title: Reproducibility of striatal and thalamic dopamine D2 receptor binding using [11C]raclopride with high-resolution positron emission tomography.
abstract: Positron emission tomography (PET) imaging of small striatal brain structures such as the ventral striatum (VST) has been hampered by low spatial resolution causing partial-volume effects. The high-resolution research tomograph (HRRT) is a brain-dedicated PET scanner that has considerably better spatial resolution than its predecessors. However, its superior spatial resolution is associated with a lower signal-to-noise ratio. We evaluated the test-retest reliability of the striatal and thalamic dopamine D(2) receptor binding using the HRRT scanner. Seven healthy male volunteers underwent two [(11)C]raclopride PET scans with a 2.5-hour interval. Dopamine D(2) receptor availability was quantified as binding potential (BP(ND)) using the simplified reference tissue model. To evaluate the reproducibility of repeated BP(ND) estimations, absolute variability (VAR) and intraclass correlation coefficients (ICCs) were calculated. VAR values indicated fairly good reproducibility and were 3.6% to 4.5% for the caudate nucleus and putamen and 4.5% to 6.4% for the lateral and medial part of the thalamus. In the VST, the VAR value was 5.8% when the definition was made in the coronal plane. However, the ICC values were only moderate, in the range of 0.34 to 0.66, for all regions except the putamen (0.87). Experimental signal processing methods improved neither ICC nor VAR values significantly.
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland. khalak@utu.fi
authors.forename: Kati
authors.initials: K
authors.lastname: Alakurtti
authors.forename: Sargo
authors.initials: S
authors.lastname: Aalto
authors.forename: Jarkko J
authors.initials: JJ
authors.lastname: Johansson
authors.forename: Kjell
authors.initials: K
authors.lastname: Någren
authors.forename: Terhi
authors.initials: T
authors.lastname: Tuokkola
authors.forename: Vesa
authors.initials: V
authors.lastname: Oikonen
authors.forename: Matti
authors.initials: M
authors.lastname: Laine
authors.forename: Juha O
authors.initials: JO
authors.lastname: Rinne
mesh_terms: D000328:Adult; D000465:Algorithms; D019540:Area Under Curve; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000378:metabolism*; D018492:Dopamine Antagonists; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007553:Isotope Labeling; D008297:Male; D049268:Positron-Emission Tomography; D020891:Raclopride; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000378:metabolism*; D055815:Young Adult
chemical_list: D018492:Dopamine Antagonists; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2; D020891:Raclopride