CSF and venous blood flow from childhood to adulthood studied by real-time phase-contrast MRI

Abstract

Purpose: In vivo measurements of CSF and venous flow using real-time phase-contrast (RT-PC) MRI facilitate new insights into the dynamics and physiology of both fluid systems. In clinical practice, however, use of RT-PC MRI is still limited. Because many forms of hydrocephalus manifest in infancy and childhood, it is a prerequisite to investigate normal flow parameters during this period to assess pathologies of CSF circulation. This study aims to establish reference values of CSF and venous flow in healthy subjects using RT-PC MRI and to determine their age dependency.

Methods: RT-PC MRI was performed in 44 healthy volunteers (20 females, age 5-40 years). CSF flow was quantified at the aqueduct (Aqd), cervical (C3) and lumbar (L3) spinal levels. Venous flow measurements comprised epidural veins, internal jugular veins and inferior vena cava. Parameters analyzed were peak velocity, net flow, pulsatility, and area of region of interest (ROI).

Statistical tests: linear regression, student's t-test and analysis of variance (ANOVA).

Results: In adults volunteers, no significant changes in flow parameters were observed. In contrast, pediatric subjects exhibited a significant age-dependent decrease of CSF net flow and pulsatility in Aqd, C3 and L3. Several venous flow parameters decreased significantly over age at C3 and changed more variably at L3.

Conclusion: Flow parameters varies depending on anatomical location and age. We established changes of brain and spinal fluid dynamics over an age range from 5-40 years. The application of RT-PC MRI in clinical care may improve our understanding of CSF flow pathology in individual patients.

Keywords: Age-related changes of flow; CSF dynamics; Childhood hydrocephalus; Real-time phase-contrast MRI; Venous flow.

Fig. 1

ROIs for CSF and venous flow analyses. a The sagittal image indicates the slice locations chosen for Aqd, spinal level C3 and L3. ROIs are shown on axial magnitude images: b Aqd, c C3 CSF (yellow) and C3 EV (blue), d C3 IJV, e L3 CSF (yellow) and L3 EV (blue), and f L3 IVC. ROI = region of interest, Aqd = aqueduct, C3 = cervical spinal level 3, L3 = lumbar spinal level 3, EV = epidural veins, IJV = internal jugular vein, IVC = inferior vena cava

Fig. 2

Linear regression between flow parameters and age at the aqueduct. Parameters are (from top to bottom): ROI Area (mm²), peakVelocity (cm/s), netFlow (ml/min), and stdFlow (ml/min). Stars indicate a slope significantly different from zero, i.e. p < 0.05. Shaded regions represent 95% confidence interval. Aqd = aqueduct, stdFlow = standard deviation over flow time series

Fig. 3

Linear regression between flow parameters and age at cervical spinal level C3. Parameters are (from top to bottom): ROI Area (mm²), peakVelocity (cm/s), netFlow (ml/min), and stdFlow (ml/min). ROIs from left to right C3 CSF (a), C3 EV (b), C3 IJV (c). CSF flow is shown in left column, venous flow in middle and right columns. Stars indicate a slope significantly different from zero, i.e. p < 0.05. Shaded regions represent 95% confidence interval. C3 = cervical spinal level 3, stdFlow = standard deviation over flow time series, EV = epidural veins, IJV = internal jugular vein

Fig. 4

Linear regression between flow parameters and age at lumbar spinal level L3. Parameters are (from top to bottom): ROI Area (mm²), peakVelocity (cm/s), netFlow (ml/min), and stdFlow (ml/min). Stars indicate a slope significantly different from zero, i.e. p < 0.05. Shaded regions represent 95% confidence interval. CSF flow is shown in left column, venous flow in middle and right column. L3 = lumbar spinal level 3, stdFlow = standard deviation over flow time series, EV = epidural veins, IVC = inferior vena cava