4.2 Study limitations
A mean follow up time of 6 years (median 5.6 years) is not long enough
to allow for the development of all potential recurrences, therefore we
expect that the recurrence rate may increase with time. The focus of
this study was to detect occult recurrences at an early stage with
imaging rather than define the incidence of RPA after CD which has
already been discussed in the literature2,6. Another
limitation is that a small recurrence may not be obvious on MRI or CT
and therefore repeat imaging may be necessary. Lesions as small as 1 mm
have been detected with MRI5. However,
histopathological studies show that recurrences can be multiple and less
than 1mm9 so there is a theoretical risk of missing
them by imaging. CT scans have inferior detection capability compared to
MRI but only few patients underwent this modality in our study.