Comparative evaluation of image quality between virtual grid and grid portable radiographic systems

Area of Science:

• Medical Imaging
• Radiography
• Image Processing

Background:

• Scattered radiation in radiography degrades image quality and can obscure diagnostic details.
• Physical grids, while effective, introduce artifacts and workflow inefficiencies.
• Virtual Grid (VG) is a digital image processing technique designed to mitigate scattered radiation without a physical grid.

Purpose of the Study:

• To evaluate and compare the image quality of Virtual Grid (VG) technology against traditional grid-based radiographic systems.
• To assess performance across a range of simulated patient thicknesses.
• To determine the impact of VG on contrast resolution, noise levels, and overall image granularity.

Main Methods:

• Image quality was assessed using modulation transfer function (MTF), noise power spectrum (NPS), low contrast resolution (LCR), and contrast-to-noise ratio (CNR).
• Simulated patient thicknesses from 2 cm to 40 cm were created using water blocks.
• Objective measurements and subjective visual assessments by four readers were performed.

Main Results:

• Virtual Grid (VG) demonstrated comparable or superior performance in terms of contrast resolution and noise reduction across various simulated patient thicknesses.
• No significant differences were found in LCR and CNR (P > 0.30) between VG and grid systems.
• Qualitative analysis showed VG provided better low contrast response for patient sizes ≥10 cm.

Conclusions:

• Virtual Grid (VG) technology effectively mitigates scattered radiation, enhancing image granularity and low-contrast resolution compared to physical grid systems.
• VG offers a promising alternative for improving radiographic workflow efficiency and potentially reducing patient radiation dose.
• The findings support the clinical utility of VG in digital radiography.