Informing and supporting decision making when considering if a Patient Group Direction (PGD) is an appropriate mechanism for administering contrast agents

Before an individual may receive a medical exposure of ionising radiation, there are specific clinical circumstances that must be considered at each stage of the care pathway.

There are separate legal frameworks to consider – the authorisation of the medical exposure to ionising radiation and the authorisation of the supply and administration of medicines. One does not confer legal authority for the other.


The Ionising Radiation (Medical Exposure) Regulations 2017 is the legislation which provides a framework intended to protect individuals from the hazards associated with ionising radiation.


Responsibility for compliance with IR(ME)R firmly rests with the employer and all of the “entitled” duty holders as defined in the Regulations. Specific individuals will be named and entitled to undertake these roles within each radiology department.

Clinical assessment and justification

Both IR(ME)R Referrers and Practitioners are required to assess an individual’s clinical needs and suitability for a particular medical exposure.

Before a request for clinical imaging is accepted, the IR(ME)R Practitioner, who must be a registered healthcare professional, makes a judgement to justify and authorise the exposure of an individual to ionising radiation. To perform this action, the request for the exposure is assessed against the clinical data supplied by the Referrer. The Practitioner must have had adequate training and be competent to consider the potential detriment of the exposure against the potential benefits for that individual. Further detail is available in the 2020 document IR(ME)R: Implications for clinical practice in diagnostic imaging, interventional radiology and diagnostic nuclear medicine

The practitioner may allocate the task of authorisation of a requested medical exposure to an entitled IR(ME)R Operator (Regulation 6[5]) but the practitioner retains responsibility for its justification. This requires the Operator to follow precisely the authorisation guidelines provided by the Practitioner.

After reviewing the referral form and if the referral is accepted, the IRMER Practitioner justifies the medical radiation exposure required.

If the examination requires the use of contrast media or other adjunct medicines, then the Operator must also have a legal authority to be able to administer that medicine. This requires careful consideration.

A locally agreed clinical imaging protocol does not in itself confer any legal authority to the Radiographer or any other healthcare professional to administer any medicines/contrast specified within that protocol.

The preferred way for individuals to receive medicines is for a prescriber to provide care for an individual on a one-to-one basis.

Contrast, if required, may be prescribed by the Radiologist who justifies an imaging procedure, but this is not commonly undertaken as at the time of an individual presenting to the imaging service, further assessment is required such as confirmation of current renal status, allergies and pregnancy status which may affect the contrast type/dose etc required. These checks are in addition to the normal IR(ME)R checks being undertaken by the IR(ME)R Operator, who is usually a Radiographer.

In practice, it is the Radiographer who is responsible for determining the suitability for contrast and commonly PGDs are used to support administration.

A PGD must be a standalone written instruction for the registered health professional to follow and all the information that they need should be within it to make the decision to administer the medicine. If practice requires clinical judgement beyond the written instruction within the PGD, then a PGD is not appropriate.

In the case of imaging the decision to undertake an imaging procedure requiring contrast is not made by the radiographer administering the contrast but the healthcare professional justifying the imaging procedure. Therefore, the radiographer working under the PGD is unable to do so completely autonomously as the decision that contrast is required is made by another healthcare professional.

The use of PGDs has been considered by representatives from NHSEI, the RCR, the Society and College of Radiographers (SCoR) and SPS. It has been acknowledged that whilst PGDs are not the most appropriate legal mechanism for the administration of contrast in imaging services they are required to ensure services can be maintained until other, more suitable mechanisms, are introduced into legislation.

The RCR, the SCoR working with the MHRA, NHSEI and the DHSC are exploring the use of exemptions under the Human Medicines Regulations 2012 and the extension of non-medical prescribing to diagnostic Radiographers, but these mechanisms will take time to realise.

Whilst these legislation changes are realised PGDs may continue to be used in the interim to support services and ensure that individuals access timely access to care.

SPS have worked with the RCR and SCoR and specialist radiographers and pharmacists to produce exemplar PGD templates for commonly used contrast media which can then be adopted by NHS organisations and independent providers of NHS commissioned imaging services.

The aim of these templates is to produce a consistent presentation which has been reviewed by specialists within the field who will ensure that the legislative and clinical parameters have been fully considered and accomplished as far as is possible.

It is intended that these PGDs will remain available, and updated as required, until other legal mechanisms for the administration of contrast agents are achieved.

The published contrast template PGDs are available here

Update history

  1. Page reviewed and updated with SCoR.
  1. Published

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