The difference in image quality assessment between radiographers and radiologists and its relationship with diagnostic accuracy

Introduction

Radiographers must ensure that the radiographs they produce are of sufficient quality before reporting by radiologists. However, does radiographers’ perception of image quality relates to the diagnostic accuracy of radiologists?

Methods

38 unique postero-anterior (PA) chest radiographs containing either no pathology, well defined or diffuse lesions were presented to four radiologists and 24 radiographers. Image quality was rated using RadLex quality descriptors. Additionally, radiologists rated their confidence of a radiograph being were normal or abnormal on a 5-point scale. Radiographers rated visibility of anatomical structures, satisfaction with positioning, collimation and adequacy of detector dose. Modelling correlation explored relationships between radiologists' detection of pathology and radiographers’ ratings.

Results

Radiographers rated image quality of 56 % of radiographs as non-diagnostic or limited, compared to 30.7 % by radiologists. Modelling revealed that chances of a radiograph being classified in lower quality categories by radiographers increased inversely proportionally with perceived dose, and suddenly increased when positioning was considered unacceptable. No correlation (p = 0.10) was found between quality descriptors by radiographers and diagnostic accuracy of radiologists.

Conclusion

Findings suggest that perceived “better” image quality, as defined by radiographers, may not necessarily correlate with diagnostic accuracy. This implies that radiographs repeated in clinical practice might not enhance diagnostic value.

Implications for practice

These findings raise the question which elements in the radiography or actual content (such as representation of anatomical structures) are key elements used to diagnose, which may have implications for image quality studies. Exploring the evolution of decision-making in radiographers trained to report could provide further valuable insights.