An investigation into the validity of utilising the CDRAD 2.0 phantom for optimisation studies in digital radiography

Abstract

<jats:sec><jats:title>Objectives:</jats:title><jats:p> To determine if a relationship exists between low contrast detail (LCD) detectability using the CDRAD 2.0 phantom, visual measures of image quality (IQ) and simulated lesion visibility (LV) when performing digital chest radiography (CXR). </jats:p></jats:sec><jats:sec><jats:title>Methods:</jats:title><jats:p> Using a range of acquisition parameters, a CDRAD 2.0 phantom was used to acquire a set of images with different levels of image quality. LCD detectability using the CDRAD 2.0 phantom, represented by an image quality figure inverse (IQF<jats:sub>inv</jats:sub>) metric, was determined using the phantom analyser software. A Lungman chest phantom was loaded with two simulated lesions, of different sizes/placed in different locations, and was imaged using the same acquisition factors as the CDRAD 2.0 phantom. A relative visual grading analysis (VGA) was used by seven observers for IQ and LV evaluation of the Lungman images. Correlations between IQF<jats:sub>inv</jats:sub>, IQ and LV were investigated. Results: Pearson’s correlation demonstrated a strong positive correlation (r = 0.91; p &lt; 0.001) between the IQ and the IQF<jats:sub>inv</jats:sub>. Spearman’s correlation showed a good positive correlation (r = 0.79; p &lt; 0.001) and (r = 0.68; p &lt; 0.001) between the IQF<jats:sub>inv</jats:sub> and the LV for the first lesion (left upper lobe) and the second lesion (right middle lobe), respectively. </jats:p></jats:sec><jats:sec><jats:title>Conclusions:</jats:title><jats:p> From results presented in this study, the automated evaluation of LCD detectability using CDRAD 2.0 phantom is likely to be a suitable option for IQ and LV evaluation in digital CXR optimisation studies. </jats:p></jats:sec><jats:sec><jats:title>Advances in knowledge:</jats:title><jats:p> This research establishes the potential of the CDRAD 2.0 phantom in digital CXR optimisation studies. </jats:p></jats:sec>

Comparative analysis of radiation dose and low contrast detail detectability using routine paediatric chest radiography protocols

“…De Crop et al [16]. More recently, a study undertaken by our research group confirmed the validity of physical evaluation for LCD detectability using CDRAD 2.0 phantom for evaluating visual IQ and lesion visibility along with its validity in CXR optimisation studies [36]. Within this work it was concluded that there is a good correlation between the LCD detectability and the visibility of the lesions and the general visual IQ within CXR.…”

Correlation between physical measurements and observer evaluations of image quality in digital chest radiography

“…Implementation of the VGA method is not feasible within a routine quality assurance program because it requires a substantial additional workload for the radiologists and large patient numbers or phantom images. 10,16,18 The psychophysical measurements based on CD images analysis are more practical than VGA method because no patient data are required and images can be analyzed by the medical physicist or dedicated image analyzer software. The eDQE measurement technique is a new metric when compared with VGA and CD analysis methods and provides overall performance of the digital radiographic imaging system in clinical conditions.…”

“…For the determination of the correlation between ordinal data (e.g., Likert scale) and continuous (interval) data Spearman correlation method was suggested in other studies. 10,18,32 Therefore, we used this statistical method to determine the correlation between VGA score (ordinal data), IQFinv and IeDQE (continuous data), respectively. But Keeble et al have demonstrated that this should not be the way to analyze correlations between VGA (noncontinuous) and numerical metrics (continuous) and there is considerable debate within the statistics community on this subject.…”

“…However, the statistical significance of their results was limited with three cadavers and the results were case dependent. Al-Murshedi et al 18 investigated the correlation between inverse image quality figure (IQF inv ) and relative visual grading analysis for image quality (IQ) and lesion visibility (LV). They found a strong positive correlation between the IQ and the IQF inv (r = 0.91; P < 0.001) and a good positive correlation between the IQF inv and the LV (r = 0.68; P < 0.001).…”

IBEX Trueview® Study, version 1.0

“…Secondly, a quantitative assessment was conducted using accepted methodology. Images of the internationally recognised "CDRAD" contrast and detail phantom (Al-Murshedi, et al, 2018) were collected on both a standard system and the Trueview software and the processed images assessed by the included software to quantify performance. Images were taken on the standard system both with and without an ASG present to highlight the negative effect of scatter on the image.…”