Dommaraju Sujithraj, Nakhaei Masoud, Zhang Da, Camacho Andres, Boos Johannes, Appel Elisabeth, Brook Olga R
From the Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
J Comput Assist Tomogr. 2020 May/Jun;44(3):443-449. doi: 10.1097/RCT.0000000000001013.
To assess impact of single-energy metal artifact reduction (SEMAR) algorithm utilizing retrospective adaptive thresholding in reducing metal artifacts in the abdomen and pelvis.
In this prospective institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study, 90 patients with various metals (n = 97) on computed tomography of abdomen and pelvis (Canon Medical, Aquilion ONE and PRIME) scanned 07/2017-09/2018 with SEMAR retrospectively applied were included. Density was measured in the near and far field to the metals. Density standard deviation (SD), representing artifact severity, was compared with and without SEMAR applied. Two trained human observers independently evaluated severity of artifacts on a five-point scale (0, no artifact; 5, severe artifact).
The SEMAR significantly decreased artifact severity in the near field of high-density metal implants (SD of 204 ± 101HU without vs. 66 ± 40HU with SEMAR, P < 0.001). In the far field, the artifact severity was similar (40 ± 31HU without vs. 36 ± 27HU with SEMAR, P = 0.41). Artifact severity was decreased adjacent to low-density metal in the near field (SD of 86 ± 56HU without vs 49 ± 30HU with SEMAR, P < 0.001). In the far field to the low-density metals artifact severity was similar (33 ± 29HU without vs. 31 ± 27HU with SEMAR, P = 0.79). Subjectively, artifacts severity decreased for high-density metals in near field by 1.3 ± 1.0, and in far field by 0.7 ± 0.7 and for low-density metals in the near field by 0.7 ± 1.0, far field 0.4 ± 0.5, all P < 0.05.
The SEMAR retrospective algorithm with adaptive thresholding subjectively and objectively reduced near-field artifacts generated by high- and low-density metals.
评估采用回顾性自适应阈值处理的单能量金属伪影减少（SEMAR）算法在减少腹部和骨盆金属伪影方面的效果。
在这项经机构审查委员会前瞻性批准、符合《健康保险流通与责任法案》的研究中，纳入了90例在2017年7月至2018年9月期间接受腹部和骨盆计算机断层扫描（佳能医疗，Aquilion ONE和PRIME）且体内有各种金属（n = 97）的患者，对其扫描数据进行回顾性应用SEMAR处理。在金属的近场和远场测量密度。将代表伪影严重程度的密度标准差（SD）在应用和未应用SEMAR的情况下进行比较。两名经过培训的人类观察者独立地以五点量表（0，无伪影；5，严重伪影）评估伪影的严重程度。
SEMAR显著降低了高密度金属植入物近场的伪影严重程度（未应用时SD为204±101HU，应用后为66±40HU，P<0.001）。在远场，伪影严重程度相似（未应用时为40±31HU，应用后为36±27HU，P = 0.41）。在近场，低密度金属附近的伪影严重程度降低（未应用时SD为86±56HU，应用后为49±30HU，P<0.001）。在低密度金属的远场，伪影严重程度相似（未应用时为33±29HU，应用后为31±27HU，P = 0.79）。主观上，高密度金属在近场的伪影严重程度降低了1.3±1.0，在远场降低了0.7±0.7；低密度金属在近场降低了0.7±1.0，在远场降低了0.4±0.5，所有P<0.05。
具有自适应阈值处理的SEMAR回顾性算法在主观和客观上均减少了由高密度和低密度金属产生的近场伪影。
