IAEA International Atomic Energy Agency RADIATION PROTECTION IN DIAGNOSTIC AND INTERVENTIONAL RADIOLOGY Part 19.07: Optimization of protection in Mammography Practical exercise IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology

IAEA : Optimization of protection in Mammography2 Overview To be able to apply quality control protocol to mammography equipment To determine the spatial resolution (lp/mm) both parallel and perpendicular to the tube axis using This is an evaluation of the whole system (blur due to focal spot combined with the film-screen system)

IAEA International Atomic Energy Agency Part 19.07: Optimization of protection in Mammography Phantom image quality evaluation IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology

IAEA : Optimization of protection in Mammography4 Image quality - spatial resolution The spatial resolution can be measured by imaging two resolution lead bar patterns, (20 line pairs/mm) These should be placed on top of the PMMA plates (45 mm total thickness) to measure worst-case resolution.

IAEA : Optimization of protection in Mammography5 Image quality - spatial resolution Image the patterns at the reference point Determine the resolution in both directions using a 6X magnifying loupe. Note: In some cases the three bars may blur but there are smaller bars visible. This is known as false resolution—there will be fewer bars visible in the area with false resolution. The resolution is the smallest group where all bars are just visible.

IAEA : Optimization of protection in Mammography6 Image quality - spatial resolution

IAEA : Optimization of protection in Mammography7 Image quality - spatial resolution

IAEA : Optimization of protection in Mammography8 Image quality phantom

IAEA : Optimization of protection in Mammography9 Image quality - spatial resolution

IAEA : Optimization of protection in Mammography10 Image quality - spatial resolution The distance from the chest wall edge is critical, but the position parallel to the thorax side is not critical within ± 5 cm from the reference point. Resolution is generally lower parallel to the tube axis due to the asymmetrical shape of the focal spot.

IAEA : Optimization of protection in Mammography11 Image quality - spatial resolution Limiting value :> 12 lp/mm acceptable > 15 lp/mm desirable at the reference point Frequency :Weekly Equipment :PMMA plates 150 x 240 mm, resolution pattern(s) up to 20 lp/mm, 6X magnifying loupe

IAEA Where to Get More Information 12 European protocol for the quality control of the physical and technical aspects of mammography screening. wnload&view=category&id=1&Itemid=8 American College of Radiology Mammography Quality Control Manual, Reston VA, : Optimization of protection in Mammography