1. Neurosurgery Department University of Arkansas for Medical Sciences, and St. Vincent's Infirmary, Little Rock, Arkansas
2. Radiology Department University of Arkansas for Medical Sciences and Radiology Service, Little Rock Veterans Administration Medical Center, Little Rock, Arkansas
3. Radiology Department, Bowman Gray Medical School, and Forsyth Memorial Hospital, Winston-Salem, North Carolina
4. Pathology Department University of Arkansas for Medical Sciences, and St. Vincent's Infirmary, Little Rock, Arkansas
5. Neurosurgery Department, University of Arkansas for Medical Sciences, and St. Vincent's Infirmary, Little Rock, Arkansas