title: Estimating local surface complexity maps using spherical harmonic reconstructions.
abstract: Cortical surface complexity is a potential structural marker for certain diseases such as schizophrenia. In this study, we developed a measure of fractal dimension (FD) calculated from lowpass-filtered spherical harmonic brain surface reconstructions. A local FD measure was also computed at each vertex in a cortical surface mesh, visualizing local variations in surface complexity over the brain surface. We analyzed the surface complexity for 87 patients with DSM-IV schizophrenia (with stable psychopathology and treated with antipsychotic medication) and 108 matched healthy controls. The global FD for the right hemisphere in the schizophrenic group was significantly lower than that in controls. Local FD maps showed that the lower complexity was mainly due to differences in the prefrontal cortex.
authors.affiliation: Friedrich-Schiller University, Department of Psychiatry, Jahnstr. 3, 07743 Jena, Germany. Rachel.Yotter@uni-jena.de
authors.forename: Rachel Aine
authors.initials: RA
authors.lastname: Yotter
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.forename: Igor
authors.initials: I
authors.lastname: Nenadic
authors.forename: Christian
authors.initials: C
authors.lastname: Gaser
mesh_terms: D000465:Algorithms; D001921:Brain / Q000473:pathology*; D003627:Data Interpretation, Statistical; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis*; D012680:Sensitivity and Specificity