Size-specific dose estimates: Localizer or transverse abdominal computed tomography images?

Figure 1 Anterior-posterior diameters and lateral diameters were measured on lateral localizer radiograph at every 5 cm interval (along the Z axis) from the start to the end of the scan length, as well as mid-location, minimum and maximum. In addition, Antero-Posterior diameters and Lateral diameters were also measured from the transverse computed tomography images.

Figure 2 Difference between measurements on localizer and transverse computed tomography images for all values, including averages of interval measurements, maximum, minimum, and mid-scan location are illustrated. A: Several diameters were measured at different locations from transverse CT images (blue) and localizer radiographs (red). Diameter measurements were significantly different from localizer radiograph as compared to transverse CT images; B: SSDE values obtained from several diameters at different locations from transverse CT images (blue) and localizer radiographs (red). SSDE values were significantly different in maximum and minimum Antero-Posterior diameters. Ave: Average; max: Maximum; min: Minimum; mid: Mid location; CT: Computed tomography; SSDE: Size specific dose estimate; D_Eff: Effective Diameter; D_Sum: Sum of anterior-posterior + Lateral diameter; D_L: Lateral diameter; D_AP:Anteroposterior Diameter.