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Information for mammography facility personnel, inspectors, and consumers               about the implementation of the Mammography Quality Standards Act of 1992 (MQSA)

Recent Inspection Results by W. G. Mourad, Ph.D. Information Management Branch Division of Mammography Quality and Radiation Programs

Our first topic will be recent inspection results regarding the percentage of facilities having MQSA violations nationwide, grouped by the highest noncompliance level cited. Level 1 is the highest potential noncompliance level, and refers to issues presenting the most serious health risk to patients. Level 2 is the next level, which we view as moderately serious. Level 3 is the third level and refers to issues that present only a minor health risk.

The graph below shows inspection results from 10/1/1999 to 6/30/2002: The numbers represent, for each fiscal year, the percentage of facilities whose worst citation(s) is at each of the levels shown.

% of Facilities w/Highest Level of Findings – FY00 to FYTD02

The graph shows that for each group, the percentage of facilities cited has steadily decreased over the past three years, and the percentage of facilities with no citations whatsoever (no findings) has steadily increased. While this is encouraging, there is still significant room for improvement. Because we view Level 1 and Level 2 citations as most detrimental to the quality of mammography, we reviewed these citations to determine which MQSA standards were violated most frequently. Our review indicated that a sizeable fraction of such citations has been, and continues to be, in the daily and weekly QC records, e.g., processor and phantom QC tests, as shown in the graph below.

Facilities Cited with Processor or Phantom QC Violations

The remainder of this article will focus on these violations and discuss their significance to the practice of mammography.

Although QC testing includes quarterly and semiannual testing, the daily processor and the weekly phantom tests are considered the most important. For this reason, FDA has assigned Level 1 and Level 2 citations for a variety of findings relating to these two tests, and only Level 3 citations for findings involving the quarterly and semi-annual tests.

A. The Daily Processor QC

The quality of clinical images in screen-film mammography is greatly influenced by the processor. Producing quality images on a routine basis requires a processor that has been set according to the film manufacturer’s recommendations, seasoned and stabilized, and routinely maintained for operational consistency.

The initial set up and optimization of the processor includes choosing the appropriate chemicals and replenishment rates, and establishing the operating levels for mid-density (MD), density difference (DD), and base plus fog (B+F). Establishing the operating levels requires a seasoned processor and routinely takes about five days for most facilities. However, it could take longer, depending on processor size, replenishment rate, type of film, and processing volume at the facility.

The processing operation is a dynamic process in which the conditions are constantly changing with every film run through the processor. It is therefore, very important to check those processing conditions frequently, to ensure that the processor continues to operate at or near the operating levels initially established for MD, DD, and B+F, and never exceed the action limits for any. Monitoring these conditions is the function of the daily processor QC test, e.g., the processing and subsequent measuring and recording of MD, DD, and B+F on the daily sensitometry forms.

FDA regulations require that the daily processor QC test be conducted before processing any mammograms on any day that mammograms are to be processed. Furthermore, if the test fails (MD or DD deviates more than ± 0.15, or B+F deviates more than +0.03 in optical density from the operating level), the facility must not process any mammograms until it has identified the cause of the failure, successfully corrected the problem(s), and documented the results of the successful retest.

To emphasize the seriousness of this test, FDA has designated any of the following failures as a Level 1 or a Level 2 noncompliance, as shown in Table 1. Hence, facilities cited with any of these failures would be included in the graph above.

Table 1

B. The Weekly Phantom Image QC Test

While other QC tests are designed to ensure that certain parts of the imaging chain function consistently over time, the phantom image test ensures that the whole imaging system (x-ray unit, processor, darkroom, and image receptor) functions properly and consistently as a whole, over time.

If the test fails, clinical images produced by the system are likely to be of poor quality and could be degraded to the point that makes them useless or difficult to interpret. Also, because it is a whole system test, a failed phantom image necessitates checking every component of the imaging chain to determine the cause of failure. From a regulatory standpoint, such failure requires the facility to correct the problem that caused the failure before conducting any clinical examinations using the part of the system that caused the phantom image to fail.

This is one of the reasons FDA and the mammography community considers the phantom image test to be one of the most significant tests in the hierarchy of quality control testing. To maintain the quality and consistency of clinical images in practice, MQSA’s final regulations mandated that facilities conduct the phantom image test weekly (instead of monthly as under the interim regulations).

Furthermore, FDA has designated any of the following failures as a Level 1 or a Level 2 noncompliance, as shown in Table 2. Hence, facilities cited with any of these failures would be included in the graph above

Table 2

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