Related Experiment Video
Updated: Mar 3, 2026

Construction of a Preclinical Multimodality Phantom Using Tissue-mimicking Materials for Quality Assurance in Tumor Size Measurement
Published on: July 29, 2013
EFFECT OF PATIENT SIZE, ANATOMICAL LOCATION AND MODULATION STRENGTH ON DOSE DELIVERED AND IMAGE-QUALITY ON CT
Joël Greffier1, Ahmed Larbi1, Francesco Macri1
1Department of Radiology, Nîmes University Hospital, Nîmes, France.
Abstract:
To study the effect of patient size, anatomical location and modulation strength (MS) on image-quality and delivered dose of CT scans acquired with automatic-exposure-control system (AEC). Four anthropomorphic phantoms (three paediatric and one thin adult) were studied, and normal and obese adults were simulated by placing bolus plates around the adult phantom. Thorax and abdomen-pelvis CT were performed using an AEC system equipped with five possible MS. Modulated tube current (mAsmod) was compared to Reference mAs and image-noise was assessed. Effective-mAs were lower than Reference-mAs for all but the obese phantom. However, reversal points were estimated for an effective diameter of 27.8 cm in thorax and 26.9 cm in abdomen-pelvis scans, beyond which the patterns of MS were inversed. mAsmod were dependent on attenuation differences among distinct anatomical location. Finally, dose delivered was associated to the mAsmod and patient's size, with both affecting image-quality.
Related Concept Videos
Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
Radiological Investigation I: X-ray and CT
Imaging Studies for Cardiovascular System V: CT
Imaging Studies I: CT and MRI
Description of the Procedures
Computed Tomography (CT) scan:
Computed Tomography (CT) scans use X-ray technology to generate detailed images of bones, organs, and tissues. During the scan, the patient lies on a moving table...
Imaging Studies III: Computed Tomography

