Measures of Ventricles and Evans' Index: From Neonate to Adolescent

Abstract

Ventricle sizes are important for the early diagnosis of hydrocephalus or for follow-up after ventriculostomy. Diameters of ventricles may change, especially in childhood. This study aims to provide normative data about ventricle diameters. Among 14,854 cranial MRI performed between 2011 and 2013, 2,755 images of Turkish children aged 0-18 years were obtained. After exclusions, 517 images were left. Four radiologists were trained by a pediatric radiologist. Twenty images were assessed by all radiologists for a pilot study to see that there was no interobserver variation. There were 10-22 children in each age group. The maximum width of the third ventricle was 5.54 ± 1.29 mm in males in age group 1 and 4.98 ± 1.08 mm in females in age group 2. The Evans' index was <0.3 and consistent with the literature. The third ventricle/basilar artery width ratio was found to be >1 and <2 in all age groups and both gender groups. Our study showed the ventricle size data of children in various age groups from newborn to adolescent. The ventricle volume/cerebral parenchyma ratio seems to decrease with age. We think that these data can be applied in clinical practice, especially for the early diagnosis of hydrocephalus.

Pseudofeeders on fetal magnetic resonance imaging predict outcome in vein of Galen malformations

“…2 However, although Evans index < 0.31 is considered normal at any age in the literature, volumetric measurements would yield a more accurate estimate of the degree of hydrocephalus. 18,19 Moreover, although VGAM-related hydrocephalus usually demonstrates a fully patent aqueduct, 2 hydrovenous disorders can also cause enlargement of the pericerebral CSF spaces, which would be overlooked by the Evans index. Unfortunately, volumetric measurement cannot be performed retrospectively.…”

“…18,19 The volume of the VGAM was assessed using the formula V 5 4pABC/3, where A, B, and C are the 3 parameters (length, height, and width) of the vein of Galen (Fig 2). Increased cerebrospinal fluid (CSF) volume was defined as an Evans index 0.31 (ratio of the maximum width of the frontal horns of the lateral ventricles to the maximum internal diameter of skull).…”

“…Increased cerebrospinal fluid (CSF) volume was defined as an Evans index 0.31 (ratio of the maximum width of the frontal horns of the lateral ventricles to the maximum internal diameter of skull). 18,19 The volume of the VGAM was assessed using the formula V 5 4pABC/3, where A, B, and C are the 3 parameters (length, height, and width) of the vein of Galen (Fig 2). Encephalomalacia was defined as a loss of brain parenchymal thickness (atrophy) combined with parenchymal hyperintensity on T1-weighted spin echo sequences (laminar necrosis).…”

Brain morphology in children with nevoid basal cell carcinoma syndrome

“…The longitudinal and transverse diameter of the cerebrum and the maximal width of the frontal horns were measured from the axial slice of T1‐weighted images showing visualization of the genu and splenium of corpus callosum. Evans’ index, the ratio of the maximal width of the frontal horns to the internal diameter of the cranium, was calculated and used as an indirect marker of ventricular volume (Sarı et al, ). At the midsagittal section of T1‐weighted images, the proportion of corpus callosum, pons, bulbar, and cerebellar vermis were also measured.…”

The third ventricle of the human fetal brain: Normative data and pathologic correlation. A 3D transvaginal neurosonography study

“…2,3 In the neonate, the normal and abnormal aspects of the third ventricle have been mainly described on MR, and to a lesser extent on ultrasound (US). 4,5 In particular, neonatal nomograms of the third ventricular width, measured both in the coronal and axial planes by using transfontanelle ultrasound, have been published. 4,6,7 In the fetus, ultrasound studies of the third ventricle of the brain are scarce.…”