to determine whether i-123 isopropyl iodoamphetamine ( imp ) uptake is reduced in the basal ganglia of patients with huntington 's disease compared with that in aged-matched normal and abnormal control subjects , a caudate ratio was defined that compared the average separation ( in pixel units ) between the midline and the left and right caudate heads to the width of the brain as measured on transaxial cross-sections of i-123 imp spect brain images .
C0004781
basal ganglia
C0006104
brain