Quality Control Tests Other Than Annual

Applicable Citations: 

900.12(e)(1)(i),(ii),(iii): Daily quality control tests. Film processors used to develop mammograms shall be adjusted and maintained to meet the technical development specifications for the mammography film in use. A processor performance test shall be performed on each day that clinical films are processed before any clinical films are processed that day. The test shall include an assessment of base plus fog density, mid-density, and density difference, using the mammography film used clinically at the facility.

 

(i) The base plus fog density shall be within +0. 03 of the established operating level.

 

(ii) The mid-density shall be within ±0.15 of the established operating level.

 

(iii) The density difference shall be within ±0.15 of the established operating level.

 

900.12(e)(2)(i),(ii),(iii),(iv): Weekly quality control tests. Facilities with screen-film systems shall perform an image quality evaluation test, using an FDA-approved phantom, at least weekly.

 

(i) The optical density of the film at the center of an image of a standard FDA-accepted phantom shall be at least 1.20 when exposed under a typical clinical condition.

 

(ii) The optical density of the film at the center of the phantom image shall not change by more than ±0.20 from the established operating level.

 

(iii) The phantom image shall achieve at least the minimum score established by the accreditation body and accepted by FDA in accordance with 900.3(d) or 900.4(a)(8).

 

(iv) The density difference between the background of the phantom and an added test object, used to assess image contrast, shall be measured and shall not vary by more than ±0.05 from the established operating level.

 

900.12(e)(3)(i),(ii): Quarterly quality control tests. Facilities with screen-film systems shall perform the following quality control tests at least quarterly:

 

(i) Fixer retention in film. The residual fixer shall be no more than 5 micrograms per square cm.

 

(ii) Repeat analysis. If the total repeat or reject rate changes from the previously determined rate by more than 2.0 percent of the total films included in the analysis, the reason(s) for the change shall be determined. Any corrective actions shall be recorded and the results of these corrective actions shall be assessed

 

900.12(e)(4)(i),(ii),(iii)(A)(B): Semiannual quality control tests. Facilities with screen-film systems shall perform the following quality control tests at least semiannually:

 

(I) Darkroom fog. The optical density attributable to darkroom fog shall not exceed 0.05 when a mammography film of the type used in the facility, which has a mid-density of no less than 1.2 OD, is exposed to typical darkroom conditions for 2 minutes while such film is placed on the counter top emulsion side up. If the darkroom has a safelight used for mammography film, it shall be on during this test.

 

(ii) Screen-film contact. Testing for screen-film contact shall be conducted using 40 mesh copper screen. All cassettes used in the facility for mammography shall be tested.

 

(iii) Compression device performance.

 

(A) A compression force of at least 111 newtons (25 pounds) shall be provided.

 

(B) Effective October 28, 2002, the maximum compression force for the initial power drive shall be between 111 newtons (25 pounds) and 200 newtons (45 pounds).

 

---

Discussion:

The tests listed in Summary Table of Quality Control Tests Other Than Annual below are normally performed by (or fall under the responsibility of) the quality control (QC) technologist and must be performed according to the frequencies shown in the Table.

 

FDA recommends that the facility adopt and follow documented procedures for all QC tests. Examples of such procedures are given in the Radiologic Technologist's Section of the most recent version of the American College of Radiology (ACR) Mammography Quality Control Manual. However, a facility using such a manual must ensure that the procedures it adopts are consistent with the final regulations. For example, the phantom QC test, which is listed as a monthly test in the 1994 ACR manual, is a weekly test under the final regulations.

 

FDA's experience with MQSA inspections to date indicates that under the interim regulations, some facilities have interpreted the words "weekly," "quarterly," and "semi-annually" in ways different from that intended by FDA. To ensure a uniform application of the final regulations to all facilities, FDA will enforce the following interpretation of test frequencies starting October 1, 1999.

 

• Weekly Phantom Image Test: Must be performed each week. However, the test need not be performed on the same day each week.

• Quarterly Tests: Must be performed 4 times a year. The 4 months that are chosen must be spaced 3 months apart (i.e., February, May, August, and November). However for any of the 4 selected months, each test may be performed on any day (not necessarily the same day) in the month.

• Semi-annual Tests: Must be performed 2 times a year. The 2 months that are chosen must be spaced 6 months apart (such as January and July.) However, for any of the 2 selected months, each test may be performed on any day (not necessarily the same day) in the month.

Questions:

1. What records must the facility keep for the daily, weekly, quarterly, and semi-annual quality control tests and what is considered acceptable documentation for each?

2. What is the facility required to do if a test result falls outside the limits defined in the regulations?

3. We perform a required quality assurance test more frequently than stated in the regulations. If the results of this test lie outside the regulatory action limits, must we take corrective actions based on this test or can we wait until the test is repeated at its regularly scheduled time?

4. Under the final regulations, must facilities chart the data for quality control tests, such as processor sensitometry or phantom image evaluation?

 

---

 

---