Ghost infarct core: A systematic review of the frequency, magnitude, and variables of CT perfusion overestimation

Abstract

Background and PurposeCT perfusion (CTP) imaging is now widely used to select patients with large vessel occlusions for mechanical thrombectomy. Ghost infarct core (GIC) phenomenon has been coined to describe CTP core overestimation and has been investigated in several retrospective studies. Our aim is to review the frequency, magnitude, and variables associated with this phenomenon.MethodsA primary literature search resulted in eight studies documenting median time from symptom onset to CTP, median estimated core size, median final infarct volume, median core overestimation of the GIC population, recanalization rates, good outcomes, and collateral status for this systematic review.ResultsAll the studies investigated patients who underwent CTP within 6 hours of symptom onset, ranging from median times of 105 to 309 minutes. The frequency of core overestimation varied from 6% to 58.4%, while the median estimated ischemic core and final infarction volume ranged from 7 to 27 mL and 12 to 31 mL, respectively. The median core overestimation ranged from 3.6 to 30 mL with upper quartile ranges up to 58 mL. GIC was found to be a highly time‐and‐collateral‐dependent process that increases in frequency and magnitude as the time from symptom onset to imaging decreases and in the presence of poor collaterals.ConclusionsCTP ischemic core overestimation appears to be a relatively common phenomenon that is most frequent in patients with poor collaterals imaged within the acute time window. Early perfusion imaging should be interpreted with caution to prevent the inadvertent exclusion of patients from highly effective reperfusion therapies.

Comparison of two automated CT perfusion software packages in patients with ischemic stroke presenting within 24 hours of onset

“…7 Gradually, relative CBF (rCBF) has emerged as the preferred metric for determining the ischemic core. 8 A threshold for the time to peak of the residue function (Tmax) exceeding 6 seconds has been identified as a reliable predictor for tissues at risk of infarction if there is no reperfusion. 9 However, the extent to which different software solutions can be used interchangeably, especially in terms of their clinical significance for planning treatment and estimating prognosis, remains uncertain.…”

Comparison of two automated CT perfusion software packages in patients with ischemic stroke presenting within 24 h of onset

“…Nonetheless, there has been considerable inconsistency in the parameters of CTP and the quantitative benchmarks set for delineating the ischemic core and penumbra ( Yedavalli et al, 2023 ). Gradually, relative CBF (rCBF) has emerged as the preferred metric for determining the ischemic core ( Ballout et al, 2023 ). A threshold for the time to peak of the residue function ( T max ) exceeding 6 s has been identified as a reliable predictor for tissues at risk of infarction if there is no reperfusion ( Fainardi et al, 2022 ).…”