Design and Validation of Synchronous QCT Calibration Phantom: Practical Methodology

Malakeh Malekzadeh; Shahrokh Abbasi-Rad; Mohamad Shahgholi; Parisa Naghdi; Marzieh Sadat Hoseini; Niloofar Ayoobi Yazdi; Mohammad Bagher Shiran; Hamidreza Saligheh Rad

doi:10.1016/j.jmir.2018.10.002

Design and Validation of Synchronous QCT Calibration Phantom: Practical Methodology

J Med Imaging Radiat Sci. 2019 Mar;50(1):157-162. doi: 10.1016/j.jmir.2018.10.002. Epub 2018 Nov 9.

Authors

Malakeh Malekzadeh¹, Shahrokh Abbasi-Rad², Mohamad Shahgholi³, Parisa Naghdi⁴, Marzieh Sadat Hoseini⁴, Niloofar Ayoobi Yazdi⁵, Mohammad Bagher Shiran¹, Hamidreza Saligheh Rad⁶

Affiliations

¹ Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
² Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran.
³ Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
⁴ Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran.
⁵ Advanced Diagnostic and Interventional Radiology (ADIR) Research Center, Tehran University of Medical Sciences, Tehran, Iran.
⁶ Quantitative Medical Imaging Systems Group, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran; Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: h-salighehrad@tums.ac.ir.

PMID: 30777238
DOI: 10.1016/j.jmir.2018.10.002

Abstract

Introduction: Quantitative computed tomography (QCT) can supplement dual x-ray absorptiometry by enabling geometric and compartmental bone assessments. Whole-body spiral CT scanners are widely available and require a short scanning time of seconds, in contrast to peripheral QCT scanners, which require several minutes of scanning time. This study designed and evaluated the accuracy and precision of a homemade QCT calibration phantom using a whole-body spiral CT scanner.

Materials and methods: The QCT calibration phantom consisted of K₂HPO₄ solutions as reference. The reference material with various concentrations of 0, 50, 100, 200, 400, 1000, and 1200 mg/cc of K₂HPO₄ in water were used. For designing the phantom, we used the ABAQUS software.

Results: The phantoms were used for performance assessment of QCT method through measurement of accuracy and precision errors, which were generally less than 5.1% for different concentrations. The correlation between CT numbers and concentration were close to one (R² = 0.99).

Discussion: Because whole-body spiral CT scanners allow central bone densitometry, evaluating the accuracy and precision for the easy to use calibration phantom may improve the QCT bone densitometry test.

Conclusion: This study provides practical directions for applying a homemade calibration phantom for bone mineral density quantification in QCT technique.

Keywords: ABAQUS software; Quantitative computed tomography; bone mineral density; calibration phantom.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Calibration
Equipment Design
Phantoms, Imaging*
Reproducibility of Results
Tomography, X-Ray Computed / instrumentation*
Tomography, X-Ray Computed / standards*