(123I) beta-CIT and single-photon emission computed tomographic imaging vs clinical evaluation in Parkinsonian syndrome: unmasking an early diagnosis

Arch Neurol. 2004 Aug;61(8):1224-9. doi: 10.1001/archneur.61.8.1224.


Background: The diagnosis of Parkinson disease is currently based on clinical evaluation. Functional neuroimaging using (123I) beta-carboxymethyoxy-3-beta-(4-iodophenyl) tropane (CIT) and single-photon emission computed tomography (SPECT) provides information on the integrity of the dopaminergic system in vivo and is a promising diagnostic tool in early Parkinson disease.

Objective: To evaluate the diagnostic accuracy of dopamine transporter imaging using (123I)beta-CIT in patients with suspected parkinsonian syndrome (PS).

Design: Community neurologists referred patients with suspected PS for imaging evaluation. Clinical diagnoses (positive PS or negative PS) were provided by the community neurologists and 2 movement disorder experts. We performed (123I)beta-CIT and SPECT imaging, and imaging diagnoses of positive PS or negative PS were assigned. A 6-month follow-up clinical diagnosis was assigned by a movement disorder expert blind to the imaging data, which represented the "gold standard" diagnosis for the study.

Results: Thirty-five patients with suspected PS were referred. Diagnoses in question included essential tremor, psychogenic parkinsonism, drug-induced parkinsonism, primary dystonia, and unspecified gait disorder. Comparing the community neurologist's diagnoses at referral with the gold standard diagnosis, there was dis agreement in 25.7% (sensitivity, 0.92; specificity, 0.30). Comparing the quantitative imaging diagnoses with the gold standard, there was disagreement in 8.6% (sensitivity, 0.92; specificity, 1.00).

Conclusion: Performing (123I)beta-CIT and SPECT imaging at baseline appears to be a useful diagnostic tool to detect patients thought to have PS at baseline but who, after follow-up, do not have PS.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Area Under Curve
  • Cocaine* / analogs & derivatives
  • Female
  • Follow-Up Studies
  • Humans
  • Iodine Radioisotopes
  • Male
  • Middle Aged
  • Parkinsonian Disorders / diagnosis*
  • Parkinsonian Disorders / metabolism*
  • Reproducibility of Results
  • Tomography, Emission-Computed, Single-Photon* / methods


  • Iodine Radioisotopes
  • 2beta-carbomethoxy-3beta-(4-iodophenyl)tropane
  • Cocaine