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Targeting murine heart and brain: visualisation conditions for multi-pinhole SPECT with (99m)Tc- and (123)I-labelled probes.

Pissarek M, Meyer-Kirchrath J, Hohlfeld T, Vollmar S, Oros-Peusquens AM, Flögel U, Jacoby C, Krügel U, Schramm N - Eur. J. Nucl. Med. Mol. Imaging (2009)

Bottom Line: Alterations of maximal cerebral uptake of [(123)I]IBZM by >20% (116 kBq) were verified with the prerequisite of 50% striatal of total uptake.The labelling with [(99m)Tc]sestamibi revealed a 30% lower uptake in cardiomyopathic hearts compared to wild types. [(123)I]IPPA uptake could be visualised at activity doses of 0.8 MBq/g body weight.The thresholds of detection for differences in the tracer uptake determined under the conditions of our experiments well reflect distinctions in molar activity and uptake characteristics of the tracers.

View Article: PubMed Central - PubMed

Affiliation: Institute of Neurosciences and Biophysics-Nuclear Chemistry (INB-4), Research Centre Juelich, Leo-Brandt-Str., 52428, Juelich, Germany. m.pissarek@fz-juelich.de

ABSTRACT

Purpose: The study serves to optimise conditions for multi-pinhole SPECT small animal imaging of (123)I- and (99m)Tc-labelled radiopharmaceuticals with different distributions in murine heart and brain and to investigate detection and dose range thresholds for verification of differences in tracer uptake.

Methods: A Triad 88/Trionix system with three 6-pinhole collimators was used for investigation of dose requirements for imaging of the dopamine D(2) receptor ligand [(123)I]IBZM and the cerebral perfusion tracer [(99m)Tc]HMPAO (1.2-0.4 MBq/g body weight) in healthy mice. The fatty acid [(123)I]IPPA (0.94 +/- 0.05 MBq/g body weight) and the perfusion tracer [(99m)Tc]sestamibi (3.8 +/- 0.45 MBq/g body weight) were applied to cardiomyopathic mice overexpressing the prostaglandin EP(3) receptor.

Results: In vivo imaging and in vitro data revealed 45 kBq total cerebral uptake and 201 kBq cardiac uptake as thresholds for visualisation of striatal [(123)I]IBZM and of cardiac [(99m)Tc]sestamibi using 100 and 150 s acquisition time, respectively. Alterations of maximal cerebral uptake of [(123)I]IBZM by >20% (116 kBq) were verified with the prerequisite of 50% striatal of total uptake. The labelling with [(99m)Tc]sestamibi revealed a 30% lower uptake in cardiomyopathic hearts compared to wild types. [(123)I]IPPA uptake could be visualised at activity doses of 0.8 MBq/g body weight.

Conclusion: Multi-pinhole SPECT enables detection of alterations of the cerebral uptake of (123)I- and (99m)Tc-labelled tracers in an appropriate dose range in murine models targeting physiological processes in brain and heart. The thresholds of detection for differences in the tracer uptake determined under the conditions of our experiments well reflect distinctions in molar activity and uptake characteristics of the tracers.

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Transversal and sagittal slices of murine brains with different uptake of [123I]IBZM. Brains of four mice are shown following application of 0.95 (a), 0.61 (b), 0.56 (c) and 0.44 (d) MBq/g during the fifth acquisition period (A transversal slices, B sagittal slices). MPS was performed using acquisition times of 100 s per scan, 10 steps of rotation and a radius of rotation of 37 mm. Body weights of the mice were 42 g (a), 34 g (b), 34 g (c) and 50 g (d). Maximum intensity projections of a have been shown in [30]
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Fig2: Transversal and sagittal slices of murine brains with different uptake of [123I]IBZM. Brains of four mice are shown following application of 0.95 (a), 0.61 (b), 0.56 (c) and 0.44 (d) MBq/g during the fifth acquisition period (A transversal slices, B sagittal slices). MPS was performed using acquisition times of 100 s per scan, 10 steps of rotation and a radius of rotation of 37 mm. Body weights of the mice were 42 g (a), 34 g (b), 34 g (c) and 50 g (d). Maximum intensity projections of a have been shown in [30]

Mentions: Uptake of [123I]IBZM was observed for 3 h. Figure 1 presents transversal slices of the brain after application of 0.61 MBq/g [123I]IBZM (34 g body weight) in relation to transversal MR images (36 g body weight). Figure 2 shows transversal and sagittal slices of the brains at the four dose levels during the fifth acquisition period.Fig. 1


Targeting murine heart and brain: visualisation conditions for multi-pinhole SPECT with (99m)Tc- and (123)I-labelled probes.

Pissarek M, Meyer-Kirchrath J, Hohlfeld T, Vollmar S, Oros-Peusquens AM, Flögel U, Jacoby C, Krügel U, Schramm N - Eur. J. Nucl. Med. Mol. Imaging (2009)

Transversal and sagittal slices of murine brains with different uptake of [123I]IBZM. Brains of four mice are shown following application of 0.95 (a), 0.61 (b), 0.56 (c) and 0.44 (d) MBq/g during the fifth acquisition period (A transversal slices, B sagittal slices). MPS was performed using acquisition times of 100 s per scan, 10 steps of rotation and a radius of rotation of 37 mm. Body weights of the mice were 42 g (a), 34 g (b), 34 g (c) and 50 g (d). Maximum intensity projections of a have been shown in [30]
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2724637&req=5

Fig2: Transversal and sagittal slices of murine brains with different uptake of [123I]IBZM. Brains of four mice are shown following application of 0.95 (a), 0.61 (b), 0.56 (c) and 0.44 (d) MBq/g during the fifth acquisition period (A transversal slices, B sagittal slices). MPS was performed using acquisition times of 100 s per scan, 10 steps of rotation and a radius of rotation of 37 mm. Body weights of the mice were 42 g (a), 34 g (b), 34 g (c) and 50 g (d). Maximum intensity projections of a have been shown in [30]
Mentions: Uptake of [123I]IBZM was observed for 3 h. Figure 1 presents transversal slices of the brain after application of 0.61 MBq/g [123I]IBZM (34 g body weight) in relation to transversal MR images (36 g body weight). Figure 2 shows transversal and sagittal slices of the brains at the four dose levels during the fifth acquisition period.Fig. 1

Bottom Line: Alterations of maximal cerebral uptake of [(123)I]IBZM by >20% (116 kBq) were verified with the prerequisite of 50% striatal of total uptake.The labelling with [(99m)Tc]sestamibi revealed a 30% lower uptake in cardiomyopathic hearts compared to wild types. [(123)I]IPPA uptake could be visualised at activity doses of 0.8 MBq/g body weight.The thresholds of detection for differences in the tracer uptake determined under the conditions of our experiments well reflect distinctions in molar activity and uptake characteristics of the tracers.

View Article: PubMed Central - PubMed

Affiliation: Institute of Neurosciences and Biophysics-Nuclear Chemistry (INB-4), Research Centre Juelich, Leo-Brandt-Str., 52428, Juelich, Germany. m.pissarek@fz-juelich.de

ABSTRACT

Purpose: The study serves to optimise conditions for multi-pinhole SPECT small animal imaging of (123)I- and (99m)Tc-labelled radiopharmaceuticals with different distributions in murine heart and brain and to investigate detection and dose range thresholds for verification of differences in tracer uptake.

Methods: A Triad 88/Trionix system with three 6-pinhole collimators was used for investigation of dose requirements for imaging of the dopamine D(2) receptor ligand [(123)I]IBZM and the cerebral perfusion tracer [(99m)Tc]HMPAO (1.2-0.4 MBq/g body weight) in healthy mice. The fatty acid [(123)I]IPPA (0.94 +/- 0.05 MBq/g body weight) and the perfusion tracer [(99m)Tc]sestamibi (3.8 +/- 0.45 MBq/g body weight) were applied to cardiomyopathic mice overexpressing the prostaglandin EP(3) receptor.

Results: In vivo imaging and in vitro data revealed 45 kBq total cerebral uptake and 201 kBq cardiac uptake as thresholds for visualisation of striatal [(123)I]IBZM and of cardiac [(99m)Tc]sestamibi using 100 and 150 s acquisition time, respectively. Alterations of maximal cerebral uptake of [(123)I]IBZM by >20% (116 kBq) were verified with the prerequisite of 50% striatal of total uptake. The labelling with [(99m)Tc]sestamibi revealed a 30% lower uptake in cardiomyopathic hearts compared to wild types. [(123)I]IPPA uptake could be visualised at activity doses of 0.8 MBq/g body weight.

Conclusion: Multi-pinhole SPECT enables detection of alterations of the cerebral uptake of (123)I- and (99m)Tc-labelled tracers in an appropriate dose range in murine models targeting physiological processes in brain and heart. The thresholds of detection for differences in the tracer uptake determined under the conditions of our experiments well reflect distinctions in molar activity and uptake characteristics of the tracers.

Show MeSH