Background: Cross-sectional imaging techniques, including ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) are increasingly used for evaluation of Crohn's disease (CD).
Aim: To review the accuracy of cross-sectional imaging indexes for measurement of disease activity and severity in patients with CD, and to evaluate its applicability on daily clinical practice and research.
Methods: Relevant publications were identified by literature search, and selected based on predefined quality parameters, including a sample size and reference standard. Nineteen publications were chosen.
Results: The US-based indexes of activity showed high correlation with reference standard indexes. There is a good or very good agreement between the MR-based indexes and the reference standard when the comparison is limited to small segments of intestine. Significant discrepancies have been found between indexes that evaluate the colon. Only one CT-based index was included. The main strengths and weaknesses of the indexes, according to its design, are discussed.
Conclusion: Standardization of image acquisition protocols and patient preparation should be procured, especially for MRI. In daily practice, a simple, semi-quantitative index providing relevant information on disease activity and severity is preferable. For research purposes, a precise and reproducible index should be mandatory.