Morphometry of the internal capsule on MR images in adult healthy individuals

Abstract

Objectives: There is substantial information on the morphometric differences of the pathways passing through the internal capsule according to the dominant extremity; however, the diameters of the internal capsule in the horizontal plane have not been previously evaluated. The aim of this study was to evaluate the diameters of parts of the internal capsule (anterior limb, posterior limb and genu) and angle in between these parts in healthy subjects. Methods: MRI images of 80 females and 37 males (age: 18–65) with no obvious intracranial pathology were evaluated. The diameters of the anterior and posterior limb and the genu of the internal capsule and the angle between the anterior and posterior limbs were measured. Results: There was no statistically significant difference in measurements of internal capsule when compared bilaterally in all individuals (p>0.05). The right and left genu angles were significantly wider in females. This angle in the present study was found as 122°, while the classical knowledge reveals it as around 90°. Conclusion: Understanding the normal morphometry of this region may help clinicians in the diagnosis and follow-up of some neurological diseases. Some morphometric characteristics of this region have shown differences from the classical knowledge. Further studies in larger samples should be done for re-evaluating the normal ranges of these morphometric values.