Regional Structural Characterization of the Brain of Schizophrenia Patients Abraham Dubb, PaulYushkevich, Zhiyong Xie, Ruben Gur, Raquel Gur, and James Gee Departments of Psychiatry and Radiology University of Pennsylvania Philadelphia, PA, USA 19104 {adubb,pauly2,zxie}@grasp.cis.upenn.edu {gur,raquel}@bbl.med.upenn.edu gee@rad.upenn.edu Abstract. Abnormal neuro-development and brain structure may play a role in the pathophysiology of schizophrenia. To study morphology and age-related changes in this disease, we started with a set of cranial MRI’s of 46 schizophrenia patients and age/gender matched healthy controls. First, we deformed a template brain image to our set of subject images. The Jacobian fields of these deformations were then reduced to sets of 52 normalized region volumes for each subject using a neuro-anatomical atlas. The normalized regional volumes of the control and patient groups were compared using Student’s t-test. In addition, the age correlation of each region volume was calculated for the two groups. All results were corrected for multiple comparisons using permutation testing. Finally, we used a classifier based on support vector machines and a feature selection method in order to determine our ability to discriminate brains of controls from those of patients. RESULTS:Analysis of the region-integrated Jacobians showed an enlargement of the third ventricle in patients. The age-correlation study demonstrated significant positive correlation in the third ventricle and right thalamus of controls, but not patients. Using an average of 6.5 features, our classifier was able to correctly identify 72% of patients and 70% of controls. CONCLUSIONS: In addition to enlargement of the third ventricle, the brains of schizophrenia patients demonstrate a different pattern of age-related changes. 1 Introduction The study of schizophrenia has benefited from the advent of high resolution MRI and ad- vanced morphometry techniques. Investigators have reported volumetric differences in multiple regions including the frontal and temporal lobes, ventricles, hippocampus and extra-pyramidal structures [1, 2, 3, 4, 5]. The existence of morphologic differences has motivated evaluation of the developmental course of neuroanatomic measures to assess whether abnormal neuro-development or neuro-degeneration play a role in schizophre- nia. Several studies reported regional age-related changes of the brain [6, 7, 8]. While these studies have produced conflicting results, there is a growing consensus that brain plasticity is altered in schizophrenia, underscoring the importance of studying age-related changes in neuroanatomy [6]. C. Barillot, D.R. Haynor, and P. Hellier (Eds.): MICCAI 2004, LNCS 3217, pp. 688–695, 2004. c  Springer-Verlag Berlin Heidelberg 2004