[Quantitative evaluation of SPECT with FP-CIT. Importance of the reference area].
OBJECTIVE
The aim of this study is to compare several uptake indexes between specific and non-specific activity to determine the existence of degenerative Parkinsonism according to different reference areas.


METHODS
A total of 46 patients (23 men and 23 women), randomly selected from individuals referred to our center with a movement disorder, were included in the study. Mean age was 70.2 ± 10.2 years (41-87). The uptake indexes were obtained through the areas of interest (ROIs) located in the striate (specific uptake) and other reference ROIs located in areas with different concentrations of serotonin receptors: low-cerebellum, medium-occipital cortex and high-midbrain.


RESULTS
A high linear correlation was found between indexes having low and medium concentration of serotonin receptors. The ROC curve analysis shows an area under the curve of 0.874, 0.886 and 0.739 and regression coefficients of 5.41, 6.62 and 3.41, respectively for the striatum/cerebellum (E/C), striatum/occipital (E/O) and striatum midbrain (E/M) indexes. Optimal cutoff for E/O (1.35), index with the best behavior, provides a sensitivity of 0.84 and specificity of 0.89.


CONCLUSIONS
The reference area selected may alter the predictive power of the different indexes to determine the existence of a degenerative Parkinsonism.
Ortega Lozano
S J
SJ
Servicio de Medicina Nuclear, Hospital Universitario «Virgen de la Victoria», Málaga, España. simeon.ortega.sspa@juntadeandalucia.es
Martinez Del Valle Torres
M D
MD
Ramos Moreno
E
E
Sanz Viedma
S
S
Amrani Raissouni
T
T
Jiménez-Hoyuela
J M
JM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D002531:Cerebellum / Q000737:chemistry / Q000000981:diagnostic imaging; D003342:Corpus Striatum / Q000737:chemistry; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008636:Mesencephalon / Q000737:chemistry; D008875:Middle Aged; D009410:Nerve Degeneration / Q000000981:diagnostic imaging; D009928:Organ Specificity; D010300:Parkinson Disease / Q000000981:diagnostic imaging; D010302:Parkinson Disease, Secondary / Q000000981:diagnostic imaging; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D012372:ROC Curve; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D011985:Receptors, Serotonin / Q000032:analysis; D012189:Retrospective Studies; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes / Q000493:pharmacokinetics
D002250:Carbon Radioisotopes; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D011985:Receptors, Serotonin; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane