Breast tomosynthesis: Dosimetry and image quality assessment on phantom

Area of Science:

• Medical Imaging
• Radiology
• Radiation Dosimetry

Background:

• Digital breast tomosynthesis (DBT) offers potential advantages in breast cancer screening.
• Evaluating radiation dose and image quality is crucial for clinical adoption of DBT.

Purpose of the Study:

• To assess the average glandular dose (AGD) and image quality of breast tomosynthesis using a phantom study.
• To compare 2D mammography with 3D tomosynthesis in terms of radiation exposure and diagnostic performance.

Main Methods:

• A full-field digital mammography system with tomosynthesis capabilities was used.
• Polymethyl methacrylate (PMMA) plates and a dosimeter measured absorbed doses for AGD evaluation.
• Three accredited mammography phantoms (MTM 100, ACR RMI 156, BR3D) were imaged in both 2D and 3D for image quality assessment.

Main Results:

• No significant difference was found between measured and displayed AGD.
• AGD was significantly higher in 3D tomosynthesis compared to 2D mammography (P<0.01).
• Image quality, assessed by visible inserts, showed no significant difference for MTM 100 and ACR RMI 156 phantoms, but was significantly higher in 3D for the BR3D phantom (P<0.0001).

Conclusions:

• Breast tomosynthesis delivers a significantly higher average glandular dose than conventional 2D mammography.
• Tomosynthesis demonstrated improved image quality, specifically for the BR3D phantom, suggesting potential for enhanced lesion detection.