Introduction
death, PAD, CNR, CM, disability
PAD, SECONDARY, PERIPHERAL ARTERY DISEASE
Peripheral artery disease (PAD) is an important cause of death and disability worldwide [Computed tomography angiography (CTA) is considered the examination of choice in PAD due to its availability, non-invasive nature, fast image acquisition, cost efficiency, and high diagnostic accuracy [Reduction of CM dosage in CT, based on the increasing attenuation of iodine as photon energies approach the k-edge at 33.2 keV, may be accomplished with low kilovolt peak (kVp) or dual energy monoenergetic reconstruction [Since dual-energy CT (DECT) was first described in 1973, vendors have introduced different techniques [With DECT, virtual monoenergetic images (VMI) are widely used to increase iodine attenuation and image contrast, especially in vascular imaging. The lowest energy levels of 40 and 50 keV, roughly equivalent to 70 and 80 kVp on single energy scanners, are the most promising with potential reductions in CM of 60%and 40%, respectively [Imaging protocols with greatly reduced CM-dosages may only be applied if clinical feasibility is ascertained, and the examination quality is adequate, and preferably equal or improved compared to conventional imaging [Our hypothesis was that we could achieve a higher vascular attenuation by a half iodine-load SDCT lower limb CTA at 40 or 50 keV than with standard iodine-load at 120 kVp, and our primary objective was to compare the VA of these acquisitions. Our secondary objectives were to assess and compare contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), image noise (noise), and subjective examination quality (SEQ) between the two groups.