双层探测器光谱CT在宫颈癌诊断中的应用价值

Clinical value of dual-layer spectral detector CT in diagnosis of cervical cancer

目的:评估双层探测器光谱CT(dual-layer spectral detector CT,SDCT)在宫颈癌病灶显示及临床国际妇产科联合会(International Federation of Gynecology and Obstetrics,FIGO)分期中的应用价值。方法:选取2019年10月至2022年8月间经手术病理证实为宫颈癌的患者50例,均于治疗前行SDCT腹盆增强扫描。分别测量和比较常规CT 120 kVp混合能量图像(polyenergetic image,PI)及SDCT 40 keV虚拟单能量图像(virtual monoenergetic images,VMI)的病灶CT值、髂总动脉CT值及皮下脂肪CT值,比较2种图像质量客观评分和主观评分的差异。同时,比较动脉期、静脉期宫颈癌SDCT碘图碘浓度(iodine concentration,IC)及同层主动脉碘浓度差异,计算标准化碘浓度(normalized iodine concentration,NIC)值。以病理结果证实的临床FIGO分期为金标准,比较常规CT 120 kVp PI和SDCT 40 kVp VMI对宫颈癌FIGO分期的诊断准确性,并采用ROC曲线分析IC、NIC值对早期和进展期宫颈癌的诊断效能。结果:动脉期、静脉期宫颈癌40 keV VMI的对比噪声比(contrast to noise ratio,CNR)及髂总动脉CT值均优于常规CT PI,差异均有统计学意义(P均<0.001);动脉期、静脉期肿瘤IC值均高于正常宫体,差异有统计学意义(P均<0.05)。静脉期肿瘤NIC值高于动脉期,差异有统计学意义(P<0.001)。40 keV VMI的主观图像质量均优于常规CT PI(P均<0.05)。40 keV VMI和常规CT PI术前诊断宫颈癌FIGO分期的准确率分别为78.0%、58.0%,差异有统计学意义(χ^(2)=13.5,P<0.001)。动脉期宫颈癌IC、NIC值的AUC值分别为0.728、0.651,静脉期宫颈癌IC、NIC值的AUC值分别为0.589、0.570。结论:SDCT 40 keV VMI及碘图显示宫颈癌病灶较好,可提高宫颈癌FIGO诊断及分期的准确率。

Objective To evaluate the value of dual-layer spectral detector CT(SDCT)in the visualization and the Interna-tional Federation of Gynecology and Obstetrics(FIGO)staging of cervical cancer lesions.Methods Fifty patients with surgical pathologically confirmed cervical cancer between October 2019 and August 2022 were selected,all of whom underwent enhanced Abdominal and Pelvic SDCT scanning before treatment.The CT values of the lesions,common iliac artery and subcutaneous fat were measured for conventional CT 120 kVp polyenergetic images(PI)and SDCT 40 keV virtual monoener-getic images(VMI),then PI and VMI images were compared in terms of the CT values and the objective and subjective quality scores.The iodine concentrations(IC)of SDCT iodine maps and aortas on the same axial slice at arterial stage were compared with those at venous stage,and the standardized iodine concentration(NIC)was calculated.The diagnostic accuracy of con-ventional CT 120 kVp PI and SDCT 40 kVp VMI for FIGO staging of cervical cancer was compared using clinical FIGO staging results confirmed by pathological findings as the gold standard,and the diagnostic efficacy of IC and NIC for early and progressive cervical cancer was analyzed using ROC.Results SDCT 40 keV VMI behaved better significantly than conventional CT 120 kVp PI in the contrast to noise ratio(CNR)and CT value of the common iliac artery at arterial and venous stages(all P<0.001);the ICs of cervical cancer at arterial and venous stages were significantly higher than those of normal uterus(all P<0.05).The cervical cancer NICs at venous stage were significantly higher than those at arterial stage(P<0.001).The subjective quality scores of SDCT 40 keV VMI were significantly higher than those of CT 120 kVp PI(all P<0.05).SDCT 40 keV VMI had the accuracy of preoperative diagnosis of cervical cancer FIGO staging(78.0%)significantly higher than that(58.0%)of CT 120 kVp PI(χ^(2)=13.5,P<0.001).The AUCs of IC and NIC values were 0.728 and 0.651 for arterial stage cervical cancer,and 0.589 and 0.570 for venous stage cervical cancer,respectively.Conclusion SDCT 40 keV VMI and iodine map gains advantages in showing cervical cancer lesions,which can improve the accuracy of FIGO diagnosis and staging of cervical cancer.