【摘要】 目的探讨FLASH双源CT双能量虚拟平扫在胃癌评估临床应用中的可行性。方法对41例经胃镜和手术病理明确为胃癌的患者利用FLASH双源CT行常规平扫、双能量动脉期、双能量静脉期及双能量延迟期扫描。利用Liver VNC软件得到动脉期及静脉期虚拟平扫图像。由两位放射科医师对三组平扫图像(常规平扫、动脉期虚拟平扫及静脉期虚拟平扫)分别进行5分制主观图像质量评分,对两位医师评价结果的一致性行Kappa检验,并对三组图像的评分进行单因素方差分析;利用配对t检验对动脉期虚拟平扫、静脉期虚拟平扫及常规平扫图像的图像质量进行比较;利用配对t检验三期的辐射剂量进行比较。结果两位医师对动脉期虚拟平扫、静脉期虚拟平扫图像与常规平扫图像的图像质量评价一致性很好(Kappa=0.926);三组图像的图像质量评分比较,差别无统计学意义(P>0.05);三组图像的SNR值进行比较,差异无统计学意义(P>0.05);省去常规平扫的三期扫描辐射剂量是(13.331±2.777)m Sv,四期扫描的辐射剂量是(19.135±3.773)m Sv,三期扫描较四期扫描降低的辐射剂量约为30.3%,差异有统计学意义(P<0.01)。结论 FLASH双源CT胃癌评估成像中,双能量虚拟平扫具有替代常规平扫的可行性,可以减少常规平扫的放射剂量,具有潜在的临床应用价值。更多还原

【Abstract】 Objective To evaluate the feasibility of dual-energy virtual non-enhanced computed tomography replacing true non-enhanced CT(TNC) in the evaluation of gastric cancer using Dual-source CT. Methods CT scans were performed on forty-one patients with gastric cancer proved by gastroscopy and postoperative pathologic results, which included TNC, dual-energy CT scans in arterial phase, venous phase and delay phase using SOMATOM Definition Flash. Virtual non-enhanced CT image sets in arterial phase(VNCa) and Virtual non-enhanced CT image sets in venous phase(VNCv) were reformatted from ‘Liver VNC’ software. Interobserver agreement with regard to image quality was assessed using Cohen’s kappa. The image quality scores of the VNCa, VNCv and TNC were compared by using chi-square test. According to postoperative pathologic results, the accuracy of serosal invasion in TNC and VNCa, VNCv were calculated and compared them with chi-square test. Results Interobserver agreement with regard to three images was excellent(Kappa=0.926). There was no significant difference in the image quality of VNCa, VNCv and TNC(P>0.05). There was no significant difference in the SNR of images in VNCa, VNCv and TNC(P>0.05). There was no significant difference in the accuracy of serosal invasion in TNC and VNCa, VNCv(P>0.05). Radiation dose was(13.331±2.777) m Sv in CT scan of three phases(arterial, venous and delay phases) and(19.135±3.773) m Sv in CT scan of four phases(non-enhanced, arterial, venous and delay phases), which was significant difference(P<0.01). Conclusion Dual-energy VNCT requires less radiation dose and therefore has a potential to replace TNC in the evaluation of gastric cancer using Dual-source CT.更多还原