TY - JOUR
T1 - Metal artifact reduction from reformatted projections for hip prostheses in multislice helical computed tomography techniques and initial clinical results
AU - Yu, Lifeng
AU - Li, Hua
AU - Jan Mueller, M. S.
AU - Kofler, James M.
AU - Liu, Xin
AU - Primak, Andrew N.
AU - Fletcher, Joel G.
AU - Guimaraes, Luis S.
AU - Macedo, Thanila
AU - McColloagh, Cynthia H.
PY - 2009/11
Y1 - 2009/11
N2 - Purpose: Hip prosthesis is one of the most common typos of metal implants and can cause significant artifacts in computed tomography (CT) examinations. The puipose of this work was to develop a projection-based method for reducing metal artifacts caused by hip prostheses in multislice helical CT. Method and Materials: The proposed method is based on a novel concept, reformatted projection, which is formed by combining the projection data at the same view angle over the full longitudinal scan range. Detection and segmentation of the metal were performed on each reformatted projection image. Two dimensional interpolation based on Delaunay triangulation was used to fill voids left after removal of the metal in the reformatted projection. The corrected data were then reconstructed using a commercially available algorithm. The main advantage of this method is that both the detection of the metal objects and the interpolations are performed on complete reformatted projections with the entire metal region present, which is particularly useful for long hip prostheses. Twenty clinical abdominal/pelvis exams with hip prostheses were corrected and clinically evaluated. Results: The overall image quality and the conspicuity in some critical organs were significantly improved compared with the uncorrected images: overall quality (P = 0.0024): bladder base (P = 0.0027), and rectum (P = 0.0078). The average noise level in the bladder base was reduced from 86.7 HU to 36.2 HU. In 17 of 20 cases, the radiologists preferred either coronal (13) or axial (4) views of the corrected images. Conclusions: A novel method for reducing metal artifact in multislice helical CT was developed. Initial clinical results showed that the proposed method can effectively reduce the artifacts caused by metal implants for the cases of unilateral and bilateral hip prothesis.
AB - Purpose: Hip prosthesis is one of the most common typos of metal implants and can cause significant artifacts in computed tomography (CT) examinations. The puipose of this work was to develop a projection-based method for reducing metal artifacts caused by hip prostheses in multislice helical CT. Method and Materials: The proposed method is based on a novel concept, reformatted projection, which is formed by combining the projection data at the same view angle over the full longitudinal scan range. Detection and segmentation of the metal were performed on each reformatted projection image. Two dimensional interpolation based on Delaunay triangulation was used to fill voids left after removal of the metal in the reformatted projection. The corrected data were then reconstructed using a commercially available algorithm. The main advantage of this method is that both the detection of the metal objects and the interpolations are performed on complete reformatted projections with the entire metal region present, which is particularly useful for long hip prostheses. Twenty clinical abdominal/pelvis exams with hip prostheses were corrected and clinically evaluated. Results: The overall image quality and the conspicuity in some critical organs were significantly improved compared with the uncorrected images: overall quality (P = 0.0024): bladder base (P = 0.0027), and rectum (P = 0.0078). The average noise level in the bladder base was reduced from 86.7 HU to 36.2 HU. In 17 of 20 cases, the radiologists preferred either coronal (13) or axial (4) views of the corrected images. Conclusions: A novel method for reducing metal artifact in multislice helical CT was developed. Initial clinical results showed that the proposed method can effectively reduce the artifacts caused by metal implants for the cases of unilateral and bilateral hip prothesis.
KW - Computed tomography (ct)
KW - Metal artifact reduction
KW - Multi-slice helical ct
UR - http://www.scopus.com/inward/record.url?scp=73949111106&partnerID=8YFLogxK
U2 - 10.1097/RLI.0b013e3181b0a2f9
DO - 10.1097/RLI.0b013e3181b0a2f9
M3 - Article
C2 - 19809345
AN - SCOPUS:73949111106
SN - 0020-9996
VL - 44
SP - 691
EP - 696
JO - Investigative Radiology
JF - Investigative Radiology
IS - 11
ER -