Recent advances in the use of ultrasound in Crohn’s disease

ABSTRACT

Introduction

A clear consensus exists on the role of IUS for the assessment and monitoring of Crohn’s disease (CD) in the ‘treat-to-target’ strategy.

Areas covered

IUS is an accurate tool for the management of CD. It is noninvasive and well tolerated. IUS has good-to-optimal inter-operator reliability either for assessing disease activity or for evaluating treatment response, especially combining Bowel Wall Thickness (BWT) and Color Doppler Signals (CDS). IUS is able to evaluate transmural remission (TR), the ultimate goal of the ‘treat-to-target’ strategy. Several studies confirmed its accuracy in the assessment of the post-operative recurrence (POR). Thanks to recent advances in trans-perineal ultrasound technique (TPUS), it allows to characterize peri-anal disease and its complications. Small intestine contrast ultrasound (SICUS) and contrast-enhancement ultrasound (CEUS) may improve IUS performance, particularly in stricturing or penetrating CD. Ultrasound elastography (USE) is raising interest for its accuracy in differentiating CD phenotypes (fibrotic versus inflamed).

Expert opinion

IUS is a pivotal step in the management of CD, in early assessment as in therapeutic monitoring, with advantages of evaluating transmural response. Development and validation of novel ultrasound biomarkers of activity and fibrosis, especially those linked to advanced ultrasound techniques, are expected in the coming years.

KEYWORDS:

• Intestinal ultrasound
• ultrasound Elastography
• CEUS
• SICUS
• TPUS

Article highlights

• IUS is an accurate, easy-to-perform, noninvasive tool for IBD, especially for CD assessment.

• Its use has implemented the ‘treat-to-target’ strategy, on which IBD management is based.

• BWT above all, is the most reliable and validated marker of CD activity at IUS evaluation, followed by CDS, bowel wall stratification (BWS), and inflammatory mesenteric fat (i-fat).

• Concerning monitoring treatment response, IUS has highlighted high correlation with endoscopic improvement, with good consistency and has been incorporated in the latest guidelines.

• Post-operatory evaluation is an important setting for CD with several studies confirming IUS as a valid assessment of POR.

• TPUS is an accurate tool for the assessment of peri-anal CD, being able to discriminate fistulas, abscesses, and to accurately describe the anatomic features of the perineal region.

• CEUS and SICUS may be valuable tools to assess CD complications and to further characterize CD phenotypes.

• USE is an advanced, feasible, technique which may increase CD lesion characterization, possibly differentiating fibrotic from inflammatory strictures.

Declaration of interest

Barchi, A. Zilli, T.L. Parigi declares no conflict of interest. F D’Amico has served as a speaker for Sandoz, Janssen, Galapagos, and Omega Pharma; he also served as advisory board member for Galapagos, Abbvie and Nestlè. F Furfaro received consulting fees from Amgen, Abbvie, Janssen and Pfizer; L Peyrin-Biroulet has served as a speaker, consultant and advisory board member for Merck, Abbvie, Janssen, Genentech, Mitsubishi, Ferring, Norgine, Tillots, Vifor, Hospira/Pfizer, Celltrion, Takeda, Biogaran, Boerhinger-Ingelheim, Lilly, HAC- Pharma, Index Pharmaceuticals, Amgen, Sandoz, For- ward Pharma GmbH, Celgene, Biogen, Lycera, Samsung Bioepis, Theravance; G Fiorino served as a Consultant for AbbVie, Amgen, Celltrion, Ferring, Galapagos, Janssen, Pfizer, Sandoz and Takeda. S Danese has served as a speaker, consultant, and advisory board member for Schering-Plough, AbbVie, Actelion, Alphawasserman, AstraZeneca, Cellerix, Cosmo Pharmaceuticals, Ferring, Genentech, Grunenthal, Johnson and Johnson, Millenium Takeda, MSD, Nikkiso Europe GmbH, Novo Nordisk, Nycomed, Pfizer, Pharmacosmos, UCB Pharma and Vifor. A Dal Buono has received speaker’s fees from Abbvie, Galapagos, Celltrion. M Allocca received consulting fees from Nikkiso Europe, Mundipharma, Janssen, Abbvie, and Pfizer.

Reviewer disclosure

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

MA, ADB, and FD conceived the article. AB wrote the article and created tables and figures. FD, FF, AZ, GF, LPB, TLP, MA, and SD critically reviewed the content of the paper and supervised the project.

Additional information

Funding

This paper was not funded.