment of middle cerebral artery occlusions.
Background and Purpose
To determine reasons for failed recanalization in mechanical thrombectomy (MT) of the posterior circulation.
Methods
Retrospective single center analysis of reasons for MT ...failure in the posterior circulation. Failed MTs were categorized according to the reason for procedure failure in failed vascular access, failed passage of the target vessel occlusion and MT failure after passing the occluded target vessel. Patient characteristics were compared between failed and successful MT.
Results
Patients with failed MT (30/218 patients, 13.8%) were categorized into futile vascular access (13/30, 43.3%), abortive passage of the target vessel occlusion (6/30, 20.0%) and MT failure after passing the vessel occlusion (11/30, 36.7%). In 188/218 (86.2%) successful MTs alternative vascular access, local intra-arterial (i.a.) thrombolysis and emergency stent-assisted PTA prevented 65 MT failures. Patients with failed MT showed a higher NIHSS at discharge, a higher pc-ASPECTS in follow-up imaging, a higher mRS 90 days after stroke onset and a high mortality rate of 77.0% (mRS at 90 days, median (IQR): 6 (6–6) vs. 4 (2–6) for successful MT,
p
-value < 0.001). Co-morbidities and stroke etiology were not different compared to sufficient recanalization with atherosclerotic disease as the leading stroke etiology in both groups.
Conclusion
Failure of MT in posterior circulation ischemic stroke patients is associated with a high mortality rate. Reasons for MT failure are diverse with futile vascular access and MT failure after passing the vessel occlusion as the leading causes. Alternative vascular access, local i.a. thrombolysis and stent-assisted PTA can prevent MT failure.
Background
A major drawback of liquid embolic agents (LEAs) is the generation of imaging artifacts (IA), which may represent a crucial obstacle for the detection of periprocedural hemorrhage or ...subsequent radiosurgery of cerebral arteriovenous malformations (AVMs). This study aimed to compare the IAs of Onyx, Squid and PHIL in a novel three-dimensional in vitro AVM model in conventional computed tomography (CT) and cone-beam CT (CBCT).
Methods
Tubes with different diameters were configured in a container resembling an AVM with an artificial nidus at its center. Subsequently, the AVM models were filled with Onyx 18, Squid 18, PHIL 25% or saline and inserted into an imaging phantom (
n
= 10/LEA). Afterwards CT and CBCT scans were acquired. The degree of IAs was graded quantitatively (Hounsfield units in a defined region of interest) and qualitatively (feasibility of defining the nidus)—Onyx vs. Squid vs. PHIL vs. saline, respectively.
Results
Quantitative density evaluation demonstrated more artifacts for Onyx compared to Squid and PHIL, e.g. 48.15 ± 14.32 HU for Onyx vs. 7.56 ± 1.34 HU for PHIL in CT (
p
< 0.001) and 41.88 ± 7.22 density units (DU) for Squid vs. 35.22 ± 5.84 DU for PHIL in CBCT (
p
= 0.044). Qualitative analysis showed less artifacts for PHIL compared to Onyx and Squid in both imaging modalities while there was no difference between Onyx and Squid regarding the definition of the nidus (
p
> 0.999).
Conclusion
In this novel three-dimensional in vitro AVM model, IAs were higher for the EVOH/tantalum-based LEAs Onyx and Squid compared to iodine-based PHIL. Onyx induced the highest degree of IAs with only minor differences to Squid.
Background and Purpose
Several studies have shown that thrombectomy is safe and effective in occlusions of the M2 segment of the middle cerebral artery. This retrospective study compared superior and ...inferior division occlusions regarding radiological and clinical outcomes.
Methods
Between 2009 and 2017, patients treated with thrombectomy due to occlusion of the superior or inferior division were selected. Univariate and multivariate analyses were performed to identify predictors of outcome and compare superior and inferior division occlusions.
Results
A total of 140 patients with superior (
n
= 87) and inferior (
n
= 53) division occlusion were included. Of patients with inferior division occlusion 66.0% achieved good outcome compared to 48.3% in patients with superior division occlusion (
P
= 0.041). Time from groin puncture to reperfusion, recanalization success, complication rate, hemorrhage rate and follow-up infarct size were similar in both groups. Independent predictors of good outcome were baseline Alberta Stroke Program Early CT Score (ASPECTS) (odds ratio, OR 1.74, 95% confidence interval, CI 1.21–2.58,
P
= 0.004), time from groin puncture to reperfusion (OR 0.99, 95% CI 0.98–1.0,
P
= 0.019) and Thrombolysis In Cerebral Infarction (TICI) score 2b-3 (OR 4.51, 95% CI 1.31–18.74,
P
= 0.024). Superior division occlusion was an independent predictor of poor outcome (OR 2.41, 95% CI 1.05–5.80,
P
= 0.042). Dominance of the occluded vessel and side of occlusion were not predictive.
Conclusion
Patients with superior division occlusion appear to have a lower chance of achieving good outcome despite similar recanalization rates and complication rates compared to inferior division occlusions.
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