We evaluated the noise magnitude in VMIs at 70 keV reconstructed from three different tube voltages using second-generation dual-layer detector computed tomography. The noise magnitude in the 70 keV VMIs reconstructed from 100 kVp was higher than that in images reconstructed from 120 kVp and 140 kVp, regardless of CTDIvol level, particularly when a small focal spot size was used. Previous studies have shown that differences between DECT systems significantly influence noise magnitude [11]. In our study, we demonstrated that even within the same DECT system, variations in tube voltage and focal spot size can affect noise magnitude. However, images with equal noise magnitudes but differing noise textures may not exhibit the same image quality [12]. Achieving a comprehensive analysis requires evaluating noise magnitude along with its frequency characteristics. This approach will enable the characterization of noise and noise textures across different DECT systems under various conditions, helping to establish baseline values for specific imaging requirements.