Fig. 3
From: Improved precision of noise estimation in CT with a volume-based approach
Results of the Bland-Altman analyses. Each plot shows the difference between the noise measured with either ROI or VOI and ground truth noise on the y-axis, versus ground truth on the x-axis. Regular radiation dose computed tomography protocol measured with an ROI (a) or a VOI (b), same data for ultra-low dose protocol (c and d, respectively). ROI, region of interest; VOI, volume of interest; LoA, limits of agreement; HU, Hounsfield units