MR enterography sequence evaluation for patients with Crohn's disease

Purpose: To evaluate a routine MR enterography (MRE) protocol for patients with Crohn's disease (CD) in order to assess and rank the subjectively most important sequences regarding diagnostic decisions. Materials and Methods: We prospective ly examined 84 patients (42 male) with known CD using a coronal T2/T1-weighted balanced SSFP (TrueFISP), axial T2-weighted single shot TSE (HASTE) as well as an axial T1-weighted gradient-echo sequence (2D-FLASH) before intravenous contrast application and a 2D-FLASH sequence with axial and coronal orientation after in travenous contrast application. 4 experienced radiologists subjectively evaluate d the sequences independently using a scale between 1 and 5 (1 = excellent; 5 = non-diagnostic) regarding their diagnostic significance for a final radiologic d ecision. The ranking of the different sequences was statistically tested by the Friedman analysis. Results: The following ranking was found: HASTE sequences wer e ranked prior to contrast-enhanced axial gradient-echo (2D-FLASH). The third to fifth ranking was TrueFISP, the axial contrast-enhanced 2D-FLASH and the 2D-FLA SH without contrast, respectively. Differences between the first and second rank were significant (p < 0.05), and all other differences were highly significant (p < 0.01). Conclusion: The stable and fast T2-weighted MR sequences without intravenous contrast represented by axial HASTE and coronal TrueFISP were ranked as number 1 and 3. The examination protocol should be completed by a coronal T 1-weighted gradient-echo-sequence after contrast injection, which can be supplemented by an axial acquisition. The T1-weighted gradient-echo sequence without contrast could be omitted. (orig.)