Evaluation of pinhole collimator materials for micron-resolution < i > ex-vivo < /i > SPECT.

Evaluation of pinhole collimator materials for micron-resolution <i>ex-vivo</i> SPECT. Phys Med Biol. 2019 Apr 04;: Authors: Nguyen MP, Goorden MC, Kamphuis C, Beekman FJ Abstract Pinhole collimation is widely recognized for offering superior resolution-sensitivity trade-off in SPECT imaging of small subjects. The newly developed EXIRAD-3D autoradiography technique (MILabs B.V.) based on a highly focusing multi-pinhole collimator achieves micron-resolution SPECT for cryo-cooled tissue samples. For such high resolutions, the choice of pinhole material may have a significant impact on images. Therefore, this paper aims to compare the performance of EXIRAD-3D with lead, tungsten, gold, and depleted uranium pinhole collimators designed such that they achieve equal sensitivities. Performance in terms of resolution is characterized for several radioisotopes, namely &lt;sup&gt;111&lt;/sup&gt;In (171 keV and 245 keV), &lt;sup&gt;99m&lt;/sup&gt;Tc (140 keV), &lt;sup&gt;201&lt;/sup&gt;Tl (71 keV), and &lt;sup&gt;125&lt;/sup&gt;I (27 keV). Using Monte Carlo simulation, point spread functions were simulated and their profiles as well as their full-width-at-half-maximum and full-width-at-tenth-maximum were determined and evaluated for different materials and isotopes. Additionally, reconstructed images of a Derenzo resolution phantom, validated with experimental data, wer...
Source: Physics in Medicine and Biology - Category: Physics Authors: Tags: Phys Med Biol Source Type: research
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