title: Magnetic resonance imaging-based measures predictive of short-term surgical outcome in patients with Chiari malformation Type I: a pilot study.
abstract: OBJECTIVE This study identifies quantitative imaging-based measures in patients with Chiari malformation Type I (CM-I) that are associated with positive outcomes after suboccipital decompression with duraplasty. METHODS Fifteen patients in whom CM-I was newly diagnosed underwent MRI preoperatively and 3 months postoperatively. More than 20 previously described morphological and physiological parameters were derived to assess quantitatively the impact of surgery. Postsurgical clinical outcomes were assessed in 2 ways, based on resolution of the patient's chief complaint and using a modified Chicago Chiari Outcome Scale (CCOS). Statistical analyses were performed to identify measures that were different between the unfavorable- and favorable-outcome cohorts. Multivariate analysis was used to identify the strongest predictors of outcome. RESULTS The strongest physiological parameter predictive of outcome was the preoperative maximal cord displacement in the upper cervical region during the cardiac cycle, which was significantly larger in the favorable-outcome subcohorts for both outcome types (p < 0.05). Several hydrodynamic measures revealed significantly larger preoperative-to-postoperative changes in the favorable-outcome subcohort. Predictor sets for the chief-complaint classification included the cord displacement, percent venous drainage through the jugular veins, and normalized cerebral blood flow with 93.3% accuracy. Maximal cord displacement combined with intracranial volume change predicted outcome based on the modified CCOS classification with similar accuracy. CONCLUSIONS Tested physiological measures were stronger predictors of outcome than the morphological measures in patients with CM-I. Maximal cord displacement and intracranial volume change during the cardiac cycle together with a measure that reflects the cerebral venous drainage pathway emerged as likely predictors of decompression outcome in patients with CM-I.
authors: Departments of 1 Radiology and.
authors: Noam
authors: N
authors: Alperin
authors: Departments of 1 Radiology and.
authors: James Ryan
authors: JR
authors: Loftus
authors: Departments of 1 Radiology and.
authors: Ahmet M
authors: AM
authors: Bagci
authors: Departments of 1 Radiology and.
authors: Sang H
authors: SH
authors: Lee
authors: Departments of 1 Radiology and.
authors: Carlos J
authors: CJ
authors: Oliu
authors: Neurological Surgery, University of Miami, Florida.
authors: Ashish H
authors: AH
authors: Shah
authors: Neurological Surgery, University of Miami, Florida.
authors: Barth A
authors: BA
authors: Green
mesh_terms: D000328:Adult; D001139:Arnold-Chiari Malformation / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology; D002555:Cerebrospinal Fluid / Q000000981:diagnostic imaging / Q000502:physiology; D019299:Decompression, Surgical / Q000379:methods; D005260:Female; D006439:Hemodynamics; D006801:Humans; D057446:Hydrodynamics; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010865:Pilot Projects; D011379:Prognosis; D013116:Spinal Cord / Q000000981:diagnostic imaging / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: CCOS = Chicago Chiari Outcome Scale; CM-I = Chiari malformation Type I; CSF flow dynamics; Chiari malformation; ICC = intracranial compliance; ICP = intracranial pressure; ICV = intracranial volume; ICVC = ICV change; MRI; MRI-ICP = MRI-derived ICP; PCF = posterior cranial fossa; STV = supratentorial volume; congenital; decompressive surgery outcome; multivariate analysis