Dr. Tianye Niu from Georgia Tech has developed a spectral imaging system, method, and apparatus based on a total modulation method. In one variation, the system includes a series of strip of metal modulators between the object and the detector. The energies of the photons reaching the detector can be controlled by adjusting the thickness of the metal strips to modulate the total signal arriving at the detector. In other variations, the system also incorporates an energy spectrum computed tomography (CT) material decomposition technique. The iterative reconstruction and material decomposition techniques are combined in the proposed system to achieve direct conversion from the line-integral to the basis material images.
- Low cost: This modified system is easily obtained from an existing system by adding an inexpensive modulator.
- Safer: The system significantly reduces the radiation dose to the patient.
- Upgrading the cone beam CT scanner installed on any image-guided radiation therapy machines
- New spectral cone beam CT scanners
- New X-ray CT detector design
Spectral CT imaging plays an important role in advanced CT applications, including iodine quantification, virtual monochromatic imaging, virtual non-enhanced imaging, CT pulmonary angiogram, and kidney stone characterization. The basic principle of spectral CT is to use the attenuation characteristics of different materials at various energy levels to achieve material decomposition. The existing spectral CT imaging techniques include the multiple scans, fast X-ray tube voltage switching, dual-source scanning, and dual-layer and photon-counting detector schemes. This scheme is challenged since the exposure at different tube voltages is hard to control. Georgia Tech's system is designed to address the limitation.