An iterative projection-based motion estimation and compensation scheme for head x-ray CT

Purpose: Although current computed tomography (CT) systems can scan the head in a very short time, patient motion sometimes still induces artifacts. If motion occurs, one has to repeat the scan; to avoid motion, sedation or anesthesia is sometimes applied. Methods: The authors propose a method to it...

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Vydáno v:	Medical physics (Lancaster) Ročník 43; číslo 10; s. 5705 - 5716
Hlavní autoři:	Sun, Tao, Kim, Jung-Ha, Fulton, Roger, Nuyts, Johan
Médium:	Journal Article
Jazyk:	angličtina
Vydáno:	United States American Association of Physicists in Medicine 01.10.2016
Témata:	Analysis of motion Biological material, e.g. blood, urine; Haemocytometers Computed tomography Computerised tomographs computerised tomography Digital computing or data processing equipment or methods, specially adapted for specific applications General statistical methods Humans Image data processing or generation, in general Image enhancement or restoration, e.g. from bit‐mapped to bit‐mapped creating a similar image Image Processing, Computer-Assisted - methods Image reconstruction image resolution image restoration Image scanners iterative methods iterative reconstruction Kinematics mean square error methods Medical image artifacts medical image processing Medical image reconstruction motion compensation motion estimation Movement Movement sensors phantoms Phantoms, Imaging Reconstruction rigid motion Spatial resolution Tomography, X-Ray Computed computed tomography motion estimation iterative reconstruction rigid motion motion compensation
ISSN:	0094-2405, 2473-4209, 2473-4209
On-line přístup:	Získat plný text
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Popis
Shrnutí:	Purpose: Although current computed tomography (CT) systems can scan the head in a very short time, patient motion sometimes still induces artifacts. If motion occurs, one has to repeat the scan; to avoid motion, sedation or anesthesia is sometimes applied. Methods: The authors propose a method to iteratively estimate and compensate this motion during the reconstruction. In every iteration, the rigid motion was estimated view-by-view and then used to update the system matrix. A multiresolution scheme was used to speed up the convergence of this joint estimation of the image and the motion of the subject. A final iterative reconstruction was performed with the last motion estimate. Results: The method was evaluated on simulations, patient scans, and a phantom study. The quality of the reconstructed images was improved substantially after the compensation. In simulation and phantom studies, root-mean-square error was reduced and mean structural similarity was increased. In the patient studies, most of the motion blurring in the reconstructed images disappeared after the compensation. Conclusions: The proposed method effectively eliminated motion-induced artifacts in head CT scans. Since only measured raw data are needed for the motion estimation and compensation, the proposed method can be applied retrospectively to clinical helical CT scans affected by motion.
Bibliografie:	tao.sun@uzleuven.be Electronic mail ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0094-2405 2473-4209 2473-4209
DOI:	10.1118/1.4963218