Introduction

The term ‘quality assurance’, or QA, has many definitions and is used in a variety of contexts. Most often it refers to schemes for maintaining the outcomes of some process or activity as measured against a required standard or yardstick. In ultrasound, the outcome is normally the creation of a series of images which have a clinical utility. The concept of QA normally would include a description of the remedial action which needs to be taken when performance falls short of the required standard. Many factors influence the extent to which this is achieved, including: the nature of the clinical problem; the patient; the equipment quality; and the operator's skill level. In this Chapter only the equipment quality aspects are considered and there is no discussion about remedial action which might be taken if a fault is identified. The emphasis is on the detection of a fault or a change in performance at as early a stage as possible in order that technical help can be summoned as appropriate. This approach underpins recent guidance produced within the UK (IPEM in press), and this chapter has been written to be consistent with that guidance.

Standards and guidance

Standards aimed primarily at manufacturers are produced by the International Electrotechnical Commission (IEC) based in Geneva. IEC ultrasound standards are mostly concerned with measurements related to safety (see Chapter 12).