Diagnostic performance of a 3-D automated quantification method of dopamine D2 receptor SPECT studies in the differential diagnosis of parkinsonism

Nucl Med Commun. 2005 Jan;26(1):39-43. doi: 10.1097/00006231-200501000-00007.


Background: Assessment of post-synaptic D2 receptors with 123I-IBZM SPECT is helpful in distinguishing idiopathic (IPS) from other parkinsonian syndromes (non-IPS).

Aim: To evaluate the diagnostic performance of a recently introduced three-dimensional automated quantification method in a large group of parkinsonian patients.

Methods: IBZM SPECT was performed in 101 consecutive patients with IPS (n = 49) and non-IPS (n = 52). Striatal/frontal cortex binding ratios were assessed by a standard manual quantification method and by the automated method. For the latter patient studies were registered to a mean template of healthy controls (n = 13). IBZM binding was calculated from a 3-D volume-of-interest map established on the normal template. The diagnostic performance of the automated and manual approaches were assessed by receiver operating characteristic (ROC) analyses.

Results: Specific striatal binding ratios of both quantification methods showed a close linear relationship (y = 0.81x + 0.1188; R2 = 0.8062). At optimal decision thresholds sensitivity and specificity were 87% and 90% for the automated, and 85% and 90% for the manual method, respectively. The area under the ROC curve was 0.92 for the automated and 0.93 for the manual method, showing no statistical difference. The area under the ROC curve corresponding to a false positive fraction from 0% to 20% was 0.163 for the automated and 0.166 for the manual evaluation.

Conclusions: The diagnostic performance of an automated 3-D quantification method for IBZM SPECT studies has been shown to be equal to, or even better than, a standard manual technique. Advantages of automated quantifications are observer independence and fast processing times. This method may be also used as a platform for processing large data sets/multicentre studies in order to objectively evaluate basal ganglia disorders.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Algorithms
  • Benzamides* / pharmacokinetics
  • Corpus Striatum / diagnostic imaging*
  • Corpus Striatum / metabolism*
  • Diagnosis, Differential
  • Female
  • Humans
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods*
  • Imaging, Three-Dimensional / methods*
  • Male
  • Middle Aged
  • Neurodegenerative Diseases / diagnostic imaging
  • Neurodegenerative Diseases / metabolism
  • Parkinson Disease / diagnostic imaging*
  • Parkinson Disease / metabolism*
  • Pyrrolidines* / pharmacokinetics
  • Radionuclide Imaging
  • Radiopharmaceuticals / pharmacokinetics
  • Receptors, Dopamine D2 / metabolism*
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Benzamides
  • Pyrrolidines
  • Radiopharmaceuticals
  • Receptors, Dopamine D2
  • 3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide