Quantitative evaluation of bowel perfusion in patients with food allergy using Dynamic Contrast-Enhanced Ultrasound (DCE-US) in comparison to healthy controls and patients with crohns disease

Introduction:

Abdominal imaging in patients with functional gastrointestinal disorders like food allergy or irritable bowel syndrome is challenging and little data is available in this field. The aim of this study was an evaluation of the bowel wall perfusion with quantitative contrast-enhanced ultrasound (DCE-US) in patients with proven food allergy under provocation diet compared to healthy controls and patients with active crohn's disease.

Material and Methods:

Patients with food allergy (PFA), healthy subjects (HS) and patients with active crohn's disease (PCD) scheduled for therapy escalation were included. We performed DCE-US examinations of the terminal ileum in PFA and HS after hypoallergic diet (potatoe-rise-diet – PRD) and intake of food with high allergenicity and in PCD. The following DCE-US paramters were calculated and compared: Peak Enhancement (PE), Wash-in Area Under the Curve (WiAUC), Rise Time (RT), Mean Transit Time (MTT), Time-To-Peak (TTP), Wash-in-Rate (WiR), Wash-in Perfusion Index (WiPI), Wash-out Area under the Curve (WoAUC), Wash-in Wash-out Area under the Curve (WiWoAUC), Fall Time (FT) and Wash-out Rate (WoR).

Results:

37 individuals were included (14 PFA, 8 HS, 15 PCD). There was no statistical significant difference between PFA and HS, neither under PRD, nor by hyperallergic food. Amplitude related DCE-US parameters, representing the regional blood volume (PE, WiAUC, WiR, WiPi, WoR) were significantly increased in PCD compared to PFA (e.g. PE: p = 0.02) and PCD compared to HS (e.g. PE: p < 0.01) under hyperallergic food, indicating mural hyperemia in PCD. Time related parameters representing blood flow (RT, TTP, mTTl, FT) were consistently insignificant.

Conclusion:

Transmural hyperemia can be visualized by DCE-US in PCD, but not in patients with PFA and HS.