Summary
Objectives: 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.
Keywords
Image reconstruction - computed tomography
