Ultrasound Capsule Endoscopy With a Mechanically Scanning Micro-ultrasound: A Porcine Study.

Area of Science:

• Gastroenterology
• Biomedical Engineering
• Medical Imaging

Background:

• Wireless capsule endoscopy (WCE) primarily uses optical imaging for gastrointestinal (GI) tract examination.
• Current WCE limitations include inability to detect subsurface GI wall pathology.
• Micro-ultrasound (μUS) offers cross-sectional imaging with high resolution for subsurface visualization.

Purpose of the Study:

• To develop and evaluate a novel ultrasound capsule endoscopy (USCE) device.
• To assess the capability of USCE for imaging GI wall layers.
• To demonstrate USCE as a complementary tool to optical capsule endoscopy.

Main Methods:

• Development of a USCE device with a ~30 MHz ultrasonic transducer for 360° imaging.
• Performance evaluation using a wire phantom to determine axial and lateral resolution.
• In vivo imaging in anesthetized pigs (esophagus and small intestine) to assess layer differentiation.

Main Results:

• The developed USCE device achieved axial resolution of 69.0 μm and lateral resolution of 262.5 μm in phantom tests.
• In vivo porcine imaging demonstrated clear differentiation of GI lumen wall layers.
• Measured tissue thicknesses in B-scan images showed good agreement with literature data.

Conclusions:

• The high-resolution USCE device successfully visualized subsurface GI wall layers in a porcine model.
• This technology offers a complementary sensing modality to optical capsule endoscopy.
• The results represent a promising step towards clinical translation of advanced capsule endoscopy.