Article

The role of topogram views on dose indices and image quality in thorax and abdomen-pelvis CT scan

¹ Student Research Committee, Babol University of Medical Sciences, Babol, Iran
² Cancer Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
³ Department of Medical Physics, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
⁴ Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, Iran
⁵ Department of Radiology and Radiotherapy, School of Medicine, Babol University of Medical Sciences, Babol, Iran

^* Corresponding author: monfared1345@gmail.com

Received: 28 December 2021
Accepted: 31 July 2022

Abstract

This study was designed to investigate the effect of the different topograms (AP and dual AP/Lateral) on patient dose indices and image quality in thorax and abdomen-pelvis CT. Size-specific dose estimation (SSDE), volumetric CT dose index (CTDI_vol), milliampere seconds (mAs), effective dose, as well as signal to noise ratio (SNR) and contrast to noise ratio (CNR) of 60 thorax and 60 abdomen-pelvis CT scans were analyzed. In thorax CT, SSDE, mAs, CTDI_vol and effective dose were significantly reduced by using dual topograms (p < 0.05) but not significantly reduced in abdominal-pelvic scans (p > 0.05). There was no significant difference between CNR parameter in the two groups for thorax CT (p > 0.05) and SNR parameter in abdomen-pelvic CT (p < 0.05) and all images were diagnostically acceptable. The use of two topograms in thorax CT is an efficient approach to reduce dose indices without decreasing the image quality.