title: Analysis of cerebrospinal fluid flow dynamics and morphology in Chiari I malformation with cine phase-contrast magnetic resonance imaging.
abstract: BACKGROUND
  To determine cerebrospinal fluid (CSF) dynamics and morphology in Chiari I malformation (CMI) and assess the response to surgery of the posterior cranial fossa, we examined midsagittal imaging along with anterior cervical 2-3 (AC2-3), posterior cervical 2-3 (PC2-3), and aqueduct CSF flow hydrodynamics in axial imaging by using cine phase-contrast magnetic resonance imaging (PCMR).
  
  
  METHODS
  We examined 52 patients with CMI, both with and without syringomyelia (SM), pre-/post-surgery, and compared them to 17 healthy volunteers. Statistical analyses included paired t-tests, independent-samples t-tests, binary logistic regression, and crosstab with MedCalc software.
  
  
  RESULTS
  Patients with CMI had significantly shorter clivus length and larger tentorial angle than the healthy controls (P = 0.004, P = 0.019, respectively). The AC2-3 cranial/caudal peak velocity (PV), PC2-3 cranial/caudal PV and aqueduct cranial peak PV of patients with CMI were significantly lower than healthy volunteers pre-surgery (P = 0.034 AC2-3 cranial PV, P = 0.000002 AC2-3 caudal PV; P = 0.046 PC2-3 cranial PV, P = 0.015 PC2-3 caudal PV; P = 0.022 aqueduct cranial PV) and increased after surgery (P = 0.024 AC2-3 cranial PV, P = 0.002 AC2-3 caudal PV; P = 0.001 PC2-3 cranial PV, P = 0.032 PC2-3 caudal PV; P = 0.003 aqueduct cranial PV). The aqueduct caudal PV of patients with CMI was higher than that of healthy controls (P = 0.004) and decreased post-surgery (P = 0.012). Patients with pre-surgery PC2-3 cranial PV >2.63 cm/s and aqueduct cranial PV >2.13 cm/s, respectively, experienced primary symptom improvement after surgery.
  
  
  CONCLUSIONS
  The innate bony dysontogenesis in patients with CMI contributes to tonsilar ectopia and exacerbates CSF flow obstruction. A pressure gradient that existed between SM and SAS supports the perivascular space theory that is used to explain SM formation. Our findings demonstrate that PCMR maybe a useful tool for predicting patient prognosis.
authors.affiliation: Department of Neurosurgery, Southwest Hospital, Third Military Medical University, No. 29, GaoTanYan Street, Chong-Qing, 400038, People's Republic of China.
authors.forename: Cheng-Shi
authors.initials: CS
authors.lastname: Wang
authors.forename: Xing
authors.initials: X
authors.lastname: Wang
authors.forename: Chu-Hua
authors.initials: CH
authors.lastname: Fu
authors.forename: Lu-Qing
authors.initials: LQ
authors.lastname: Wei
authors.forename: Dai-Quan
authors.initials: DQ
authors.lastname: Zhou
authors.forename: Jiang-Kai
authors.initials: JK
authors.lastname: Lin
mesh_terms: D000328:Adult; D001139:Arnold-Chiari Malformation / Q000473:pathology* / Q000601:surgery*; D016022:Case-Control Studies; D002535:Cerebral Aqueduct / Q000473:pathology / Q000601:surgery; D002555:Cerebrospinal Fluid / Q000502:physiology*; D003388:Cranial Fossa, Posterior / Q000473:pathology / Q000601:surgery; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D057446:Hydrodynamics; D016015:Logistic Models; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D011184:Postoperative Period; D057234:Preoperative Period; D011379:Prognosis; D013595:Syringomyelia / Q000473:pathology* / Q000601:surgery*