Radiomic-based nonlinear supervised learning classifiers on non-contrast CT to predict functional prognosis in patients with spontaneous intracerebral hematoma

PURPOSE

To evaluate if nonlinear supervised learning classifiers based on non-contrast CT can predict functional prognosis at discharge in patients with spontaneous intracerebral hematoma.

METHODS

Retrospective, single-center, observational analysis of patients with a diagnosis of spontaneous intracerebral hematoma confirmed by non-contrast CT between January 2016 and April 2018. Patients with HIE > 18 years and with TCCSC performed within the first 24 h of symptom onset were included. Patients with secondary spontaneous intracerebral hematoma and in whom radiomic variables were not available were excluded. Clinical, demographic and admission variables were collected. Patients were classified according to the Modified Rankin Scale (mRS) at discharge into good (mRS 0-2) and poor prognosis (mRS 3-6). After manual segmentation of each spontaneous intracerebral hematoma, the radiomics variables were obtained. The sample was divided into a training and testing cohort and a validation cohort (70-30% respectively). Different methods of variable selection and dimensionality reduction were used, and different algorithms were used for model construction. Stratified 10-fold cross-validation were performed on the training and testing cohort and the mean area under the curve (AUC) were calculated. Once the models were trained, the sensitivity of each was calculated to predict functional prognosis at discharge in the validation cohort.

RESULTS

105 patients with spontaneous intracerebral hematoma were analyzed. 105 radiomic variables were evaluated for each patient. P-SVM, KNN-E and RF-10 algorithms, in combination with the ANOVA variable selection method, were the best performing classifiers in the training and testing cohort (AUC 0.798, 0.752 and 0.742 respectively). The predictions of these models, in the validation cohort, had a sensitivity of 0.897 (0.778-1;95%CI), with a false-negative rate of 0% for predicting poor functional prognosis at discharge.

CONCLUSION

The use of radiomics-based nonlinear supervised learning classifiers are a promising diagnostic tool for predicting functional outcome at discharge in HIE patients, with a low false negative rate, although larger and balanced samples are still needed to develop and improve their performance.

First-Pass Effect in M1-Occlusion Stroke Patients Treated with Combined Stent-Retriever/Large-Bore Distal Aspiration Catheter Thrombectomy

INTRODUCTION

Combined stent-retriever/large-bore distal aspiration catheter (LB-DAC) thrombectomy was recently introduced to treat large-vessel occlusion; however, it is unclear whether larger inner diameters improve outcomes. We compared angiographic and clinical outcomes in patients with occlusions of the M1 segment of the middle cerebral artery treated with mechanical thrombectomy using extra-LB-DAC versus LB-DAC in combination with stent-retrievers.

METHODS

We analyzed consecutive patients with M1 occlusion included in the ROSSETTI registry treated with non-balloon guide catheter combined LB-DAC/stent-retriever thrombectomy between June 2019 and April 2022. We compared demographics, baseline clinical variables, procedural variables, angiographic outcomes, and clinical outcomes [National Institute of Health Stroke Scale score at 24 h (24h-NIHSS) and modified Rankin scale score at 3 months] between patients treated with extra-LB-DAC (Sofia Plus, MIVI Q6, Catalyst7; inner diameter, 0.068″-0.070″) versus LB-DAC (Sofia 5F, MIVI Q5, Catalyst 6; inner diameter, 0.055″-0.064″). Primary outcome was the first-pass effect (FPE) rate, defined as near-complete/complete reperfusion (mTICI 2c-3) after a single pass of the device.

RESULTS

We included 324 patients (extra-LB-DAC, 185, 57.1% patients). Demographics, clinical data, and clinical outcomes were similar between the two groups; however, there was a trend towards improvement in National Institute of Health Stroke Scale score at 24 h (24h-NIHSS) in the cohort treated with extra-LB-DAC 9 points (IQR 4;16 points) vs. 12 points (IQR 4;18 points, P = 0.083). Patients treated with extra-LB-DAC had higher FPE rate (47% vs. 30.9%; P = 0.003) and higher modified FPE (mTICI ≥ 2b after a single pass) rate (65.9% vs 46.8%; P = 0.001). The use of extra-LB-DAC was an independent factor in predicting FPE (odds ratio 1.982, 95% confidence interval 1.250-3.143, P = 0.004).

CONCLUSION

Our results suggest that in combined LB-DAC/stent-retriever thrombectomy, a larger aspiration catheter inner diameter is associated with higher rates of FPE and mFPE.

Difficult withdrawal of an inferior vena cava filter: Technical considerations and associated variables

OBJECTIVE

To analyse the efficacy of the procedure for withdrawing an inferior vena cava (IVC) filter and the clinical and radiological factors associated with difficult withdrawal.

MATERIAL AND METHODS

This retrospective observational study included patients who underwent IVC filter withdrawal at a single centre between May 2015 and May 2021. We recorded demographic, clinical, procedural, and radiological variables: type of IVC filter, angle with the IVC > 15°, hook against the wall, and legs embedded in the IVC wall > 3 mm. The efficacy variables were fluoroscopy time, success of IVC filter withdrawal, and number of attempts to withdraw the filter. The safety variables were complications, surgical removal, and mortality. The main variable was difficult withdrawal, defined as more than 5 min fluoroscopy or more than 1 attempt at withdrawal.

RESULTS

A total of 109 patients were included; withdrawal was considered difficult in 54 (49.5%). Three radiological variables were more common in the difficult withdrawal group: hook against the wall (33.3% vs. 9.1%; p = 0.027), embedded legs (20.4% vs. 3.6%; p = 0.008), and >45 days since IVC filter placement (51.9% vs. 25.5%; p = 0.006). These variables remained significant in the subgroup of patients with OptEase IVC filters; however, in the group of patients with Celect IVC filters, only the inclination of the IVC filter >15 ° was significantly associated with difficult withdrawal (25% vs 0%; p = 0.029).

CONCLUSION

Difficult withdrawal was associated with time from IVC placement, embedded legs, and contact between the hook and the wall. The analysis of the subgroups of patients with different types of IVC filters found that these variables remained significant in those with OptEase filters; however, in those with cone-shaped devices (Celect), the inclination of the IVC filter >15° was significantly associated with difficult withdrawal.

Recommendations on the use of computed tomography in the stroke code: Consensus document SENR, SERAU, GEECV-SEN, SERAM

The Spanish Society of Emergency Radiology (SERAU), the Spanish Society of Neuroradiology (SENR), the Spanish Society of Neurology through its Cerebrovascular Diseases Study Group (GEECV-SEN) and the Spanish Society of Medical Radiology (SERAM) have met to draft this consensus document that will review the use of computed tomography in the stroke code patients, focusing on its indications, the technique for its correct acquisition and the possible interpretation mistakes.

Anomalous location of intracranial vessels in adults

Anomalous intracranial vessels are not uncommon, and this finding is not always associated with arteriovenous malformations. Other conditions such as anomalous connections between arteries or phlebitc patterns can also present as vessels with abnormal intracranial locations. Noninvasive diagnosis is important to determine whether to do more invasive tests such as cerebral digital subtraction angiography or to estimate the risk of bleeding in arteriovenous malformations and therefore to evaluate the need for endovascular/surgical treatment. In this paper, we present an algorithm for the differential diagnosis of anomalous intracranial vessels according to their location (intra/extra-axial) and function (whether the vessels are arterialized). Moreover, we analyze the important points of the angioarchitecture of the principal arteriovenous malformations with risk of intracranial bleeding, such as pial arteriovenous malformations and dural fistulas.

Multicenter Retrospective Registry of Anterior Communicating Artery Aneurysms with Endovascular Therapy (MACAARET): safety and efficacy study according to morphological considerations and spatial orientations

AIM

To analyse the safety and efficacy parameters of endovascular treatment of anterior communicating artery (ACoA) aneurysms, according to their morphological considerations and three-dimensional orientation in a multicentric registry.

MATERIALS AND METHODS

A retrospective analysis was undertaken of a prospective database of consecutive patients that underwent endovascular embolisation for ACoA aneurysm in four high-volume neuroradiology interventional departments. The study has been registered in ClinicalTrial.gov. Data were collected regarding the clinico-demographic variables of the patients, anatomical variations of the circle of Willis, morphological considerations and spatial orientation of ACoA aneurysms were recorded. Safety and efficacy variables were also recorded. Associations between anatomical variations of the circle of Willis, morphological considerations, and spatial orientation of the ACoA aneurysms and safety and efficacy variables were assessed.

RESULTS

Data from 122 consecutive patients were collected in the MACAARET study (mean age (±SD) was 55 (±14) and 50.8% (62/122) were male). One hundred and five patients (86.1%) presented with subarachnoid haemorrhage (SAH). ACoA aneurysms with a neck size of >4 mm had less chance of having successful endovascular treatment than those of ≤4 mm (19.8% versus 46.7%; p=0.002) and were also more likely to recanalise during follow-up (61.5% versus 19.5%; p=0.003). Moreover, ACoA aneurysms with an aspect ratio of >1.7 had more chance of having immediate therapeutic success than those with a ratio of ≤1.7 (70.7% versus 44.8%; p=0.012). There were no other associations between the anatomical variables of the ACoA aneurysms and the safety-efficacy variables.

CONCLUSION

ACoA aneurysms are suitable for both endovascular and microsurgical approaches, but more data are required to determine which is the best approach regarding the morphological and spatial orientation of the aneurysm and the anatomical variations of the circle of Willis.

Synthetic MRI in subarachnoid haemorrhage

AIM

To evaluate the reliability of synthetic magnetic resonance imaging (SyMRI) for detecting complications associated with subarachnoid haemorrhage (SAH), such as ischaemic lesions, hydrocephalus, or bleeding complications.

MATERIALS AND METHODS

Twenty patients with SAH, who underwent a conventional brain MRI and a SyMRI on a 3 T MRI machine. Comparable conventional and synthetic T2-weighted fluid attenuated inversion recovery (FLAIR) images were acquired. The presence of ischaemic lesions, hydrocephalus, extra-axial blood collections as well as the volumes of grey matter (GMv), white matter (WMv), and cerebrospinal (CSFv) were compared. The acquisition times of both sequences was also analysed.

RESULTS

The concordance between the two techniques was excellent for the detection of ischaemic lesions and extra-axial collections (kappa = 0.80 and 0.88 respectively) and good for the detection of hydrocephalus (kappa = 0.69). No significant differences were detected in the number of ischaemic lesions (p=0.31) or in the Evans index (p=0.11). The WMv and CSFv measures were also similar (p=0.18 and p=0.94, respectively), as well as the volume of ischaemic lesions (p=0.79). Compared to conventional MRI, the SyMRI acquisition time was shorter regardless of the number of sections (32% and 6% time reduction for 4 or 3 mm section thickness, respectively).

CONCLUSIONS

SyMRI allows the detection of potential complications of SAH in a similar way to conventional MRI with a shorter acquisition time.

Stroke units could be a valid alternative to intensive care units for patients with low-grade aneurysmal subarachnoid haemorrhage

BACKGROUND AND PURPOSE

According to current guidelines, patients with aneurysmal subarachnoid haemorrhage (aSAH) are mostly managed in intensive care units (ICUs) regardless of baseline severity. We aimed to assess the prognostic and economic implications of initial admission of patients with low-grade aSAH into a stroke unit (SU) compared to initial ICU admission.

METHODS

We reviewed prospectively registered data from consecutive aSAH patients with a World Federation of Neurosurgery Societies grade <3, admitted to our Comprehensive Stroke Centre between April 2013 and September 2018. Clinical and radiological baseline traits, in-hospital complications, length of stay (LOS) and poor outcome at 90 days (modified Rankin Scale score > 2) were compared between the ICU and SU groups in the whole population and in a propensity-score-matched cohort.

RESULTS

Of 131 patients, 74 (56%) were initially admitted to the ICU and 57 (44%) to the SU. In-hospital complication rates were similar in the ICU and SU groups and included rebleeding (10% vs. 7%; P = 0.757), angiographic vasospasm (61% vs. 60%; P = 0.893), delayed cerebral ischaemia (12% vs. 12%; P = 0.984), pneumonia (6% vs. 4%; P = 0.697) and death (10% vs. 5%; P = 0.512). LOS did not differ between groups (median [interquartile range] 22 [16-30] vs. 19 [14-26] days; P = 0.160). In adjusted multivariate models, the location of initial admission was not associated with long-term poor outcome either in the whole population (odds ratio [OR] 1.16, 95% confidence interval [CI] 0.32-4.19; P = 0.825) or in the matched cohort (OR 0.98, 95% CI 0.24-4.06; P = 0.974).

CONCLUSIONS

A dedicated SU, with care from a multidisciplinary team, might be an optimal alternative to ICU for initial admission of patients with low-risk aSAH.

Angioplasty with a retrievable stent to treat vasospasm secondary to subarachnoid hemorrhage due to an aneurysm: a multicenter study of safety and efficacy

OBJECTIVE

To determine the safety and efficacy of angioplasty with a retrievable stent in treating vasospasm secondary to subarachnoid hemorrhage (SAH) due to an aneurysm.

METHODS

We retrospectively analyzed prospectively collected data from consecutive patients undergoing endovascular angioplasty with a retrievable stent to treat vasospasm related to SAH due to an aneurysm in four neurointerventional radiology departments between January 2018 and July 2019. We included patients aged>18 years with vasospasm>50% of the internal carotid artery (ICA), anterior cerebral artery (ACA), and / or middle cerebral artery (MCA) secondary to SAH due to an aneurysm treated with endovascular angioplasty with a retrievable stent. The variables used to measure safety were complications of the procedure and clinical complications. The variables used to measure radiological efficacy were improvement in the degree of stenosis after endovascular treatment and improvement or normalization of cerebral circulation time CTT).

RESULTS

We included 16 angioplasty procedures with retrievable stents in 13 patients, in which 33 arterial segments were treated (10 ICA, 15 MCA, and 8 ACA). We observed no complications of the procedure in any patients and no clinical complications in patients who were not intubated. All but one of the patients who had delayed CTT at the beginning of the procedure showed improvements in CTT. The mean improvement in the degree of stenosis was 18%±11.65% in the ICA, 30.67%±18.45% in the MCA, and 28.38%±15.49% in the ACA. No statistically significant associations were observed between endovascular treatment variables and the degree of improvement in stenosis.

CONCLUSION

Angioplasty with a retrievable stent is a safe and efficacious treatment for vasospasm secondary to SAH due to an aneurysm, improving CTT and stenosis.

Assessment of enlarged perivascular spaces and their relation to target organ damage and mild cognitive impairment in patients with hypertension

BACKGROUND AND PURPOSE

Enlarged perivascular spaces (EPVS) have been recently considered a feature of cerebral small vessel disease. They have been related to aging, hypertension and dementia but their relationship with hypertension related variables (i.e. target organ damage, treatment compliance) and mild cognitive impairment (MCI) is not fully elucidated. Our aims were to investigate the relation between basal ganglia (BG) and centrum semiovale (CSO) EPVS with vascular risk factors, hypertension related variables and MCI.

METHODS

In all, 733 hypertensive individuals free of stroke and dementia from the Investigating Silent Strokes in Hypertensives, a magnetic resonance imaging Study (ISSYS) underwent brain magnetic resonance imaging and cognitive testing to diagnose MCI or normal cognitive aging.

RESULTS

The numbers of participants presenting high grade (>10) EPVS at the BG and CSO were 23.3% and 40.0%, respectively. After controlling for vascular risk factors, high grade BG EPVS were associated with age (odds ratio 1.68; 95% confidence interval 1.37, 2.06), poor antihypertensive compliance (1.49; 1.03, 2.14) and the presence of microalbuminuria (1.95; 1.16, 3.28), whereas in the CSO only age (1.38; 1.18, 1.63) and male sex were associated with EPVS (1.73; 1. 24, 2.42). MCI was diagnosed in 9.3% of the participants and it was predicted by EPVS in the BG (1.87; 1.03, 3.39) but not in the CSO. This last association was greatly attenuated after correction for lacunes and white matter hyperintensities.

CONCLUSIONS

Basal ganglia EPVS are associated with the presence of microalbuminuria and poor adherence to antihypertensive drugs. The BG EPVS relation with MCI is not independent of the presence of other cerebral small vessel disease markers.

Perfusion Deficits and Mismatch in Patients with Acute Lacunar Infarcts Studied with Whole-Brain CT Perfusion

BACKGROUND AND PURPOSE

The incidence and significance of perfusion abnormalities on brain imaging in patients with lacunar infarct are controversial. We studied the diagnostic yield of CTP and the type of perfusion abnormalities in patients presenting with a lacunar syndrome and in those with MR imaging-confirmed lacunar infarcts.

MATERIALS AND METHODS

A cohort of 33 patients with lacunar syndrome underwent whole-brain CTP on admission. Twenty-eight patients had an acute ischemic lesion at follow-up MR imaging; 16 were classified as lacunar infarcts. Two independent readers evaluated NCCT and CTP to compare their diagnostic yield. In patients with DWI-confirmed lacunar infarcts and visible deficits on CTP, the presence of mismatch tissue was measured by using different perfusion thresholds.

RESULTS

The symptomatic acute lesion was seen on CTP in 50% of patients presenting with a lacunar syndrome compared with only 17% on NCCT, and in 62% on CTP compared with 19% on NCCT, respectively, in patients with DWI-confirmed lacunar infarcts. CTP was more sensitive in supratentorial than in infratentorial lesions. In the nonblinded analysis, a perfusion deficit was observed in 12/16 patients with DWI-confirmed lacunar infarcts. The proportion of mismatch tissue was similar in patients with lacunar infarcts or nonlacunar strokes (32% versus 36%, P = .734).

CONCLUSIONS

Whole-brain CTP is superior to NCCT in identifying small ischemic lesions, including lacunar infarcts, in patients presenting with a lacunar syndrome. Perfusion deficits and mismatch are frequent in lacunar infarcts, but larger studies are warranted to elucidate the clinical significance of these CTP findings.