Pediatric digital chest radiography, comparison of grid versus non-grid techniques

Introduction

The usefulness of anti-scatter grid in digital pediatric chest radiography was investigated by a phantom study assessing image quality using subjective evaluations and dose measurements.

Method

A contrast detail study was undertaken. Images were taken with and without anti-scatter grids (grid ratio 15:1), for PMMA phantom thickness ranging from 1 to 15 cm. Fourteen radiographers, experienced in digital pediatric and/or skeletal radiography, read 96 images. At each thickness, the image with and without grid technique was read three times, and in random order. Correct Observation Ratio (COR) and Image Quality Figures (IQF) were calculated. Dose Area Products were measured with DAP-meter.

Results

The COR and IQF values indicated statistically significant (p < 0.05) enhanced image quality when using anti-scatter grid for all thicknesses 5 cm and more. The DAP values increased significantly by grid techniques (p = 0.01).

Conclusions

Grid techniques may be beneficial to image quality for PMMA objects over 5 cm, but this leads to a higher dose. Although the magnitude of dose may be low, the dose should be kept at a minimum. In conclusion, improving image quality should be based on optimizing post-processing settings and image evaluation conditions.