Structural, functional, and clinical studies in schizophrenia have, for several decades, consistently implicated
dysfunction of the prefrontal cortex in the etiology of the disease. Functional and structural imaging studies,
combined with clinical, psychometric, and genetic analyses in schizophrenia have confirmed the key roles
played by the prefrontal cortex and closely linked "prefrontal system" structures such as the striatum, amygdala,
mediodorsal thalamus, substantia nigra-ventral tegmental area, and anterior cingulate cortices. The nodal
structure of the prefrontal system circuit is the dorsal lateral prefrontal cortex (DLPFC), or Brodmann area 46,
which also appears to be the most commonly studied and cited brain area with respect to schizophrenia.1, 2, 3, 4
In 1986, Weinberger et. al. tied cerebral blood flow in the DLPFC to schizophrenia.1 In 2001, Perlstein et. al.
demonstrated that DLPFC activation is essential for working memory tasks commonly deficient in schizophrenia.
2 More recently, groups have linked morphological changes due to gene deletion and increased DLPFC
glutamate concentration to schizophrenia.3, 4
Despite the experimental and clinical focus on the DLPFC in structural and functional imaging, the variability
of the location of this area, differences in opinion on exactly what constitutes DLPFC, and inherent difficulties in
segmenting this highly convoluted cortical region have contributed to a lack of widely used standards for manual
or semi-automated segmentation programs.
Given these implications, we developed a semi-automatic tool to segment the DLPFC from brain MRI scans
in a reproducible way to conduct further morphological and statistical studies. The segmenter is based on
expert neuroanatomist rules (Fallon-Kindermann rules), inspired by cytoarchitectonic data and reconstructions
presented by Rajkowska and Goldman-Rakic.5 It is semi-automated to provide essential user interactivity. We
present our results and provide details on our DLPFC open-source tool.