Interesting ImagesPearls and Pitfalls of Quantitative Software Analysis of Dopamine Transporter SPECTMushtaq, Raza MD∗; Kay, Matthew D. MBBS∗; Steinmeyer, Laura MD∗; Warhadpande, Devdutta MD, MS∗; Kuo, Phillip H. MD, PhD∗,†Author Information From the ∗Department of Medical Imaging, University of Arizona College of Medicine †Department of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ. Received for publication January 6, 2020; revision accepted May 14, 2020. Conflicts of interest and sources of funding: P.H.K. is a speaker, consultant, and recipient of grants from GE Healthcare. He is also a consultant for Invicro. The remaining authors have no conflicts of interest to disclose. Correspondence to: Matthew D. Kay, MBBS, Department of Medical Imaging, University of Arizona College of Medicine, 1501 N Campbell Ave, Tucson, AZ 85724. E-mail: email@example.com. Clinical Nuclear Medicine: November 2020 - Volume 45 - Issue 11 - p e469-e476 doi: 10.1097/RLU.0000000000003183 Buy Metrics Abstract Dopamine transporter SPECT with 123I-N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) nortropane (123I-ioflupane) aids in the diagnosis of parkinsonian syndrome by demonstrating loss of striatal dopamine transporters, proportional to nigrostriatal dopaminergic neuronal loss. Quantitative software analysis (QSA) is a helpful adjunct to visual interpretation. An atlas of pearls and pitfalls of QSA is presented. Examples include correction for head tilt/orientation, scaling artifacts, and detection of balanced loss of activity. Additional examples are provided where QSA can potentially fail such as patient variation and vascular disease. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.