Endovascular therapy outcome in isolated posterior cerebral artery occlusion strokes: A multicenter analysis of the Swiss Stroke Registry.

PURPOSE: There is little data on the safety and efficacy of endovascular treatment (EVT) in comparison with intravenous thrombolysis (IVT) in acute ischemic stroke due to isolated posterior cerebral artery occlusion (IPCAO). We aimed to investigate the functional and safety outcomes of stroke patients with acute IPCAO treated with EVT (with or without prior bridging IVT) compared to IVT alone. METHODS: We did a multicenter retrospective analysis of data from the Swiss Stroke Registry. The primary endpoint was overall functional outcome at 3 months in patients undergoing EVT alone or as part of bridging, compared with IVT alone (shift analysis). Safety endpoints were mortality and symptomatic intracranial hemorrhage. EVT and IVT patients were matched 1:1 using propensity scores. Differences in outcomes were examined using ordinal and logistic regression models. FINDINGS: Out of 17,968 patients, 268 met the inclusion criteria and 136 were matched by propensity scores. The overall functional outcome at 3 months was comparable between the two groups (EVT vs IVT as reference category: OR = 1.42 for higher mRS, 95% CI = 0.78-2.57, p = 0.254). The proportion of patients independent at 3 months was 63.2% in EVT and 72.1% in IVT (OR = 0.67, 95% CI = 0.32-1.37, p = 0.272). Symptomatic intracranial hemorrhages were overall rare and present only in the IVT group (IVT = 5.9% vs EVT = 0%). Mortality at 3 months was also similar between the two groups (IVT = 0% vs EVT = 1.5%). CONCLUSION: In this multicenter nested analysis, EVT and IVT in patients with acute ischemic stroke due to IPCAO were associated with similar overall good functional outcome and safety. Randomized studies are warranted.

Effective Dose Measurements of the Latest-Generation Angiographic System in Patients with Acute Stroke: A Comparison with the Newest Multidetector CT Generation.

BACKGROUND AND PURPOSE: Patients with acute ischemic stroke are increasingly triaged with one-stop management approaches, resulting in baseline imaging with a flat detector CT scanner. This study aimed to estimate the effective dose to a patient of a novel cervical and intracranial flat detector CT angiography and a flat detector CT perfusion protocol and to compare it with the effective dose of analogous multidetector row CT protocols. MATERIALS AND METHODS: We estimated the effective dose to the patient according to the International Commission on Radiological Protection 103 using an anthropomorphic phantom with metal oxide semiconductor field effect transistor dosimeters. Placement was according to the organ map provided by the phantom manufacturer. We used 100 measurement points within the phantom, and 18 metal oxide semiconductor field effect transistor dosimeters were placed on the surface of the phantom. All protocols followed the manufacturer's specifications, and patient positioning and collimation were performed as in routine clinical practice. Measurements were obtained on the latest-generation angiography and multidetector row CT systems with identical placement of the metal oxide semiconductor field effect transistor dosimeters. RESULTS: The estimated effective doses of the investigated perfusion protocols were 4.52 mSv (flat detector CT perfusion without collimation), 2.88 mSv (flat detector CT perfusion with collimation), and 2.17 mSv (multidetector row CT perfusion). A novel protocol called portrait flat detector CT angiography that has a z-axis coverage area comparable with that of multidetector row CT angiography had an estimated effective dose of 0.91 mSv, while the dose from multidetector row CT was 1.35 mSv. CONCLUSIONS: The estimated effective dose to the patient for flat detector CT perfusion and angiography on a modern biplane angiography system does not deviate substantially from that of analogous multidetector row CT protocols.

Impact of Implementing an Elaborated CT Perfusion Protocol for Aneurysmal SAH on Functional Outcome: CTP Protocol for SAH.

BACKGROUND AND PURPOSE: The acute phase of aneurysmal SAH is characterized by a plethora of impending complications with the potential to worsen patients' outcomes. The aim of this study was to evaluate whether an elaborated CTP-based imaging protocol during the acute aneurysmal SAH phase is able to prevent delayed infarctions and contribute to a better outcome. MATERIALS AND METHODS: In 2012, an elaborated CTP-based protocol was implemented for the management of patients with aneurysmal SAH. Retrospective analysis of patients with aneurysmal SAH treated from 2010 to 2013 was performed, comparing the patients treated before (group one, 2010-2011) with those treated after the protocol implementation (group two, 2012-2013) with regard to delayed infarctions and outcome according to the mRS at 3-months' follow-up. RESULTS: A total of 133 patients were enrolled, of whom 57 were included in group 1, and 76, in group 2. There were no significant differences between the groups concerning baseline characteristics. In the multivariate analysis, independent predictors of a good outcome (mRS ≤ 2) were younger age (P < .001), lower World Federation of Neurosurgical Societies grade (P < .001), absence of delayed infarction (P = .01), and management according to the CTP protocol (P = .01). Larger or multiple infarctions occurred significantly more often in group 1 compared with group 2 (88% versus 33% of all delayed infarctions, P = .03). The outcome in group 2 was significantly better compared with group 1 (P = .005). CONCLUSIONS: The findings suggest that implementation of an elaborated CTP protocol is associated with a better outcome. An earlier initiation of further diagnostics and treatment with prevention of large territorial and/or multiple infarctions might have led to this finding.

Endovascular Thrombectomy of Calcified Emboli in Acute Ischemic Stroke: A Multicenter Study.

BACKGROUND AND PURPOSE: Large intracranial vessel occlusion due to calcified emboli is a rare cause of major stroke. We assessed the prevalence, imaging appearance, the effectiveness of mechanical thrombectomy, and clinical outcome of patients with large-vessel occlusion due to calcified emboli. MATERIALS AND METHODS: We performed a retrospective analysis of clinical and procedural data of consecutive patients who underwent mechanical thrombectomy due to calcified emboli in 7 European stroke centers. RESULTS: We screened 2969 patients, and 40 patients matched the inclusion criteria, accounting for a prevalence of 1.3%. The mean maximal density of the thrombus was 327 HU (range, 150-1200 HU), and the mean thrombus length was 9.2 mm (range, 4-20 mm). Four patients had multiple calcified emboli, and 2 patients had an embolic event during an endovascular intervention. A modified TICI score of ≥2b was achieved in 57.5% (23/40), with minimal-to-no reperfusion (modified TICI 0-1) in 32.5% (13/40) and incomplete reperfusion (modified TICI 2a) in 10% (4/40). Excellent outcome (mRS 0-1) was achieved in only 20.6%, functional independence (mRS 0-2) in 26.5% and 90-day mortality was 55.9%. CONCLUSIONS: Acute ischemic stroke with large-vessel occlusion due to calcified emboli is a rare entity in patients undergoing thrombectomy, with considerably worse angiographic outcome and a higher mortality compared with patients with noncalcified thrombi. Good functional recovery at 3 months can still be achieved in about a quarter of patients.

Impact of Time on Thrombolysis in Cerebral Infarction Score Results.

PURPOSE: Extended thrombolysis in cerebral infarction (eTICI) score results of 2b or higher are known to be predictors for favorable outcome after acute stroke. Additionally, time is a major factor influencing outcome after ischemic stroke. Until today only little is known about the impact of time on angiographic results regarding the outcome after mechanical thrombectomy; however, this impact might be of interest if an initially unfavorable angiographic result has to be improved. METHODS: Retrospective study of 164 patients with large vessel occlusion of the anterior circulation treated by mechanical thrombectomy. Multiple logistic regression analysis of relevant periprocedural and procedural times in respect to the probability of achieving functional independence at 90 days in respect to different eTICI results was performed to build a time and TICI score-dependent model for outcome prediction in which the influence of time was assumed to be steady among the TICI grades. RESULTS: The probability of achieving a favorable outcome is significantly different between eTICI2b-50, 67, TICI2c and TICI3 results (p < 0.001). The odds for achieving a favorable outcome decrease over time and differ for each TICI category and time point. The individual odds for each patient, time point and TICI grade can be calculated based on this model. CONCLUSION: The impact of periprocedural and procedural times and eTICI reperfusion results adds a new dimension to the decision-making process in patients with primary unfavorable angiographic results.

One-Stop Management with Perfusion for Transfer Patients with Stroke due to a Large-Vessel Occlusion: Feasibility and Effects on In-Hospital Times.

BACKGROUND AND PURPOSE: In-hospital time delays lead to a relevant deterioration of neurologic outcomes in patients with stroke with large-vessel occlusions. At the moment, CT perfusion is relevant in the triage of late-window patients with stroke. We conducted this study to determine whether one-stop management with perfusion is feasible and leads to a reduction of in-hospital times. MATERIALS AND METHODS: In this observational study, we report the first 15 consecutive transfer patients with stroke with externally confirmed large-vessel occlusions who underwent flat panel detector CT perfusion and thrombectomy in the same room. Preinterventional imaging consisted of noncontrast flat panel detector CT and flat panel detector CT perfusion, acquired with a biplane angiography system. The flat panel detector CT perfusion was used to reconstruct a flat panel detector CT angiography to confirm the large-vessel occlusions. After confirmation of the large-vessel occlusion, the patient underwent mechanical thrombectomy. We recorded time metrics and safety parameters prospectively and compared them with those of transfer patients whom we treated before the introduction of one-stop management with perfusion. RESULTS: Fifteen transfer patients underwent flat panel detector CT perfusion and were treated with mechanical thrombectomy from June 2017 to January 2019. The median time from symptom onset to admission was 241 minutes. Median door-to-groin time was 24 minutes. Compared with 23 transfer patients imaged with multidetector CT, it was reduced significantly (24 minutes; 95% CI, 19-37 minutes, versus 53 minutes; 95% CI, 44-66 minutes; P < .001). Safety parameters were comparable between groups. CONCLUSIONS: In this small series, one-stop management with perfusion led to a significant reduction of in-hospital times compared with our previous workflow.

The problem of strict image-based inclusion criteria for mechanical thrombectomy - an analysis of stroke patients with an initial low CBV-ASPECTS score.

INTRODUCTION: Endovascular treatment for acute ischaemic stroke with large artery occlusion has become the standard of care. However, the question if a subgroup of patients, with a low cerebral blood volume Alberta Stroke Program Early CT score (CBV-ASPECTS) ≤ 7 should be excluded from endovascular treatment remains open. Therefore; we investigated the difference of outcome between patients who were treated by endovascular treatment vs patients who did not receive endovascular treatment. METHODS: We retrospectively analysed our stroke database for all patients who presented within six hours of onset with unfavourable imaging findings and who received endovascular treatment or best medical treatment alone. Unfavourable imaging was defined as a CBV-ASPECTS ≤ 7, which was an exclusion criterion for endovascular treatment at our institution before 2015. RESULTS: From 60 patients with an initial CBV-ASPECTS ≤ 7, 40 received best medical treatment and 20 were treated with endovascular treatment. Arterial hypertension and atrial fibrillation was more present in patients without endovascular treatment, the other baseline characteristics and percentage of patients treated with intravenous recombinant tissue plasminogen activator were not significantly different in both groups. At discharge, 40% of the interventional treated patients had a favourable outcome (eight of 20 (40%) vs six of 40 (15%; p = 0.031). The median values of the National Institute of Health Stroke Score and modified Rankin Scale at discharge were significantly lower in the treated cohort (6.5 (2.5-10.5) vs 16 (9.5-22.5); p = 0.006; 3 (0-5.5) vs 5 (4.5-5.5); p = 0.003). CONCLUSION: Patients with a CBV-ASPECTS ≤ 7 are likely to benefit from therapy and therefore may not be excluded from endovascular treatment. Further randomised trials are warranted to validate the data.

How to Size Intracranial Aneurysms: A Phantom Study of Invasive and Noninvasive Methods.

BACKGROUND AND PURPOSE: Endovascular treatment of intracranial aneurysms has relevantly changed over the past decades. Multiple new devices such as intrasaccular flow diverters have broadened the treatment spectrum but require very exact aneurysm sizing. In this study, we investigated multidetector and flat panel angiographic CT and digital subtraction imaging as well as different postprocessing methods (multiplanar reconstruction, volume-rendering technique, 3D DSA, and conventional 2D angiography) for their ability to exactly size 2 aneurysm models. MATERIALS AND METHODS: Two aneurysm models with known aneurysm sizes were placed inside a human skull. After injection of iodine contrast media, imaging was performed using a 128-slice CT scanner or an Artis Q biplane angiosuite, respectively. Aneurysms were measured for width, neck, and height, and the mean difference from the known sizes was calculated for each technique. The technique with the most exact measurement was defined as the criterion standard. We performed Bland-Altman plots comparing all techniques against the criterion standard. RESULTS: Angiograms adjusted according a previous 3D run with a short object-to-detector distance resulted in the most exact aneurysm measurement: -0.07 ± 0.61 mm for aneurysm 1 and 0.17 ± 0.39 mm for aneurysm 2. Measurements of conventional DSA images were similar, and CT-based images were significantly inferior to the criterion standard. CONCLUSIONS: 2D DSA with a short objective-to-detector distance adjusted according to a previous 3D run resulted in the most exact aneurysm measurement and should therefore be performed before all endovascular aneurysm treatments.

Impact of intravenous thrombolysis and emergent carotid stenting on reperfusion and clinical outcomes in patients with acute stroke with tandem lesion treated with thrombectomy: a collaborative pooled analysis.

BACKGROUND AND PURPOSE: Tandem anterior circulation lesions in the setting of acute ischemic stroke (AIS) are a complex endovascular situation that has not been specifically addressed in trials. We determined the predictors of successful reperfusion and good clinical outcome at 90 days after mechanical thrombectomy (MT) in patients with AIS with tandem lesions in a pooled collaborative study. METHODS: This was a retrospective analysis of consecutive patients presenting to 18 comprehensive stroke centers with AIS due to tandem lesion of the anterior circulation who underwent MT. RESULTS: A total of 395 patients were included. Successful reperfusion (modified thrombolysis in cerebral infarction score 2b-3) was achieved in 76.7%. At 90 days, 52.2% achieved a good outcome (modified Rankin Scale score 0-2), 13.8% suffered a parenchymal hematoma and 13.2% were dead. Lower National Institutes of Health Stroke Scale score [odds ratio (OR), 1.26; 95% confidence intervals (CI), 1.07-1.48, P = 0.004], Alberta Stroke Program Early CT Score ≥7 (OR, 2.00; 95% CI, 1.07-3.43, P = 0.011), intravenous thrombolysis (OR, 1.47; 95% CI, 1.01-2.12, P = 0.042) and stenting of the extracranial carotid lesion (OR, 1.63; 95% CI, 1.04-2;53, P = 0.030) were independently associated with successful reperfusion. Lower age (OR, 1.58; 95% CI, 1.26-1.97, P < 0.001), absence of hypercholesterolemia (OR, 1.77; 95% CI, 1.10-2.84, P = 0.018), lower National Institutes of Health Stroke Scale scores (OR, 2.04; 95% CI, 1.53-2.72, P < 0.001), Alberta Stroke Program Early CT Score ≥7 (OR, 2.75; 95% CI, 1.24-6.10, P = 0.013) and proximal middle cerebral artery occlusion (OR, 1.59; 95% CI, 1.03-2.44, P = 0.035) independently predicted a good 90-day outcome. CONCLUSIONS: Intravenous thrombolysis and emergent stenting of the extracranial carotid lesion were predictors of a successful reperfusion after MT of patients with AIS with tandem lesion of the anterior circulation.

Diagnosing Early Ischemic Changes with the Latest-Generation Flat Detector CT: A Comparative Study with Multidetector CT.

BACKGROUND AND PURPOSE: One-stop management of mechanical thrombectomy-eligible patients with large-vessel occlusion represents an innovative approach in acute stroke treatment. This approach reduces door-to-reperfusion times by omitting multidetector CT, using flat detector CT as pre-mechanical thrombectomy imaging. The purpose of this study was to compare the diagnostic performance of the latest-generation flat detector CT with multidetector CT. MATERIALS AND METHODS: Prospectively derived data from patients with ischemic stroke with large-vessel occlusion and mechanical thrombectomy were analyzed in this monocentric study. All included patients underwent multidetector CT before referral to our comprehensive stroke center and flat detector CT in the angiography suite before mechanical thrombectomy. Diagnosis of early ischemic signs, quantified by the ASPECTS, was compared between modalities using cross tables, the Pearson correlation, and Bland-Altman plots. The predictive value of multidetector CT- and flat detector CT-derived ASPECTS for functional outcome was investigated using area under the receiver operating characteristic curve analysis. RESULTS: Of 25 patients, 24 (96%) had flat detector CT with sufficient diagnostic quality. Median multidetector CT and flat detector CT ASPECTSs were 7 (interquartile range, 5.5-9 and 4.25-8, respectively) with a mean period of 143.6 ± 49.5 minutes between both modalities. The overall sensitivity was 85.1% and specificity was 83.1% for flat detector CT ASPECTS compared with multidetector CT ASPECTS as the reference technique. Multidetector CT and flat detector CT ASPECTS were strongly correlated (r = 0.849, P < .001) and moderately predicted functional outcome (area under the receiver operating characteristic curve, 0.738; P = .007 and .715; P = .069, respectively). CONCLUSIONS: Determination of ASPECTS on flat detector CT is feasible, showing no significant difference compared with multidetector CT ASPECTS and a similar predictive value for functional outcome. Our findings support the use of flat detector CT for emergency stroke imaging before mechanical thrombectomy to reduce door-to-groin time.

[Percutaneous Phil™-Embolization for Preoperative Therapy of Carotid Body Paragangliomas]. / Perkutane Phil™-Embolisation zur präoperativen Therapie von Karotis-Paragangliomen.

Introduction: Paragangliomas are rare tumors representing a therapeutic challenge. In particular, the surgical removal may lead to life-threatening bleeding. The preoperative percutaneous embolization is an alternative that allows a high closure rate of tumor-feeding vessels in a short intervention time and thus significantly reduces intraoperative bleeding probability. Complete tumor resection is facilitated thereby. The use of a new non-adhesive liquid embolic agent is presented here. Methods: A 50-year old patient presented with 4 cm large paraganglioma of the carotid body (Shamblin II). A percutaneous embolization with 7 ml PHIL™ (injectable precipitating hydrophobic liquid) was performed preoperatively. 24 h later the complete surgical resection of the tumor was performed. Results: A good distribution of the liquid embolic agent could be achieved over the entire tumor. Intraoperative resection of the tumor was much easier and faster due to low bleeding tendency over the entire surface of the tumor. Total blood loss was less than 50 ml. All adjacent nerve and arterial structures could be spared. Postoperative nerve function was normal and the patient was discharged on the 4th postoperative day. Conclusion: The combination of percutaneous embolization and surgical resection provides a safe combination in the treatment of advanced carotid body paragangliomas. The use of a novel liquid embolic agent may possibly further optimize the therapy.

Emergency Stenting of the Extracranial Internal Carotid Artery in Combination with Anterior Circulation Thrombectomy in Acute Ischemic Stroke: A Retrospective Multicenter Study.

BACKGROUND AND PURPOSE: Several small case series reported a favorable clinical outcome for emergency stent placement in the extracranial internal carotid artery combined with mechanical thrombectomy in acute stroke. The rate of postinterventional symptomatic intracranial hemorrhages was reported to be as high as 20%. Therefore, we investigated the safety and efficacy of this technique in a large multicentric cohort. MATERIALS AND METHODS: The data bases of 4 German stroke centers were screened for all patients who received emergency stent placement of the extracranial internal carotid artery in combination with mechanical thrombectomy of the anterior circulation between 2007 and 2014. The primary outcome measure was the rate of symptomatic intracranial hemorrhage according to the European Cooperative Acute Stroke Study III criteria; secondary outcome measures included the angiographic revascularization results and clinical outcome. RESULTS: One hundred seventy patients with a median age of 64 years (range, 25-88 years) were treated. They presented after a median of 98 minutes (range, 52-160 minutes) with a median NIHSS score of 15 (range, 12-19). Symptomatic intracranial hemorrhages occurred in 15/170 (9%) patients; there was no statistically significant difference among groups pertaining to age, sex, intravenous rtPA, procedural timings, and the rate of successful recanalization. In 130/170 (77%) patients, a TICI score of ≥ 2b could be achieved. The in-hospital mortality rate was 19%, and 36% of patients had a favorable outcome at follow-up. CONCLUSIONS: Emergency stent placement in the extracranial internal carotid artery in combination with anterior circulation thrombectomy is effective and safe. It is not associated with a significantly higher risk of symptomatic intracranial hemorrhage compared with published series for mechanical thrombectomy alone.

Recanalization of large intracranial vessels using the penumbra system: a single-center experience.

BACKGROUND AND PURPOSE: The PS is an innovative mechanical device designed to recanalize large-vessel occlusions by thrombus aspiration. The purpose of this study was to evaluate the effectiveness and neurologic outcome of patients treated with the PS in the setting of acute ischemic stroke. MATERIALS AND METHODS: A total of 91 patients with acute ischemic stroke due to large-vessel occlusion were treated with the PS and were included in our retrospective study. In 14 patients, only the PS was used for treatment; in 77 patients, mechanical recanalization was combined with IA and/or IV thrombolysis. Outcome was measured by using the mRS; recanalization was assessed with the TICI score. RESULTS: Mean patient age was 62 ± 19.4 years; the average NIHSS score at hospital admission was 17. Successful recanalization was achieved in 77% of patients. Median time from arterial puncture to recanalization was 49 minutes (quartiles, 31-86 minutes). At follow-up, 36% of the patients showed an NIHSS improvement of ≥10%, and 34% of the patients with an anterior circulation occlusion had an mRS score of ≤2, whereas only 7% of the patients with a posterior occlusion had a favorable outcome at follow-up. In total, 20 patients died during hospitalization; none of these deaths were device-related. CONCLUSIONS: In this study, the PS was an effective device for mechanical recanalization. Successful recanalization with the PS was associated with significant improvement of functional outcome in patients experiencing ischemic stroke secondary to anterior circulation occlusions.

Feasibility of flat panel angiographic CT after intravenous contrast agent application in the postoperative evaluation of patients with clipped aneurysms.

BACKGROUND AND PURPOSE: Important findings, such as aneurysm remnants or major arterial occlusion, can be detected on intra- or postoperative angiography after surgical clipping of intracranial aneurysms. The purpose of this study was to evaluate the feasibility of IV-ACT for the postoperative detection of residual aneurysms and parent vessel patency compared with IA-DSA, which was selected as the standard reference method. MATERIALS AND METHODS: Twenty-two patients with 27 aneurysms treated by surgical clipping were examined by using both IA-DSA and IV-ACT. Both diagnostic procedures were performed on an FPD-equipped angiography system. Postprocessing of IV-ACT acquisitions was performed on a dedicated workstation producing multiplanar reformations and maximum intensity projections of the clip region and other intracranial arteries. Three interventional neuroradiologists independently evaluated both procedures. RESULTS: A residual aneurysm was delineated in 10 cases with IA-DSA. Sufficient opacification of the intracranial vessels was assigned in 26 IV-ACT cases. Due to metal artifacts, IV-ACT images were tagged as "not diagnostic" on 8 occasions. In the other 19 aneurysms, a residual aneurysm was delineated in 6 cases-all 6 being true-positive compared with IA-DSA-and was excluded in the remaining 13 cases-all true-negative. Even small aneurysm remnants with a diameter of 1.5 mm were detected with IV-ACT. CONCLUSIONS: Currently IV-ACT cannot be recommended as a routine tool for postoperative evaluation of clipped aneurysms due to metal artifacts in 30% of the examinations. These artifacts appear with multiple normal-sized or large clips. In patients with single or multiple small clips, IV-ACT can reliably show aneurysm remnants.

Angiographic CT after intravenous contrast agent application: A noninvasive follow-up tool after intracranial angioplasty and stenting.

BACKGROUND AND PURPOSE: ICAS is one of the therapeutic options in symptomatic cerebral artery stenosis. iaDSA is the current criterion standard examination after ICAS for the detection of ISR. In this study, we evaluated ivACT as a potential noninvasive follow-up alternative. MATERIALS AND METHODS: In 17 cases, ivACT and iaDSA were performed after ICAS. Both procedures were carried out on a flat-panel-detector-equipped angiography system. Postprocessing of ivACT acquisitions was performed on a dedicated workstation producing multiplanar reformations of the stent region and other intracranial arteries. Restenotic lesions were compared with iaDSA measurements. All studies were independently evaluated by 2 experienced neuroradiologists blinded to patients data. RESULTS: In 5 cases, ISR was diagnosed on iaDSA images. All restenotic lesions were reliably detected (sensitivity, 100%; 95%CI, 48%-100%) and could be correctly quantified on ivACT images in comparison with iaDSA. The neuroradiologists correctly excluded ISR in 11 of 12 lesions after viewing the ivACT examinations (specificity, 92%; 95%CI, 62%-100%). Measurements of ISR on ivACT were highly correlated to iaDSA (Pearson r = 0.94, P < .01). CONCLUSIONS: IvACT is a promising noninvasive follow-up examination after ICAS. With its high spatial resolution, it can reliably detect or exclude ISR. Contrary to iaDSA, there is no need for a recovery period after ivACT and the risk of neurologic complications is practically lowered to zero.

Feasibility of angiographic CT in peri-interventional diagnostic imaging: a comparative study with multidetector CT.

BACKGROUND AND PURPOSE: The ability to perform neuroimaging on the angiography suite is important in making decisions during neurointerventions. Our aim was the evaluation of ACT as a fast available diagnostic tool during and after neuroendovascular procedures and the comparison of ACT with postinterventional MDCT. MATERIALS AND METHODS: Eighty-four peri-interventional ACT acquisitions were obtained and evaluated: 38 after coil embolization of cerebral aneurysms, 16 after intracranial angioplasty with stent placement, and 30 after endovascular mechanical thrombectomy and lysis. Interventions and ACTs were performed on a biplane angiography system equipped with flat panel detectors. Postprocessing was performed on a dedicated workstation, and multiplanar reformations were generated. Reference studies were performed on a 16- or 128-section MDCT scanner. All studies were independently evaluated by 3 blinded neuroradiologists. The Wilcoxon test was applied for the statistical analysis. RESULTS: ACT and MDCT images were of equal diagnostic quality in most cases related to the supratentorial ventricular system and the detection of hemorrhages (subarachnoidal, intraparenchymal, and intraventricular). Regarding the supratentorial ventricular system, an adequate diagnostic quality was assigned to 94% of the ACT acquisitions. For the detection of hemorrhage, no statistically significant difference was noted between ACT and MDCT. However, for the infratentorial region, ACT performed relatively poorly compared with MDCT. The diagnostic evaluation of gray matter (basal ganglia, insular cortex, and central cortex) by ACT is not sufficient, with <20% of the acquisitions scoring a diagnostic value. CONCLUSIONS: After neuroendovascular procedures and within the angiography suite, ACT enables an immediate detection of peri-interventional hemorrhage or hydrocephalus. However, for the detection of cerebral infarction, ACT is not yet reliable.