Metal Artifact Reduction for Orthopedic Implants: Brain CT Angiography in Patients with Intracranial Metallic Implants

• Published in: Journal of Korean medical science Vol. 33; no. 21; pp. e158 - 11
• Main Authors: Sunwoo, Leonard, Park, Sun-Won, Rhim, Jung Hyo, Kang, Yeonah, Chung, Young Seob, Son, Young-Je, Kim, Soo Chin
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Academy of Medical Sciences 21.05.2018; 대한의학회
• Subjects: Adult; Aged; Aged, 80 and over; Brain - blood supply; Brain - diagnostic imaging; Computed Tomography Angiography; Female; Humans; Image Processing, Computer-Assisted; Intracranial Aneurysm - diagnostic imaging; Intracranial Aneurysm - surgery; Male; Middle Aged; Original; Prostheses and Implants; Surgical Instruments; 의학일반; Computed Tomography; Metal Artifact Reduction for Orthopedic Implants; Computed Tomographic Angiography; Aneurysm; Image Noise
• ISSN: 1011-8934; 1598-6357; 1598-6357
• DOI: 10.3346/jkms.2018.33.e158

The purpose of this study was to qualitatively and quantitatively evaluate the effects of a metal artifact reduction for orthopedic implants (O-MAR) for brain computed tomographic angiography (CTA) in patients with aneurysm clips and coils. The study included 36 consecutive patients with 47 intracranial metallic implants (42 aneurysm clips, 5 coils) who underwent brain CTA. The computed tomographic images with and without the O-MAR were independently reviewed both quantitatively and qualitatively by two reviewers. For quantitative analysis, image noises near the metallic implants of non-O-MAR and O-MAR images were compared. For qualitative analysis, image quality improvement and the presence of new streak artifacts were assessed. Image noise was significantly reduced near metallic implants ( < 0.01). Improvement of implant-induced streak artifacts was observed in eight objects (17.0%). However, streak artifacts were aggravated in 11 objects (23.4%), and adjacent vessel depiction was worsened in eight objects (17.0%). In addition, new O-MAR-related streak artifacts were observed in 32 objects (68.1%). New streak artifacts were more prevalent in cases with overlapping metallic implants on the same axial plane than in those without ( = 0.018). Qualitative assessment revealed that the overall image quality was not significantly improved in O-MAR images. In conclusion, the use of the O-MAR in patients with metallic implants significantly reduces image noise. However, the degree of the streak artifacts and surrounding vessel depiction were not significantly improved on O-MAR images.