IMPLEMENTATION AND VALIDATION OF A FULLY-AUTOMATIC SYSTEM FOR INTRAINDIVIDUAL AND INTERINDIVIDUAL REGISTRATION OF PET BRAIN-SCANS

Purpose: Stereotactic coordinate spaces and methods to adapt subjects to that space are required when performing averaging of functional stu dies across subjects. Methods: A rapid and fully automatic method to p erform intersubject registration and adaptation to a previously define d coordinate space has been developed and implemented. The implementat ion has been performed within an existing software developed to facili tate manual registration and adaptation, thus offering a versatile com bination of automatic and manual tools. Furthermore, a novel measure, based on the F-statistic for intersubject (block) differences, for the assessment of intersubject goodness of fit was suggested and validate d. Results: The intra- and intersubject registration was validated by its application to data from six human subjects participating in an ac tivation study. The registration was performed both manually and autom atically, and the results indicated that the automatic method performe d at least as well as the manual. The block F-statistic was lower for the automatic method, and the z-scores were not significantly differen t for the methods. The localization of activated regions showed good a greement and differed by an average of 6 mm between the methods. Concl usion: It is concluded that the suggested method is a valuable alterna tive to the current manual approach.