目的：探讨应用器官剂量调制（ODM）技术降低胸部CT中女性敏感器官辐射剂量的作用。方法：采用前瞻性研究，选取2019年1—8月于我医院行胸部CT平扫检查的成年女性患者80例，采用随机数字表法将患者分成A组（n=40）和B组（n=40），设置A组为实验组，B组为对照组。A组患者开启ODM技术；B组患者为常规CT扫描，其余参数同A组。记录两组患者乳腺组织层面（前、左、后、右）四个方位管电流、容积CT剂量指数（CTDIvol）、剂量长度乘积（DLP）并计算有效剂量（ED）。在乳腺组织中心层面腺体区域和胸主动脉区域选取感兴趣区（ROI），比较客观噪声（SD）、信噪比（SNR）。采用双盲法由两位资深影像科医师对两组患者乳腺区域层面横轴位图像质量在肺窗和纵隔窗下进行5分制主观评分。结果：两组患者胸部CT乳腺组织层面4个方位中，A组前方管电流显著低于B组前方，具有统计学意义（P<0.05）；其他方向上管电流差异无统计学意义（P>0.05）。两组患者乳腺区域图像的SD、SNR水平之间比较，具有统计学意义（P<0.05）；胸主动脉区域的SD、SNR水平之间比较，无统计学意义（P>0.05）。经比较两组患者的CTDIvol、DLP，差异具有统计学意义（P<0.05），X线ED值A组比B组降低7.9%，具有统计学意义（P<0.05）。两组患者横轴位肺窗和纵隔窗图像的主观评分差异无统计学意义（P>0.05）。结论：ODM技术可有效降低胸部CT扫描中对女性乳腺组织的辐射剂量，并可获得满足诊断要求的图像质量。
Abstract
Objective: To investigate the effect of organ dose modulation(ODM) on reducing radiation dose of sensitive organs in chest CT. Methods: Using a prospective case-control study design, 80 cases of patients with chest CT scan in our hospital from January to August 2019 were selected. Patients were divided into group A(n=40) and group B(n=40) by random number table method. Group A was the experimental group and group B was the control group. Patients in group A were scanned by ODM technology. Patients in group B had routine CT scan, and other parameters were as same as those in group A. Four directions tube currents, volumetric CT dose index(CTDIvol), dose length product(DLP), and effective dose(ED) were recorded at breast tissue level(anterior, left, posterior, and right) in the two groups. The region of interest(ROI) was selected from the gland region and thoracic aorta region at the breast tissue center level, and objective noise(SD) and signal-to-noise ratio(SNR) were compared. Two senior radiologists were employed to evaluate the quality of breast regional plane images on a 5-point subjective scale under the pulmonary and mediastinal Windows. Results: Among the 4 directions of breast CT tissue level in the two groups, the anterior tube current in group A was significantly lower than that in group B(P<0.05). There was no significant difference in tube current in other directions(P>0.05). Comparison of SD and SNR levels in breast region images between the two groups was statistically significant(P<0.05). Comparison of SD and SNR levels in thoracic aorta region showed no statistical significance(P>0.05). By comparing the CTDIvol and dose DLP of the two groups of patients, the difference was statistically significant(P<0.05). ED of X-ray in group A was 7.9% lower than that in group B(P<0.05). There was no significant difference in the subjective scores of the images of the transverse pulmonary window and mediastinal window between the two groups(P>0.05). Conclusion: ODM technique can effectively reduce the radiation dose of breast tissue in chest CT scan, the image quality that meets the diagnostic requirements can be obtained.
关键词
胸部 /
体层摄影术 /
螺旋计算机 /
女（雌）性
Key words
Thorax /
Tomography, spiral computed /
Female
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