Relevance of Magnetic Resonance Imaging for Ventricular Endoscopy

Abstract

Objective: Endoscopic procedures may represent an alternative to microsurgery or shunt operations in intra- or paraventricular pathologies. However, the operative results mainly depend on the selection of suitable patients. In the present study of 30 patients with occlusive hydrocephalus, the relevance of differentiated magnetic resonance (MR) imaging for evaluation of the pathophysiological and anatomic prerequisites was investigated. Patients and Methods: Apart from conventional axial T₂-weighted turbo spin echo (TSE) sequences (TR/TE 2126/100 ms) and T₁-weighted spin echo (SE) sequences (TR/TE 450/15 ms) with and without the administration of Gd-DTPA, the MR protocol included sagittal and coronal thin-sliced T₂-weighted TSE sequences, cardiac-triggered (TR/TE > 2700/120 ms, slice thickness 3.0 mm) or in volume technique (TR/TE 4000/180 ms, slice thickness 1.4 mm). For the visualization of CSF flow, a sagittal and axial phase-contrast-multi-heart-phase (PCMHP) measurement with 16 phases per cardiac cycle and flow sensitivity in the cranio-caudal direction (TR/TE 18/9.5 ms and 14/9.5 ms) was performed. Results: The combination of imaging and flow sequences provided most information about the extent and the etiology of hydrocephalus. An obstruction of CSF pathways could be detected by the absence of flow voids in T₂-weighted TSE sequences or of flow signals in PCMHP sequences. The size of the foramen of Monro and of the third ventricle could be evaluated in thin-sliced T₂-weighted TSE sequences, for the foramen of Monro in coronal and sagittal and for the third ventricle in coronal and axial slice direction, respectively. The basal structures of the third ventricle, including its floor, the infundibular recess, the mamillary bodies, and the basilar artery, could be best identified in sagittal thin-sliced T₂-weighted TSE scans, cardiac-triggered or in volume technique. Conclusion: In occlusive hydrocephalus, a differentiated MR protocol with thin-sliced T₂-weighted TSE sequences and phase-contrast sequences allows a very precise estimation of the pathophysiological and the anatomic prerequisites for endoscopic procedures. Furthermore, MR imaging can be used for the follow-up documentation of ventriculo-cisternostomies, -cytostomies, or openings of other membranes.

Endoscopy - Hydrocephalus - Magnetic Resonance Imaging - Third Ventriculostomy

References

• 1 Bauer B L, Hellwig D. Minimally invasive endoscopic neurosurgery. A survey.  Acta Neurochir (Wien) Suppl. 1994;  61 1-12
• 2 Caemaert J, Abdullah J, Calliauw L, Carton D, Dhooge C, van Coster R. Endoscopic treatment of suprasellar arachnoid cysts.  Acta Neurochir (Wien). 1992;  119 68-73
• 3 Cohen A R. Endoscopic ventricular surgery.  Pediatr Neurosurg. 1993;  19 127-134
• 4 Gangemi M, Donati P, Maiuri F, Longatti P, Godano U, Mascari C. Endoscopic third ventriculostomy for hydrocephalus.  Minim Invas Neurosurg. 1999;  42 128-132
• 5 Grant J A, McLone D G. Third ventriculostomy: A review.  Surg Neurol. 1997;  47 210-212
• 6 Hopf N J, Grunert P, Fries G, Resch K DM, Perneczky A. Endoscopic third ventriculostomy: Outcome analysis of 100 consecutive procedures.  Neurosurgery. 1999;  44 795-806
• 7 Hopf N J, Perneczky A. Endoscopic neurosurgery and endoscopic-assisted microneurosurgery for the treatment of intracranial cysts.  Neurosurgery. 1998;  43 1330-1337
• 8 Jones R F, Kwok B C, Stening W A, Vonau M. The current status of endoscopic third ventriculostomy in the management of non-communicating hydrocephalus.  Minim Invas Neurosurg. 1994;  37 28-36
• 9 Manwaring K H. Endoscopic ventricular fenestration. In: Manwaring KH, Crone KR (eds). Neuroendoscopy. New York: Mary Ann Liebert 1992 1: 79-89
• 10 Murshid W R. Endoscopic third ventriculostomy: Towards more indications for the treatment of non-communicating hydrocephalus.  Minim Invas Neurosurg. 2000;  43 75-82
• 11 Perneczky A, Fries G. Endoscope-assisted brain surgery: Part 1 - evolution, basic concept, and current technique.  Neurosurgery. 1998;  42 219-225
• 12 Rieger A, Rainov N G, Brucke M, Marx T, Holz C. Endoscopic third ventriculostomy is the treatment of choice for obstructive hydrocephalus due to pediatric pineal tumors.  Minim Invas Neurosurg. 2000;  43 83-86
• 13 Sainte-Rose C, Chumas P. Endoscopic third ventriculostomy. Techniques.  Neurosurgery. 1996;  1 176-184
• 14 Schroeder H WS, Gaab M R, Niendorf W R. Neuroendoscopic approach to arachnoid cysts.  J Neurosurg. 1996;  85 293-298
• 15 Teo C. Third ventriculostomy in the treatment of hydrocephalus: Experience with more than 120 cases. In: Hellwig D, Bauer BL (eds). Minimally Invasive Techniques for Neurosurgery. Berlin, Heidelberg: Springer Verlag 1998: 73-76
• 16 Tuli S, Alshail E, Drake J. Third ventriculostomy versus cerebrospinal fluid shunt as a first procedure in pediatric hydrocephalus.  Pediatr Neurosurg. 1999;  30 11-15
• 17 Tisell M, Almstrom O, Stephensen H, Tullberg M, Wikkelso C. How effective is endoscopic third ventriculostomy in treating adult hydrocephalus caused by primary aqueductal stenosis?.  Neurosurgery. 2000;  46 104-110
• 18 Bhadelia R A, Bogdan A R, Wolpert S M. Analysis of cerebrospinal fluid flow waveforms with gated phase-contrast MR velocity measurements.  AJNR Am J Neuroradiol. 1995;  16 389-400
• 19 Enzmann D R, Pelc N J. Cerebrospinal fluid flow measured by phase-contrast cine MR.  AJNR Am J Neuroradiol. 1993;  14 1301-1307 discussion 1309-1310
• 20 Caemaert J, Abdullah J. Diagnostic and therapeutic stereotactic cerebral endoscopy.  Acta Neurochir (Wien). 1993;  124 11-13
• 21 Goodman R R. Magnetic resonance imaging-directed stereotactic endoscopic third ventriculostomy.  Neurosurgery. 1993;  32 1043-1047
• 22 Grunert P, Perneczky A, Resch K DM. Endoscopic procedures through the foramen interventriculare of Monro under stereotactic conditions.  Minim Invas Neurosurg. 1994;  37 2-8
• 23 Hellwig D, Benes L, Bertalanffy H, Bauer B L. Endoscopic stereotaxy - an eight years experience.  Stereotact Funct Neurosurg. 1997;  68 90-97
• 24 Kelly P J. Stereotactic third ventriculostomy in patients with nontumoral adolescent/adult onset aquaeductal stenosis and symptomatic hydrocephalus.  J Neurosurg. 1991;  75 865-873
• 25 Rieger A, Rainov N G, Sanchin L, Schöpp G, Burkert W. Ultrasound-guided endoscopic fenestration of the third ventricular floor for non-communicating hydrocephalus.  Minim Invas Neurosurg. 1996;  39 17-20
• 26 Scholz M, Deli M, Wildförster U, Wentz K, Recknagel A, Preuschoft H, Harders A. MRI-guided endoscopy in the brain: A feasibility study.  Minim Invas Neurosurg. 1996;  39 33-37
• 27 Hopf N J, Grunert P, Darabi K, Busert C, Bettag M. Frameless neuronavigation applied to endoscopic neurosurgery.  Minim Invas Neurosurg. 1999;  42 187-193
• 28 Resch K DM, Perneczky A. Endo-Neuro-Sonography: Basics and current use. In: Hellwig D, Bauer BL (eds). Minimally Invasive Techniques for Neurosurgery. Berlin, Heidelberg: Springer Verlag 1998: 21-31
• 29 Kunz U, Goldmann A, Bader C, Waldbaur H, Oldenkott P. Endoscopic fenestration of the third ventricular floor in aquaeductal stenosis.  Minim Invas Neurosurg. 1994;  37 42-47
• 30 Wilcock D J, Jaspan T, Worthington B S, Punt J. Neuro-endoscopic third ventriculostomy: Evaluation with magnetic resonance imaging.  Clin Radiol. 1997;  52 50-54
• 31 Kulkarni A V, Drake J M, Armstrong D C, Dirks P B. Imaging correlates of successful endoscopic third ventriculostomy.  Neurosurgery. 2000;  92 915-919