Petra Cimflová

Single-Phase Versus Multiphase CT Angiography in Middle Cerebral Artery Clot Detection—Benefits for Less Experienced Radiologists and Neurologists

OBJECTIVES CT angiography (CTA) is recommended as a standard of stroke imaging. We investigated accuracy and precision of standard or single-phase CTA as compared with novel technique or multiphase CTA in clot detection in the middle cerebral artery. METHODS Twenty single-phase CTA and twenty multiphase CTA with prevailing M2 occlusion were assessed by 10 radiologists and 10 neurologists blinded to clinical information (7 less experienced and 3 experienced). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated as compared with reading by two seniors. Reliability was calculated using Krippendorffs alpha (K-alpha). RESULTS Sensitivity, specificity, PPV, and NPV of single-phase CTA compared with multiphase CTA for M2 clot presence were, respectively, .86, .75, .90, and .67 versus .88, .82, .92, and .72. For secondary or distal clots, sensitivity, specificity, PPV, and NPV of single-phase CTA compared with multiphase CTA were .41, .83, .50, and .78 versus .65, .77, .71, and .67. Agreement increased significantly in favor of multiphase CTA for detection of primary clots from moderate (.43) to substantial (.65) in less experienced radiologists and from slight (.10) to moderate (.30) in less experienced neurologists. Agreement significantly increased for distal or secondary clot detection in favor of multiphase CTA from fair (.24) to moderate (.49) in experienced radiologists and from slight (.12) to moderate (.46) in experienced neurologists. CONCLUSIONS Multiphase CTA is a reliable imaging tool in M2 clot detection and might represent a beneficial imaging tool in clot detection for less experienced physicians.

Inter-Rater Reliability for Thrombolysis in Cerebral Infarction with TICI 2c Category

BACKGROUND AND PURPOSE Thrombolysis in cerebral infarction (TICI) with 2b/3 (>50% of occluded territory/complete reperfusion) has been regarded as a successful angiographic outcome. To account for near-perfect angiographic results, the category TICI 2c (near-complete reperfusion) has been introduced. As the degree of inter-rater reliability for TICI with 2c category remains poorly studied, we strived to evaluate the agreement among stroke-treating specialists. METHODS All consecutive patients, who underwent stent-retriever thrombectomy for acute ischemic stroke in the period between January 2014 and April 2016 at the Department of Neurointerventional Radiology, were analyzed. Digital subtraction angiography (DSA) images were interpreted using previously reported modified TICI score with TICI 2c (near-complete reperfusion). All DSA runs were scored independently by stroke-treating specialist, by consensus of neuroradiologist and stroke neurologist, and by consensus of neurointerventional fellow and attending. Reliability analysis was performed using Krippendorffs alpha (K-alpha). RESULTS Sixty-one patients were included into analysis of inter-rater agreement. Mean age was 70 years (SD ± 12), 48% were women, and median admission National Institutes of Health Stroke Scale was 16 (IQR = 12-19). Median admission ASPECTS (Alberta Stroke Program Early CT Score) was 8 (IQR 7-9). Forty patients (65%) received intravenous thrombolysis. Agreement for complete modified TICI scale (compared with consensus of neurointerventional fellow and attending) was as follows: fair for stroke physician (K-alpha .36), moderate for neuroradiologist (K-alpha .48), and moderate for neurointerventional fellow (K-alpha .56). Agreement increased to almost perfect when evaluated by consensus of stroke neurologist and neuroradiologist (K-alpha .82). CONCLUSION Inter-rater agreement for modified TICI increased to almost perfect when scored by consensus of stroke-treating specialists.

Mechanical thrombectomy performs similarly in real world practice: a 2016 nationwide study from the Czech Republic

Background Randomized clinical trials have proven mechanical thrombectomy (MT) to be a highly effective and safe treatment in acute stroke. The purpose of this study was to compare neurothrombectomy data from the Czech Republic (CR) with data from the HERMES meta-analysis. Methods Available nationwide data for the CR from 2016 from the Safe Implementation of Treatments in Stroke–Thrombectomy (SITS-TBY) registry for patients with terminal internal carotid artery (ICA) and/or middle cerebral artery (MCA) occlusions were compared with data from HERMES. CR and HERMES patients were comparable in age, sex, and baseline National Institutes of Health Stroke Scale scores. Results From a total of 1053 MTs performed in the CR, 845 (80%) were reported in the SITS-TBY. From these, 604 (72%) were included in this study. Occlusion locations were as follows (CR vs HERMES): ICA 22% versus 21% (P=0.16), M1 MCA 62% versus 69% (P=0.004), and M2 MCA 16% versus 8% (P<0.0001). Intravenous thrombolysis was given to 76% versus 83% of patients, respectively (P=0.003). Median onset to reperfusion times were comparable: 232 versus 285 min, respectively (P=0.66). A modified Thrombolysis in Cerebral Infarction score of 2b/3 was achieved in 74% (433/584) versus 71% (390/549) of patients, respectively (OR 1.17, 95% CI 0.90–1.5, P=0.24). There was no statistically significant difference in the percentage of parenchymalhematoma type 2 (OR 1.12, 95% CI 0.66–1.90, P=0.68). A modified Rankin Scale score of 0–2 at 3 months was achieved in 48% (184/268) versus 46% (291/633) of patients, respectively (OR 0.92, 95% CI 0.71–1.18, P=0.48). Conclusions Data on efficacy, safety, and logistics of MT from the CR were similar to data from the HERMES collaboration.

Ipsilateral Sinus Hypoplasia and Poor Leptomeningeal Collaterals as Midline Shift Predictors.

BACKGROUND We explore the role of dural sinus morphology, leptomeningeal collaterals, and clot localization in the development of malignant brain edema in acute ischemic stroke in anterior circulation. METHODS This is a single-center retrospective study of consecutive stroke patients with acute occlusion (middle cerebral artery M1 ± intracranial internal carotid artery) treated with intravenous thrombolysis (from November 2009 to November 2014). Admission computed tomography angiography data were evaluated for hypoplasia of dural sinuses, leptomeningeal collaterals, and clot location. Primary outcome was midline shift (<5 mm versus ≥5 mm) on follow-up computed tomography. Secondary outcomes were infarct volume and modified Rankin Scale score of 2 or lower at 90 days. Multivariate logistic regression was used. RESULTS Of 86 patients (49 females), 36 (42%) had poor collaterals, 26 (30%) had ipsilesional sinus hypoplasia, and 38 (44%) had proximal clots. A midline shift of 5 mm or higher was diagnosed in 14 patients (16%). Infarct volume was larger in the group with midline shift (median: 318 mL [interquartile range {IQR} = 260-350]) than in the group without midline shift (median: 44 mL [IQR = 28-60]) (P = .007). In multivariate analysis, poor leptomeningeal collaterals (odds ratio [OR] = .11, 95% confidence interval [CI] = .03-.44, P = .002 for good collaterals) and ipsilesional sinus hypoplasia (OR = 6.43, 95% CI = 1.5-46.1, P = .008) were independently associated with a midline shift of 5 mm or higher. CONCLUSION Patients with poor leptomeningeal collaterals and ipsilesional hypoplasia of dural sinuses are more likely to develop midline shift.

24-Hour Alberta Stroke Program Early CT Score Assessment in Post-Stroke Spasticity Development in Patients with a First Documented Anterior Circulation Ischemic Stroke

BACKGROUND Neuroanatomic substrates responsible for development of post-stroke spasticity are still poorly understood. The study is focused on identification of brain regions within the territory of the middle cerebral artery associated with spasticity development. METHODS This is a single-center prospective cohort study of first documented anterior circulation ischemic strokes with a neurologic deficit lasting >7 days (from March 2014 to September 2016, all patients are involved in a registry). Ischemic cerebral lesions within the territory of middle cerebral artery were evaluated using the Alberta Stroke Program Early CT Score (ASPECTS) on control 24-hour computed tomography or magnetic resonance imaging. Spasticity was assessed with modified Ashworth scale. RESULTS Seventy-six patients (mean age 72 years, 45% females; 30% treated with IV tissue plasminogen activator, 6.5% mechanical thrombectomy) fulfilled the study inclusion criteria. Forty-nine (64%) developed early elbow or wrist flexor spasticity defined as modified Ashworth scale >1 (at day 7-10), in 44 (58%) the spasticity remained present at 6 months. There were no differences between the patients who developed spasticity and those who did not when comparing admission stroke severity (National Institutes of Health Stroke Scale 5 [interquartile range {IQR} 4-8] versus 6 [IQR 4-10]) and vascular risk factors (hypertension, diabetes mellitus, dyslipidemia, atrial fibrillation, coronary artery disease). Nor was there a difference in 24-hour ASPECTS score (9 [IQR 8-10] versus 9 [IQR 7-10]). No differences were found between the groups with and without the early upper limb flexor spasticity of particular regions (M1, M2, M3, M4, M5, M6, lentiform, insula, caudate, internal capsule) and precentral-postcentral gyrus, premotor cortex, supplementary motor area, posterior limb of internal capsule, and thalamus were compared. CONCLUSIONS We did not find any middle cerebral artery territory associated with post-stroke spasticity development by detailed evaluation of ASPECTS.

Permeability surface area product analysis in malignant brain edema prediction – A pilot study

BACKGROUND AND PURPOSE Using an extended CT perfusion acquisition (150s), we sought to determine the association between perfusion parameters and malignant edema after ischemic stroke. METHODS Patients (from prospective study PROVE-IT, NCT02184936) with terminal internal carotid artery±proximal middle cerebral occlusion were involved. CTA was assessed for clot location and status of leptomeningeal collaterals. The following CTP parameters were calculated within the ischemic territory and contralaterally: permeability surface area product (PS), cerebral blood flow (CBF) and cerebral blood volume (CBV). PS was calculated using the adiabatic approximation to the Johnson and Wilson model. Outcome was evaluated by midline shift and infarction volume on follow-up imaging. RESULTS Of 200 patients enrolled, 7 patients (3.5%) had midline shift≥5mm (2 excluded for poor-quality scans). Five patients with midline shift and 5 matched controls were analysed. There was no significant difference in mean PS, CBF and CBV within the ischemic territory between the two groups. A CBV threshold of 1.7ml/100g had the highest AUC=0.72, 95% CI=0.54-0.90 for early midline shift prediction, sensitivity and specificity were 0.83 and 0.67 respectively. CONCLUSION Our preliminary results did not show significant differences in permeability surface area analysis if analysed for complete ischemic region. CBV parameter had the highest accuracy and there was a trend for the mean PS values for midline shift prediction.