Functional analysis of third ventriculostomy patency with phase-contrast MRI velocity measurements

Abstract

Our purpose was to explore the utility of cine phase-contrast MRI velocity measurements in determining the functional status of third ventriculostomies, and to correlate the quantitative velocity data with clinical follow-up. We examined six patients with third ventriculostomies and 12 normal subjects by phase-contrast MRI. The maximum craniocaudal to maximum caudocranial velocity range was measured at regions of interest near the third ventricular floor, and in cerebrospinal fluid anterior to the upper pons and spinal cord on midline sagittal images. Ratios of the velocities of both the third ventricle and prepontine space to the space anterior to the spinal cord were obtained. The velocities near the third ventricular floor and in the pontine cistern were significantly higher in patients than in normal subjects, but the velocity anterior to the spinal cord was similar between the groups. The velocity ratios, used to normalize individual differences, were also higher in patients than in controls. Two patients had lower velocity ratios than their fellows at the third ventricular floor and in the pontine cistern; one required a shunt 11 months later, while in the other, who had a third ventricular/thalamic tumor, the lower values probably reflect distortion of the third ventricular floor. We conclude that phase-contrast MR velocity measurements, specifically the velocity ratio between the high pontine cistern and the space anterior to the spinal cord, can help determine the functional status of third ventriculostomies.

Failed Endoscopic Third Ventriculostomy in Children: Management Options

“…In 2DPC studies, the CSF flow is the result of alternating upward (diastolic) and downward (systolic) motion in each cardiac cycle across the third ventriculostomy site [16]. We performed T2 FSE sagittal MRI sequences and 2DPC studies in our patients to demonstrate the flow.…”

Cine Phase-Contrast MR Images Failed to Predict Clinical Outcome Following ETV

“…[1][2][3] A number of studies worldwide have reported favorable outcomes; 4-6 however, in some cases, ETV fails to resolve symptoms, even when it is technically successful with adequate patent stoma and fenestrated Lillequist membrane. [7][8][9][10][11] It has been hypothesized that patients might suffer from hydrocephalus caused by other obstructive membranes or by fibrosis in the subarachnoid space, especially around basal cisterns. Cine phase-contrast magnetic resonance imaging (PC MR) has been utilized as a method of distinguishing between ABSTRACT: Background: To predict success of endoscopic third ventriculostomy (ETV) in patients with obstructive hydrocephalus, we evaluated pre-and post-operative phase-contrast cine magnetic resonance images (PC MRI) on cerebrospinal fluid (CSF), cine flow in basal cisterns around the brain stem, and cervical medullar junction (CMJ) retrospectively.…”

Teaching Neuro Image : Tremor in aqueductal stenosis and response to endoscopic third ventriculostomy

“…These features were consistent with the diagnosis of AS. 3 Endoscopic third ventriculostomy was performed to arrest progression of the hydrocephalus. 4 Ventriculographic guidance provided visualization of the distended architecture of the lateral ventricle and vascular structures ( figure 1D).…”