Quantitative Image Quality Metrics of the Low-Dose 2D/3D Slot Scanner Compared to Two Conventional Digital Radiography X-ray Imaging Systems.

Oke Gerke,Alistair Mackenzie,Ahmed Jibril Abdi,Poul Erik Andersen,Benedikte Klaerke,Bo R. Mussmann

doi:10.3390/diagnostics11091699

Abstract

The aim of this study was to determine the quantitative image quality metrics of the low-dose 2D/3D EOS slot scanner X-ray imaging system (LDSS) compared with conventional digital radiography (DR) X-ray imaging systems. The effective detective quantum efficiency (eDQE) and effective noise quantum equivalent (eNEQ) were measured using chest and knee protocols. Methods: A Nationwide Evaluation of X-ray Trends (NEXT) of a chest adult phantom and a PolyMethylmethacrylate (PMMA) phantom were used for the chest and knee protocols, respectively. Quantitative image quality metrics, including effective normalised noise power spectrum (eNNPS), effective modulation transfer function (eMTF), eDQE and eNEQ of the LDSS and DR imaging systems were assessed and compared. Results: In the chest acquisition, the LDSS imaging system achieved significantly higher eNEQ and eDQE than the DR imaging systems at lower and higher spatial frequencies (0.001 ≤ p ≤ 0.044). For the knee acquisition, the LDSS imaging system also achieved significantly higher eNEQ and eDQE than the DR imaging systems at lower and higher spatial frequencies (0.001 ≤ p ≤ 0.002). However, there was no significant difference in eNEQ and eDQE between DR systems 1 and 2 at lower and higher spatial frequencies (0.10 < p < 1.00) for either chest or knee protocols. Conclusion: The LDSS imaging system performed well compared to the DR systems. Thus, we have demonstrated that the LDSS imaging system has the potential to be used for clinical diagnostic purposes.

Highlights

The low-dose 2D/3D EOS slot scanner (LDSS) imaging system is a relatively new imaging modality that emits less radiation to patients when compared with conventional digital radiography (DR) imaging systems [1]
The linear detector response function of the imaging systems was determined by plotting the mean pixel value against detector air kerma (AK)
According to the image quality parameter Effective Noise Equivalent Quanta (eNEQ) and effective detective quantum efficiency (eDQE) results presented in Table 3 and the subsequent statistical analysis, the LDSS imaging system has shown better eDQE and eNEQ characteristics compared to the DR imaging systems in both chest and knee examination protocols

Summary

Introduction

The low-dose 2D/3D EOS slot scanner (LDSS) imaging system is a relatively new imaging modality that emits less radiation to patients when compared with conventional digital radiography (DR) imaging systems [1]. In conventional DR systems, the X-ray beam is cone-shaped and the dose follows the law of being reduced by the square root of the focus to detector distance (inverse square law). Another difference between the LDSS imaging and conventional DR systems is the detector technology. LDSS is a bi-plane with two X-ray tubes and two image detectors that move synchronously in lateral and frontal projections.

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Conclusion