Phantom study to evaluate contrast-medium-enhanced digital subtraction mammography with a full-field...

Area of Science:

• Medical Imaging
• Radiology
• Mammography

Background:

• Contrast-enhanced digital subtraction mammography (CEDM) is crucial for breast lesion detection.
• Optimizing spectral combinations is key to improving image quality and reducing radiation dose.
• Existing spectral options require evaluation for CEDM performance.

Purpose of the Study:

• To compare image quality and mean glandular dose of two spectral combinations for CEDM.
• To evaluate the performance of traditional (Mo25-Rh40) versus hardened (Rh34-Rh45H) spectra.
• To assess the impact of spectral choice on contrast-over-noise ratio (CNR) and iodine detection limits.

Main Methods:

• A phantom study simulating CEDM using custom phantoms with iodine-based contrast agent.
• Acquisition of images using two spectral combinations: Mo/Mo at 25 kV & Rh/Rh at 40 kV (Mo25-Rh40) and Rh/Rh at 34 kV & Rh/Rh+5 mm Al at 45 kV (Rh34-Rh45H).
• Evaluation of image quality, signal-to-noise ratio (SNR), CNR, and iodine contrast across five temporal and dual-energy subtraction modalities within a dose limit.

Main Results:

• The Rh34-Rh45H spectral combination yielded a 7% higher iodine contrast than Mo25-Rh40.
• Temporal subtraction modalities achieved higher CNR than non-temporal dual-energy subtraction.
• CNR for 4 mg iodine/cm2 was 1.7 times higher with Rh34-Rh45H (iodine at high energy) compared to Mo25-Rh40 (iodine at low energy).
• Iodine thicknesses required to meet Rose's criterion were lower with Rh34-Rh45H (0.54 mg/cm2) than Mo25-Rh40 (0.78 mg/cm2).
• Single-energy temporal subtraction with Mo25-Rh40 resulted in a 1.2 mGy lower dose than the highest CNR modality.

Conclusions:

• The Mo25-Rh40 spectral combination is a viable alternative for CEDM, especially for dynamic contrast uptake studies.
• Hardened spectra (Rh34-Rh45H) offer superior iodine contrast and CNR, enabling detection of lower iodine concentrations.
• While hardened spectra improve contrast, traditional spectra like Mo25-Rh40 provide a good balance of image quality, dose, and suitability for dynamic imaging in CEDM.