ISSN 1004-4140
CN 11-3017/P

自适应统计迭代重建技术在髋关节64排CT低管电流检查中的应用

Application of ASIR Techniques in Hip with Low Tube Current 64 Row CT

  • 摘要: 目的:探讨自适应统计迭代重建 (ASIR) 技术在髋关节64排CT低管电流检查中的应用。方法:106例髋关节64排螺旋CT扫描患者, 随机选取53例患者采用常规管电流220 mAs扫描, 并采用滤过反投影 (FBP) 方式重建。另外53例患者采用低管电流50 mAs扫描, 并采用30%ASIR技术。对两组髋关节图像的辐射剂量和图像质量进行评价, 并比较不同重建图像在同一层面的图像噪声值和信噪比。结果:常规管电流组与低管电流组的CT剂量指数 (CTDIvol) 分别为 (15.55±0.20) mGy、 (3.56±0.15) mGy, 低管电流组平均CTDIvol较常规管电流组降低77.1%;常规管电流组与低管电流组的剂量长度乘积 (DLP) 分别为 (297.82±2.9) mGy·cm、 (67.59±3.3) mGy·cm, 低管电流组平均DLP较常规管电流组降低77.3%, 低管电流组与常规管电流组相比, 辐射剂量大大降低 (P<0.05) 。常规管电流组图像质量评分为优、良、差的患者分别为49、4和0例;低管电流组图像质量评分为优、良、差的患者分别为42、11及0例。两组图像的差异无统计学意义 (P>0.05) 。图像噪声值分别为31.44、44.29, 差异有统计学意义 (P<0.05) 。图像信噪比分别为11.03、10.06, 差异有统计学意义 (P<0.05) 。结论:ASIR技术应用于64排螺旋CT髋关节低管电流扫描, 大幅降低辐射剂量的同时, 图像质量也能满足临床诊断的需要。

     

    Abstract: Objective: To explore the feasibility of adaptive statistical iterative reconstruction (ASIR) technique in 64-slice CT of hip with low tube current application. Methods: Of 106 patients with 64 row helical CT scan of hip, 53 patients were treated with conventional tube current of 220 m As scanning, and were reconstructed with filtered back projection (FBP) , 53 patients were treated with low tube current of 50 m As scanning and were reconstructed with 30% of adaptive statistical iterative reconstruction (ASIR).The radiation dose, image noise (S D value) and signal-to-noise ratio of different reconstruction images of two groups were compared respectively at the same level. Results: The CTDIvol value was (15.55 ± 0.20) m Gy in the conventional group and (3.56 ± 0.15) m Gy in the low tube current group, the CTDIvol in the low tube current group was 77.1% of that in the conventional group, the DLP was (297.82 ± 2.9) m Gy·cm in the conventional group and (67.59 ± 3.3) m Gy·cm in the low tube current group, the DLP in the low tube current group was 77.3% of that in the conventional group. Compared with the conventional group, the radiation dose of low tube current group was reduced greatly (P< 0.05). The image quality with excellent、good、bad was 49, 4 and 0 cases, respectively, in the conventional group. 42, 11 and 0 cases in the low tube current group, difference of image quality between two groups were no statistically significant (P> 0.05). The difference of image noise value and SNR between two groups were statistically significant, respectively (P< 0.05). Conclusion: It is feasible to apply 30% of ASIR technology in 64 row helical CT of hip with low-current of 50 m A, resulting with the reduction of radiation dose, meanwhile, the image quality can meet the need of clinical diagnosing.

     

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