Signal interpretation from low-dosage acquisition. An investigation for computed tomographic imaging.
OBJECTIVE
This paper focuses on how we could analyze and interpret filtered back-projection reconstructed signals from low-dose computed tomographic (CT) imaging systems. There exists a growing imbalance between dosage reduction and effective signal interpretation. At the same time, low-dose applications are undergoing alarming growth.


METHODS
This paper interprets filtered back-projection images in low-dose CT systems and details the possible properties of the artifacts. The interpretation leads to design of a new multi-image filtered back-projection approach that allows artifacts to be effectively identified across multiple images. We use this approach as a building block to propose a new reconstruction method that enables effective artifacts reduction and efficient implementation.


RESULTS
Experiments with both clinical and simulated low-dose images demonstrate the validity and effectiveness of the proposed approach.


CONCLUSIONS
This study discusses a new FBP-based reconstruction approach based on signal interpretation from low-dosage acquisition. This method uses multiple filtered back-projection images from projection subsets to provide clues for distinguishing underlying clinical structure from artifacts. A framework is derived for effective signal interpretation and artifacts reduction. It requires no hardware change and a minimum amount of extra software support compared with current CT systems. Clinical and simulated low-dose CT scans demonstrated effectiveness of the proposed method.
Cheng
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Department of Engineering, Trinity College, 300 Summit St, Hartford, CT 06106, USA. lin.cheng@trincoll.edu
D000465:Algorithms; D016477:Artifacts; D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D014057:Tomography, X-Ray Computed / Q000379:methods*