Reproducibility of striatal and thalamic dopamine D2 receptor binding using [11C]raclopride with high-resolution positron emission tomography.
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.
Alakurtti
Kati
K
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland. khalak@utu.fi
Aalto
Sargo
S
Johansson
Jarkko J
JJ
Någren
Kjell
K
Tuokkola
Terhi
T
Oikonen
Vesa
V
Laine
Matti
M
Rinne
Juha O
JO
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
D018492:Dopamine Antagonists; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2; D020891:Raclopride