Rehearsals using patient-specific 3D-printed aneurysm models for simulation of endovascular embolization of complex intracranial aneurysms: 3D SIM study.

BACKGROUND: In neurovascular treatment planning, endovascular devices to manage complex intracranial aneurysms requiring intervention are often selected based on conventional measurements and interventional neuroradiologist experience. A recently developed technology allows a patient-specific 3D-printed model to mimic the navigation experience. The goal of this study was to assess the effect of pre-procedure 3D simulation on procedural and clinical outcomes for wide-neck aneurysm embolization. MATERIALS & METHODS: In this unblinded, non-randomized, prospective, multicenter study conducted from November 18 through December 20, patients with complex intracranial aneurysms (neck > 4 mm or ratio < 21) were treated by WEB or flow diverter stents (FDS). The primary endpoint was concordance between simulation and procedure, 3D-printed model accuracy as well as embolization outcomes including complications, procedure times, and radiation dose were also assessed. Secondary endpoint was to compare versus a retrospective WEB cohort. RESULTS: Twenty-one patients were treated, 76% of cases by WEB and 24% by FDS. Concordance between post-simulation and real procedure efficiency was 0.85 [0.69 - 1.00] for size device selection and 0.93 [0.79 - 1.00] for wall-apposition/aneurysm neck closure. Geometrical accuracy of the 3D-printed model showed a mean absolute shift of 0.11 mm. Two complications without major clinical impact were reported with a post-operative mRS similar to pre-procedure mRS for all patients. CONCLUSIONS: Rehearsal using accurate 3D-printed patient-specific aneurysm models enabled optimization of embolization strategy, resulting in reduced procedure duration and cumulative fluoroscopy time which translated to reduced radiation exposure compared to procedures performed without simulation.

Intraoperative Complications of Endovascular Treatment of Intracranial Aneurysms with Coiling or Balloon-assisted Coiling in a Prospective Multicenter Cohort of 1088 Participants: Analysis of Recanalization after Endovascular Treatment of Intracranial Aneurysm (ARETA) Study.

Background Thromboembolic events and intraoperative rupture are the most frequent neurologic complications of intracranial aneurysm coiling. Their frequency has not been evaluated in recent series. Purpose To provide an analysis of complications, clinical outcome, and participant and aneurysm risk factors after aneurysm coiling or balloon-assisted coiling within the Analysis of Recanalization after Endovascular Treatment of Intracranial Aneurysm, or ARETA, cohort. Materials and Methods Sixteen neurointerventional departments prospectively enrolled participants treated for ruptured and unruptured aneurysms between December 2013 and May 2015. Participant demographics, aneurysm characteristics, and endovascular techniques were recorded. Data were analyzed from participants within the overall cohort treated with coiling or balloon-assisted coiling for a single aneurysm. Rates of neurologic complications were analyzed, and associated factors were studied by using univariable analyses (Student t test, χ2 test, or Fisher exact test, as appropriate) and multivariable analyses (logistic regressions). Results A total of 1088 participants (mean age ± standard deviation, 54 years ± 13; 715 women [65.7%]) were analyzed. Thromboembolic events and intraoperative rupture were reported in 113 of 1088 participants (10.4%) and 34 of 1088 participants (3.1%), respectively. Poor clinical outcome (defined as modified Rankin Scale score of 3-6) was reported in 29 of 113 participants (25.7%) with thromboembolic events and in 11 of 34 participants (32.4%) with intraoperative rupture (P = .44). Factors associated with thromboembolic events were female sex (odds ratio [OR], 1.7; 95% confidence interval [CI]: 1.1, 2.8; P = .02) and middle cerebral artery location (OR, 1.9; 95% CI: 1.2, 3.0; P = .008). Factors associated with intraoperative rupture were anterior communicating artery location (OR, 2.2; 95% CI: 1.1, 4.7; P = .03) and small aneurysm size (OR, 3.0; 95% CI: 1.5, 6.3; P = .003). Conclusion During aneurysm coiling or balloon-assisted coiling, thromboembolic events were more frequent than were intraoperative rupture. Both complications were associated with poor clinical outcome in a similar percentage of participants. Risk factors for thromboembolic events were female sex and middle cerebral artery location. Risk factors for intraoperative rupture were small aneurysm size and anterior cerebral or communicating artery location. © RSNA, 2020.

Acute Neurologic Disorder from an Inhibitor of Fatty Acid Amide Hydrolase.

BACKGROUND: A decrease in fatty acid amide hydrolase (FAAH) activity increases the levels of endogenous analogues of cannabinoids, or endocannabinoids. FAAH inhibitors have shown analgesic and antiinflammatory activity in animal models, and some have been tested in phase 1 and 2 studies. In a phase 1 study, BIA 10-2474, an orally administered reversible FAAH inhibitor, was given to healthy volunteers to assess safety. METHODS: Single doses (0.25 to 100 mg) and repeated oral doses (2.5 to 20 mg for 10 days) of BIA 10-2474 had been administered to 84 healthy volunteers in sequential cohorts; no severe adverse events had been reported. Another cohort of participants was then assigned to placebo (2 participants) or 50 mg of BIA 10-2474 per day (6 participants). This report focuses on neurologic adverse events in participants in this final cohort. A total of 4 of the 6 participants who received active treatment consented to have their clinical and radiologic data included in this report. RESULTS: An acute and rapidly progressive neurologic syndrome developed in three of the four participants starting on the fifth day of drug administration. The main clinical features were headache, a cerebellar syndrome, memory impairment, and altered consciousness. Magnetic resonance imaging showed bilateral and symmetric cerebral lesions, including microhemorrhages and hyperintensities on fluid-attenuated inversion recovery and diffusion-weighted imaging sequences predominantly involving the pons and hippocampi. One patient became brain dead; the condition of two patients subsequently improved, but one patient had residual memory impairment, and the other patient had a residual cerebellar syndrome. One patient remained asymptomatic. CONCLUSIONS: An unanticipated severe neurologic disorder occurred after ingestion of BIA 10-2474 at the highest dose level used in a phase 1 trial. The underlying mechanism of this toxic cerebral syndrome remains unknown.

Predictive Factors of Silent Brain Infarcts after Asymptomatic Carotid Endarterectomy.

BACKGROUND: The optimization of medical treatment regularly challenges the role of carotid surgery for asymptomatic patients. Current research seeks to determine which of these patients will benefit most from surgery. The goal of this study was to identify in a multicenter study, using magnetic resonance imaging (MRI), the risk factors for postoperative silent cerebral ischemic lesions after carotid surgery for asymptomatic stenosis. METHODS: The multicenter, retrospective study included patients with asymptomatic severe carotid stenosis suitable for surgical treatment and who did not have a history of cerebral ischemia. A diffusion MRI scan was performed the day before and in the 3 days after the procedure. An analysis by an independent neuroradiologist determined the presence of preoperative silent ischemia and the appearance of new lesions postoperatively. The analysis also took into account the plaque type, lesions of supra-aortic trunks, the circle of Willis, the type of surgery, and anesthesia, shunt use, and clamp time. RESULTS: Between April 2011 and November 2015, 141 patients were included. The mean degree of carotid stenosis in the patients who underwent surgery was 78.2% ± 6.5, with 9 (6.4%) cases of contralateral stenosis ≥70% and 6 (4.3%) of which were thrombosis. The circle of Willis was incomplete in 23 (16.3%) patients. Twenty-one (14.9%) plaques were of high embolic risk. The preoperative MRI found 34 (24.1%) patients with embolic ischemic lesions. The majority of procedures were eversions performed under general anesthesia, 7 (5%) required a shunt, and the mean clamp time was 39 ± 16 min. The postoperative MRI revealed that 10 (7%) patients had a new ischemic lesion on the operated side. None of these lesions were symptomatic. On multivariate analysis, the risk factors for appearance of a new ischemic lesion on the operated side were significant severe stenosis of the vertebral artery ipsilateral to the lesion (odds ratio [OR] = 9.2, 95% confidence interval [CI] [2.1-39.8], P = 0.003) and insertion of a shunt (OR = 9.1, 95% CI [1.1-73.1], P = 0.039). The 30-day follow-up showed one death at D4 due to hemorrhagic stroke on the operated side and one contralateral stroke. None of the study patients had a myocardial infarction. CONCLUSIONS: In this multicenter study, the rate of silent ischemic lesions in asymptomatic carotid surgery showed 43.3% of preoperative silent ischemic lesions and 9.2% of new silent lesions after surgery. The use of a shunt and presence of ipsilateral vertebral stenosis are risk factors for perioperative embolism.

CT angiography for one-year follow-up of intracranial aneurysms treated with the WEB device: Utility in evaluating aneurysm occlusion and WEB compression at one year.

BACKGROUND AND PURPOSE: The WEB is an innovative flow disruption device for cerebral aneurysm embolization with rapidly expanding indications. Our purpose was to evaluate the diagnostic performance of computed tomography angiography (CTA) at 1-year follow-up of aneurysms treated with the WEB. MATERIALS AND METHODS: Between April 2014 and May 2016, the study prospectively included patients treated with the WEB at our institution, and followed up within 24hours by CTA and at 1year by CTA, time-of-flight magnetic resonance angiography (TOF MRA) and digital subtraction angiography (DSA). The diagnostic quality of imaging data was assessed based on the confidence index, artifacts, and WEB shape depiction. The imaging diagnostic performance was assessed using 3 criteria at 1year: aneurysm occlusion status and worsening, and WEB shape compression. Interobserver and intermodality agreement was determined by calculating κ values. RESULTS: The study ultimately included 16 patients (9 women, mean age 53±7.6years). CTA quality confidence was scored as 2/2, artifacts 0.4/2 and WEB shape depiction 1.9/2, superior to TOF MRA for the latter two criteria. Aneurysm occlusion was adequate in 93.7% of patients, with CTA showing excellent interobserver reproducibility and agreement with DSA on a 4-grade scale (κ=1.00), while TOF MRA yielded good reproducibility (κ=0.76) and agreement with DSA (κ=0.69). CTA also identified aneurysm occlusion worsening (43.7%) and WEB compression (81.2%) in excellent agreement with DSA (κ=0.85 and 1.00). CONCLUSIONS: CTA is a reproducible and reliable technique for the follow-up of aneurysms treated with the WEB device.

Evaluation by Magnetic Resonance Imaging of Silent Brain Infarcts in Preoperative and Postoperative Asymptomatic Carotid Surgery.

BACKGROUND: To report the prevalence of silent brain infarcts (SBI) at magnetic resonance imaging (MRI) before and after surgery for asymptomatic high grade carotid stenosis. METHODS: This is a single center retrospective observational study. Asymptomatic patients who underwent carotid endarterectomy between October 2012 and October 2014 were included. The preoperative assessment included a Doppler and a computed tomographic (CT) scan dating less than 3 months. A neurological examination was performed during the anesthesia consultation and in the 15 days before surgery. An MRI angiography was performed the day before and 3 days after surgery and was analyzed by an independent neuroradiologist. Preoperative analysis focused on the presence of ischemic events at MRI. The type of plaque, the supra aortic trunk lesions, and the quality of the circle of Willis were analyzed using Doppler and CT scanning. Postoperatively, we searched for signs of postoperative ischemic events at MRI. RESULTS: Forty-one patients were included (85.4% of men), and the mean age was 72.4 ± 8.3 years. We noted 7 (17.1%) contralateral stenoses (>50%) and 2 (4.9%) contralateral thromboses, 6 (14.6%) vertebral stenoses, and 7 (17.1%) abnormalities of the circle of Willis. The morphological analysis described 6 unstable plaques including 4 ulcerated, 1 pseudodissection, and 1 intraplaque hemorrhage. Preoperatively, we noted the presence of 21 (51.2%) ischemic lesions including 9 (21.9%) multiple lacunar ischemic events and 12 (29.3%) silent arterial territory infarcts. Eversion was performed for all patients except for 6 (14.6%), for whom a bypass was necessary. No deaths or major complications were observed in the 30 postoperative days. Postoperatively, MRI showed 3 (7.3%) asymptomatic recent ischemic strokes, 1 ipsilateral middle cerebral artery (MCA) stroke, and 2 contralateral (cerebellar and MCA) strokes. CONCLUSIONS: Patients with asymptomatic significant carotid stenosis show many preoperative SBI indicating a significant embolic risk. It is difficult to conclude about intraoperative embolic risk, but we hope that more data could demonstrate the importance of MRI for the preoperative evaluation of carotid plaques and brain parenchyma, to identify high-risk embolic patients.

Endovascular treatment of acute ischemic stroke with ERIC device.

BACKGROUND AND PURPOSE: After 6 positive randomized trials, mechanical thrombectomy with stent-retriever is now recommended as a first-line treatment for acute ischemic stroke (AIS). The ERIC device is a device with several interlinked cage-like spheres fixed on a pusher wire. Neurothrombectomy France (NTF) is a registry conducted in France to analyze the results of mechanical thrombectomy. In order to analyze its performances, the subgroup of patients treated with the ERIC device was analyzed. MATERIALS AND METHODS: NTF is a prospective, multicenter registry dedicated to the evaluation of endovascular treatment for AIS. Primary endpoint was modified Rankin Scale (mRS) at 3months. Secondary endpoints were revascularization at the end of the procedure evaluated with the Thrombolysis In Cerebral Infarction (TICI) scale and rate of procedural complications. Patients treated with the ERIC device were extracted from the NTF registry and analyzed. RESULTS: From April 2013 to May 2014, 230 patients were included in the NTF registry. Thirty-one patients (13.5%) were treated with ERIC (male: 64.5%; median age: 61years). Median baseline NIHSS was 16. Median ASPECTS was 6. Occlusion location was internal carotid artery (51.6%), middle cerebral artery-M1 (45.2%), and basilar artery (3.2%). Cervical occlusion was associated in 16.1%. Revascularization (TICI 2b-3) was obtained in 87.1%. Good clinical outcome (mRS 0-2) at 3months was obtained in 55.2%. Death rate was 6.9% related to the stroke. CONCLUSION: This prospective, multicenter series shows good performances of the ERIC device in the treatment of acute ischemic stroke with revascularization in 87.1% and favorable clinical outcome in 55.2%.

Hemodynamic quantification in brain arteriovenous malformations with time-resolved spin-labeled magnetic resonance angiography.

BACKGROUND AND PURPOSE: Unenhanced time-resolved spin-labeled magnetic resonance angiography enables hemodynamic quantification in arteriovenous malformations (AVMs). Our purpose was to identify quantitative parameters that discriminate among different AVM components and to relate hemodynamic patterns with rupture risk. METHODS: Sixteen patients presenting with AVMs (7 women, 9 men; mean age 37.1±15.9 years) were assigned to the high rupture risk or low rupture risk group according to anatomic AVM characteristics and rupture history. High temporal resolution (<70 ms) unenhanced time-resolved spin-labeled magnetic resonance angiography was performed on a 3-T MR system. After dedicated image processing, hemodynamic quantitative parameters were computed. T tests were used to compare quantitative parameters among AVM components, between the high rupture risk and low rupture risk groups, and between the hemorrhagic and nonhemorrhagic groups. RESULTS: Among the quantitative parameters, time-to-peak (P<0.001) and maximum outflow gradient (P=0.01) allowed discriminating various intranidal flow patterns with significantly different values between feeding arteries and draining veins. With 9 AVMs classified into the high rupture risk group (whose 6 were hemorrhagic) and 7 into the low rupture risk group, the observed venous-to-arterial time-to-peak ratio was significantly lower in the high rupture risk (P=0.003) and hemorrhagic (P=0.001) groups. CONCLUSIONS: Unenhanced time-resolved spin-labeled magnetic resonance angiography allows AVM-specific combined anatomic and quantitative analysis of AVM hemodynamics.

Template-based approach for detecting motor task activation-related hyperperfusion in pulsed ASL data.

Arterial spin labeling (ASL) permits the noninvasive measurement of quantitative values of cerebral blood flow (CBF) and is thus well adapted to study inter- and intrasubject perfusion variations whether at rest or during an fMRI task. In this study, a template approach to detect brain activation as a CBF difference between resting and activated groups was compared with a standard generalized linear model (GLM) analysis. A basal perfusion template of PICORE-Q2TIPS ASL images acquired at 3T from a group of 25 healthy subjects (mean age 31.6 ± 8.3 years) was created. The second group of 12 healthy subjects (mean age 28.6 ± 2.7 years) performed a block-design motor task. The template was compared with the mean activated image of the second group both at the individual and at the group level to extract activation maps. The results obtained using a GLM analysis of the whole sequence was used as ground truth for comparison. The influences of spatial normalization using DARTEL registration and of correction of partial volume effects (PVE) in the construction of the template were assessed. Results showed that a basal perfusion template can detect activation-related hyperperfusion in motor areas. The true positive ratio was increased by 2.5% using PVE-correction and by 3.2% using PVE-correction with DARTEL registration. On average, the group comparison presented a 2.2% higher true positive ratio than the one-to-many comparison.

Time-resolved spin-labeled MR angiography for the depiction of cerebral arteriovenous malformations: a comparison of techniques.

PURPOSE: To assess time-resolved spin-labeled (SL) magnetic resonance (MR) angiographic imaging with a large acquisition time window over two cardiac cycles for characterization of cerebral arteriovenous malformations (AVMs). MATERIALS AND METHODS: This study was institutional review board-approved. Sixteen patients presented with an AVM, provided informed consent, and were prospectively included. Time-resolved SL MR angiographic images with acquisition window that covered two cardiac cycles (acquisition time, 10-12 min; temporal resolution, 60 msec) or one cardiac cycle and time-of-flight (TOF) MR angiographic images were acquired with a 3-T MR imager. A diagnostic confidence index was used for image quality evaluation; scores were 0, no diagnosis, to 3, high image quality. AVM characterization consisted of arterial feeder, nidus size, and venous drainage type identification compared with those at digital subtraction angiography (DSA). κ coefficients were computed to determine interobserver and intermodality agreement. RESULTS: Time-resolved SL MR angiographic imaging over two cardiac cycles provided a median diagnostic confidence index of 2.5 for arterial feeders, 3.0 for nidus, and 3.0 for venous drainage. Venous drainage depiction quality was higher with time-resolved SL MR angiography over two cardiac cycles than with time-resolved SL MR angiography over one cardiac cycle (P < .001) and TOF MR angiography (P < .001). For AVM characterization, interobserver agreement was very good to excellent, and agreement with DSA showed κ of 0.85 for arterial feeders, κ of 1.00 for nidus size, and κ of 0.82 for venous drainage. CONCLUSION: Time-resolved SL MR angiographic imaging over two cardiac cycles is a reliable clinical tool for cerebral AVM characterization, which showed very good to excellent agreement with DSA.

Supra-aortic arteries: three-dimensional time-resolved k-t BLAST contrast-enhanced MRA using a nondedicated body coil at 3 tesla in acute ischemic stroke.

PURPOSE: To assess the image quality and diagnostic performance achieved by using supra-aortic 3D-TR-CE-k-t BLAST MRA and a nondedicated body coil as compared with conventional CE-MRA in patients with acute ischemic stroke. MATERIALS AND METHODS: In this prospective study, 36 consecutive patients with a suspected acute ischemic stroke underwent both k-t BLAST MRA and conventional CE-MRA. Image quality was assessed using visual and quantitative criteria and the techniques were compared. Both techniques were compared for degree of visual and quantitative measurement of carotid stenosis. RESULTS: Delineation of vessel lumen and overall diagnostic confidence were significantly better with CE-MRA, respectively 3.4 ± 0.5 and 3.3 ± 0.6 (mean score ± SD), than with k-t BLAST MRA, respectively 2.8 ± 0.4 and 2.9 ± 0.5 (P < 0.02). SNR and CNR were significantly higher for k-t BLAST MRA, respectively 33.5 ± 19.3 and 27.9 ± 19.3, than for CE-MRA, respectively 25.7 ± 10 and 20.4 ± 8.4 (P < 0.03). Intertechnique agreement was good for carotid stenosis characterization (κ = .763). For the 14 relevant stenosis, stenosis measurements were highly correlated between techniques (0.96; P < 0.0001). The Bland-Altman plot showed a low bias in assessment of the degree of stenosis (mean bias 2.1% ± 7.7). CONCLUSION: k-t BLAST MRA using a nondedicated coil offering and dynamic information was a effective diagnostic tool for detection and characterization of carotid stenosis.

Improving detection of ischemic lesions at 3 Tesla with optimized diffusion-weighted magnetic resonance imaging.

BACKGROUND AND PURPOSE: This study compared three different combinations of DWI parameters: three and six diffusion imaging directions (3dir and 6dir, respectively) using b=1000 or 2000 s/mm(2) (b1000 or b2000, respectively) to improve detection of recent ischemic lesions at 3 Tesla (3 T). MATERIALS AND METHODS: A total of 47 consecutive patients underwent three DWI scans: 3dir b1000; 6dir b1000; and 6dir b2000. Qualitative visual analysis was performed by three readers based on evaluation of the number of lesions, presence of artifacts and diagnostic confidence. Interobserver agreement, sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: Forty-five lesions were detected by 3dir b1000, 52 by 6dir b1000 and 56 by 6dir b2000 in 30 patients. The additional lesions identified by 6dir b2000 were either small or located in the posterior fossa. Sensitivity with 6dir b2000 was significantly higher than with 3dir b1000 (98.1% vs 77.4%; P<0.05). CONCLUSION: At 3 T, 6dir b2000 DWI detected more acute ischemic lesions than 3dir b1000, particularly small lesions and those located in the brain stem.

Effects of low-dose protocols in endovascular treatment of intracranial aneurysms: development of workflow task analysis during cerebral endovascular procedures.

OBJECTIVE: Reducing radiation exposure through the use of low-dose protocols during cerebral endovascular procedures is recommended, but evaluation of the impact on the procedure itself is difficult and subjective. A workflow task analysis could provide an objective comparison of two different radiation exposure protocols. SUBJECTS AND METHODS: Twenty endovascular aneurysm treatments were analyzed using a low-dose protocol (reducing radiation exposure by 20%) in 10 cases and a normal-dose protocol in the other 10 cases. The procedure was subdivided into five phases, each comprising a sequence of tasks. Each task was defined as a triplet, associating an action, an instrument, and an anatomic structure. A workflow editor was used to record tasks and phases with a tablet PC. The total duration of the entire procedure, the duration of each task, and the number of task repetitions were isolated and used as the metric. Moreover, the tasks involving x-ray use, essential for navigation and treatment phases, were separated and analyzed. RESULTS: For the microcatheter navigation and treatment phases, no statistically significant difference was found between the two radiation exposure protocols. For guide catheter navigation in cervical vessels, the total phase duration and total and mean time of tasks specifically involving x-ray use increased with age, but there was no difference between the two radiation protocols. CONCLUSION: Workflow task analysis of endovascular aneurysm treatment shows no difference between low-dose and normal-dose protocols in the guide catheter navigation, microcatheter navigation, or treatment phases.

Optimal individual inversion time in brain arterial spin labeling perfusion magnetic resonance imaging: correlation with carotid hemodynamics measured with cine phase-contrast magnetic resonance imaging.

OBJECTIVE: The quantification of cerebral blood flow using pulsed arterial spin labeling could be erroneous with a nonoptimal inversion time (TI). We suggest that the optimal individual TI is dependent on the hemodynamic values of the supra-aortic vessels. METHODS: Twenty-two healthy volunteers (mean age, 31.8 years) underwent 7 pulsed arterial spin labeling scans at 3 T with TI ranging from 1200 to 1800 milliseconds every 100 milliseconds. The quantitative hemodynamic values of carotids were computed using a cine phase-contrast sequence. Optimal TIs were determined using visual and quantitative criteria. A correlation was sought between each optimal individual TI criterion and the hemodynamic parameter values. RESULTS: The optimal group TI was 1700 milliseconds. The individual analysis showed a significant correlation between the optimal TI of white matter signal-to-noise ratio and stroke distance, and the optimal TI of contrast-to-noise ratio with mean velocity. CONCLUSIONS: A correlation was found between optimal individual TIs and carotid hemodynamic parameters.

Systematic combined noncontrast CT-CT angiography in the management of unexplained nontraumatic coma.

BACKGROUND: Nontraumatic impaired consciousness is a common issue in emergency departments with a serious but widely variable prognosis. STUDY OBJECTIVES: The aim of this prospective study was to evaluate the ability of systematic combined noncontrast computed tomography (NCCT)/computed tomography angiography (CTA) imaging, firstly to provide a neurologic prognosis and secondly to ensure early detection of basilar artery occlusion (BAO), in unexplained nontraumatic impaired consciousness management. METHODS: Combined NCCT/CTA imaging was performed on 65 patients with impaired consciousness and no history of trauma prospectively over 14 months in a single center. Images were assessed based on visual and quantitative criteria. Clinical outcome was assessed using the modified Rankin Scale at 3 months. Statistical analysis aimed to identify the prognostic value of combined NCCT/CTA imaging and its ability for early BAO detection. RESULTS: This study shows that combined NCCT/CTA imaging was a significant predictor of poor neurological outcome, with a positive predictive value of 94.6%. The combination was also crucial for early detection of BAO, given that 42.8% of cases were misdiagnosed with NCCT alone. Basilar artery occlusion represented 10.8% of all unexplained nontraumatic impaired consciousness. CONCLUSIONS: Systematic combined NCCT/CTA imaging is an efficient tool for predicting poor neurologic prognosis in cases of unexplained nontraumatic impaired consciousness and is also essential for detecting BAO.

Anatomical variations of the anterior cerebral arterial circle visualized by multidetector computed tomography angiography: comparison with 3D rotational angiography.

OBJECTIVES: Multidetector computed tomography angiography (MD-CTA) has become the first-line screening technique for patients with subarachnoid hemorrhage not only for detecting aneurysms, but also for providing decisive angioarchitectural information. The anterior cerebral arterial circle (ACAC) is the most common location for anatomical variations and aneurysms. The aim of this study was to assess the diagnostic performance of 64-section MD-CTA in the detection and characterization of anatomical variations of the ACAC compared with three-dimensional rotational angiography (3DRA). MATERIAL AND METHODS: In 104 patients, MD-CTA and 3DRA images of the internal carotid arteries were independently reviewed by two radiologists for variations, focusing on four arterial segments of the ACAC: the anterior communicating artery (ACoA); the A1 segments; the A2-A4 complexes; and the M1 segments. The percentages of variations detected by MD-CTA and 3DRA were compared using the chi-square test. Characterizations of the variations by MD-CTA compared with 3DRA were evaluated using the kappa statistic. RESULTS: A total of 114 variations in 624 segments (18.3%) were detected by MD-CTA compared with 90 variations in 453 segments (19.9%) by 3DRA. The difference was not significant (P=0.56). In 453 selected segments analyzed with both techniques, 15 discordances in characterization were noted, mostly in the ACoA (10/15). However, the overall intertechnical κ was excellent. Sensitivity, specificity, positive predictive values and negative predictive values were all greater than 90%. CONCLUSION: The overall diagnostic performance of MD-CTA in detecting anatomical variations of the ACAC was excellent compared with 3DRA. However, its lower spatial resolution led to misclassifications, especially in the ACoA.

Development of workflow task analysis during cerebral diagnostic angiographies: time-based comparison of junior and senior tasks.

OBJECTIVE: Assessing neuroradiologists' skills in the operating room (OR) is difficult and often subjective. This study used a workflow time-based task analysis approach while performing cerebral angiography. METHODS: Eight angiographies performed by a senior neuroradiologist and eight performed by a junior neuroradiologist were compared. Dedicated software with specific terminology was used to record the tasks. Procedures were subdivided into phases, each comprising multiple tasks. Each task was defined as a triplet, associating an action, an instrument and an anatomical structure. The duration of each task was the metric. Total duration of the procedure, task duration and the number of times a task was repeated were identified. The focus was on tasks using fluoroscopy and for moving the X-ray table/tube. RESULTS: The total duration of tasks to complete the entire procedure was longer for the junior operators than for the seniors (P=0.012). The mean duration per task during the navigation phase was 86s for the juniors and 43s for the seniors (P=0.002). The total and mean durations of tasks involving the use of fluoroscopy were also longer for the juniors (P=0.002 and P=0.033, respectively). For tasks involving the table/tube, the total and mean durations were again longer for the juniors (P=0.019 and P=0.082, respectively). CONCLUSION: This approach allows reliable skill assessment in the radiology OR and comparison of junior and senior competencies during cerebral diagnostic angiography. This new tool can improve the quality and safety of procedures, and facilitate the learning process for neuroradiologists.

Prognostic factors for outcomes after mechanical thrombectomy with solitaire stent.

BACKGROUND AND PURPOSE: Endovascular mechanical thrombectomy is emerging as a promising therapeutic approach for acute ischemic stroke. This study was aimed at identifying factors influencing outcomes after thrombectomy with a Solitaire stent device. MATERIALS AND METHODS: Forty-five consecutive patients treated with thrombectomy using Solitaire FR were retrospectively included. Clinical, imaging and logistic variables were analyzed. A multivariate logistic regression analysis was used to identify variables influencing clinical outcome, based on discharge NIHSS score change and mRS at 3 months. RESULTS: Patient mean age and initial NIHSS score was 58 years (range 24-88) and 17 (range 6-32), respectively. An MRI was performed for 80% of patients, showing severe DWI lesion for 28% of patients and associated FLAIR hyperintensity for 58% of patients. Mean time from symptom onset to recanalization was 299min for the 32 ACO and 473min for the 13 PCO. Angiographic efficacy (TICI 2b-3) was achieved for 93% of patients and good clinical outcomes at discharge and at 3 months (mRS≤2) were achieved for 49% and 58% of patients, respectively. Independent prognostic factors for predicting good clinical outcomes at discharge were a short time to recanalization and FLAIR negativity. At 3 months, they were a short time to recanalization and patient age. DWI lesion severity was an associated prognostic factor. CONCLUSION: Two main prognostic factors for predicting a good clinical outcome after thrombectomy at 3 months were short time from symptom onset to recanalization and patient age.

Management of patients suffering from mild traumatic brain injury 2023.

OBJECTIVE: To develop a multidisciplinary French reference that addresses initial pre- and in-hospital management of a mild traumatic brain injury patient. DESIGN: A panel of 22 experts was formed on request from the French Society of Emergency Medicine (SFMU) and the French Society of Anaesthesiology and Critical Care Medicine (SFAR). A policy of declaration and monitoring of links of interest was applied and respected throughout the process of producing the guidelines. Similarly, no funding was received from any company marketing a health product (drug or medical device). The expert panel had to respect and follow the Grade® (Grading of Recommendations Assessment, Development and Evaluation) methodology to evaluate the quality of the evidence on which the recommendations were based. Given the impossibility of obtaining a high level of evidence for most of the recommendations, it was decided to adopt a "Recommendations for Professional Practice" (RPP) format, rather than a Formalized Expert Recommendation (FER) format, and to formulate the recommendations using the terminology of the SFMU and SFAR Guidelines. METHODS: Three fields were defined: 1) pre-hospital assessment, 2) emergency room management, and 3) emergency room discharge modalities. The group assessed 11 questions related to mild traumatic brain injury. Each question was formulated using a PICO (Patients Intervention Comparison Outcome) format. RESULTS: The experts' synthesis work and the application of the GRADE® method resulted in the formulation of 14 recommendations. After two rounds of rating, strong agreement was obtained for all recommendations. For one question, no recommendation could be made. CONCLUSION: There was strong agreement among the experts on important, transdisciplinary recommendations, the purpose of which is to improve management practices for patients with mild head injury.