摘要
目的评价低剂量CT扫描在外伤性肋骨骨折检查中的影像质量及可行性。方法30例胸部外伤拟行CT检查的病人随机分为2组：A组15例．扫描方案为固定管电流200mA；B组15例，扫描方案为固定噪声指数（NI）为12．5，应用自动管电流调节技术自动调节管电流（10～500mA）。2位医师采用双盲法对肺尖、中肺及下肺进行影像质量评分（IQS），测量影像标准差，记录容积CT剂量指数（CTDI刊）及剂量长度乘积（DLP）。对2组CTDI值、DLP值、影像噪声及影像质量评分采用t检验进行比较，P〈0．05为差异有统计学意义；应用kappa一致性检验评价2名医师评定结果的一致性。结果影像质量：B组噪声高于A组，但2组比较IQS差异无统计学意义（乃0．05），所有病人影像质量均满足诊断要求，影像的满足诊断率为100％；辐射剂量：B组CTDIvd[（9．9±2．5）mGy]及DLP[（223．8±23．4）mGy·cm]较A组CTDI“[（12．8±0．5）mGy]及DLP[（398．7±12．86）mGy·cm]，分别下降22．5％及43．8％．差异有统计学意义（P〈0．01）。结论NI为12．5的低剂量CT扫描可以满足临床对肋骨骨折诊断的要求。
Objective To evaluate images quality and flexibility of low-dose CT in patients with traumatic rib fractures. Methods Thirty patients presented with thoracic injury were enrolled in this study and were divided into two groups. Fifteen subjects of group A underwent chest CT scanning with a fixed tube current of 200 mA, and 15 subjects of group B underwent chest CT scanning using Automatic Tube Current Modulation with noise index of 12.5. CT images were evaluated by two radiologists with double blind method. Images quality scores （IQS） of lung apex, middle lung and lower lung were made, the image standard deviation （SD） was measured, and the CT dose index volume （CTDL） and dose length produce （DLP） were also recorded. Student t test was used to compare two group＇s CTDLol values, DLP values, image noise and IQS. P〈0.05 represented the significant difference. The difference of the inter-observer was determined by kappa statistics. Results SD value of group B were higher than group A, but there was no statistical difference in IQS between the two groups. The diagnostic accuracy of two groups was 100%. The values of CTDI and DLP of group A were （12.8±0.5） mGy and （398.7± 12.86） mGy.cm, respectively. The values of CTDLa and DLP of group B were （9.9±2.5） mGy and （223.8±23.4） mGy.cm, respectively, reducing 22.5% and 43.8% intrinsic dose compared to group A （P〈0.01）. Conclusion Rib fracture can be detected by the low-dose CT using the scan protocol with NI of 12.5.
出处
《国际医学放射学杂志》
2014年第1期6-8,27,共4页
International Journal of Medical Radiology
