Purpose: This paper discusses the role of different imaging modalities
in the diagnostic work-up of Crohn's disease (CD). Methods: We presen
t a concept, which emphasizes different diagnostic aspects with regard
to primary diagnosis, follow-up and assessment of complications of CD
. The most effective imaging approach to various diagnostic problems o
f CD is discussed in detail. Discussion: With regard to the primary di
agnosis barium studies should contribute to differentiate between CD a
nd ulcerative colitis. Beyond that, these studies should evaluate loca
tion and extent of disease. During the follow-up bowel sonography prov
ides staging of disease and enables the detection of complications at
an early stage. CT is a valuable tool in the preoperative assessment o
f complications, such as fistulae and abscesses.