Quantification of bowel ischaemia using real-time multispectral Single Snapshot Imaging of Optical Properties (SSOP)

Abstract

Background Single snapshot imaging of optical properties (SSOP) is a relatively new non-invasive, real-time, contrast-free optical imaging technology, which allows for the real-time quantitative assessment of physiological properties, including tissue oxygenation (StO2). This study evaluates the accuracy of multispectral SSOP in quantifying bowel ischaemia in a preclinical experimental model. Methods In six pigs, an ischaemic bowel segment was created by dividing the arcade branches. Five regions of interest (ROIs) were identified on the bowel loop, as follows: ROI 1: central ischaemic; ROI 2: left marginal; ROI 3: left vascularised; ROI 4: right marginal; and ROI 5: right vascularised. The Trident imaging system, specifically developed for real-time tissue oxygenation imaging using SSOP, was used to image before (T0) and after ischaemia induction. Capillary and systemic lactates were measured at each time point (T0, T15, T30, T45, T60), as well as StO2 values acquired by means of SSOP (SSOP-StO2). Results The mean value of SSOP-StO2 in ROI 1 was 30.08 ± 6.963 and was significantly lower when compared to marginal ROIs (ROI 2 + ROI 4: 45.67 ± 10.02 p = < 0.0001), and to vascularised ROIs (ROI 3 + ROI 5: 48.08 ± 7.083 p = < 0.0001). SSOP-StO2 was significantly correlated with normalised lactates r = − 0.5892 p < 0.0001 and with histology r =− 0.6251 p = 0.0002. Conclusion Multispectral SSOP allows for a contrast-free accurate assessment of small bowel perfusion identifying physiological tissue oxygenation as confirmed with perfusion biomarkers.

Ultra-miniature dual-wavelength spatial frequency domain imaging for micro-endoscopy

“…14,15 SSOP has been shown to successfully quantify bowel ischaemia. 16 SFDI has shown to return successful contrast between healthy and malignant resected esophageal and colon tissue. 17,18 Sweer et al imaged resected esophageal tissue from eight patients undergoing esophagectomy.…”

“…SSOP uses a Fourier demodulation method to perform spatial frequency demodulation, which typically results in poorer image quality, although a method to retain more spatial resolution has been proposed using a Hilbert transform instead, 13 and emerging convolutional neural network techniques can improve the resolution 14 , 15 . SSOP has been shown to successfully quantify bowel ischaemia 16 …”

Designing and simulating realistic spatial frequency domain imaging systems using open-source 3D rendering software

“…Conventional white light endoscopes and capsule endoscopes are the standard method of imaging the GI tract but provide limited information about tissue properties that are hallmarks of a range of potential tumours [ 3 ], leading to low five-year survival rates of oesophageal cancer (15% [ 4 ]) and colon cancer (63% [ 5 ]). SFDI is a well-studied, low-cost imaging technique [ 6 , 7 ], with applications for imaging blood oxygenation [ 8 ], burn depth [ 9 ], dental caries [ 10 ], bowel ischaemia [ 11 ], and indicators of cancer [ 12 ]. A range of commercial [ 13 ] and research [ 14 – 16 ] SFDI systems are now available.…”

In Vitro Antibody Quantification with Hyperspectral Imaging in a Large Field of View for Clinical Applications

“…HSI is a non-invasive, contrast-free tool recently applied in several medical and basic research fields [ 5 , 6 ], like other new emerging technologies [ 7 , 8 ]. Several innovative approaches are under investigation that exploit the capability of HSI to “see beyond” the visible range, such as intraoperative tissue recognition [ 9 ], therapy guidance, and monitoring [ 10 , 11 , 12 , 13 , 14 ].…”