Megavoltage (MV) and kilovoltage (kV) computed tomography (CT) imaging are essential in effective radiation therapy cancer treatment. MV-kV dual energy computed tomography (DECT), which utilizes both x-ray sources available on radiotherapy treatment systems, could be advantageous for imaging. Most CT machinery utilizes energy-integrating detectors (EIDs); however, emerging photon-counting detectors (PCDs) have potential to produce improved images. To assess image quality, we compared the signal-to-noise ratio (SNR) between MV-kV DECT data generated with PCDs and EIDs. A single-line integral toy model was utilized to estimate the basis material SNR for tissue and bone using various object compositions. In a second assessment, CT images were simulated of an anthropomorphic phantom. Simulated basis material images were synthesized into virtual monoenergetic images (VMIs), in which contrast-to-noise ratio (CNR) was computed. For the single-line integral toy model in the simulated 80 keV VMIs, the PCD produced a 2.774 CNR and EID produced a 2.568 CNR. This work compared the SNR of MV-kV PCD and EID, in order to quantify their image clarity.
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