Effects of tube potential and scatter rejection on image quality and effective dose in digital chest X-ray examination: An anthropomorphic phantom study

Air gap technique is recommended in axiolateral hip radiographs

Purpose

To investigate the replacement of conventional grid by air gap in axiolateral hip radiographs. The optimal air gap distance was studied with respect to radiation dose and image quality using phantom images, as well as 26 patient axiolateral hip radiographs.

Methods

The CDRAD phantom, along with polymethylmethacrylate slabs with thicknesses of 10.0, 14.6, and 20.0 cm was employed. The inverse image quality index and dose area product (DAP), as well as their combination, so called figure‐of‐merit (FOM) parameter, were evaluated for these images, with air gaps from 20 to 50 cm in increments of 10 cm. Images were compared to those acquired using a conventional grid utilized in hip radiography. Radiation dose was measured and kept constant at the surface of the detector by using a reference dosimeter. Verbal consent was asked from 26 patients to participate to the study. Air gap distances from 20 to 50 cm and tube current‐time products from 8 to 50 mAs were employed. Exposure index, DAP, as well as patient height and weight were recorded. Two radiologists evaluated the image quality of 26 hip axiolateral projection images on a 3‐point nondiagnostic — good/sufficiently good — too good scale. Source‐to‐image distance of 200 cm and peak tube voltage of 90 kVp were used in both studies.

Results and conclusion

Based on the phantom study, it is possible to reduce radiation dose by replacing conventional grid with air gap without compromising image quality. The optimal air gap distance appears to be 30 cm, based on the FOM analysis. Patient study corroborates this observation, as sufficiently good image quality was found in 24 of 26 patient radiographs, with 7 of 26 images obtained with 30 cm air gap. Thus, air gap method, with an air gap distance of 30 cm, is recommended in axiolateral hip radiography.

Optimisation of radiographic acquisition parameters for direct digital radiography: A systematic review

INTRODUCTION

The objective of this systematic review was to uncover and synthesise all available literature regarding appropriate acquisition parameters for direct digital radiography. It sought to either confirm current practices as optimal, or to uncover practices that may produce more optimised results.

METHODS

A comprehensive search of published and unpublished literature was undertaken to find studies that evaluated how adjustment of different acquisition parameters affected subjective image quality and patient radiation dose. Eight hundred and fifty-eight studies were retrieved for title and abstract screening. Eighty-nine studies were retrieved for full-text screening, and 23 were included for review and methodological quality screening.

RESULTS

Narrative synthesis of the 23 included studies revealed limited evidence to guide any potential change or acceptance of currently accepted best practice. Meta-analysis was unable to be performed for any of the included studies due to high levels of methodological heterogeneity. A key finding of this review was that the goals of optimisation research varied greatly across the included studies.

CONCLUSION

Significant methodological heterogeneity in the included studies limited the number of clinically relevant findings that would give evidence to an acceptance of, or suggest changes to, currently accepted best practice. Improving consistency in approach across future works of technique optimisation will ensure future systematic reviews will be able to provide strong evidence and meta-analysis will be able to be performed.

IMPLICATIONS FOR CLINICAL PRACTICE

This review highlights that in the literature, studies of optimisation of radiographic acquisition parameters have varying goals. This methodological heterogeneity limits the applicability of systematic reviews and precludes the use of meta-analysis. The authors recommend that a framework for optimisation research be produced as a priority to help improve homogeneity in future research.

Unified Open Hardware Platform for Digital X-Ray Devices; its Conceptual Model and First Implementation

Background: Digital radiography devices are still the gold standard for diagnosis or therapy guidance in medicine. Despite the similarities between all direct digital x-ray systems, researchers and new companies face significant challenges during the development phase of innovative x-ray devices; each component is manufactured independently, guidance towards device integration from manufacturers is limited, global standards for device integration is lacking. Method: In scope of this study a plug-integrate-play (PIP) conceptual model for x-ray imaging system is introduced and implemented as an open hardware platform, SyncBox. The researchers are free to select each individual device component from different vendors based on their intended application and target performance are utilized in criteria. Result: As its first implementation, SyncBox and its platform a full body high resolution radiographic scanner that employs a novel TDI digital detector. Conclusion: We believe that SyncBox has a potential for introducing an open source hardware platform to x-ray equipment design.