P068 The utility of contrast-enhanced trans-abdominal ultrasound in the assessment of ileal Crohn's disease

Abstract

BACKGROUND: While ileo-colonoscopy remains the gold standard for luminal evaluation of Crohn’s ileitis, repeated colonoscopies to reassess disease activity can be inconvenient (prep, lost time from work) and put the patient at additional procedure risk and increase health care cost. MRI and CT enterography can be used to assess ileal disease, but the tests involve contrast use, radiation exposure, and are lengthy and costly. Contrast-enhanced ultrasound (CEUS) has been promoted in Europe and Asia as a promising tool for assessment of disease activity with lower cost and no radiation exposure. METHODS: This is a prospective study currently enrolling patients with active Crohn's ileitis. All patients underwent evaluation with ileo-colonoscopy and serum inflammatory marker (CRP). Subsequently, all patients underwent CEUS by an independent radiologist who was blinded to the endoscopy results. Ultrasound contrast agent sulfur hexafluoride with gas-filled microbubbles was used (4.8 mL of IV Lumason, Bracco Diagnostics Inc), with real-time visualization of bowel wall microvascularization and perienteric tissue. Bowel wall thickness was measured and a time-signal intensity curve was obtained after calculating the peak enhancement and area under the curve. Prior groups (1) used a cut off point of 18.2 dB for moderate activity and 23.0 dB for severe activity. CEUS findings were compared to the endoscopic findings to assess for correlation in assessing disease activity and severity. RESULTS: Four male patients (age 22–65, 3 AA and one Caucasian) with symptomatic Crohns ileitis were enrolled in our study thus far. Patient A had moderate inflammation on CEUS with a peak intensity of 22 dB correlating with Rutgeerts i3 ileitis (large ulcers) above the ileoclonic anastomosis. Patient B had severe inflammation on CEUS with a peak intensity of 27 dB that correlated with moderate to severe ileitis with an inflammatory stricture on endoscopy. Patient C and D both had mild enhancement of distal ileum with a peak intensity of 17 dB; correlating with the findings of aphthous and larger ulcers on endoscopy. Only the 2 patients with a peak intensity of 27 dB had elevated CRP. CONCLUSION(S): In our limited experience, CEUS correlates with endoscopic findings of active ileitis and disease severity in Crohn's patients. With further patients enrollment and follow up, we aim to confirm this finding and to assess whether CEUS imaging can also evaluate inactive ileitis in treated Crohn's patients.