Assessment of Image Quality in Chest CT With Precision Matrix and Increased Framing Rate Using Single Source CT: A Phantom Study

Abstract

Background/Aim: The aim was to evaluate the effect of a combined precision matrix and high sampling rate on the delineation of anatomical structures and objective image quality in single source CT in a qualitative approach. Materials and Methods: An anthropomorphic thoracic phantom was used to evaluate the objective image quality parameters, including image noise, noise power spectrum, image stepness and Q for different CT scanners including high/ standard matrix and framing frequency setups. Scan parameters were standardized over all scanners. Additional subjective quality assessment was also performed. Results: A linear mixed effects model was used to determine the effect of sampling rate and image matrix on objective image quality parameters. Noise power spectrum and image noise were significantly influenced by both framing frequency and image matrix. There were significant differences between high and standard frequency/ matrix acquisitions. Conclusion: Higher framing frequency and image matrix allows for improved image noise texture and objective image quality in CT.

Evaluation of Image Quality of Overweight and Obese Patients in CT Using High Data Rate Detectors

“…In bariatric CT imaging cropping artefacts occur when portions of the patient fall outside the reconstruction field of view if it is selected to be smaller than the scan field of view (24). High frequency detectors allow for the reduction of such artefacts especially in regions away from the isocenter, where the overlap of projections is smaller, while allowing for increased image quality at the same time (25). Since obese patients often need the extent of most of the field of view to the peripheral parts, they might benefit from a scan setup with higher sampling rate that yields better image quality in the outer parts of the scan field.…”