ECCO-ESGAR Guideline for Diagnostic Assessment in IBD Part 1: Initial diagnosis, monitoring of known IBD, detection of complications.

White blood cell scintigraphy is not indicated for diagnosis and characterisation of fistulae. A systematic review revealed the following point estimates for diagnosis of abscesses: using surgery as a reference standard, IUS had a sensitivity of 84% and a specificity of 93%, which was dependent on disease location in CD. 81 Detection of intra-abdominal abscesses via CT, with surgery as the reference standard, revealed a sensitivity of 86% and a specificity of 88%. 350 One prospective study showed a sensitivity of 85% and specificity of 95% of CT for intra-abdominal abscesses. 372 CT and ultrasound showed an overall high and comparable accuracy in the detection of intra-abdominal abscesses, although CT showed a slightly greater positive predictive value than ultrasound.