Katsura Masaki, Sato Jiro, Akahane Masaaki, Tajima Taku, Furuta Toshihiro, Mori Harushi, Abe Osamu
Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
Department of Radiology, School of Medicine, International University of Health and Welfare, Chiba, Japan.
Neuroradiology. 2018 Nov;60(11):1141-1150. doi: 10.1007/s00234-018-2081-6. Epub 2018 Aug 24.
To evaluate the effects of the single-energy metal artifact reduction (SEMAR) algorithm on image quality of cerebral CT and CT angiography (CTA) for patients who underwent intracranial aneurysm coiling.
Twenty patients underwent cerebral CT and CTA using a 320-detector row CT after intracranial aneurysm coiling. Images with and without application of the SEMAR algorithm (SEMAR CT and standard CT images, respectively) were reconstructed for each patient. The images were qualitatively assessed by two independent radiologists in a blinded manner for the depiction of anatomical structures around the coil, delineation of the arteries around the coil, and the depiction of the status of coiled aneurysms. Artifact strength was quantitatively assessed by measuring the standard deviation of attenuation values around the coil.
The strength of artifacts measured in SEMAR CT images was significantly lower than that in standard CT images (25.7 ± 10.2 H.U. vs. 80.4 ± 67.2 H.U., p < 0.01, Student's paired t test). SEMAR CT images were significantly improved compared with standard CT images in the depiction of anatomical structures around the coil (p < 0.01, the sign test), delineation of the arteries around the coil (p < 0.01), and the depiction of the status of coiled aneurysms (p < 0.01).
The SEMAR algorithm significantly reduces metal artifacts from intracranial aneurysm coiling and improves visualization of anatomical structures and arteries around the coil, and depiction of the status of coiled aneurysms on post-interventional cerebral CT.
评估单能量金属伪影减少（SEMAR）算法对颅内动脉瘤栓塞术后患者脑CT及CT血管造影（CTA）图像质量的影响。
20例颅内动脉瘤栓塞术后患者接受320排CT脑CT及CTA检查。为每位患者重建应用和未应用SEMAR算法的图像（分别为SEMAR CT图像和标准CT图像）。由两名独立的放射科医生以盲法对图像进行定性评估，以观察线圈周围解剖结构的显示、线圈周围动脉的勾勒以及栓塞动脉瘤的状态。通过测量线圈周围衰减值的标准差对伪影强度进行定量评估。
SEMAR CT图像中测量的伪影强度显著低于标准CT图像（25.7±10.2 H.U. 对比80.4±67.2 H.U.，p<0.01，配对t检验）。在显示线圈周围解剖结构（p<0.01，符号检验）、勾勒线圈周围动脉（p<0.01）以及显示栓塞动脉瘤状态（p<0.01）方面，SEMAR CT图像与标准CT图像相比有显著改善。
SEMAR算法可显著减少颅内动脉瘤栓塞术后的金属伪影，改善线圈周围解剖结构和动脉的可视化，以及介入后脑CT上栓塞动脉瘤状态的显示。
