title: Functional analysis of third ventriculostomy patency by quantification of CSF stroke volume by using cine phase-contrast MR imaging.
abstract: OBJECTIVE
  Endoscopic third ventriculostomy (ETV) is increasingly used as alternative treatment for obstructive hydrocephalus. The aim of this study was to determine the utility of quantitative and qualitative examinations with cine phase-contrast MR imaging to determine the efficacy of ventriculostomy across time and whether CSF pulsation is restored after ETV.
  
  
  METHODS
  Thirty-eight patients treated with ETV were evaluated with cine phase-contrast MR within 1 month after surgery. Follow-up studies were performed after 1 year in 25 patients and after 2 years in 12. We evaluated flow void changes in the floor of the third ventricle and quantified the stroke volume at the site of the ventriculostomy. We also recorded changes in ventricular size and clinical outcome. To determine the restoration of CSF pulsation, we compared the CSF waveform at the ventriculostomy with the CSF waveform at the aqueduct in a healthy control group.
  
  
  RESULTS
  After ventriculostomy, restoration of pulsate motion characteristics of CSF circulation was observed. The stroke volume registered at ventriculostomy was maintained with time. There was a statistically significant relationship between clinical outcome and stroke volume. Overall flow magnitude was the most effective variable to determine which patients would improve after surgery. Values >75 mm3 showed a sensitivity of 76.7% and a specificity of 87.5% There was no relationship between ventricular size changes and clinical outcome. Patients with primary aqueduct stenosis had the best response to surgery, whereas patients with Arnold Chiari malformation or communicating hydrocephalus had the worst response.
  
  
  CONCLUSIONS
  Quantitative analysis with phase-contrast MR imaging indicates that ETV is an efficient technique for restoring CSF pulsation, with efficacy being maintained during the follow-up controls. Quantification of stroke volume at ventriculostomy is a good indicator of the functional status of ETV, and a high stroke volume in the ventriculostomy appears to be a positive predictor of favorable clinical outcome.
authors.affiliation: Department of Radiology Hospital Clínic i Provincial de Barcelona, Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Bargalló
authors.forename: Lourdes
authors.initials: L
authors.lastname: Olondo
authors.forename: Ana I
authors.initials: AI
authors.lastname: Garcia
authors.forename: Sebastian
authors.initials: S
authors.lastname: Capurro
authors.forename: Luis
authors.initials: L
authors.lastname: Caral
authors.forename: Jordi
authors.initials: J
authors.lastname: Rumia
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002535:Cerebral Aqueduct / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D002648:Child; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D011859:Radiography; D013318:Stroke Volume / Q000502:physiology; D020542:Third Ventricle / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D014654:Vascular Patency / Q000502:physiology; D014696:Ventriculostomy
chemical_list: D003287:Contrast Media