Quantification of neonatal cerebral ventricular volume by real-time ultrasonography. In vivo validation of the cylindrical coordinate method.

Abstract

Posthemorrhagic ventricular dilation is a common clinical problem in preterm infants who have incurred an intraventricular hemorrhage. Presently there are no clinically applicable methods to follow quantitatively the progression of ventricular dilation at bedside. We describe the in vivo validation of a method to measure ventricular volume using bedside real-time cranial ultrasonography. Six infants undergoing either serial lumbar punctures or cerebral ventricular reservoir taps for posthemorrhagic hydrocephalus were studied. The cerebrospinal fluid (CSF) volume removed ranged from 5.5 mL to 30 mL. A strong correlation was found (r2 = 0.84) between the volume of CSF removed by reservoir tap and the change in ventricular volume calculated by the ultrasound method, whereas the correlation between the volume of CSF removed at lumbar puncture and the change in ventricular volume calculated by the ultrasound method was not as strong (r2 = 0.70). Limitations and sources of error in the method are discussed. We conclude that this procedure is accurate and offers a quantitative method to follow longitudinally posthemorrhagic progressive ventricular dilation.