Whilst obtaining a CT or MR examination the radiographer will generate a scout or localiser to ensure accurate positioning of the patient for the subsequent diagnostic examination. There is a debate over whether these images should be included in the image set produced for the overall diagnostic interpretation. It is accepted that scout or localiser images may not necessarily be of diagnostic quality.
There are a few case series in the literature often associated with the retrospective diagnosis of lesions that only subsequently can be seen on the scout or localiser imaging.
Considering this issue, the RCR, SOR and COR, and IPEM, collectively as the Clinical Imaging Board, has decided a joint position:
A clear and agreed local policy is required so that all staff in an imaging centre are aware and able to observe the policy when archiving imaging series in CT and MRI.
It is recognised that there are varying opinions on whether or not to include localiser images in PACS data sets for reporting. However, the Clinical Imaging Board position is that these images should be sent to PACS.
A scout or localiser can include evidence of abnormality, or unexpected findings such as pregnancy, that might be useful in setting the scan parameters or in other aspects of the management of the patient.
In the case of CT scanning, the radiation dose used to obtain the scout or localiser image is an additional consideration. Please refer to the current IR(ME)R guidance.
Any local policy where it is agreed to exclude scout or localiser images from the PACS data should state clearly why the policy position is justified within the service approach to quality improvement.
Where local policy indicates that the scout or localiser should be recorded as part of the diagnostic series, it should be reviewed when the report is being generated.
If for any reason the examination is aborted after the scout image(s), there must be a clear procedure that highlights the actions to be taken in the event of unexpected findings, for example pregnancy.
Clinical Imaging Board