Clinical photon-counting CT increases CT number precision and reduces patient size dependence compared to single- and dual- energy CT.

Objectives: To study whether photon-counting computed tomography (PCCT) can improve CT number accuracy, precision and reduce patient size dependence compared to dual-energy CT (DECT) virtual monoenergetic imaging (VMI) and single-energy CT (SECT).

Methods: Clinical PCCT, DECT and SECT scanners were used to image a multi-energy quality assurance phantom and tissue-equivalent inserts with/without an outer nested annulus, representing two object sizes (18 and 33 cm). CT numbers were converted to linear attenuation coefficients (LAC) and regions-of-interest applied.

Optimization of Low-Contrast Detectability in Abdominal Imaging: A Comparative Analysis of PCCT, DECT, and SECT Systems.

Background: Clear representation of anatomy is essential in the assessment of pathology in computed tomography (CT). With the introduction of photon-counting CT (PCCT) and more advanced iterative reconstruction (IR) algorithms into clinical practice, there is potential to improve low-contrast detectability in CT protocols. As such, it is necessary to perform task-based assessments to optimize protocols and compare image quality between PCCT and energy-integrating CT, like dual-energy CT (DECT) and single-energy CT (SECT).

Direct reconstruction of anatomical change in low-dose lung nodule surveillance.

In sequential imaging studies, there exists rich information from past studies that can be used in prior-image-based reconstruction (PIBR) as a form of improved regularization to yield higher-quality images in subsequent studies. PIBR methods, such as reconstruction of difference (RoD), have demonstrated great improvements in the image quality of subsequent anatomy reconstruction even when CT data are acquired at very low-exposure settings. However, to effectively use information from past studies, two major elements are required: (1) registration, usually deformable, must be applied between the current and prior scans.