A new supportive approach in the diagnosis of Chiari malformation type 1 in pediatric patients.

Abstract

Chiari malformation type 1 (CM-1) is a posterior fossa anomaly characterized by herniation of the cerebellar tonsils from the foramen magnum (FM). This study compares FM, medulla spinalis (MS), and herniated cerebellar tonsils ratios by making area measurements from axial plane MRI in CM-1 patients and the control group. Our study evaluated 30 pediatric patients with CM-1 and 30 people in the control group. The lengths of the McRae line, twining line, and clivus line were measured on the posterior cranial fossa evaluation. The areas of FM (AFM), MS (AMS), and herniated cerebellar tonsils (ATONSILS) were measured by axial images. As a result of area measurements obtained from axial cross-sectional MRI, a statistically significant difference was found between CM-1 patients and the control group. According to the results of the ROC analysis, if an individual's AMS/AFM value is above 17.9% or the ATONSILS/AFM value is above 18.4%, it can be interpreted as a CM-1 patient. It will be easier to diagnose the patient with the new approach we obtained from axial MR images in addition to sagittal MR images. This method can be a guide in some cases when the surgeons are undecided.