低剂量CT肺动脉成像技术进展

CT肺动脉成像(CTPA)已成为评价肺栓塞(PE)主要影像技术,筛查及多次CTPA复查PE疗效等使辐射剂量增加,因此低剂量CTPA日益受到重视。低剂量CTPA采取多种措施:降低管电流和管电压最为简单有效;大螺距扫描通过缩短扫描时间降低辐射剂量;缩小扫描覆盖范围可降低边缘器官的辐射;前瞻性心电门控在固定期相扫描及迭代重建算法选择性去除噪声等均可降低辐射。低剂量意识对于降低辐射至关重要。

Advances in imaging study of low-dose computed tomography pulmonary angiography

Computed tomography pulmonary angiography（ＣＴＰＡ） has become a major imaging tool in evaluating pulmonary artery embolism. CTPA for screening and re-examination makes radiation dose higher. Hence, low-dose CTPA gets more and more attention. Low-dose CTPA can be achieved with varied ways. Decreasing tube current and tube voltage are the most simple and effective method among them. Larger pitch can decrease radiation by reducing the scan time. Narrower z-axis coverage can decrease the radiation to marginal organs. With prospectively ECG-triggered technique, radiation is applied only at predefined time and iterative reconstruction algorithm（ＩＲ） can remove noise selectivitily and consequently can decrease radiation. It is important that clinicians have the awareness of low-radiation.