Reduction of metallic coil artefacts in computed tomography body imaging: effects of a new single-energy metal artefact reduction algorithm.
OBJECTIVE
We evaluated the effect of a single-energy metal artefact reduction (SEMAR) algorithm for metallic coil artefact reduction in body imaging.


METHODS
Computed tomography angiography (CTA) was performed in 30 patients with metallic coils (10 men, 20 women; mean age, 67.9 ± 11 years). Non-SEMAR images were reconstructed with iterative reconstruction alone, and SEMAR images were reconstructed with the iterative reconstruction plus SEMAR algorithms. We compared image noise around metallic coils and the maximum diameters of artefacts from coils between the non-SEMAR and SEMAR images. Two radiologists visually evaluated the metallic coil artefacts utilizing a four-point scale: 1 = extensive; 2 = strong; 3 = mild; 4 = minimal artefacts.


RESULTS
The image noise and maximum diameters of the artefacts of the SEMAR images were significantly lower than those of the non-SEMAR images (65.1 ± 33.0 HU vs. 29.7 ± 10.3 HU; 163.9 ± 54.8 mm vs. 10.3 ± 19.0 mm, respectively; P < 0.001). Better visual scores were obtained with the SEMAR technique (3.4 ± 0.6 vs. 1.0 ± 0.0, P < 0.001).


CONCLUSIONS
The SEMAR algorithm significantly reduced artefacts caused by metallic coils compared with the non-SEMAR algorithm. This technique can potentially increase CT performance for the evaluation of post-coil embolization complications.


CONCLUSIONS
• The new algorithm involves a raw data- and image-based reconstruction technique. • The new algorithm mitigates artefacts from metallic coils on body CT images. • The new algorithm significantly reduced artefacts caused by metallic coils. • The metal artefact reduction algorithm improves CT image quality after coil embolization.
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan. masafkidoh@yahoo.co.jp.
Masafumi
M
Kidoh
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Daisuke
D
Utsunomiya
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Osamu
O
Ikeda
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Yoshitaka
Y
Tamura
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Seitaro
S
Oda
Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Yoshinori
Y
Funama
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Hideaki
H
Yuki
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Takeshi
T
Nakaura
Department of Neurosurgery, Faculty of Life Sciences Research, Kumamoto University Graduate School, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Takayuki
T
Kawano
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Toshinori
T
Hirai
Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan.
Yasuyuki
Y
Yamashita
D000005:Abdomen / Q000098:blood supply*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000792:Angiography; D016477:Artifacts; D001807:Blood Vessel Prosthesis; D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008670:Metals; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods; D011860:Radiography, Abdominal / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D008670:Metals
Aneurysm; CT; CT angiography; Coil embolization; Metal artefact reduction algorithm