Calculation of the Volume of Fourth Ventricle and the Length of Herniation Using the ImageJ Software in Patients with Chiari Type I malformation

Abstract

Objective: The Chiari type 1 malformation is a congenital anomaly which is characterized by downward displacement of the cerebellar tonsils into the cervical spinal canal. The aim of this study was to determine the volume of fourth ventricle and the length of herniated cerebellar tonsils in patients with Chiari type I malformation and control group using ImageJ program. Material and Methods: We retrospectively investigated magnetic resonance (MR) images from 27 patients with Chiari type I malformation (patient group). We also investigated MR images from 18 subjects as a control group who underwent an MRI complaining of headaches with the results showing no cranial or intracranial pathology. The volume and length were estimated using the ImageJ program Results: The mean volumes of fourth ventricle were determined as a 1.08±0.20 cm3 and 1.01±0.27 cm3 for control group and patient group, respectively. Ventricle volumes obtained from two groups were not statistically different (p>0.05). We found that the mean length of herniation was 9.48±3.22 mm in the patient group. We did not determine any relationship between age and any of these variables (volume and length) in both groups. Conclusion: This study has shown that the volume of fourth ventricle and the length of herniated cerebellar tonsils can be measured by ImageJ program. We think that when correlated with clinical findings, these measurements may contribute to the evaluation of Chiari type I malformation cases. Key Words: Arnold-Chiari Malformation; Magnetic Resonance Imaging; Fourth Ventricle.