Visual Evaluation of Image Quality of a Low Dose 2D/3D Slot Scanner Imaging System Compared to Two Conventional Digital Radiography X-ray Imaging Systems

Ahmed Jibril Abdi; Bo Mussmann; Alistair Mackenzie; Oke Gerke; Gitte Maria Jørgensen; Thor Eriksen Bechsgaard; Janni Jensen; Lone Brunshøj Olsen; Poul Erik Andersen

doi:10.3390/diagnostics11101932

Visual Evaluation of Image Quality of a Low Dose 2D/3D Slot Scanner Imaging System Compared to Two Conventional Digital Radiography X-ray Imaging Systems

Diagnostics (Basel). 2021 Oct 19;11(10):1932. doi: 10.3390/diagnostics11101932.

Authors

Ahmed Jibril Abdi^{1

2}, Bo Mussmann^{1

3}, Alistair Mackenzie⁴, Oke Gerke^{1

5}, Gitte Maria Jørgensen³, Thor Eriksen Bechsgaard³, Janni Jensen^{1

3}, Lone Brunshøj Olsen³, Poul Erik Andersen¹

Affiliations

¹ Department of Clinical Research, University of Southern Denmark, 5000 Odense, Denmark.
² Department of Clinical Engineering, Region of Southern Denmark, 5000 Odense, Denmark.
³ Department of Radiology, Odense University Hospital, 5000 Odense, Denmark.
⁴ National Coordinating Centre for the Physics of Mammography, Royal Surrey NHS Foundation Trust, Guildford GU2 7XX, UK.
⁵ Department of Nuclear Medicine, Odense University Hospital, 5000 Odense, Denmark.

Abstract

The purpose of this study was to assess the image quality of the low dose 2D/3D slot scanner (LDSS) imaging system compared to conventional digital radiography (DR) imaging systems. Visual image quality was assessed using the visual grading analysis (VGA) method. This method is a subjective approach that uses a human observer to evaluate and optimise radiographic images for different imaging technologies.

Methods and materials: ten posterior-anterior (PA) and ten lateral (LAT) images of a chest anthropomorphic phantoms and a knee phantom were acquired by an LDSS imaging system and two conventional DR imaging systems. The images were shown in random order to three (chest) radiologists and three experienced (knee) radiographers, who scored the images against a number of criteria. Inter- and intraobserver agreement was assessed using Fleiss' kappa and weighted kappa.

Results: the statistical comparison of the agreement between the observers showed good interobserver agreement, with Fleiss' kappa coefficients of 0.27-0.63 and 0.23-0.45 for the chest and knee protocols, respectively. Comparison of intraobserver agreement also showed good agreement with weighted kappa coefficients of 0.27-0.63 and 0.23-0.45 for the chest and knee protocols, respectively. The LDSS imaging system achieved significantly higher VGA image quality compared to the DR imaging systems in the AP and LAT chest protocols (p < 0.001). However, the LDSS imaging system achieved lower image quality than one DR system (p ≤ 0.016) and equivalent image quality to the other DR systems (p ≤ 0.27) in the knee protocol. The LDSS imaging system achieved effective dose savings of 33-52% for the chest protocol and 30-35% for the knee protocol compared with DR systems.

Conclusions: this work has shown that the LDSS imaging system has the potential to acquire chest and knee images at diagnostic quality and at a lower effective dose than DR systems.

Keywords: DR imaging systems; chest examination; image quality assessment; knee examination; slot scanner imaging system; visual grading analysis.