Evaluation of an optimized metal artifact reduction algorithm for flat-detector angiography compared to DSA imaging in follow-up after neurovascular procedures.

BACKGROUND: Flat detector CT - angiography (FDCTA) has become a valuable imaging tool in post- and peri-interventional imaging after neurovascular procedures. Metal artifacts produced by radiopaque implants like clips or coils still impair image quality. METHODS: FDCTA was performed in periprocedural or follow-up imaging of 21 patients, who had received neurovascular treatment. Raw data was sent to a dedicated workstation and subsequently a metal artifact reduction algorithm (MARA) was applied. Two neuroradiologists examined the images. RESULTS: Application of MARA improved image appearance and led to a significant reduction of metal artifacts. After application of MARA only 8 datasets (34% of the images) were rated as having many or extensive artifacts, before MARA 15 (65%) of the images had extensive or many artifacts. Twenty percent more cases of reperfusion were diagnosed after application of MARA, congruent to the results of digital subtraction angiography (DSA) imaging. Also 3 (13% of datasets) images, which could not be evaluated before application of MARA, could be analyzed after metal artifact reduction and reperfusion could be excluded. CONCLUSION: Application of MARA improved image evaluation, reduced the extent of metal artifacts, and more cases of reperfusion could be detected or excluded, congruent to DSA imaging.

Influence of beta-blocker therapy on the risk of infections and death in patients at high risk for stroke induced immunodepression.

BACKGROUND: Stroke-induced immunodepression is a well characterized complication of acute ischemic stroke. In experimental studies beta-blocker therapy reversed stroke-induced immunodepression, reduced infection rates and mortality. Recent, heterogeneous studies in stroke patients could not provide evidence of a protective effect of beta-blocker therapy. Aim of this study is to investigate the potential preventive effect of beta-blockers in subgroups of patients at high risk for stroke-induced immunodepression. METHODS: Data from a prospectively derived registry of major stroke patients receiving endovascular therapy between 2011-2017 in a tertiary stroke center (University Medical Center Göttingen. Germany) was used. The effect of beta-blocker therapy on pneumonia, urinary tract infection, sepsis and mortality was assessed using multivariate logistic regression analysis. RESULTS: Three hundred six patients with a mean age of 72 ± 13 years and a median NIHSS of 16 (IQR 10.75-20) were included. 158 patients (51.6%) had pre-stroke- and continued beta-blocker therapy. Beta-blocker therapy did not reduce the incidence of pneumonia (OR 0.78, 95% CI 0.31-1.92, p = 0.584), urinary tract infections (OR 1.51, 0.88-2.60, p = 0.135), sepsis (OR 0.57, 0.18-1.80, p = 0.334) or mortality (OR 0.59, 0.16-2.17, p = 0.429). Strokes involving the insula and anterio-medial cortex increased the risk for pneumonia (OR 4.55, 2.41-8.56, p<0.001) and sepsis (OR 4.13, 1.81-9.43, p = 0.001), while right hemispheric strokes increased the risk for pneumonia (OR 1.60, 0.92-2.77, p = 0.096). There was a non-significantly increased risk for urinary tract infections in patients with beta-blocker therapy and insula/anterio-medial cortex strokes (OR 3.12, 95% CI 0.88-11.05, p = 0.077) with no effect of beta-blocker therapy on pneumonia, sepsis or mortality in both subgroups. CONCLUSIONS: In major ischemic stroke patients, beta-blocker therapy did not lower post-stroke infection rates and was associated with urinary tract infections in a subgroup with insula/anterio-medial strokes.

One-Stop Management of Acute Stroke Patients: Minimizing Door-to-Reperfusion Times.

BACKGROUND AND PURPOSE: Intrahospital time delays significantly affect the neurological outcome of stroke patients with large-vessel occlusion. This study was conducted to determine whether a one-stop management can reduce intrahospital times of patients with acute large-vessel occlusion. METHODS: In this observational study, we report the first 30 consecutive stroke patients imaged and treated in the same room. As part of our protocol, we transported patients with a National Institutes of Health Stroke Scale score of ≥10 directly to the angio suite, bypassing multidetector computed tomography (CT). Preinterventional imaging consisted of noncontrast flat detector CT and flat detector CT angiography, acquired with an angiography system. Patients with large-vessel occlusions remained on the angio table and were treated with mechanical thrombectomy; patients with small artery occlusions were treated with intravenous thrombolysis, whereas patients with an intracranial hemorrhage and stroke mimics were treated as per guidelines. Door-to-groin puncture times were recorded and compared with our past results. RESULTS: Thirty patients were transferred directly to our angio suite from June to December 2016. The time from symptom onset to admission was 105 minutes. Ischemic stroke was diagnosed in 22 of 30 (73%) patients, 4 of 30 (13.5%) had an intracranial hemorrhage, and 4 of 30 (13.5) were diagnosed with a Todd's paresis. Time from admission to groin puncture was 20.5 minutes. Compared with 44 patients imaged with multidetector CT in the first 6 months of 2016, door-to-groin times were significantly reduced (54.5 minutes [95% confidence interval, 47-61] versus 20.5 minutes [95% confidence interval, 17-26]). CONCLUSIONS: In this small series, a one-stop management protocol of selected stroke patients using latest generation flat detector CT led to a significant reduction of intrahospital times.

Latest generation of flat detector CT as a peri-interventional diagnostic tool: a comparative study with multidetector CT.

BACKGROUND AND PURPOSE: Flat detector CT (FDCT) has been used as a peri-interventional diagnostic tool in numerous studies with mixed results regarding image quality and detection of intracranial lesions. We compared the diagnostic aspects of the latest generation FDCT with standard multidetector CT (MDCT). MATERIALS AND METHODS: 102 patients were included in our retrospective study. All patients had undergone interventional procedures. FDCT was acquired peri-interventionally and compared with postinterventional MDCT regarding depiction of ventricular/subarachnoidal spaces, detection of intracranial hemorrhage, and delineation of ischemic lesions using an ordinal scale. Ischemic lesions were quantified with the Alberta Stroke Program Early CT Scale (ASPECTS) on both examinations. Two neuroradiologists with varying grades of experience and a medical student scored the anonymized images separately, blinded to the clinical history. RESULTS: The two methods were of equal diagnostic value regarding evaluation of the ventricular system and the subarachnoidal spaces. Subarachnoidal, intraventricular, and parenchymal hemorrhages were detected with a sensitivity of 95%, 97%, and 100% and specificity of 97%, 100%, and 99%, respectively, using FDCT. Gray-white differentiation was feasible in the majority of FDCT scans, and ischemic lesions were detected with a sensitivity of 71% on FDCT, compared with MDCT scans. The mean difference in ASPECTS values on FDCT and MDCT was 0.5 points (95% CI 0.12 to 0.88). CONCLUSIONS: The latest generation of FDCT is a reliable and accurate tool for the detection of intracranial hemorrhage. Gray-white differentiation is feasible in the supratentorial region.