iDose^4迭代重建技术在肥胖患者CTCA中的应用

The application of the iterative reconstruction (iDose4) in CTCA for obese patients

目的探讨iDose4迭代重建技术在肥胖患者冠状动脉CT血管成像(CTCA)中的应用价值。方法将100例拟行冠状动脉CTA检查的肥胖患者(BMI≥28 kg·m2)分为2组,第1组采用回顾性心电门控扫描,采用iDose4迭代重建算法重建图像,第2组采用前瞻性心电门控扫描,前瞻性心电门控组分别采用iDose4迭代重建算法及滤波反投影(FBP)重建算法重建图像。比较前瞻性心电门控组及回顾性心电门控组图像质量及辐射剂量的差异,比较前瞻性心电门控组iDose4迭代重建算法及FBP重建算法图像噪声、CT值、信噪比(SNR)、对比噪声比(CNR)的差异。结果前瞻性心电门控组及回顾性心电门控组主观图像质量、图像噪声、CT值、左冠状动脉主干及右冠状动脉近段的SNR、CNR,差异均无统计学意义(P>0.05);前瞻性心电门控组iDose4迭代重建算法较FBP重建算法图像噪声下降34.9%,2组间差异有统计学意义(P<0.05);前瞻性心电门控组iDose4迭代重建算法下右冠状动脉近段及左冠状动脉主干的CNR、SNR均较FBP重建算法提高,2组间差异有统计学意义(P<0.05)。回顾性心电门控组及前瞻性心电门控组的辐射剂量分别为(8.9±1.2)msV、(1.6±0.2)msV,2组间差异有统计学意义(P<0.05);肥胖患者前瞻性心电门控组较回顾性心电门控组辐射剂量降低82.1%。结论 iDose4迭代重建前瞻性心电门控技术能够降低肥胖患者CTCA图像噪声,提高图像质量,并且能够明显降低辐射剂量。

Objective To explore practical applications of iDose4 iteration reconstruction in CTCA for obese patients. Methods 100 obese patients scheduled for coronary CT were divided into two groups ,the first group using retrospective ECG -gated scanning and iDose4 iter- ative reconstruction ,the second group using propective ECG - gated scanning and iDose4 iterative reconstruction and the filtered back projec- tion （FBP） reconstruction. Compared the difference between prospective ECG- gated and retrospective ECG- gated image quality and radia- tion,studied the difference between prospectively ECG -gated iDose4 iterative reconstruction and the FBP reconstruction on image noise, CT values,CNR and SNR. Results There is no significant difference between prospectively ECG - gated group and retrospective ECG - gated group on image quality（P〉0.05） ,as well as the image noise,CT values ,SNR,CNR of left and right coronary artery. There was significant difference between iDose4 iterative reconstruction and FBP reconstruction in image noise （ P 〈 0. 05 ）, and the image noise reduced up to 34.99% under iDose4 iterative reconstruction. The CNR,SNR of right and left coronary ＇artery raised in iDose4 iterative reconstruction of pro- spective ECG -gated group ,and there was significant difference between the two groups （P 〈 0. 05 ）. The effective radiation dose for the retro- spective and prospective ECG - gated group were （ 8.9 ± 1.2 ） mSv and （ 1.6±0.2） mSv; there was significant difference between the two groups （P〈0.05） ,with prospectively ECG gated group radiation decreased 82.09%. Conclusion iDose4 iterative reconstruction prospective ECG- gated technique can reduce obese patients CTCA image noise ,improve image quality and reduce radiation close.