Quantitative 3D and 2D Head Ultrasound to Determine Thresholds for Intervention In Preterm Neonates with Posthemorrhagic Ventricular Dilation

Abstract

Abstract BACKGROUND: Preterm neonates with intraventricular hemorrhage (IVH) often acquire post hemorrhagic ventricle dilation (PHVD), which, when severe, can lead to neurological impairment. Cranial 2D ultrasound (US) images are used for the diagnosis and monitoring of PHVD; however, there is no consensus on the use of 2D US images to guide treatment. This can lead to delays in interventions, and the potential for brain injury. We have developed a 3D US system that has been shown to accurately detect changes ventricle volumes (VV). OBJECTIVES: We investigate the utility of using 3D and 2D US measurements to determine thresholds for treatment of neonates with PHVD and to predict the need for further treatments. DESIGN/METHODS: Neonates were imaged twice weekly in accordance to a protocol approved by the research ethics board. 3D US images were manually segmented to obtain VV. 2D measurements included ventricle index, anterior horn widths, third ventricle width, and largest thalamo-occipital distance. The rate of change for each measurement was calculated. Decisions to perform ventricular taps (VTs) to relieve intracranial pressure were made independently by neurosurgeons who were blinded to study images. Receiver operator curves (ROC) were generated using the sensitivity and specificity of the rates of change of sonographic parameters in predicting the need for V T. For each parameter optimal threshold for intervention was estimated by the area under ROC; and positive and negative predictive values (PPV, NPV) were calculated. Additionally, we investigated whether US measurements predicted the need for multiple interventions. RESULTS: 23 neonates with PHVD were enrolled, 8 required interventions. The best predictor to determine initial intervention was the rate of change in VV when a threshold of >2.04 cm3/day was used within the first three weeks of life (NPV and PPV of 1) and, this measurement was able to determine if then a patient would require further interventions when a threshold of -0.04 cm3/day was used looking at imaging time points after the first intervention (NPV and PPV of 1). 2D measurements were less sensitive and/or less specific (sensitivity of 88-57%, specificity of 100-79%, PPV of 0.88-0.57 and NPV of 0.93-0.79). CONCLUSION: 3D US VV can predict the requirement for interven-tional ventricular tap in neonates with IVH, and can identify patients that have resolving PHVD following initial intervention, with higher sensitivity and specificity than 2D US measurements. These findings show promise for early classification of neonates using 3D US for prediction of interven-tional therapy, potentiallyaiding in timely management of these patients.