Edge of film error

Edge of film errors, also known as corner of film errors, are a classical perceptual error in radiology where a pertinent finding, whether incidental or not, is at the margin or edge of the image.

It is now used for all modalities, in both a literal sense, i.e. actually at the edge of the image, or more metaphorically, perhaps just the last slice in an image series or only seen on a single MRI localizer image.

Under the Renfrew classification of errors in radiology, these errors are generally thought to be "type 4: under-reading", although it could also be argued that in some cases they are also "type 9: location", i.e. outside the area of interest ³.