Implementation of quality criteria and directive for audit

Introduction:

The European quality criteria were designed in such a way that they could be easily implemented in the practice of rdg departments without the need for special instrumentation to measure the radiation dose of patients. They are designed so that the standard of good practice can be achieved during their application, both with regard to the good quality of the obtained x-ray image, as well as an acceptably low radiation dose for the patient.

Quality criteria, however, have a real benefit for the department only if they allow to correctly identify and, on the basis of this, to correct the insufficient level of some performance. The manifestation of the KK application at the relevant RDG department, in the sense of the achieved improvement in the level of performance, can only be adequately evaluated by a properly structured medical audit process.

Necessary components of a medical audit:

• Application of standards
• Control of their use
• Correction of incorrect practice
• Applying new standards
• Repetition of previous points

In our case, the KKs represent initial "standards" for image quality and patient dose assessment.

The exact procedure during the audit:

• The individual steps of the audit can be described in more detail in a special case:
• Choosing a certain type of x-ray examination at a certain one x-ray workplace.
• Taking a random sample of at least 10 medium-sized patients (60-80 kg body weight).
• Acquiring the appropriate image for each selected patient.
• Recording of relevant technical and instrumental parameters for each selected image (according to the questionnaire for recording the parameters of the used technique and x-ray equipment and according to the patient radiation dose data questionnaire).
• Measurement or determination of the entrance surface dose for each image (direct measurement using a thermoluminescent dosimeter attached to the patient's skin in a place corresponding to the action of the center of the x-ray beam. The entrance surface dose for a representative sample of patients can also be estimated from the exposure parameters used (kV and mAs) and from the measurement yield of the x-ray lamp using an ionization chamber calibrated per unit of dose absorbed in air, or kerma in air. ). Comparison of the average value of a sample of at least 10 medium-sized patients (70 ± 3 kg) with the relevant reference value from the dose from KK. Recording of detected radiation dose data in the dose questionnaire.
• At least two observers should check the use of the standard. It is recommended to use the form for the assessment of image quality, which was designed and used by a group of radiologists who performed an extensive study of the usability of KK within the framework of large trial studies (1. 1987 - 24 X-ray departments from 10 European countries (they evaluated all 6 types of examinations. 2. in 1987 regarding mammography. The results were analyzed in detail in the work of Maccia et al. 1989, 1990. The 1991 trial included 83 X-ray departments from 16 countries and was focused on only 3 types of examinations: chest, L spine and breast. The results were analyzed in detail in the work of Maccia et al. 1996).The mentioned form is in accordance with the European KK, it also contains more general aspects of image quality assessment, such as blackening, contrast, sharpness, beam deflection and diagnostic acceptability, it has 3 parts (for individual examination projections - e.g. PA projection and lateral projection and general questionnaire) .

As an aid to defending these phenomena, both during the audit and in normal departmental practice, it is recommended to have "ideal" images available where all aspects of the assessment are optimized. Other images are then compared to these "ideal" images. It is imperative that "ideal" images are taken using a patient radiation dose below the relevant reference dose.

• Identifying where the standard was not met (image quality or dose criterion).
• Finding the cause of non-compliance with a certain parameter of the standard. When identifying such an aspect, the part of the standard given in the paragraph: "Examples of correct display technique" can be used.
• Correction of the unfulfilled parameter by removing the cause responsible for the unfulfilled parameter (change of technique or device).
• After a short period of using the revised technique or device, repeat steps 2-7.
• If there is no improvement, repeat steps 7-10.
• If during the initial evaluation the parameters were evaluated in accordance with the content of the standard, an effort should be made to improve this standard, for example by using a lower value of reference doses in accordance with the optimization principle ALARA ("As Low As Reasonably Achievable" = "as low as possible will give").
• In an effort to achieve a more uniform and standardized level of diagnostic radiology performance, it would be desirable for this audit to be performed by independent observers who are not from the audited department. Gradually, this audit should be extended to larger groups than individual rdg departments.

References:

Carmichael J.H.E., Maccia C., Moores B.M., Oestmann J.W., Schibilla H., Teunen D., Van Tiggelen R., Wall B.: European Guidelines on Quality Criteria for Diagnostic Radiographic Images. Report EUR 16260. 1996
ICRP Publication 60. "1990 Recommendations of the International Commission on Radiological Protection". Annals of the IVRP Vol. 21, Nos. 1-3 (Oxford, Pergamon Press).
Zoetelief J., Fitzerald M., Leitz W., Säbel N.: European protocol on Dosimetry in Mammography. Report EUR 16263, 1996.

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