不同阳极靶与滤过器组合的乳腺DR成像性能比较

Comparision of imaging quality of different anode/filter combination for digital mammography

目的对数字乳腺X线摄影不同阳极靶与滤过器组合的成像性能进行对比。方法采用不同厚度乳腺成像体模,选择不同的阳极靶与滤过器组合在自动曝光模式下成像。测量图像信噪比和腺体吸收剂量,并引入图像品质因数综合评价成像性能。结果对于不同厚度的乳腺体模,使用钨铑阳极滤过器组合平均腺体吸收剂量比其他组合可以降低26.32%～42.11%,图像品质因数高于其他组合5.06%～37.43%。随着腺体厚度的增加平均腺体吸收剂量逐步增加,而图像信噪比和图像品质因数则随厚度的增加而下降。结论当体模厚度在4.0～9.0cm时,采用钨铑阳极滤过器组合可以在保证图像质量的同时减少腺体吸收剂量,总体成像性能要优于其他两种组合。

Objective To compare the imaging quality of different anode/filter combination for digital mammography system.Methods Mammography accreditation phantom with phantom thickness from 4.0 cm to 9.0 cm was used to simulate human breast tissue,and three different combinations of anode/filter material were employed under the automatic exposure mode.The image signal to noise ratio（SNR） and mean glandular dose（MGD） were measured.The figure of merit（FOM） was used to evaluate the imaging performance of digital mammography.Results For 4.0-9.0 cm phantom thicknesses,the MGD of tungsten anode and rhodium filter combination（W/Rh） was lower by 26.32%-42.11% than other two combinations;the FOM of W/Rh achieved higher by 5.06%-37.43% than the others.SNR and FOM decreased with the increase of phantom thickness,and the MGD became higher with thicker phantom.Conclusion For 4.0-9.0 cm phantom thicknesses,W/Rh anode/filter has the best imaging quality with good image performance and low radiation dose.