[1] Univ Michigan, Div Neuroradiol, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Dept Radiol, Div Nucl Med, Ann Arbor, MI 48109 USA
[3] Univ Michigan, Morris K Udall Ctr Excellence Parkinsons Dis Res, Ann Arbor, MI 48109 USA
[4] Univ Michigan, Parkinsons Fdn, Res Ctr Excellence, Ann Arbor, MI 48109 USA
[5] Univ Michigan, Dept Neurol, Ann Arbor, MI 48109 USA
[6] VAAAHS, GRECC Neurol Serv, Ann Arbor, MI USA