Validation of a resolution-independent method for the quantification of 123I-FP-CIT SPECT scans.
OBJECTIVE
To verify the applicability of a recently described resolution-independent method for the semi-quantification of 123I-FP-CIT scans.


METHODS
Visual interpretation, 'conventional' and resolution-independent semi-quantification was performed on 60 123I-FP-CIT scans. Using ROC analysis, the results were compared to the final clinical diagnosis after a follow-up of at least 18 months. Sensitivity and specificity values were calculated and a cut-off value of the specific binding, which differentiated between normal and abnormal scans with high sensitivity and specificity, was given.


RESULTS
Application of the resolution-independent method to a new set of 123I-FP-CIT SPECT data yielded a cut-off value of the specific striatal binding of 55 ml. Corresponding values of sensitivity and specificity were 95% and 72%, respectively. Further, based on the values of the area under the ROC curve and the 95% confidence interval of different semi-quantitative methods, the resolution-independent semi-quantification agreed best with the final clinical diagnosis.


CONCLUSIONS
We found a similar value of the specific 123I-FP-CIT binding as the one previously described in the literature, which proved the validity of the resolution-independent method. Further, this method, among other 'conventional' semi-quantitative methods, agreed best with the final clinical diagnosis. For this reason we recommend its use to aid in the diagnostic process.
Goethals
Ingeborg
I
Department of Nuclear Medicine, Ghent University Hospital, Belgium. ingeborg.goethals@ugent.be
Dobbeleir
André
A
Ham
Hamphrey
H
Santens
Patrick
P
D'Asseler
Yves
Y
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014326:Tropanes
D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane