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High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals
Published on: December 16, 2022
Scanning rats on the high resolution research tomograph (HRRT): a comparison study with a dedicated micro-PET
Stephan A L Blinder1, Katherine Dinelle, Vesna Sossi
1Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada. blinder@phas.ubc.ca
Medical Physics
|August 17, 2012
Summary
The Siemens HRRT scanner is not suitable for quantitative small animal brain imaging due to insufficient spatial resolution and artifacts introduced by point spread function (PSF) modeling, despite its potential for simultaneous rodent imaging.
Area of Science:
- Nuclear Medicine
- Neuroscience Imaging
- Small Animal PET Imaging
Background:
- The Siemens ECAT High Resolution Research Tomograph (HRRT) is a high-sensitivity, high-resolution PET camera designed for human brain imaging.
- Its specifications are comparable to dedicated small animal PET scanners, suggesting potential for cost-effective rodent imaging.
- The HRRT's larger field of view could enable simultaneous imaging of multiple rodents.
Purpose of the Study:
- To investigate the feasibility of using the Siemens HRRT for quantitative small animal brain studies.
- To compare the performance of the HRRT with a dedicated small animal PET scanner (Siemens microPET FOCUS 120) for rodent brain imaging.
Main Methods:
- Comparison of nondisplaceable binding potentials (BP(ND)) in rat striata using [(11)C]methylphenidate scans on both HRRT and microPET FOCUS 120.
- Evaluation of magnitude, reproducibility, and asymmetry of BP(ND) values between scanners.
- Phantom study to assess noise properties relevant to small rat brain regions of interest.
Main Results:
- BP(ND) values were 38% lower on HRRT without PSF modeling and 7% higher with PSF modeling compared to the microPET FOCUS 120.
- Within-animal reproducibility was worse on HRRT (18% without PSF, 27% with PSF) compared to the microPET FOCUS 120 (6%).
- Image asymmetry worsened significantly on HRRT (7.8% without PSF, 14.8% with PSF) compared to the microPET FOCUS 120 (4.7%).
- HRRT images with PSF modeling exhibited overshooting artifacts and clumpiness.
Conclusions:
- The spatial resolution of the HRRT without resolution recovery is insufficient for reliable quantitative small animal brain imaging.
- While PSF modeling improves resolution, it introduces artifacts that preclude accurate quantitative analysis in small animal brain studies.
- The HRRT is not suitable for quantitative small animal brain imaging due to resolution limitations and reconstruction-induced artifacts.
