Proceedings Article | 9 March 2017
Ronen Lifshitz, Yoav Kimchy, Nir Gelbard, Avi Leibushor, Oleg Golan, Avner Elgali, Salah Hassoon, Max Kaplan, Michael Smirnov, Boaz Shpigelman, Omer Bar-Ilan, Daniel Rubin, Alex Ovadia
KEYWORDS: Colonoscopy, Virtual colonoscopy, Imaging systems, Photons, Iodine, Compton scattering, Image segmentation, Colon, Colorectal cancer, Sensors, Single photon, Photon counting, Structural imaging, Medical imaging, X-ray technology, X-rays, Endoscopy
An ingestible capsule for colorectal cancer screening, based on ionizing-radiation imaging, has been developed and is in advanced stages of system stabilization and clinical evaluation. The imaging principle allows future patients using this technology to avoid bowel cleansing, and to continue the normal life routine during procedure. The Check-Cap capsule, or C-Scan ® Cap, imaging principle is essentially based on reconstructing scattered radiation, while both radiation source and radiation detectors reside within the capsule. The radiation source is a custom-made radioisotope encased in a small canister, collimated into rotating beams. While traveling along the human colon, irradiation occurs from within the capsule towards the colon wall. Scattering of radiation occurs both inside and outside the colon segment; some of this radiation is scattered back and detected by sensors onboard the capsule. During procedure, the patient receives small amounts of contrast agent as an addition to his/her normal diet. The presence of contrast agent inside the colon dictates the dominant physical processes to become Compton Scattering and X-Ray Fluorescence (XRF), which differ mainly by the energy of scattered photons. The detector readout electronics incorporates low-noise Single Photon Counting channels, allowing separation between the products of these different physical processes. Separating between radiation energies essentially allows estimation of the distance from the capsule to the colon wall, hence structural imaging of the intraluminal surface. This allows imaging of structural protrusions into the colon volume, especially focusing on adenomas that may develop into colorectal cancer.
