Inter-operator Reliability of Magnetic Resonance Image-Based Computational Fluid Dynamics Prediction of Cerebrospinal Fluid Motion in the Cervical Spine

Abstract

For the first time, inter-operator dependence of MRI based computational fluid dynamics (CFD) modeling of cerebrospinal fluid (CSF) in the cervical spinal subarachnoid space (SSS) is evaluated. In vivo MRI flow measurements and anatomy MRI images were obtained at the cervico-medullary junction of a healthy subject and a Chiari I malformation patient. 3D anatomies of the SSS were reconstructed by manual segmentation by four independent operators for both cases. CFD results were compared at nine axial locations along the SSS in terms of hydrodynamic and geometric parameters. Intraclass correlation (ICC) assessed the inter-operator agreement for each parameter over the axial locations and coefficient of variance (CV) compared the percentage of variance for each parameter between the operators. Greater operator dependence was found for the patient (0.19<ICC<0.99) near the craniovertebral junction compared to the healthy subject (ICC > 0.78). For the healthy subject, hydraulic diameter and Womersley number had the least variance (CV= ~2%). For the patient, peak diastolic velocity and Reynolds number had the smallest variance (CV= ~3%). These results show a high degree of inter-operator reliability for MRI-based CFD simulations of CSF flow in the cervical spine for healthy subjects and a lower degree of reliability for patients with Type I Chiari malformation.

Non-invasive MRI quantification of cerebrospinal fluid dynamics in amyotrophic lateral sclerosis patients

“…The MR image set for each spinal segment was manually reconstructed from an axial view with the semi-automatic contrastbased segmentation tool (Fig. 1c), as performed by our group in previous work [17]. Segmentation from the FM to the end of the dural sac was completed by one of two trained operators (Figs.…”

“…The kinematic viscosity of CSF, given by ν = µ/ρ , was assumed to be the same as water at body temperature. At peak systole, the presence of laminar flow along the spine was characterized using Reynolds number (Re < 2300) similar to previous studies in CSF mechanics [13,17,26]. The Womersley number, α = D H √ ω/ν , was computed where ω is the angular velocity of the volumetric flow waveform with ω = 2/T and ν is the kinematic viscosity of CSF as defined above.…”

“…Inter-operator reliability of MRI based hydrodynamics has also been studied by our group [17]. T2-weighted MRI data collected using a 1.5 T magnet and 1.0 mm isotropic scan resolution of a healthy subject was analyzed by four operators using identical methods as the present study.…”

“…The goal of the present study was to characterize CSF flow dynamics and geometry in people with ALS compared to healthy controls. A few groups have made strides towards characterizing CSF dynamics in conditions such as Chiari malformation [15][16][17][18][19][20][21], Syringomyelia [20][21][22], and hydrocephalus [23], as well as investigation of CSF flow dynamics in people with ALS [24]. We expand on this characterization by providing a more complete analysis of the hydrodynamic environment.…”

Accuracy of 4D Flow Measurement of Cerebrospinal Fluid Dynamics in the Cervical Spine: An In Vitro Verification Against Numerical Simulation

“…Thus, the present study results support that the previous in vivo 4D Flow measurements were likely correct and that the differences in CFD results were due to modeling simplification and/or assumptions such as the SAS geometry and absence of compliance and/or porosity in the model. These differences were not likely to be due to operator segmentation error 27 .…”