Room: Exhibit Hall | Forum 8
Purpose: The purpose of this work was to investigate changes in input detector exposure rate (IDER) for a new automatic dose regulation feature configured on a Siemens Artis Pheno system.
Methods: IDER were measured for a Siemens Artis Pheno system, that incorporated a new proprietary automatic dose regulation feature, using a Radcal 60cc ion chamber with an AGDM digitizer module. Measurements were performed for a typical protocol (â€˜Fl-Coroâ€™) for different magnification modes (50cm-16cm) with externally added 2mm Cu filtration in the beamâ€™s path (SID:100cm). Measurements were made with the grid and repeated with grid removed. For comparison of observed trends, similar measurements were performed on a Siemens Artis Zee system that utilized a standard automatic dose regulation feature.
Results: IDER measured with the grid were 0.29ÂµGy/s, 0.35ÂµGy/s, 0.42ÂµGy/s, 0.48ÂµGy/s and 0.55ÂµGy/s, and with grid removed were 0.84ÂµGy/s, 1.07ÂµGy/s, 1.31ÂµGy/s, 0.84ÂµGy/s and 0.82ÂµGy/s for 50cm (no magnification), 42cm, 32cm, 22cm and 16cm magnification modes, respectively. Interestingly, the IDER were lower when the grid was used and higher when the grid was removed. This may be due to the new proprietary automatic dose regulation feature on the Artis Pheno systems which probably aims to maintain a constant contrast-to-noise ratio (CNR). Additionally, the measurements with the grid removed showed an initial increase and then a decrease in IDER with higher magnification modes. For the Artis Zee system, the IDER were higher when the grid was used relative to measurements done without the grid which is characteristic of standard automatic dose regulation.
Conclusion: New trends in IDER were noted as a characteristic of a new automatic dose regulation feature configured on a Siemens Artis Pheno system that possibly aims to maintain constant CNR.