The Utility of Contrast Enhanced Ultrasound and Elastography in the Early Detection of Fibro-Stenotic Ileal Strictures in Children with Crohn's Disease

Contrast-enhanced ultrasound of Crohn's disease in children and young adults: quantitative metric correlations and MRI disease severity associations

BACKGROUND

There is a paucity of data comparing contrast-enhanced ultrasound (CEUS) to MR enterography in children and young adults with Crohn's disease.

OBJECTIVE

To measure correlations across CEUS quantitative metrics in children and young adults with Crohn's disease, and to evaluate if these metrics are associated with MRI features of disease activity.

MATERIALS AND METHODS

Patients <21 years old with Crohn's disease affecting the terminal ileum who underwent clinically-indicated MR enterography were recruited between 2021 and 2024. Research CEUS of the terminal ileum was performed using sulfur hexafluoride lipid-type A microspheres, and images were analyzed using VueBox (Bracco Group). MRI exams were independently reviewed by three radiologists to document features of disease activity. Pearson's correlation (r) was used to measure associations across nine CEUS quantitative metrics and between CEUS metrics and mean or consensus MRI features.

RESULTS

Twenty-five participants, 13 (52%) male, with a mean age of 16.5 years (range, 13-20 years) were included. The mean terminal ileal maximum bowel wall thickness at MRI was 7.5 mm±1.8 mm. The mean sMaRIA score was 3.4±0.8, consistent with severely active disease. CEUS quantitative measurements were highly variable across participants. The mean rise time was 7.0±2.7 s, while the mean peak enhancement was 3,282±3,754 a.u. Twelve of 36 (36%) CEUS quantitative metric bivariate comparisons were highly collinear with r>0.8 (P<0.0001). There were significant positive correlations between CEUS rise time and MRI maximum bowel wall thickness (r=0.40; P=0.046), visual analog scale assessment of overall inflammation (r=0.43; P=0.032), and postcontrast enhancement ratio (r=0.47; P=0.018); there were no other significant correlations between CEUS metrics and MRI measures of inflammation.

CONCLUSION

CEUS quantitative measurements are highly variable across patients with Crohn's disease, with multiple metrics being highly correlated with one another. CEUS rise time correlates with MRI features of disease activity.

Elastography as a Discriminator Between Fibrotic and Inflammatory Strictures in Crohn's Disease: A Dead End or Bright Future in Clinical Decision-Making? Critical Review

BACKGROUND

Crohn's disease (CD) is a complex systemic entity, characterized by the progressive and relapsing inflammatory involvement of any part of the gastrointestinal tract. Its clinical pattern may be categorized as penetrating, stricturing or non-penetrating non-stricturing.

METHODS

In this paper, we performed a database search (Pubmed, MEDLINE, Mendeley) using combinations of the queries "crohn", "stricture" and "elastography" up to 19 June 2024 to summarize current knowledge regarding the diagnostic utility of ultrasound (US) and magnetic resonance (MR) elastography techniques in the evaluation of stricturing CD by means of an assessment of the transmural intestinal fibrosis. We decided to include papers published since 1 January 2017 for further evaluation (n = 24).

RESULTS

Despite growing collective and original data regarding numerous applications of mostly ultrasound elastography (quantification of fibrosis, distinguishing inflammatory from predominantly fibrotic strictures, assessment of treatment response, predicting disease progression) constantly emerging, to date, we are still lacking a uniformization in both cut-off values and principles of measurements, i.e., reference tissue in strain elastography (mesenteric fat, abdominal muscles, unaffected bowel segment), units, not to mention subtle differences in technical background of SWE techniques utilized by different vendors. All these factors imply that ultrasound elastography techniques are hardly translatable throughout different medical centers and practitioners, largely depending on the local experience.

CONCLUSIONS

Nonetheless, the existing medical evidence is promising, especially in terms of possible longitudinal comparative studies (follow-up) of patients in the course of the disease, which seems to be of particular interest in children (lack of radiation, less invasive contrast media) and terminal ileal disease (easily accessible).

Novelties and Perspectives of Intestinal Ultrasound in the Personalised Management of Patients with Inflammatory Bowel Diseases-A Systematic Review

Inflammatory bowel diseases (IBDs) affect over 4.9 million individuals worldwide. Colonoscopy (CS) is the gold-standard technique for diagnosis. The remissive-recurrent pattern of evolution raises the need for non-invasive techniques to monitor disease activity. This review aims to present the advantages of intestinal ultrasound (IUS) in managing IBDs. Our search was conducted on the PubMed, Embase, and Cochrane (CENTRAL) databases, selecting original studies comparing IUS with other imaging and invasive monitoring methods. Our search yielded 8654 results, of which 107 met the inclusion criteria. Increased bowel wall thickness (BWT) and colour Doppler signal (CDS) are discriminative for disease activity. IUS can predict disease outcomes and detect response to treatment or postoperative recurrence. Contrast-enhanced ultrasound (CEUS) and elastography help differentiate fibrotic from inflammatory stenoses. The difficult rectal assessment limits the use of IUS in ulcerative colitis (UC). Transmural healing may develop as a therapeutic target as it is associated with better outcomes. Patients are compliant with this technique, and its results correlate well with CS and other imaging methods. In conclusion, IUS proves to be essential in assessing IBD activity and treatment response, predicting outcomes and detecting complications. CEUS and elastography are researched to improve the diagnostic values of IUS.

Ultrasound in Pediatric Inflammatory Bowel Disease-A Review of the State of the Art and Future Perspectives

Inflammatory bowel disease (IBD) comprises a group of relapsing, chronic diseases of the gastrointestinal tract that, in addition to adults, can affect children and adolescents. To detect relapses of inflammation, these patients require close observation, frequent follow-up, and therapeutic adjustments. While reference standard diagnostics include anamnestic factors, laboratory and stool sample assessment, performing specific imaging in children and adolescents is much more challenging than in adults. Endoscopic and classic cross-sectional imaging modalities may be invasive and often require sedation for younger patients. For this reason, intestinal ultrasound (IUS) is becoming increasingly important for the non-invasive assessment of the intestine and its inflammatory affection. In this review, we would like to shed light on the current state of the art and provide an outlook on developments in this field that could potentially spare these patients more invasive follow-up procedures.