Evaluation of Organ Dose and Image Quality Metrics of Pediatric CT Chest-Abdomen-Pelvis (CAP) Examination: An Anthropomorphic Phantom Study

Nor Azura Muhammad,Muhammad Khalis Abdul Karim,Jeannie Hsiu Ding Wong,Kwan Hoong Ng,Zunaide Kayun,Hasyma Abu Hassan

doi:10.3390/app11052047

Nor Azura Muhammad, Muhammad Khalis Abdul Karim + Show 4 more

Open Access

https://doi.org/10.3390/app11052047

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Abstract

The aim of this study is to investigate the impact of CT acquisition parameter setting on organ dose and its influence on image quality metrics in pediatric phantom during CT examination. The study was performed on 64-slice multidetector CT scanner (MDCT) Siemens Definition AS (Siemens Sector Healthcare, Forchheim, Germany) using various CT CAP protocols (P1–P9). Tube potential for P1, P2, and P3 protocols were fixed at 100 kVp while P4, P5, and P6 were fixed at 80 kVp with used of various reference noise values. P7, P8, and P9 were the modification of P1 with changes on slice collimation, pitch factor, and tube current modulation (TCM), respectively. TLD-100 chips were inserted into the phantom slab number 7, 9, 10, 12, 13, and 14 to represent thyroid, lung, liver, stomach, gonads, and skin, respectively. The image quality metrics, signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were obtained from the CT console. As a result, this study indicates a potential reduction in the absorbed dose up to 20% to 50% along with reducing tube voltage, tube current, and increasing the slice collimation. There is no significant difference (p > 0.05) observed between the protocols and image metrics.

Highlights

The transformation and sophistication of the computed tomography (CT) system have led to the increased use of CT examinations
As observed, was found in the liver andand the lowlowest was presented in the thyroid for kVp with a mean value of mSv est was presented in the thyroid for 100 kVp with a mean value of 1.22 ± 0.13 mSv (P1)
This study found that the organ dose measurements in thythyroid, lungs, liver, stomach, gonads, and skin were reduced by almost with lessening roid, lungs, liver, stomach, gonads, and skin were reduced by almost 50% with lessening tube voltage from 100 to 80 kVp

Summary

Introduction

The transformation and sophistication of the computed tomography (CT) system have led to the increased use of CT examinations. Recent advances in the technological breakthrough of CT scan performance, such as application of automatic tube current modulation (ATCM) and utilization of iterative reconstruction algorithm technique, have decreased CT radiation exposure while retaining diagnostic image consistency [3,4,5]. The imaging of pediatric CT examination is still challenging even though the performance and technology of the latest generation of CT scanners have been introduced. With growing involvement in radiation-induced cancer, this debate is again in the spotlight, as radiation exposure optimization is a particular problem in pediatric patients receiving repeated CT examination [6,7,8]. Despite the high frequency of CT procedure usage amongst children, radiation burden from CT examination needs to be considered as children are more sensitive to radiation as compared to adults [9,10]. Since 2007, the American College of Radiology (ACR), the Society for Pediatric Radiology (SPR), the American

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