能谱纯化技术诊断颅内动脉瘤

目的 观察具有能谱纯化（SPS）技术的双能量（DE）CTA扫描（SPS-DECTA）在CTA诊断颅内动脉瘤中的应用价值。方法 对80例临床疑诊颅内动脉瘤患者行CTA，将其随机均分为 SPS-DECTA组及DECTA组，CT容积剂量指数均设为20.0 mGy，分别行SPS-DECTA及不具有SPS技术的DECTA扫描，比较两组图像质量。以3D-DSA及手术结果为金标准，对比两组动脉瘤部位、数目、检出率、瘤颈大小、瘤长径及短径。结果 两组平均CT值和噪声的差异均无统计学意义（P均>0.05），SNR、CNR差异均有统计学意义（P均<0.05）；颅内血管主观评分差异无统计学意义（P>0.05），颅底血管岩段、虹吸段主观评分差异有统计学意义（P均<0.05），而后交通段及基底段差异无统计学意义（P>0.05）。与3D-DSA及手术结果相比，SPS-DECTA组中动脉瘤检出率为100%（30/30），DECTA组检出率为92.86%（26/28）。应用两种检查方法诊断动脉瘤部位、数目差异无统计学意义（P>0.05）；测量动脉瘤大小与3D-DSA及手术结果差异均无统计学意义（P均>0.05），且具有很好的相关性。结论 相同曝光剂量下，SPS-DECTA能保证较高图像质量，具有降低辐射剂量的潜在能力，同时对颅内动脉瘤有较高诊断准确性，可作为常规无创筛查方法。

Selective photon shield in diagnosis of intracranial aneurysms

Objective To explore the value of selective photon shield (SPS) in dual-energy CT angiography (DECTA) in diagnosis of intracranial aneurysms. Methods Totally 80 patients with clinically suspected intracranial aneurysms and underwent CTA were equally divided into SPS-DECTA group and DECTA group. CT dose index of volume of the two groups was set to 20.0 mGy before scanning. SPS-DECTA and DECTA scanning were performed respectively. The image quality of the two groups were compared. Taking the results of 3D-DSA and the surgery as the gold criteria, the aneurysm location, aneurysm numbers, morphology, aneurysmal neck size and long or short diameter in the two groups were compared. Results CT value and the noise were not significantly different (all P>0.05) between the two groups. SNR and CNR were significantly different (P<0.05), and the subjective scores of intracranial vascular between SPS-DECTA group and DECTA group had no significantly different (all P>0.05). The differences in petrosal and syphon segment of skull base vascular were statistically significant (all P<0.05), whereas in posterior communicating artery (PCOA) and basilar artery (BA) segments were not statistically significant (all P>0.05). The detection rate of aneurysm in SPS-DECTA group was 100% (30/30), in DECTA group was 92.86% (26/28). The aneurysm location, aneurysm numbers diagnosed by the two methods were not statistically significant (P>0.05). Compared to 3D-DSA and operation results, the differences of the aneurysms sizes measured by the two methods were not statistically significant (all P>0.05), while good correlation was found among results of SPS-DECTA, DECTA, 3D-DSA and surgical operation. Conclusion Under the same exposure dose, SPS can improve image quality, reduce radiation dosage with high accuracy in diagnosis of intracranial aneurysms simultaneously, therefore can be used as a routine non-invasive screening methods for intracranial aneurysms.