双层探测器光谱CT在颅内血管成像中的应用研究

Application study of dual-layer spectral detector CT in intracranial angiography

目的对比双层探测器光谱CT(SDCT)不同keV单能级与常规颅内血管CTA的图像质量。方法回顾性分析于首都医科大学附属北京天坛医院放射科自2020年4月至2021年3月行颅内血管光谱CT成像的80例患者的临床和影像资料。比较40~90 keV(间隔10 keV)能级图像和常规图像上血管的CT值及相对于胼胝体的对比噪声比(CNR)、图像质量、血管容积重建(VR)难易程度。结果能级降低(90 keV降至40 keV),血管CT值显著升高(颈内动脉C7段:242.16~1090.28 HU;基底动脉:217.17~1021.79 HU),而胼胝体压部CT值无明显变化(29.30~37.76 HU)。低能级(40~60 keV)图像上血管的CNR、图像质量评分显著高于常规图像,且比常规图像易于VR,差异均有统计学意义(P<0.05)。结论双层SDCT的低能级(40~60 keV)图像比常规图像更利于血管的显示,亦易于进行VR。

Objective To compare the image quality between virtual mono-energetic images(VMIs)with different keV and conventional images in intracranial CT angiography(CTA)using dual-layer spectral detector CT(SDCT).Methods The clinical and imaging data of 80 patients who underwent intracranial CTA utilizing the SDCT in Radiology Department of Beijing Tiantan Hospital,Capital Medical University from April 2020 to March 2021 were retrospectively analyzed.CT values of the intracranial arteries,their contrast to noise ratio(CNR)compared to the corpus callosum,overall image quality,and difficulty degree of volume rendering(VR)for the intracranial artery were compared between the VMIs(40-90 keV,interval of 10 keV)and the conventional images.Friedman test was used for the statistical analysis.Results With the decrease of the energy level(from 90 keV to 40 keV),CT values of the arteries increased significantly(C7 segment of the internal carotid artery:242.16-1090.28 HU;the basilar artery:217.17-1021.79 HU),while CT value of the corpus callosum increased slightly(29.30-37.76 HU).Performance of the CNR and the overall image quality on the lower-energy(40-60 keV)images were significantly better than those on the conventional images(P<0.05),meanwhile,VR of the arteries on the lower-energy(40-60 keV)images was easier than that on the conventional images(P<0.05).Conclusion Visualization of the intracranial arteries on the lower-energy(40-60 keV)images was better than that on the conventional images,and VR of the intracranial arteries on the lower-energy(40-60 keV)images was easier than that on the conventional images when utilizing the dual-layer SDCT.