Dual-energy computed tomography (DECT) has become a cornerstone of modern radiology, offering unique imaging capabilities not attainable with conventional single-energy CT. However, many DECT systems operating in dual-energy mode cannot directly acquire conventional 120 kVp images [1-3]. Instead, virtual monochromatic images (VMIs) at 70 keV are commonly used as substitutes, providing a practical alternative for clinical diagnostics [4,5].

               DECT encompasses various systems, each based on different technological principles that affect the performance of the VMIs [6]. Moreover, technological advancements in DECT, such as the development of second-generation dual-layer detectors, have enabled imaging at lower tube voltages, for instance 100 kVp, in addition to conventional 120 and 140 kVp [7,8]. Although this advancement holds the potential to reduce radiation exposure, its impact on noise, a critical determinant of image quality, remains unclear. Optimizing the trade-off between image quality and radiation exposure requires a detailed understanding of noise behavior in VMIs [9]. This study aimed to compare the noise magnitudes of VMIs at 70 keV reconstructed from a lower tube voltage100 kVp versus conventional tube voltages of 120 and 140 kVp.