Low-dose whole-spine imaging using slot-scan digital radiography: a phantom study

Area of Science:

• Radiological Imaging
• Medical Physics
• Diagnostic Radiology

Background:

• Slot-scan digital radiography (SSDR) systems feature detachable scatter grids and variable copper filters.
• These components offer potential for optimizing imaging parameters, particularly for dose reduction.

Purpose of the Study:

• To determine optimal low-dose imaging parameters for whole-spine imaging using SSDR.
• To evaluate the effectiveness of variable copper filters in dose reduction for SSDR.

Main Methods:

• SSDR was employed with scatter grids removed and variable beam-hardening (BH) filters (0.0-0.3 mm).
• Tube voltage and exposure time were adjusted across 20 parameters to achieve equivalent image quality in phantom studies.
• Optimal parameters were identified using the figure of merit, followed by visual evaluation of dose reduction in whole-spine phantoms.

Main Results:

• Optimal parameters varied with BH filter thickness, with specific kV, mA, and ms values determined for each.
• Entrance surface doses ranged from 59.44 µGy to 39.48 µGy as BH filter thickness increased.
• The 0.3 mm BH filter demonstrated the lowest radiation dose (39.48 µGy) while maintaining image quality.

Conclusions:

• Whole-spine SSDR utilizing variable copper filters can achieve substantial dose reduction.
• A dose reduction of 79% was realized for whole-spine imaging with SSDR, maintaining diagnostic image quality.