Magnetic resonance imaging for quantitative flow measurement in infants with hydrocephalus: a prospective study

Abstract

Object Raised intracranial pressure (ICP) that is associated with hydrocephalus may lead to alterations in cerebral hemodynamics and ischemic changes in the brain. In infants with hydrocephalus, defining the right moment for surgical intervention based on clinical signs alone can sometimes be a difficult task. Clinical signs of raised ICP are known to be unreliable and sometimes even misleading. Furthermore, when sutures are closed, ICP does not always correlate with the size of the ventricles or with the clinical signs or symptoms. In this study the authors investigated whether cerebral blood flow (CBF) can be measured by using quantitative MR angiography in infants with progressive hydrocephalus. In addition, the authors investigated the relationship between CBF and ICP, before and after cerebrospinal fluid (CSF) diversion. Methods Fifteen infants with progressive hydrocephalus (age range 1 day–7 months) were examined. All patients underwent anterior fontanel pressure measurement, MR angiography, and mean arterial blood pressure measurements before and after CSF diversion. Brain volume was measured to compensate for the physiological increase in CBF during brain maturation in infants. Results The mean preoperative ICP was 19.1 ± 8.4 cm H2O (± standard deviation). The mean postoperative ICP was 6.7 ± 4.0 cm H2O (p < 0.005). The mean preoperative CBF was 25.7 ± 11.3 ml/100 cm3 brain/min. After CSF diversion, CBF increased to 50.1 ± 12.1 ml/100 cm3 brain/min (p < 0.005). The mean arterial blood pressure did not change after surgical intervention. Conclusions Magnetic resonance imaging can be used to measure CBF in infants with hydrocephalus. Raised ICP was related to a decrease in CBF. After CSF diversion, CBF and ICP improved to values within the normal range.