Optimization of Automated Quantification of 123I-IBZM Uptake in the Striatum Applied to Parkinsonism

• Published in: The Journal of nuclear medicine (1978) Vol. 41; no. 2; pp. 220 - 227
• Main Authors: Radau, Perry E, Linke, Rainer, Slomka, Piotr J, Tatsch, Klaus
• Format: Journal Article
• Language: English
• Published: Reston, VA Soc Nuclear Med 01-02-2000; Society of Nuclear Medicine
• Subjects: Benzamides; Biological and medical sciences; Corpus Striatum - diagnostic imaging; Corpus Striatum - metabolism; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Diagnosis, Differential; Dopamine Antagonists; Female; Humans; Image Processing, Computer-Assisted; Iodine Radioisotopes; Male; Medical sciences; Middle Aged; Neurology; Parkinsonian Disorders - diagnostic imaging; Parkinsonian Disorders - metabolism; Pyrrolidines; Receptors, Dopamine D2 - metabolism; Reproducibility of Results; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Tomography, Emission-Computed, Single-Photon; Radionuclide study; Human; Nervous system diseases; Dopamine receptor; Parkinson disease; Retention; Photon; Differential diagnostic; Optimization; Cerebral disorder; Reproducibility; Central nervous system disease; Automatic system; Degenerative disease; Performance; Extrapyramidal syndrome; Quantitative analysis; Iodine; Emission tomography
• ISSN: 0161-5505; 1535-5667

Evaluation of therapies for parkinsonism by dopamine receptor SPECT requires a reproducible, optimized quantitation technique. This study presents a new, objective, automated technique for semiquantitative analysis of dopamine receptor density, as applied to the differential diagnosis of parkinsonism.
Dopamine receptor density measured by 123I-iodobenzamide (IBZM) SPECT was retrospectively analyzed in nonidiopathic parkinsonism (NIPS), in Parkinson's disease (PD), and in healthy volunteers (n = 19, 38, and 13, respectively). A mean template was created from coregistered control studies. Registration errors were assessed using studies with simulated binding deficits. Patient studies were registered to the mean template, and striatal binding was calculated from a corresponding map of 3-dimensional regions of interest (ROIs). The striatal binding ratio and deficits determined by voxelwise comparison with the normal template were investigated and tested with various 3-dimensional ROI sizes and positions. Separation of patient groups was determined by tscore after automatically processing all studies. Results were compared with manual ROI analyses.
The automatic method was completely reproducible in 64 of 70 cases. The best diagnostic discriminator was the minimum binding ratio of the 2 striatal nuclei, with the following values: NIPS, 1.33+/-0.13; PD, 1.50+/-0.12; healthy volunteers, 1.49+/-0.08 (+/-SD). The deficit size from voxelwise analysis was: NIPS, 20.5+/-8.2 mL; PD, 9.5+/-8.3; healthy volunteers, 8.9+/-6.0 (+/-SD). The accuracy, measured by receiver operating characteristic areas, was 0.85+/-0.05, 0.77+/-0.06, and 0.80+/-0.06 (+/-SE) for the optimal predictor (automated) and 2 blinded observers (manual), respectively.
A new 3-dimensional, automated technique has been developed to semiquantitate receptor density that dramatically improves reproducibility. The optimal diagnostic discriminator of parkinsonism determined by the automatic technique has good accuracy compared with the manual technique.