Enhanced endoscopic ultrasound imaging for pancreatic lesions: The road to artificial intelligence

Figure 1 Endoscopic ultrasound-elastography. A and B: Endoscopic ultrasound-elastography (EUS-E) use in demonstrating stiffness of pancreatic ductal adenocarcinoma tissue (encircled A) against normal pancreatic parenchyma (encircled B); C: EUS-E use in demonstrating stiffness of metastatic lymph nodes in patient from B. The nodes in B-mode when seen with elastography are blue, indicating that it’s hard and potentially malignant.

Figure 2 The clinical application of endoscopic ultrasound-elastography (with contrast-enhanced endoscopic ultrasound) to target fine needle biopsy sampling in a patient with a degenerated intraductal papillary mucinous neoplasm under our surveillance. A: Case demonstration of a degenerated intraductal papillary mucinous neoplasm and combination use of endoscopic ultrasound-elastography (EUS-E) to direct fine needle biopsy (FNB) sampling. Pre-EUS-E, the area of concern was iso-echoic, resembling normal parenchyma; however, under EUS-E, the area is stiff (blue); B: Contrast use post-FNB showing hypo-enhancement of the area of concern, confirming the area previously highlighted by EUS-E; C: Post-EUS-E and contrast-enhanced EUS guided FNB sampling in the same patient, allowing targeted sampling of the hard area.

Figure 3 Three-dimensional surface fractal dimension estimate. A and B: Endoscopic ultrasound-elastography images (A) are used to highlight representative parenchymal regions (B) of solid pancreatic lesions; C: A computer-aided image analysis system generates an irregularly-shaped three-dimensional surface as a “shape matrix” of points with the column and row numbers proportional to the x and y coordinates and with the depth information z (x, y) stored as a matrix element. The three-dimensional fractal dimension, which is an index of the “surface roughness”, is automatically determined using the box-counting algorithm. The fractal dimension of a surface is expressed by a real number greater than 2 (the Euclidean dimension of a two-dimensional surface) and less than 3 (the Euclidean dimension of a solid). A surface with a higher surface fractal dimension is wrinkled than one with a lower dimension.

Figure 4 Use of contrast-enhanced endoscopic ultrasound to study the evolution of a degenerated intraductal papillary mucinous neoplasm and the vegetations within, allowing differentiate between mucus and vegetations as only tumor vegetations will show inhomogeneous enhancement.

Figure 5 Graphical representation of existing diagnostic applications to endoscopic ultrasound imaging in the form of a fractal tree, fractal analysis with artificial intelligence being the possible future of enhanced endoscopic ultrasound imaging. AI: Artificial intelligence; CH-EUS: Contrast-enhanced harmonic endoscopic ultrasound; FNB: Fine needle biopsy.