Evaluation on image quality and radiation dose of 640-slice CT coronary arteriography with AIDR3D reconstruction algorithm / 重庆医学

ABSTRACT

Objective To investigate the image quality and radiation dose of 640-slice CT coronary arteriography(CTCA) with adaptive iterative dose reduction three-dimensional (AIDR3D)reconstrucction algoritym.Methods 640-slice CTCA with auto-matic exposure was performed on 84 consecutive patients.The original image data were reconstructed with AIDR3D and the filtered back-projection (FBP)algorithms at the image postprocessing workstation.Two experienced radiologists without knowing clinical information and reconstruction algorithms independently measured and calculated the image noise,signal-to-noise ratio and contrast-to-noise ratio with AIDR3D and FBP reconstruction algorithms.The qualitative image quality was assessed by using the 4-point scale.The radiation dose was calculated based on dose-length product exported on CT scanner.The quantitative and qualitative im-age quality with two kinds of reconstruction algorithm was analyzed statistically.Results The CTCA image noise was (27.20± 4.40)HU with AIDR3D and (60.00±12.40)HU with FBP,which with AIDR3D was decreased by 46.10% than that with FBP;the signal-to-noise ratio was 21.10 ± 5.10 with AIDR3D and 11.40 ± 2.80 with FBP,which with AIDR3D was increased by 84.70% than that with FBP;the contrast-to-noise ratio was 24.70±5.10 with AIDR3D and 13.50±3.20 with FBP,which with AIDR3D was raised by 82.20% than that with FBP,the differences in 3 indexes between the two kinds of reconstruction algorithm were statistically significant(P < 0.05 ).The CTCA qualitative image quality scores of proximal,middle and distal parts with AIDR3D were (3.90±0.30),(3.70±0.50)and (3.60±0.60)respectively,which all were higher than (2.60±0.60),(2.30± 0.60)and (2.10±0.70)with FBP respectively,the differences in 3 items between 2 kinds of algorithm had statistical significance (P <0.05).The total segments which could be used to diagnose the CTCA images with AIDR3D and FBP algorithms were 1 216 segments (96.50%)and 504 segments (40.00%),respectively,the difference had statistical significance(P <0.05).The mean ef-fective radiation dose was (2.10±1.00)mSv.Conclusion 640-slice CTCA with AIDR3D reconstruction algorithm not only signifi-cantly reduces the image noise than the conventional FBP algorithm,improves the quantitative and qualitative image quality,but also decreases the effective radiation dose.