Table 1

Grading of image comparability between different time points

ComparabilityDescriptionComment
GoodSimilar projections/techniques, good images, free from relevant artifactsHighest quality comparisons, choice for questions with highest precision requirements
SufficientDeviating projections/techniques but still usable for change assessment, no substantial artifacts in any of the visitsStandard quality comparisons, can be used
InsufficientImage projections/techniques do not allow for change assessment, substantial artifacts from any source in any of the visits, also related to contrast applicationDiscard comparisons as ‘cannot determine’