1. Department of Radiology, Nuclear Medicine Division, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
2. Department of Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, Illinois, United States
3. Department of Pathology, Rush University Medical Center, Chicago, Illinois, United States
4. Department of Radiology, Neurointervention Radiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States