Assessment of third ventriculostomy patency with the 3D-SPACE technique: a preliminary multicenter research study

Abstract

E ndoscopic third ventriculostomy (ETV) is a minimally invasive, safe, and relatively new CSF diversion method; it is mostly used in aqueductal stenosis, but may also be indicated in the treatment of other causes of hydrocephalus.1 With this procedure the inferior wall of the third ventricle is fenestrated, and CSF in the ventricular system is diverted into the prepontine cisternthereby bypassing the obstruction-and CSF circulation is reestablished. 4,7 It is a more physiological treatment option compared with shunt procedures, and therefore it is being done with increasing frequency. 4,7,10 Clinical, laboratory, and conventional imaging findings may be useful to determine whether the ETV stoma is patent, although advanced radiological methods are mostly required. 2,6 Ventriculography is a gold-standard technique for determination of ETV patency. 4 On the other hand, abbreviatioNs ETV = endoscopic third ventriculostomy; PC = phase-contrast cine; T1W, T2W = T1-, T2-weighted; 3D-SPACE = 3D sampling perfection with application-optimized contrasts using different flip-angle evolutions. obJect The goal of this study was to determine the value of the 3D sampling perfection with application-optimized contrasts using different flip-angle evolutions (3D-SPACE) technique in the evaluation of endoscopic third ventriculostomy (ETV) patency. methods Twenty-six patients with ETV were examined using 3-T MRI units. Sagittal-plane 3D-SPACE with variant flip-angle mode, 3D T1-weighted (T1W), and 3D heavily T2-weighted (T2W) images were obtained with isotropic voxel sizes. Also, sagittal-axial plane phase-contrast cine (PC)-MR images were obtained. The following findings were evaluated: diameters of stoma and third ventricle, flow-void sign on 3D-SPACE and PC-MR images, integrity of the third ventricle on heavily T2W images, and quantitative PC-MRI parameters of the stoma. Obtained sequences were evaluated singly, in combination with one another, and all together. results The mean area, flow, and velocity values measured at the level of stoma in patients with patent stoma were significantly higher than those measured in patients with closed stoma (p < 0.05). There was significant correlation among PC-MRI, 3D-SPACE, and 3D heavily T2W techniques regarding assessment of ETV patency (p < 0.001). The 3D-SPACE technique provided the lowest rate of ambiguous results. coNclusioNs The 3D-SPACE technique seems to be the most efficient one for determination of ETV patency. The authors suggest the use of 3D-SPACE as a stand-alone first-line sequence in addition to routine brain MRI protocols in assessing patients with ETV, thereby decreasing scan time and reserving the use of a combination of additional sequences such as PC-MRI and 3D heavily T2W images in suspicious or complex cases.

Simple Identification of Cerebrospinal Fluid Turbulent Motion Using a Dynamic Improved Motion-sensitized Driven-equilibrium Steady-state Free Precession Method Applied to Various Types of Cerebrospinal Fluid Motion Disturbance

“…On T2 that is performed postoperatively with the purpose of observing the ventricles or morphological changes in the cyst, CSF motion through the fenestration is observed as an artifact in addition to morphological information, albeit with mediocre visibility. 20,21) Imaging methods such as phase contrast (PC), [22][23][24] the time-spatial inversion pulse (Time-SLIP) method, 25) and two-dimensional fast imaging with steady-state precession magnetic resonance sequence 26) have been used for post-ETV evaluation as a superior method to visualize CSF motion. The Dynamic iMSDE SSFP method described in this manuscript is superior for visualizing the irregular CSF motions, and our results showed that fenestration of cyst or ventricle with limited CSF motion resulted in clear visualization of recovered CSF motion as a turbulent movement.…”

Assessment of the visual pathways in patients with neurofibromatosis-1 by 3d-space technique at 3-tesla

“…In our study, the 3D-SPACE sequence was adequate for imaging of our patients with hydrocephalus or ventriculoperitoneal shunt and their other intracranial findings. In the literature, the 3D-SPACE technique was reported as the easiest, fastest, and most adequate sequence to determine the ventricular system and CSFrelated pathologies [20,21].…”

“…There are many T2W 3D-SPACE or 3D-TSE sequences for evaluation of the cranium or brain [20]. The 3D-SPACE sequence of this study is not a heavily T2weighted sequence.…”

Endoscopic Third Ventriculostomy : Success and Failure

“…2), heavily weighted T2 studies and more recently 3D-SPACE sequences are being used to assess patency of the stoma1). Sometimes, a computed tomography (CT) contrast dye study may be used if one has ventricular access through an Ommaya reservoir or a similar device.…”