能谱CT碘含量定量测定技术在脑动脉介入术后的运用

In vivo measurement of iodine concentration with spectral CT imaging after intracranial intervention

目的探讨能谱CT碘含量定量测定技术在脑动脉介入术后的诊断价值。方法 37例脑动脉介入术后患者能谱CT扫描发现颅内高密度灶,以最优单能量图并金属伪影消除重建。分析高密度物质在碘基图和水基图中的表现,测定相对碘含量。结果借助能谱分析,能谱CT单能量图判断出31例脑组织碘性高密度灶和6例出血,而常规140 kVp混合能量图将18例碘性高密度灶判断为出血,6例出血判断为对比增强高密度,与单能量CT比较,差异具有统计学意义(χ2=7.719,P<0.05)。出血灶和碘性高密度灶中碘含量分别为(1.17±0.80)mg/mL和(4.53±1.54)mg/mL,两者差异具有统计学意义(P<0.01);碘性高密度灶24 h前后的相对碘含量分别为(5.25±1.87)mg/mL和(1.73±1.27)mg/mL,两者差异具有统计学意义(P<0.05)。结论能谱CT碘含量定量测定技术可准确鉴别脑动脉介入术后出血和碘性高密度灶,可作为脑动脉介入术后评价病情和指导治疗的有效手段。

[ Objective] To evaluate the diagnosis value of spectral CT imaging after intraeranial interven- tion. [Methods] 37 patients with intraeranial high densities after cerebrovascular stenting underwent CT scan- ning with spectral imaging. Optimal monochromatic images with metal artifacts reduction were reconstructed. Intraeranial high densities were analyzed using quantitative iodine-based and water-based material decomposi- tion images. [Results] Monochromatic CT images gave diagnosis to 31 cases of intracerebral hemorrhage and 6 cases of contrast enhancement hyperdensity; conventional 140 kVp polyehromatic images misdiagnosed 18 cases of contrast enhancement hyperdensity and 3 cases of intraeerebral hemorrhage. There was significant dif- ference （Xa =7.719, P〈0.05） in diagnosis accuracy between monochromatic CT images and conventional poly- chromatic images. There was a significant difference in the iodine content of intracerebral hemorrhage [（1.87 ± 0.91） mg/mL] and contrast enhancement hyperdensity [（4.73± 1.34）mg/mL] （t=2.570, P〈0.01）. There was a significant diffrence in the iodine content of intracerebral hemorrhage immediately after eerebrovaseular stenting [（5.25 ± 1.87）mg/mL] and 24 hour later [（1.45 ± 1.27）mg/mL] （t =2.457, P〈0.05）. [Conclusion] Intracerebral hemorrhage and contrast enhancement hyperdensity after cerebrovascular stenting can be correctly identified by CT spectral imaging, which can be used as effective means of evaluation of condition assessment and guidetreatment.