New stereological approach for the evaluation of patients with schizophrenia using computer tomography images: Ventricle to brain volume fraction

Abstract

There are several studies that have proposed different criteria for evaluating the volumes of the cerebral hemispheres, the lateral and third ventricles in patients with schizophrenia seen on routine computed tomography (CT) images. These approaches use solely the volume of the cerebrum and/or lateral ventricles, length and width measurements of the ventricles, and ventricle to brain ratio (VBR). In the present study, we proposed a new unbiased approach namely ventricle to brain volume fraction (VBF). CT scans of 23 patients with schizophrenia and 23 matched controls were blindly assessed by three independent observers. VBF, total brain volume and ventricle volumes were calculated and compared. The subjects with schizophrenia showed higher VBF than the control subjects (P =0.000) with mean (±SEM) VBF values of 2.71±0.16 and 1.62±0.10%, respectively. No gender difference was found. Older subjects had a higher VBF than those younger in controls but not patients. Correlation was observed for VBF estimations made by three independent observers (r = 0.979; P = 0.000). The studies measuring VBR on schizophrenia revealed inconsistent findings. Comparing solely the brain volumes or ventricle volumes between two groups, instead of using volume fraction method, will not provide reliable data. VBF described here easily could be used for the analysis of the brain structures of schizophrenia using standard CT scans not requiring any additional expense. In addition; evaluation of the whole section series gives real ventricular and cerebral volumes. Key words: Cavalieri method, computed tomography (CT), schizophrenia.