Research
X-ray Imaging Systems
Cone-beam CT
Cone-beam CT provides volumetric three-dimensional (3D) images.
To visualize distinctive volumetric and morphological information of interal body structure.
Tomosynthesis
Provide cross sectional images from a finite number of projection views within a limited data acquisition range.
Spectral CT
Utilize the multiple energy spectrum of X-ray to enable material decomposition, etc.
Spectral imaging can increase the contrast of medical images and enable noise reduction.
Image Quality Evaluation
Modulation Transfer Function (MTF)
MTF represents the ratio of the output modulation to the input modulation.
Quantitative metric describing the resolution performance of X-ray based medical imaging system.
Noise Power Spectrum (NPS)
Quantitative metric describing the noise including correlation introduced by filtering and other processing steps.
Model Observer
Evaluate lesion detection performance of medical imaging system using human or mathematical models mimicking the human visual system.
CT Image Artifacts Correction
Cone-beam Artifacts Correction
For large cone angles, cone beam projection causes the lack of information in frequency space.
To reduce the cone beam artifacts, iterative reconstruction with total variation regularization was proposed.
Motion Artifacts Correction
When the object changes during CT scanning, this motion induces blurring and streak artifacts.
The motion artifacts are corrected by the estimation of rotational and translational motion.
Metal Artifacts Correction
Metal materials can cause metal artifact and degrade image quality.
To correct the artifacts, we developed a metal artifact reduction algorithm by using an edge preserving filter.