Monte Carlo assessment of CT dose equilibration in PMMA and water cylinders with diameters from 6 to 55 cm

Abstract

The mathematical model can represent the DIL∕DI∞ curve from a single axial CT scan. Generally, n ≠ 1. The equilibrium dose, α, n, and Leq exhibit strong dependencies on phantom diameter and location in the phantom. On the other hand, α, n, and Leq have relatively weak dependencies on material (PMMA or water), tube voltage (80-140 kVp), and bowtie filter, and Leq is also insensitive to beam width (≤4 cm). A weak dependency of the DIL∕DI∞ curve on CT scanner using 80-140 kVp and beam width up to 4 cm is consistent with the results of this study and previous publications. The dose equilibration data provided in this paper can be useful for CT dose evaluation. A framework is presented for assessing dose at any point in infinitely long PMMA and water cylinders undergoing multidetector CT examinations.