The Impact of Different CT Perfusion Software on Patient Stratification Strategies in Ischemic Stroke

Different types of software to analyze CTP data in patients with ischemic stroke are available. Assessing their comparability and interchangeability in clinical practice represents an only partly addressed question. Here we present a comparison between 2 distinct commercially available CTP types of software, analyzing their performance in estimating ischemic core volumes and evaluating the possible impact on patient stratification strategies to endovascular treatment (EVT).

In this single-center retrospective monocentric observational study, 109 patients with stroke (mean age = 72.4 ± 12.4 years, M/F = 41/68) were included from January 2023 to June 2024. To evaluate the possible clinical relevance of the use of different types of software, DAWN and DEFUSE-3 criteria were applied to stratify the population. The software was compared (Viz.ai and syngo.via), and for both programs, different relative CBF thresholds were used to define the ischemic core.

The 2 software programs showed significant differences in core volume identification, independently from the used threshold (all comparisons with P < .001). When the DAWN criteria for EVT were applied, the use of one software compared with another led to a significant (P = .005) increase in subjects excluded from EVT. The use of a more conservative threshold significantly reduced (P = .68) this discrepancy.

Within-subject analysis of CTP data with different software and thresholds might lead to significantly different core estimation and treatment stratification in patients with stroke. Though this effect can be mitigated by using specific thresholds, the physician should be aware of these differences when evaluating CTP data in clinical practice, given the possible direct implications in their decision-making process.