Evaluation of Neonatal Regional Cerebral Perfusion Using Power Doppler and the Index Fractional Moving Blood Volume

Abstract

Background: The high cerebral morbidity of premature neonates is thought to be related to changes in tissue perfusion in vulnerable areas of the brain. Quantification of power Doppler (PD) images using the index fractional moving blood volume (FMBV) may allow measurement of regional cerebral perfusion. Objective: To evaluate the reproducibility of calculating FMBV using PD ultrasound images to estimate cerebral perfusion. Methods: Two experienced clinicians performed head ultrasounds on 24 normally-grown neonates at less than 33 weeks’ gestation. Both clinicians independently acquired and stored three PD images in two different coronal planes. FMBV was calculated offline after selecting two predefined regions of interest within these planes (basal ganglia and subependymal regions). Reproducibility was evaluated by calculating the intraclass correlation coefficient (intraCC) and the interclass correlation coefficient (interCC). Results: FMBV was successfully evaluated in 24/24 neonates by both clinicians. The intraCC for repeatability for observer A was 1.00 (95% CI 1.00–1.00) for the basal ganglia and 0.99 (95% CI 0.99–1.00) for the subependymal region, and for observer B was 0.99 (95% CI 0.99–1.00) for the basal ganglia and 0.96 (95% CI 0.92–0.98) for the subependymal region. The interCC was 0.86 (95% CI 0.68–0.94) for the basal ganglia and 0.93 (95% CI 0.86–0.97) for the subependymal region. Conclusion: Using standardised settings and a well-defined region of interest, the calculation of FMBV using PD images is a reproducible method of estimating neonatal regional cerebral perfusion.

Reference Ranges for Neonatal Basal Ganglia Perfusion as Measured by Fractional Moving Blood Volume

“…This was powered to detect a 10% difference in means (α = 0.05, β = 0.9) based on prior data (µ = 62.9, σ = 9.4) [5]. …”

“…The utility of FMBV as an indicator of neonatal cerebral pathology has not been studied to date. Our previous data demonstrate excellent reproducibility using this technique in a small group of neonates [5]. …”

Basal ganglia perfusion in the preterm infant during transition

“…The accuracy of our image analysis was confirmed with excellent correlation between independent analyzers. There was good internal consistency between FMBV calculations at each assessment point; however, the correlation between values does not appear to be as strong as described in our reproducibility study (12). It is important to note that the internal consistency in this study reflects the entire image acquisition and analysis sequence whereas our earlier study focuses on the accuracy of image analysis only.…”

“…This technique has been validated and shown to correlate well with actual tissue perfusion in flow phantom studies and animal models (10,11). Our research team has internally validated this technique in the neonate by demonstrating its reproducibility (12) and we have recently established a reference range for infants beyond the transitional period (13).…”

Spatiotemporal Image Correlation and Volumetric Impedance Indices in the Neonatal Brain

“…We have previously described the use of power Doppler sonography to quantify regional vascularity in the neonatal brain 3 . Power Doppler sonography uses a color map to encode the integrated power (strength, amplitude, intensity, or energy) from a Doppler‐shifted ultrasonic signal rather than the mean Doppler frequency shift 4 .…”