Use of Gray Values in CBCT and MSCT Images for Determination of Density: Influence of Variation of FOV Size

摘要

Purpose: To determine the effect of field of view (FOV) size on gray values in cone beam computed tomography (CBCT) and multislice computed tomography (MSCT) images. Material and Methods: A phantom made up of 3 cylinders containing distilled water, plaster, and motor oil was constructed and inserted into an acrylic cylinder filled with distilled water. The phantom was scanned with a CBCT and MSCT device using 3 FOV sizes. Gray value of each material was evaluated in 40 axial slices, and the comparison between the results obtained with the same FOV size was made.