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* = Presenting author

P030 Development of small bowel tissue phantom for microultrasound 
investigation

T. Anbarasan*1, C. E. M. Démoré1, H. Lay2, M. R. S. Sunoqrot1, R. Poltarjonoks1, S. Cochran2, B. F. Cox1

1University of Dundee, Dundee, United Kingdom, 2University of Glasgow, Glasgow, United Kingdom

Background

Subclinical presentation of inflammatory bowel disease may involve mural pathologies not macroscopically visible via endoscopy.1 Detecting these changes without biopsy could be possible with the use of high-resolution transmural images of the gastrointestinal (GI) tract generated by microultrasound (μUS) instruments operating at high frequencies ranging from 25.0 to >100.0 MHz.2

Methods

A porcine small bowel tissue phantom was developed and perfused with degassed phosphate buffer saline (dPBS) solution through a cannula inserted in its mesenteric vessel to simulate in-vivo conditions and achieve better μUS mucosal characterisation. Two scanning systems, the μUS step scanner and μUS sweep scanner were used to scan repeatedly regions of prepared samples of porcine small bowel tissue. The average A-scan data obtained by the μUS scanning systems after scanning the tissue phantom is processed using MATLAB through B-scan reconstruction to produce 2D images of the tissue phantom with its various features represented by a colour map and evaluated against histology for accuracy.

Results

Preliminary investigation of porcine small bowel tissue phantoms revealed visible delineation between submucosa and muscularis externa layers as illustrated in Figure 1. Comparing relative positions of fiduciary markers injected into the layers of the porcine small bowel tissue phantom, between scans, allowed for the deduction of changes within the tissue, which could potentially affect the accuracy of the μUS scan. These changes have been accredited to a possible effect of necrotic degradation and micro-displacement of the tissue phantom.

Figure 1. (a) B-scan 2D reconstructed image of porcine small bowel tissue phantom scanned on its short axis at 48.07 MHz. (b) Histological correlation of 
scan image.

Conclusion

Phantom development has allowed qualitative investigation of μUS as a transmural imaging modality of the GI tract. Further investigation is needed with diseased tissue models to evaluate μUS detection of pathologies such as granulomas and lymphocyte aggregation. Repetition of μUS scans are needed for ensuring capabilities of μUS observed are both quantitatively investigated and statistically significant. μUS scanning has demonstrated immense potential to be integrated, in the future, with endoscopic ultrasound scanners to generate higher-resolution images of the GI tract for surveillance for new pathology and to provide a basis for diagnosis and earlier medical intervention.

References:

[1] Sankey EA, Dhillon AP, Anthony A, et al. Early mucosal changes in Crohn’s disease. Gut 1993;34(3):375–81.

[2] Ødegaard S, Nesje LB, Lærum OD, et al. High-frequency ultrasonographic imaging of the gastrointestinal wall. Expert Rev of Med Dev 2012;9(3):263–73.

[3] Nelson SA, Li Z, Newton IP, et al. Tumourigenic fragments of APC cause dominant defects in directional cell migration in multiple model systems. Dis Model Mech 2012;5(6):940–47.