Ultrasound biomicroscopy in the quantification of brain perfusion parameters of a rat stroke model: Analysis of contrast agent bolus kinetic dynamics.

Background: Ischemic stroke represents a significant global health concern, necessitating thorough investigations and the utilization of stroke animal models to explore novel treatment modalities and diagnostic imaging techniques.
New Method: Ultrasound biomicroscopy (BMU), operating at a center frequency of 21 MHz, along with ultrasound contrast agents (UCAs), was used to quantify microcirculation cerebral blood flow in a rat model of ischemic stroke. The microcirculation parameters were derived from time intensity curve (TIC) plots obtained based on UCA-bolus kinetics.
Results: Semiquantitative perfusion-related parameters were assessed. The TIC curves showed differences in amplitude when compared intra-animal between the left and right sides, and three situations were observed: normal perfusion, hypoperfusion, and nonperfusion. ROC analysis of delays between the left and right time intensity peak (TIP) for regions of interest (ROIs) in the control and stroke-hypoperfusion groups revealed an optimal cutpoint of 0.39 s to indicate when hypoperfusion is occurring in rats, with a sensitivity of 93.33 % and a specificity of 80 %.
Comparison With Existing Method(s): Ultrasound perfusion imaging through the temporal bone window has been clinically applied to stroke patients using a UCA bolus for TIC analysis. TIC parameters were correlated with MRI- and CT-based measurements.
Conclusions: This investigation quantified cerebral blood flow in a rat model of ischemic stroke by measuring microcirculation parameters. The study demonstrated the efficacy of this approach as a valuable tool for conducting preclinical studies.
Competing Interests: Declaration of Competing Interest None.
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