On the dose sensitivity of a new CDMAM phantom

Area of Science:

• Medical Physics
• Radiological Imaging
• Quality Assurance

Background:

• Mammography screening protocols require rigorous technical quality assurance.
• Contrast-detail phantoms, such as the CDMAM phantom, are essential tools for this evaluation.
• Previous studies have examined the dose sensitivity of various phantoms, including the CDMAM 3.4.

Purpose of the Study:

• To compare the dose sensitivity and performance of the CDMAM 4.0 phantom with the CDMAM 3.4 phantom.
• To evaluate the impact of varying exposure parameters (mAs) on phantom performance.
• To assess the suitability of both phantoms for modern mammography systems.

Main Methods:

• Utilized CDMAM 4.0 and CDMAM 3.4 phantoms with varied mAs settings (40-140 mAs).
• Employed automatic evaluation software for both phantoms (Artinis for 4.0, NCC PM for 3.4).
• Compared relative dose sensitivity across different diameters and calculated the IQFinv parameter.

Main Results:

• The IQFinv parameter demonstrated a linear dependence on dose for both phantoms.
• CDMAM 4.0 exhibited a more monotonous dose dependence with smaller variations in threshold thickness.
• Significant differences in threshold thicknesses between the two phantoms necessitate adapted conversion factors for automatic readout.

Conclusions:

• The CDMAM 4.0 phantom shows enhanced and more stable dose sensitivity compared to CDMAM 3.4.
• The findings support the use of CDMAM 4.0 for quality assurance in modern mammography.
• Adaptation of conversion factors is required for accurate automatic evaluation of CDMAM 4.0 results.