The gastrointestinal tract has been one of the most difficult areas to evaluate with available imaging standards. Since the introduction of endoscope in 1960s, there have been continuous advances in endoscopy by replacing fiberoptics with CCD (Charge-coupled device) detectors. The Japanese method of staining mucosa with dye-spray called “chromoendoscopy” assisted diagnosis, however, did not get momentum in western world due to time-intensive and learning curves associated with it. Previous GIT studies lacked sensitivity and specificity, and recent developments have transformed the field of GIT imaging.
White light endoscopy was the bench mark for detection of GIT disorders; however, there was still a high rate of misdiagnosis. High definition (HD) endoscopy has improved the detection of GIT abnormalities like neoplastic, pre-neoplastic or inflammatory conditions. Further developments in imaging such as image-enhanced endoscopy, magnification, endo-microscopy, or virtual intelligence have enhanced histological predictions.
Video capsule endoscopy (VCE) is extremely useful in for diagnosis and management of GIT disorders due to non-invasive ability throughout image capturing and ability to cover entire GI tract. VCE is particularly helpful for small bowel imaging, however, it comes with its own limitations.
Ultrasound being ionizing radiation-free and provides real-time results, particularly useful in pediatric applications. Contrast enhanced ultrasound and hydro sonography are the latest developments. Cross-sectional imaging techniques such as CT, MRI, and PET are being used to support evaluation further.
Colonoscopy helps reduce the mortality associated with colorectal cancer (CRC) through detection and resection of neoplastic polyps; however, polyps detection can go un-noticed even by experienced and trained physicians with accuracy rate of around 80%*. To address this challenge computer-aided diagnosis (CAD) is attracting attention to help endoscopists avoid missing polyps.
Molecular probes and antibodies have enabled a combination approach by integrating fundamental research and clinical endoscopy. During molecular imaging, cellular structures are labelled with molecular probes or antibodies and visualized through endoscopy, enabling characterization of molecular profile of tissues.
Imaging tests performed can suggest the presence of cancer while biopsy or genomic can make a definite diagnosis.