Does your facility need help on applying for accreditation? In each issue of this Newsletter, I'll present frequently asked questions (FAQs) of particular importance for medical physicists. You may also check out the ACR's accreditation web site portal for more FAQs, accreditation application information and QC forms.

The Food and Drug Administration (FDA) will soon approve the ACR to accredit digital breast tomosynthesis (DBT) units. The following FAQs address the ACR's requirements for DBT accreditation. Please contact us if you have any questions.

Q. We plan to add DBT to our existing accredited FFDM unit. Do we need to accredit this new DBT system?
A. Yes.

Q. Our mammography unit is accredited for FFDM and the FDA extended our certificate to cover the unit's DBT function. Do we now need to accredit the DBT portion of the unit?
A. Yes.

Q. I heard that if I have an FFDM system with DBT, my facility must accredit that unit as two separate units - FFDM and DBT. Is that true?
A. Yes.

Q. My mammography system has the capability to perform both FFDM and DBT, but we will only perform DBT. (We will not perform FFDM.) Do we still need to accredit as two separate units?
A. Yes, the FFDM portion of the unit must be accredited, whether or not it is used clinically, as it is the basis for some of the QC testing for the DBT portion.

Q. My mammography system has the capability to perform both FFDM and DBT, but we will only perform FFDM. We will not be using the DBT portion of the unit. Do we still need to accredit the DBT portion of the unit?
A. No, if the DBT portion is not being used clinically, it does not have to be accredited.

Q. Do I need to submit DBT clinical images for DBT accreditation?
A. No, and in fact we don't accept them. See table below for clinical image submission requirements for both FFDM and DBT accreditation:

ACR Accreditation Clinical Testing for Digital Breast Tomosynthesis (DBT)

Scenario 1. DBT - 2D Synthesized Images Available (whether or not 2D-Syn is used for interpretation)

Testing to be Submitted by Facility
Type	2D FFDM Accreditation	DBT Accreditation
Clinical Testing (a clinical set = cc and mlo of 1 fatty and 1 dense case)	Whatever is performed clinically: 2D clinical set (cc and mlo), or 2D-Syn clinical set (cc and mlo), or 2D cc and 2D-Syn mlo clinical set, or 2D-Syn cc and 2D mlo clinical set	2D-Syn clinical set (cc and mlo), or 2D cc and 2D-Syn mlo clinical set, or 2D-Syn cc and 2D mlo clinical set

Scenario 2. DBT - 2D Synthesized Images Not Available on System

Testing to be Submitted by Facility
Type	2D FFDM Accreditation	DBT Accreditation
Clinical Testing (a clinical set = cc and mlo of 1 fatty and 1 dense case)	2D clinical set	2D clinical set

Q. May I submit a 2D synthesized phantom image for the accreditation of my FFDM unit?
A. No. For FFDM accreditation the facility must submit one 2D phantom acquired image.

Q. May I submit the 2D acquired phantom image for the accreditation of my DBT system?
A. No. For DBT accreditation the facility must submit one image that best demonstrates all the test objects ("best-slice" image). See the following table for the phantom image submission requirements:

ACR Accreditation Phantom Testing for Digital Breast Tomosynthesis (DBT)

Scenario 1. DBT - 2D Synthesized Images Available (whether or not 2D-Syn is used for interpretation)

Testing to be Submitted by Facility
Type	2D FFDM Accreditation	DBT Accreditation
Phantom Testing	2D phantom image	3D best-slice phantom image*

Scenario 2. DBT - 2D Synthesized Images Not Available on System

Testing to be Submitted by Facility
Type	2D FFDM Accreditation	DBT Accreditation
Phantom Testing	2D phantom image	3D best-slice phantom image*

*The 3D best-slice phantom image allows for high-level evaluation of the impact of DBT-specific parameters (e.g., target, filter, etc.) on image quality for accreditation. Best slice is defined as the slicethat demonstrates all the test objects in the phantom better than any other slice in the tomosynthesis set. As with all accreditation, the medical physicist's annual survey (and/or MEE) provides the detailed evaluation of system performance.