Computed tomography (CT) is an imaging modality commonly used as a diagnostic tool but is also utilized as a form of image guidance during clinical procedures that require 3D localization. The purpose of this study is to optimize the two most common CT procedures at OHSU: biopsy and drainage interventional procedures by adjusting the automatic tube current image quality reference setting and iterative reconstruction setting of the helical scan protocol used. The optimization will examine the impact of dose reduction on image quality.