Derivation and validation of three intracerebral hemorrhage expansion scores using different CT modalities.

OBJECTIVES: To derivate and validate three scores for the prediction of intracerebral hemorrhage (ICH) expansion depending on the use of non-contrast CT (NCCT), single-phase CTA, or multiphase CTA markers of hematoma expansion, and to evaluate the added value of single-phase and multiphase CTA over NCCT. METHODS: After prospectively deriving NCCT, single-phase CTA, and multiphase CTA hematoma expansion scores in 156 patients with ICH < 6 h, we validated them in 120 different patients. Discrimination and calibration of the three scores was assessed. Primary outcome was substantial hematoma expansion > 6 mL or > 33% at 24 h. RESULTS: The evaluation of single-phase and multiphase CTA markers gave a steadily increase in discrimination for substantial hematoma expansion over NCCT markers. The C-index (95% confidence interval) in derivation and validation cohorts was 0.69 (0.58-0.80) and 0.59 (0.46-0.72) for NCCT score, significantly lower than 0.75 ([0.64-0.87], p = 0.038) and 0.72 ([0.59-0.84], p = 0.016) for single-phase CTA score, and than 0.79 ([0.68-0.89], p = 0.033) and 0.73 ([0.62-0.85], p = 0.031) for multiphase CTA score, respectively. The three scores showed good calibration in both derivation and validation cohorts: NCCT (χ2 statistic 0.389, p = 0.533; and χ2 statistic 0.352, p = 0.553), single-phase CTA (χ2 statistic 2.052, p = 0.359; and χ2 statistic 2.230, p = 0.328), and multiphase CTA (χ2 statistic 0.559, p = 0.455; and χ2 statistic 0.020, p = 0.887) scores, respectively. CONCLUSION: This study shows the added prognostic value of more advanced CT modalities in acute ICH evaluation. NCCT, single-phase CTA, and multiphase CTA scores may help to refine the selection of patients at risk of expansion in different decision-making scenarios. KEY POINTS: • This study shows the added prognostic value of more advanced CT modalities in acute intracerebral hemorrhage evaluation. • The evaluation of single-phase and multiphase CTA markers provides a steadily increase in discrimination for intracerebral hemorrhage expansion over non-contrast CT markers. • Non-contrast CT, single-phase CTA, and multiphase CTA scores may help clinicians and researchers to refine the selection of patients at risk of intracerebral hemorrhage expansion in different decision-making scenarios.

Ghost Infarct Core and Admission Computed Tomography Perfusion: Redefining the Role of Neuroimaging in Acute Ischemic Stroke.

BACKGROUND: Determining the size of infarct extent is crucial to elect patients for reperfusion therapies. Computed tomography perfusion (CTP) based on cerebral blood volume may overestimate infarct core on admission and consequently include ghost infarct core (GIC) in a definitive lesional area. PURPOSE: Our goal was to confirm and better characterize the GIC phenomenon using CTP cerebral blood flow (CBF) as the reference parameter to determine infarct core. METHODS: We performed a retrospective, single-center analysis of consecutive thrombectomies of middle cerebral or intracranial internal carotid artery occlusions considering noncontrast CT Alberta Stroke Program Early CT Score ≥6 in patients with pretreatment CTP. We used the RAPID® software to measure admission infarct core based on initial CBF. The final infarct was extracted from follow-up CT. GIC was defined as initial core minus final infarct > 10 mL. RESULTS: A total of 123 patients were included. The median National Institutes of Health Stroke Scale score was 18 (13-20), the median time from symptoms to CTP was 188 (67-288) min, and the recanalization rate (Thrombolysis in Cerebral Infarction score 2b, 2c, or 3) was 83%. Twenty patients (16%) presented with GIC. GIC was associated with shorter time to recanalization (150 [105-291] vs. 255 [163-367] min, p = 0.05) and larger initial CBF core volume (38 [26-59] vs. 6 [0-27] mL, p < 0.001). An adjusted logistic regression model identified time to recanalization < 302 min (OR 4.598, 95% CI 1.143-18.495, p = 0.032) and initial infarct volume (OR 1.01, 95% CI 1.001-1.019, p = 0.032) as independent predictors of GIC. At 24 h, clinical improvement was more frequent in patients with GIC (80 vs. 49%, p = 0.01). CONCLUSIONS: CTP CBF < 30% may overestimate infarct core volume, especially in patients imaged in the very early time window and with fast complete reperfusion. Therefore, the CTP CBF technique may exclude patients who would benefit from endovascular treatment.

Prehospital Systolic Blood Pressure Is Related to Intracerebral Hemorrhage Volume on Admission.

BACKGROUND AND PURPOSE: Ultra-early blood pressure (BP) management in the prehospital setting could improve the efficacy of this treatment on attenuating intracerebral hemorrhage (ICH) expansion. We aimed to determine the association of prehospital systolic BP (SBP) with ICH volume, ultra-early hematoma growth, and the spot sign on admission. METHODS: We conducted a retrospective study of a prospective database of 219 consecutive patients with spontaneous ICH admitted to the emergency department of a tertiary stroke center during a 3-year period. Prehospital SBP and ICH volume, ultra-early hematoma growth (ICH volume/onset-to-imaging time), and presence of the spot sign on admission were prospectively recorded. Primary outcome was ICH volume on admission. Secondary outcomes included ultra-early hematoma growth and frequency of the spot sign in patients scanned within 6 hours from symptom onset (hyperacute group). RESULTS: Prehospital SBP was positively correlated with both SBP (r=0.552; P<0.001) and ICH volume (ρ=0.189; P=0.006) on admission. Patients with ICH volume above the median value presented higher prehospital SBP (172.3±35.0 versus 163.7±27.8 mm Hg; P=0.049). This association remained significant in adjusted multiple logistic regression analysis (odds ratio, 1.01 for a 1-U increase in SBP; 95% confidence interval, 1.01-1.02; P=0.018). In the hyperacute group (n=126), prehospital SBP was unrelated to ultra-early hematoma growth (ρ=0.115; P=0.203) nor the presence of the spot sign (172.2±27.6 versus 171.8±31.6 mm Hg; P=0.959). CONCLUSIONS: Prehospital SBP is correlated with SBP on admission and independently associated with ICH volume on admission. These findings support the rationale of testing whether prehospital initiation of BP-lowering attenuates ICH expansion.

Multiphase CT Angiography Improves Prediction of Intracerebral Hemorrhage Expansion.

Purpose To determine the prevalence of the spot sign and the accuracy of using the spot sign to predict intracerebral hemorrhage (ICH) expansion with standardized multiphase computed tomographic (CT) angiography. Materials and Methods This prospective observational cohort study included 123 consecutive patients with acute ICH (onset <6 hours). Patients underwent multiphase CT angiography in three automated phases after injection of contrast material. Patients were classified as having one of four patterns (pattern A, B, C, or D) according to the presence of the spot sign in the three phases. Pattern A was the more arterial pattern, and pattern D was the more venous pattern. Ninety-five patients underwent follow-up unenhanced CT 24 hours after symptom onset. Primary outcome was substantial hematoma expansion (>33% or >6 mL) at 24 hours. Associations between the presence of the spot sign and substantial hematoma expansion were assessed by using the Pearson χ2 test. Results The later the phase of CT angiography, the higher the frequency of the spot sign. The spot sign was seen in 29.3% of patients in phase 1, 43.1% of patients in phase 2, and 46.3% of patients in phase 3 (P < .001). The presence of the spot sign in any phase was related to substantial hematoma expansion (P < .001 for all comparisons; Bonferroni adjusted α = .0125), with highest positive predictive value in phase 1 (64.0%) and highest negative predictive value in phase 2 (90.2%). The more arterial the pattern of spot sign presentation, the greater the frequency of substantial hematoma expansion (P = .013). Absolute hematoma growth analysis revealed a hierarchical pattern of spot sign presentations, as follows: A > B > C > D > no spot sign (P = .002). Conclusion Multiphase CT angiography can help differentiate among different forms of spot sign presentation and can help stratify patients at risk for hematoma expansion. The more arterial the spot sign pattern, the greater the frequency and extent of expansion. © RSNA, 2017.

CBV_ASPECTS Improvement over CT_ASPECTS on Determining Irreversible Ischemic Lesion Decreases over Time.

The Alberta Stroke Program Early CT Score (ASPECTS) is a useful scoring system for assessing early ischemic signs on noncontrast computed tomography (CT). Cerebral blood volume (CBV) on CT perfusion defines the core lesion assumed to be irreversibly damaged. We aim to explore the advantages of CBV_ASPECTS over CT_ASPECTS in the prediction of final infarct volume according to time. METHODS: Consecutive patients with anterior circulation stroke who underwent endovascular reperfusion according to initial CT_ASPECTS ≥7 were studied. CBV_ASPECTS was assessed blindly later on. Recanalization was defined as thrombolysis in cerebral ischemia score 2b-3. Final infarct volumes were measured on follow-up imaging. We compared ASPECTS on CBV and CT images, and defined ASPECTS agreement as: CT_ASPECTS - CBV_ASPECTS ≤1. RESULTS: Sixty-five patients, with a mean age of 67 ± 14 years and a median National Institutes of Health Stroke Scale score of 16 (range 10-20), were studied. The recanalization rate was 78.5%. The median CT_ASPECTS was 9 (range 8-10), and the CBV_ASPECTS was 8 (range 8-10). The mean time from symptoms to CT was 219 ± 143 min. Fifty patients (76.9%) showed ASPECTS agreement. The ASPECTS difference was inversely correlated to the time from symptoms to CT (r = -0.36, p < 0.01). A ROC curve defined 120 min as the best cutoff point after which the ASPECTS difference becomes more frequently ≤1. After 120 min, 89.5% of the patients showed ASPECTS agreement (as compared with 37.5% for <120 min, p < 0.01). CBV_ASPECTS but not CT_ASPECTS correlated with final infarct (r = -0.33, p < 0.01). However, if CT was done >2 h after symptom onset, CT_ASPECTS also correlated to final infarct (r = -0.39, p = 0.01). CONCLUSIONS: In acute stroke, CBV_ASPECTS correlates with the final infarct volume. However, when CT is performed after 120 min from symptom onset, CBV_ASPECTS does not add relevant information to CT_ASPECTS.