title: A novel, fully automated, observer-independent program for semiquantifying striatal ¹²³I-FP-CIT uptake.
abstract: OBJECTIVE
  To describe and validate a novel, fully automated program specifically designed for the semiquantification of striatal (123)I-FP-CIT uptake using volumes of interest (VOI) analysis.
  
  
  METHODS
  The proposed algorithm is based on a template that mimics the striatal (123)I-FP-CIT uptake in a healthy subjects, derived from defined anatomical VOIs available from WFU PickAtlas. Four SPECT studies of the anthropomorphic Alderson phantom filled with variable radioactive concentrations were acquired for the experimental validation. Experimental SPECT images were spatially normalized with respect to the previously created template. The binary VOIs corresponding to left caudate and putamen and right caudate and putamen, which were used to construct the template, were projected onto the experimental images to obtain the counts for these regions. To minimize the partial volume effect, a percentage of the voxels in these regions (threshold), rather than all of them, was used. A binary occipital VOI was used to quantify the non-specific uptake. Experimental binding potentials (BPs) were calculated from the counts in these regions. True BPs were calculated from aliquots taken from the solutions used to fill the phantom.
  
  
  RESULTS
  There were statistically significant differences in the experimental BP values (p<0.002) according to the percentage of voxels used. A highly significant correlation was achieved between true and experimental BP values, regardless of the percentage of voxels included for quantification.
  
  
  CONCLUSIONS
  Our novel, observer-independent program automatically performs the semiquantification of striatal (123)I-FP-CIT uptake in experimental studies.
authors.affiliation: Nuclear Medicine Department, University Hospital of Salamanca, Spain; Institute of Biomedical Research of Salamanca, Spain. Electronic address: ptamayo@usal.es.
authors.forename: P
authors.initials: P
authors.lastname: Tamayo
authors.affiliation: Medical Physics Department, University Hospital of Salamanca, Spain; Institute of Biomedical Research of Salamanca, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Montes
authors.affiliation: Medical Physics Department, University Hospital of Salamanca, Spain.
authors.forename: M E
authors.initials: ME
authors.lastname: Perez
authors.affiliation: Nuclear Medicine Department, University Hospital of Salamanca, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Martin
authors.affiliation: Nuclear Medicine Department, University Hospital of Salamanca, Spain.
authors.forename: J R
authors.initials: JR
authors.lastname: García-Talavera
mesh_terms: D000465:Algorithms; D001331:Automation; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes / Q000032:analysis / Q000493:pharmacokinetics*; D019047:Phantoms, Imaging; D019275:Radiopharmaceuticals / Q000032:analysis / Q000493:pharmacokinetics*; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes / Q000032:analysis / Q000493:pharmacokinetics*
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane
keywords: (123)I-FP-CIT SPECT; Alderson RSD phantom; Análisis de VOIs; Maniquí RDS Alderson; SPM; Semicuantificación de la captación estriatal; Striatal uptake semiquantification; VOI analysis