Abstracts der 56. DGN-Jahrestagung 2018

Medizinphysik Vorsitz: G. Glatting, J. van den Hoff 10:30 - 12:00 Posterausstellung (Halle 4.0)

P43 CZT detector characteristics for handheld molecular imaging of “small lesions” J. Neba¹, J. Wüstemann², P. Matthies³, F. Alves Pinto³, T. Barthel⁴, K. Schwenkenbecher⁴, O. S. Großer², M. Lassmann¹ ¹Universitätsklinikum Würzburg, Klinik und Poliklinik für Nuklearmedizin, Würzburg; ²Universitätsklinikum Magdeburg, Klinik für Radiologie und Nuklearmedizin, Magdeburg; ³SurgicEye GmbH, München; ⁴Crystal Photonics, Berlin
Ziel/Aim: Investigation of the sensitivity and spatial resolution of a commercially handheld gamma camera. Methodik/Methods: The performance characteristics of the CrystalCam, a cadmium zinc telluride (CZT) small-field-of-view handheld gamma camera was investigated under different conditions. Sensitivity data were acquired from 50 to 350 mm source-detector-distance (steps: 50 mm) with and without collimator (LEHS Tungsten) by using a Co-57 point source in air (energy window: 122.1keV ± 10 %, acquisition duration 40s and 90s for sensitivity acquisitions with and without collimator). Image resolution was investigated by point spread function measurements from 50 to 150 mm (with collimator, steps: 50 mm, acquisition duration: 120 s). The camera output was generated using the Crystal-Imager software from the manufacturer and further processed with ImageJ. Plotting and additional data analysis was performed on the exported spreadsheets. Adequate count statistics (error below 1%) were achieved in all measurements; the detector was kept within the specified linear count rate range (<60kcps). Ergebnisse/Results: Without collimator, the detector followed an inverse-square-law response, with a goodness-of-fit (R²) of more than 99.4%. The system response in terms of count rate vs the source-detector-distance showed an estimated 2cps/mm loss with increasing point source distance. The PSF was used to expresses the image resolution (3.97, 5.64 and 8.08 mm) in terms of full-width-at-half-maximum at 50, 100 and 150 mm respectively, corresponding to a count rate of 700, 640 and 480 cps. Schlussfolgerungen/Conclusions: The high sensitivity and good spatial resolution of this CZT detector system in combination with its light-weight housing and fast and reliable readout make the CrystalCam very suitable for pre- and interventional target localization and imaging.

zurück zur Übersicht