The aqueduct of Sylvius: applied 3-T magnetic resonance imaging anatomy and morphometry with neuroendoscopic relevance.

Neurosurgery 2013 Dec;73(2 Suppl Operative):ons132-40; discussion ons140

*Section of Neuroradiology; and ‡Department of Neurosurgery, Addenbrooke's Hospital, Cambridge, United Kingdom; §Department of Radiology, University of Cambridge, Cambridge, United Kingdom.

Background: The aqueduct of Sylvius (AqSylv) is a structure of increasing importance in neuroendoscopic procedures. However, there is currently no clear and adequate description of the normal anatomy of the AqSylv.

Objective: To study in detail hitherto unavailable normal magnetic resonance imaging morphometry and anatomic variants of the AqSylv.

Methods: We retrospectively studied normal midsagittal T1-weighted 3-T magnetic resonance images in 100 patients. We measured widths of the AqSylv pars anterior, ampulla, and pars posterior; its narrowest point; and its length. We recorded angulation of the AqSylv relative to the third ventricle as multiple deviations of the long axis of the AqSylv from the Talairach bicommissural line. We statistically determined age- and sex-related changes in AqSylv morphometry using the Pearson correlation coefficient. We measured angulation of the AqSylv relative to the fourth ventricle and correlated this to the cervicomedullary angle (a surrogate for head position).

Results: Patients were 13 to 83 years of age (45% male, 55% female). Mean morphometrics were as follows: pars anterior width, 1.1 mm; ampulla width, 1.2 mm; pars posterior width, 1.4 mm; length, 14.1 mm; narrowest point, 0.9 mm; and angulation in relation to the third and fourth ventricles, 26° and 18°, respectively. Age correlated positively with width and negatively with length of the AqSylv. There was no correlation between AqSylv alignment relative to the foramen magnum and the cervicomedullary angle.

Conclusion: Normative dimensions of the AqSylv in vivo are at variance with published cadaveric morphometrics. The AqSylv widens and shortens with cerebral involution. Awareness of these normal morphometrics is highly useful when stent placement is an option during aqueductoplasty. Reported data are valuable in guiding neuroendoscopic management of hydrocephalus and aqueductal stenosis.

Download full-text PDF

Source
http://dx.doi.org/10.1227/01.neu.0000430286.08552.caDOI Listing
December 2013
16 Reads

Publication Analysis

Top Keywords

magnetic resonance
12
aqsylv
10
3-t magnetic
8
narrowest point
8
resonance imaging
8
angulation aqsylv
8
pars posterior
8
aqsylv relative
8
pars anterior
8
aqueduct sylvius
8
45% male
4
male 55%
4
age 45%
4
patients years
4
surrogate head
4
angle surrogate
4
head positionresults
4
positionresults patients
4
55% female
4
years age
4

References

(Supplied by CrossRef)
Endoscopic anatomy of the cerebral aqueduct
Longatti et al.
Neurosurgery 2007
The diagnosis and treatment of hydrocephalus resulting from strictures of the aqueduct of Sylvius
Dandy et al.
Surg Gynecol Obstet 1920
Stenosis of the aqueduct of Sylvius: etiology and treatment
Hirsch et al.
J Neurosurg Sci 1986
Observations on the pathology of hydrocephalus
Russell et al.
Special Report Series No. 265. Medical Research Council. London; HM Stationery Office: 1949
Endoscopic aqueductoplasty: technique and results
Schroeder et al.
Neurosurgery 1999
Endoscopic aqueductal stent placement for the treatment of a trapped fourth ventricle
Sagan et al.
J Neurosurg 2006
Pros and cons of 3 Tesla MRI
Bradley et al.
J Am Coll Radiol 2008

Similar Publications