Transcranial Doppler ultrasonography for the evaluation of shunt malfunction in pediatric patients.

Previous studies have demonstrated a high correlation between hydrocephalus and the resistive index (RI), as determined by transcranial Doppler ultrasonography. Measurements of RI, calculated by dividing the difference between the peak systolic velocity and the end-diastolic velocity by the peak systolic velocity, were attempted in 55 pediatric patients during evaluations for ventriculoperitoneal shunt malfunctions; values were obtained in 52. Indications of shunt malfunction included both clinical and radiographic evidence of increased intracranial pressure.

Duplex pulsed Doppler US versus intracranial pressure in the neonate: clinical and experimental studies.

This study was conducted to determine if the resistive index (RI) could be used for the examination and follow-up of neonates with increased intracranial pressure. First, in a laboratory model with four mongrel dogs, RI was found to correlate linearly with cerebral perfusion pressure. Second, RI was studied in 57 healthy neonates and 285 neonates with abnormal clinical or head ultrasound findings.

Cranial Doppler ultrasonography correlates with criteria for ventriculoperitoneal shunting.

Using pulsed Doppler ultrasound through the sonic window of the anterior fontanelle in infants, 46 children with ventriculomegaly had sequential evaluations of Resistive Index for comparison with the need for ventriculoperitoneal shunting. Hydrocephalus was associated with myelomeningocele in 17 patients and posthemorrhagic, postmeningitic, or congenital hydrocephalus accounted for the rest. The Resistive Index was obtained by dividing the difference between the peak systolic and end diastolic frequencies by the systolic frequency.