Endoscopic third ventriculostomy: predicting outcome with phase-contrast MR imaging.
OBJECTIVE
To determine whether phase-contrast magnetic resonance (MR) imaging measurements of preoperative cerebral blood and cerebrospinal fluid (CSF) hydrodynamics can be used as a biomarker of response to endoscopic third ventriculostomy (ETV).


METHODS
Approval from the local research ethics committee and written informed consent were obtained for this prospective study. Thirteen patients (six female patients, seven male patients; median age, 43 years) with chronic obstructive hydrocephalus, 12 of whom went on to undergo ETV, were imaged with phase-contrast MR imaging at 1.5 T to determine rates of total cerebral blood flow (CBF) and ventriculostomy defect, foramen magnum (FM), and cerebral aqueduct CSF flow. Ten control subjects (10 men; median age, 37 years) were similarly imaged. Correlations between measured values were assessed by means of Pearson correlation coefficients. Measurements were compared between groups with a Mann-Whitney test, and measurements before and after surgical intervention were compared with a Wilcoxon test for paired samples.


RESULTS
Rates of CBF (356 mL . min(-1) +/- 73 [standard deviation] vs 518 mL . min(-1) +/- 79, P < .001) and CSF flow in the FM (17.62 mL . min(-1) +/- 13.12 vs 36.35 mL . min(-1) +/- 8, P < .05) were significantly lower in patients than in control subjects.


CONCLUSIONS
ETV induces changes in brain volume and CBF that can be predicted by using simple metrics. These pilot results support a formal trial of these techniques in a larger prospective study.
Stivaros
Stavros M
SM
Department of Imaging Science, Wolfson Molecular Imaging Centre, University of Manchester, 27 Palatine Rd, Withington, Manchester M20 3LJ, England. stavros.stivaros@postgrad.manchester.ac.uk
Sinclair
Deborah
D
Bromiley
Paul A
PA
Kim
Jieun
J
Thorne
John
J
Jackson
Alan
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology; D002908:Chronic Disease; D004724:Endoscopy; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000134:cerebrospinal fluid / Q000503:physiopathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D020542:Third Ventricle / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome; D014696:Ventriculostomy / Q000379:methods*