Evaluation of the patency of endoscopic third ventriculostomy using phase contrast MRI-CSF flowmetry as diagnostic approach

Abstract

Purpose: The aim is to assess the usefulness of cine phase-contrast MRI for evaluation of patency of endoscopic third ventriculostomy operation and correlation with clinical state postoperatively. Material & methods: Prospective study performed upon 20 patients who underwent ETV operation, concerned on obstructive hydrocephalus (age range, 4–63 years; 11 male & 9 Female). Cine PC-MRI CSF flowmetry technique was applied for qualitative and quantitative assessment of CSF flow dynamics through ETV stoma to assess its patency. Results: The patency of ETV stoma was evaluated according to overall flow amplitude (OFA) as it was the most effective variable to predict the response to surgery, we found that when OFA value is ≥75 μL, the sensitivity and specificity of our technique to determine patient improvement were 71.4% and 76.9%, respectively.According to OFA, we classified the state of ETV stoma into three subcategories: patent stoma with adequate flow; OFA value ≥75 μL (10 patients), patent stoma with low flow; OFA value from 25 up to <75 μL (4 patients) and obstructed stoma with impaired flow; OFA value <25 μL (6 patients). Conclusion: Cine phase-contrast MR imaging is an effective and reliable method for evaluation and follow up of the ETV patients postoperatively. Keywords: MR phase contrast, CSF flowmetry