Challenge by the murine brain: multi-pinhole SPECT of 123I-labelled pharmaceuticals.
This protocol presents an improved method for SPECT imaging based on multi-pinhole techniques, applied to the visualisation of neurotracers in small animal models. Three types of collimators with 6-pinhole apertures adapted to special requirements for the imaging of the brain of mice and rats and to full body imaging in mice are employed in the experiments. A conventional triple-headed TRIAD/Trionix SPECT system was upgraded with pyramidal supports and shieldings onto the multi-pinhole collimators were installed. The system was employed for the assessment of the uptake of [123I]FP-CIT and [123I]IBZM, well known tracers of dopamine transport and dopamine D2/D3 receptors, respectively. Requirements regarding the applied radioactivity are reported, as well as further conditions determining the effectiveness of the detection of the uptake of [123I]FP-CIT and [123I]IBZM. The measurements in mice required only 20-25% of the activity described in previous studies. Dynamic measurements are presented, with a time resolution as high as 10 min in the brain of rats. Due to the lower signal intensity obtained for mice, the time resolution was 42min for [123I]FP-CIT, with a ratio ROI/background of 5.4, and 17 min for [123I]IBZM, with the ratio ROI/background of 4.5 (1.6-7.4).
Institute of Neurosciences and Biophysics-Nuclear Chemistry (INB-4), Research Centre Juelich, D-52425 Juelich, Germany. m.pissarek@fz-juelich.de
Margit Beate
MB
Pissarek
Ana-Maria
AM
Oros-Peusquens
Nils Uwe
NU
Schramm
D000758:Anesthesia; D000818:Animals; D001549:Benzamides; D001921:Brain / Q000000981:diagnostic imaging*; D007457:Iodine Radioisotopes; D008279:Magnetic Resonance Imaging; D051379:Mice; D015609:Organotechnetium Compounds; D011759:Pyrrolidines; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D011921:Rats, Inbred WKY; D012015:Reference Standards; D019690:Technetium Tc 99m Exametazime; D013961:Thyroid Gland / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014326:Tropanes
D001549:Benzamides; D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; D011759:Pyrrolidines; D019275:Radiopharmaceuticals; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D019690:Technetium Tc 99m Exametazime; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide