Delayed phase computed tomography angiography ASPECTS predicts clinical outcome and final infarct volume

Abstract

Background and purpose: Non-contrast computed tomography (NCCT) Alberta Stroke Program Early CT Score (ASPECTS) and assessment of collateral flow with multiphase computed tomography angiography (CTA) have been investigated as predictors of clinical outcome in patients with acute ischemic stroke. This study assessed the value of multiphase CTA ASPECTS in predicting final infarction core and clinical outcome in patients undergoing endovascular treatment of acute ischemic stroke.

Methods: We retrospectively studied consecutive patients who underwent multiphase CTA prior to endovascular treatment of acute stroke due to anterior circulation large artery occlusion. Multiphase CTA and final diffusion-weighted imaging (DWI) scans were evaluated by two independent observers for NCCT ASPECTS, acute phase CTA (CTA-AP) ASPECTS, delayed phase CTA (CTA-DP) ASPECTS, and final DWI ASPECTS. Modified Rankin Scale score ≤2 at 3 months was considered a favorable outcome.

Results: A total of 74 patients were analyzed. We found that CTA-DP ASPECTS (r = 0.82; 95% CI, 0.73-0.91; p < 0.001) correlated with final DWI ASPECTS better than NCCT ASPECTS (r = 0.49; 95% CI, 0.39-0.59) and CTA-AP ASPECTS (r = 0.71; 95% CI, 0.64-0.78). Interobserver agreement was higher for CTA-DP ASPECTS (k = 0.84). Good CTA-DP ASPECTS was an independent predictor of favorable outcome (odds ratio, 8.71; 95% CI, 3.71-17.3; p < 0.001).

Conclusion: CTA-DP ASPECTS is a reliable predictor of final infarction core and neurological outcome.

Fig 1

Correlation of ASPECTS on NCCT (A), CTA-AP (B), and CTA-DP (C) with final DWI ASPECTS.

Fig 2. A patient in their 60s’ was admitted with acute left hemiparesis and dysarthria 45 min after symptom onset.

(A) Non-contrast computed tomography showed subtle hypodensity of the right insular cortex and lentiform nucleus. (B) Arterial phase computed tomography angiography (CTA) demonstrated hypodensity involving the right insular cortex, lentiform nucleus, internal capsule, and right parietotemporal lobe. (C) Delayed phase CTA demonstrated subtle hypodensity of the right lentiform nucleus. (D) A right carotid angiogram showed an occlusion of the right middle cerebral artery. (E) The angiogram after endovascular thrombectomy showed complete recanalization of the middle cerebral artery. (F) Follow-up diffusion-weighted imaging demonstrated a small area of acute infarction in the right lentiform nucleus.