呼吸频率变化对4DCT图像重建影响研究

Research on the respiratory frequency changes of 4DCT reconstructed image

目的研究胸腹部肿瘤患者呼吸振幅及频率变化对4DCT重建图像的影响。方法收集2012-2013年在我院行4DCT定位扫描的75例胸腹部肿瘤患者的呼吸频率、呼吸振幅及4D重建图像的断层间距等数据，并分析呼吸频率、频率变化范围、呼吸振幅与4DCT重建图像断层间距的相关性。采用双变量Spearman相关性分析。结果75例患者重建图像中11例可见〉6mm的断层。46例可见3～6mm断层，18例可见〈3mm的断层。呼吸差值的变化与振幅有相关性（rs=0．369，P=0．000），呼吸差值与重建图像的断层间距也有相关性（rs=0．273，P=0．018），吸振幅变化与重建图像的断层间距还有相关性（rs=0．696，P=0．000）。结论呼吸频率的变化可影响呼吸振幅、4DCT重建图像的连续性，变化越小4DCT图像连续性越好。

Objective To study the impact of respiratory frequency and amplitude of patients with the thoracic or abdomen tumor on 4DCT＇ s reconstructed image. Methods 75 thoracic or abdomen tumor patients who performed a scanning with belly belt-type respiratory gating on 4DCT between November 2012 to March 2013 in our hospital were retrieved. Reviewed their respiratory frequency, amplitude and fault distance of 4DCT＇ s reconstructed image and analyzed the correlation fault distance of the reconstructed image. The correlation analysis was used by bivariate Spearman method. Results Among these reconstructed images, fault distance more than 6 mm could be seen in 11 cases, fault distance ranging from 3 mm to 6 mm could be found in 46 cases, and distance less than 3 mm could be detected in 18 case. Respiratory frequency correlated significantly with the amplitude （r = 0. 369, P = 0. 000） ;the respiratory rate had a tight association with the fault distance of the reconstructed image （r, = 0. 273,P= 0. 018）;and respiratory amplitude was associated obviously with the fault distance of the reconstructed image （rs = 0. 696 ,P= 0. 000）. Condusions Both 4DCT reconstructed image and respiratory amplitude are significantly correlated to the continuity of the respiratory frequency. The smaller the respiratory frequence and amplitude change are, the better continuity will be.