title: Imaging of dopamine transporters with iodine-123-beta-CIT and SPECT in Parkinson's disease.
abstract: The aim of the present study was to demonstrate the degeneration of the dopaminergic nigrostriatal pathway in Parkinson's disease by using the cocaine derivative [123I]beta-CIT (2-beta-carbomethoxy-3-beta(4-iodophenyl)-tropane or RTI-55) and SPECT and to relate the findings to the severity of the disease (Hoehn and Yahr scale, H/Y) and to clinical data such as motor score and activities of daily living.
  
  
  METHODS
  Thirteen volunteers and 47 patients with idiopathic Parkinson's disease (PD) of H/Y Stage I-V (I:n = 16, II:n = 6, III:n = 14, IV:n = 9, V:n = 2) were investigated. Acquisitions were performed 2, 4, 16, 20 and 24 hr postinjection. ROIs were drawn over the striatum and the cerebellum. Specific beta-CIT binding was defined as striatal minus cerebellar binding. The ratio of specific over nondisplaceable binding (striatum/cerebellum-1) was determined as well as the percent deviation of this ratio from age-expected control values.
  
  
  RESULTS
  The time-activity curve of striatal [123I]beta-CIT binding demonstrated a maximum around 20 hr postinjection in controls and a peak 4 hr postinjection in PD patients. Ratios differed significantly between the two groups. A significant correlation existed between this ratio and clinical measures. Hemiparkinsonian patients revealed significantly diminished [123I]beta-CIT binding not only contralateral to the clinically affected but also contralateral to the clinically unaffected side. [123I]beta-CIT binding showed a significant decrease in comparison to age-expected values ranging from 36% in H/Y stage 1 to 71% in H/Y stage V.
  
  
  CONCLUSIONS
  The present study demonstrates that it is possible to visualize and quantify the degeneration of dopaminergic nigrostriatal neurons in PD using [123I]beta-CIT and SPECT with good correlation to clinical parameters.
authors.affiliation: Department of Neurology, University of Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Asenbaum
authors.forename: T
authors.initials: T
authors.lastname: Brücke
authors.forename: W
authors.initials: W
authors.lastname: Pirker
authors.forename: I
authors.initials: I
authors.lastname: Podreka
authors.forename: P
authors.initials: P
authors.lastname: Angelberger
authors.forename: S
authors.initials: S
authors.lastname: Wenger
authors.forename: C
authors.initials: C
authors.lastname: Wöber
authors.forename: C
authors.initials: C
authors.lastname: Müller
authors.forename: L
authors.initials: L
authors.lastname: Deecke
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002352:Carrier Proteins / Q000378:metabolism*; D003042:Cocaine / Q000031:analogs & derivatives*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D017661:Receptors, Presynaptic / Q000378:metabolism*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D017661:Receptors, Presynaptic; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine