A Mathematical Model For Predicting Intracranial Pressure Based On Noninvasively Acquired PC-MRI Parameters

Purpose: To explore the correlation between intracranial pressure(ICP)and cerebrospinal fluid(CSF)parameters assessed by phase-contrast cine magnetic resonance imaging(PC-MRI)in communicating hydrocephalus.And to develop and validate a mathematical model for predicting ICP noninvasively using phase-contrast cine MRI.Materials and Methods: In an initial retrospective study,138 consecutive eligible patients diagnosed with communicating hydrocephalus were recruited,and randomly allocated to training(n=97)and validation(n=41)groups.All participants underwent lumbar puncture and PC-MRI to evaluate ICP and cerebrospinal fluid(CSF)parameters(aqueduct diameter and flow velocity),In addition to patient’s age,heart rate,blood pressure and body mass index(BMI)which were recorded.ICP and CSF hemodynamic parameters,such as flow velocity and aqueduct diameter were measured for correlation analysis.An ICP-predicting model was then developed based on the nonlinear relationships with the CSF parameters,using the Levenberg-Marquardt and general global optimization methods.Results: The average values of various parameters were: intracranial pressure(149.55±53.04 mm H2O),diameter of aqueduct(3.06±0.9mm),peak velocity(6.12±4.56 cm / s),average velocity(0.845±0.76 cm / s).After adjusting age,heart rates,blood pressure and BMI,there was no significant relationship between peak velocity and ICP(P>0.05).Furthermore,a nonlinear relationship was observed between the ICP and the average velocity of CSF,and the ICP and aqueduct diameter.The ICP increased with average velocity above 1.628cm/s(P<0.001),and aqueduct diameter more than 3.6mm(P≤0.01).The accuracy of the model for predicting ICP was 0.899 in the training cohort(n=97)and 0.861 in the validation cohort(n=41).Conclusion: This study demonstrates significant correlations between ICP and average velocity and aqueduct diameter,and a non-invasive ICP mathematical prediction model was constructed,which provided a more convenient way for clinical diagnosis and postoperative evaluation in communicating hydrocephalus.