Brain Computed Tomography Angiography Maximum Intensity Projection Images for ASPECTS Derivation and Detection of Large Infarct Volumes: Preliminary Study

Purpose: Non-contrast CT ASPECTS (NCCT_asp) has an established role in determining eligibility for mechanical thrombectomy in centers without ready access to perfusion or DWI. Moreover, it has been suggested that CTA source ASPECTS (CTA_asp) may be superior to NCCT_asp in predicting final infarct volume (FIV). In this study, we hypothesized that CTA maximum intensity projection ASPECTS (MIPS_asp) would be superior compared to both NCCT_asp and CTA_asp in predicting FIV as measured by DWI. Materials and Methods: In 41 consecutive patients with MCA territory infarcts, NCCT_asp, CTA_asp and MIPS_asp were visually assessed by 2 neuroradiologists. Disagreements were adjudicated by a third neuroradiologist, and the reconciled data used for all further analysis. MR-DWI was used as the standard for FIV determination. Receiver operating characteristic curve analysis was used to compare the area under the curve for all three CT-based methods in predicting FIV ≥70 ml. Results: MIPS_asp (AUC: 0.98, CI: 0.88–1.00) were statistically better than NCCT_asp (AUC: 0.87, 95% CI: 0.72–0.95; p=0.01) in predicting FIV ≥70 ml. MIPS_asp were also superior to CTA_asp (AUC: 0.9, CI: 0.79–.98; p˂0.05). Optimal test performance for predicting FIV ≥70 ml for MIPS_asp was ≤6 (sensitivity=100%, specificity=91.4%; Youden's J=0.98). Conclusion: Our preliminary study suggests that a novel CTA-MIPS derived ASPECTS better predicts large MCA territory infarcts compared to CTA source and non-contrast ASPECTS. Thus, MIPS_asp may be a promising technique for future studies aimed at improving ischemic stroke treatment in centers using ASPECTS for stroke management.