Abdominal Imaging and Endoscopy

Endoscopy was traditionally used to observe only digestive tract and diagnose associated diseases. Endoscopes to investigate digestive diseases are passed through the mouth, or an incision, or through the rectum.  In an upper endoscopy, the endoscope is passed through the mouth into esophagus and stomach and upper part of small intestine. But for the endoscope to be passed to the large intestine, they need to be passed through the rectum, called colonoscopy or sigmoidoscopy. Endoscopic Ultrasound is another crucial imaging technique that combines both, endoscopy and ultrasound to obtain images for further investigation of complicated diseases. Endoscopy is prescribed to evaluate unexplained stomach pains, Ulcers, gastritis, ulcerative colitis, bleeding, polyps, and gallstones, among other oesophageal, gastric, hepatobiliary, hepatopancreatic, and intestinal diseases.

To detect pancreatic cancer, various imaging tests can be used, depending on the factors, to investigate the extent of spread of cancer, or recurrence of cancer or while treating the patient to observe the prognosis. Imaging tests include CT, MRI, Ultrasound and endoscopy, Cholangiopancreatography- including ERCP, MRCP, and PTC, apart from PET scans and angiography. Endoscopic scans investigations reveal swelling, infection, bleeding, obstructions and inflammation of the pancreas. Endoscopic ultrasound (EUS), is one of the most promising modalities in the screening of pancreatic cancer, has a transducer which creates sound waves which help in creating images of the pancreas and surrounding organs to help identify small tumors and localized spread of cancer. Tissue sampling, if needed is done during the same process. In ERCP, endoscope guides a catheter into the bile duct to insert minute amount of dye. The resulting X-ray images then show blockages and tumors or other obstructions caused. ERCP can also be used to place a stent into the duct. 

Endoscopy, although traditionally a diagnostic tool has now become a therapeutic sub-specialty, is considered a very safe procedure; there are possibilities of rare complications like bleeding, infection, tearing of the gastrointestinal tract, colonoscopic perforations, abdominal pains, chest pains, fever, Cardiopulmonary, and in very rare cases, myocardial infarctions. 

During an endoscopic procedure, the surgeon uses a long flexible tubed instrument with a rotating camera attached to view and operate on the gastrointestinal and other associated internal organs with absolute no large incisions. A surgeon inserts the endoscope through a small incision, mouth, nostrils, or anus to observe the diseased part of the tract, and if needed, they use forceps and scissors on the endoscope as well to operate or sample the tissue for biopsy. Joints, lungs, colon, bladder, small intestine, uterus, pelvis, larynx, mediastinum, esophagus, ureter can be examined using different types of endoscopy. Another name for Endoscopic surgery is Minimally Invasive Surgery (MIS). 

Imaging has now become crucial in all clinical specialties especially gastroenterology. With new futuristic technologies and applications in the imaging procedures, the investigation and diagnosis of complicated diseases and hidden cancers can be detected and diagnosed in the early stages. Although the most common imaging techniques such as ultrasound, Angiograms, CT and MRI scans have been extensively used, endoscopy is emerging as the preferred imaging type in most of the gastrointestinal diseases. Liver diseases that involve imaging are Polycystic liver diseases, fatty and non-fatty liver diseases, hepatocarcinoma, diffuse liver disease, liver fibrosis, liver cirrhosis, and other chronic liver diseases, Barrett's Esophagus, Crohn’s disease, Gastritis, GERD, severe haemorrhoids, hernia, irritable bowel syndrome, and ulcerative colitis are common digestive disorders that require imaging. ERCP, Cholecystography, upper endoscopy/EGD, HIDA Scan, laparoscopy, MRI, MRCP, ultrasound and PET scans are commonly used to diagnose liver and gastrointestinal diseases.

Endoscopy is soon growing as the preferred method for diagnosis and treatment of various diseases and disorders. A long flexible tube with attached camera is used to insert through a small incision or natural openings of the body to investigate the diseased part. With numerous advances in the field of technology and life sciences, endoscopy, which earlier was purely a diagnostic tool, is now also used in surgeries and treatment, and also in diagnosing other parts of the body other than the GI tract. 

Endoscopic treatment includes treatment of the obstructions at the same time while performing endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS). ERCP combines X-rays with a dye injected into the duct to view liver and pancreas. Removal of gallstones, tissue sampling for biopsy, stent insertion, treatment of pancreatitis, diagnosis of tumors, blockages, cysts, duct leaks, or obstructions is done with the help of ERCP. While, EUS helps in sampling, ablating cysts, draining fluid retentions, injecting cancer drugs, celiac nerve block, alleviating obstructions among other functions. Advanced therapeutic endoscopy helps in treating sphincter of Oddi Dysfunction, and specialized stent placements like Transesophageal fistula, Perforated esophagus and Gastric outlet obstruction. Therapeutic endoscopy is of 9 types, endoscopic hemostasis, injection sclerotherapy, argon plasma coagulation, dilatation, polypectomy, variceal banding, stenting, percutaneous endoscopic gastrostomy, and foreign body removal.

Group of cancers of the gastrointestinal tract and associated organs refers to gastrointestinal cancer, and the study is referred to GI oncology. Cancers of the esophagus, bile duct, liver, stomach, gallbladder, pancreas, large and small intestines, anus, colon, rectum and retroperitoneum, and neoplasms, constitute under GI cancers. The cancers of liver, pancreas, and gall bladder are the major cancers that affect the majority of the population and are even lethal. Liver cancer/ hepatocellular carcinoma is caused by prolonged hepatitis infection or cirrhosis constitutes one of the second most common cancers with gastric cancer being the 4th most common and pancreatic cancer being 5th most common cancers. Treatment includes surgery, chemotherapy and immunotherapy and radiations. 

A field of diagnostic radiology, that aids in the diagnostic imaging of obstructions and diseases in the abdominal and pelvic disorders. Abdominal radiology includes imaging of the gastrointestinal and genitourinary systems using X-Rays, Ultrasound, MRI, CT, MRI, Nuclear Medicine Techniques, and Fluoroscopy to evaluate solid organ transplant evaluation, malignancies of the abdomen and pelvis, inflammatory bowel disease, and fertility imaging. Traditionally X-rays and CT were commonly used in imaging, but due to recent advances in radiology, MRI and Nuclear Imaging are being preferred over X-Rays and CTs. Imaging uses radiation that is not visible to the eye, but when directed towards the part to be pictured, the radiation produces an image which is similar to the organ on which radiation was directed. 

Abdominal and pelvic ultrasounds are most commonly used imaging tests to investigate problems in the abdominal and pelvic areas. Ultrasound is one of the safest imaging tests as it uses no known radiation; rather it employs sound waves to create images of organs that appear on a screen. Abdominal ultrasound is used to investigate unexplained pain and can help perceive complications in the upper abdominal organs viz., inflammatory diseases, appendicitis, kidney stones, gallstones, and liver diseases. While pelvic ultrasounds help diagnose pain or other symptoms in the pelvis or lower abdomen. Obstetrical ultrasound is used in pregnant women to evaluate the health of the baby and mother. Color Doppler is another type of imaging analysis to measure arterial and venous blood flow of the internal organs. 

Transplantation can be associated with various complications ranging from vascular to immunologic. Traditionally, the complications were checked using biopsies, but with the advances, the complications are now investigated using non-invasive imaging techniques like Color Doppler Ultrasound, CT and MRI angiography, and nuclear imaging. But, ultrasound is the ideal initial imaging modality followed by color Doppler ultrasound, as they are readily available, and provide an almost complete diagnosis in the first imaging modality in both renal and pancreatic transplants. Accurate imaging is crucial in the precise description of abnormalities, fluid collections, and the localization of leaks. An ultrasound followed by CT or MRI and angiography are the prescribed imaging modalities after a transplant. 

Technological advancements in imaging have led to various non-invasive and safe imaging modalities to visualize the organs of the abdomen and pelvis, without the need for the “explorative surgical techniques” that cause more harm than good. CT, MRI, and ultrasonography have improved the ability of the surgeons to visualize, investigate and diagnose abdominopelvic complications and monitor treatment efficacy. Although X-rays are still fundamental and are often used as the first line of imaging modality, they are now being succeeded by cross-sectional imaging. Endoscopic ultrasound and positron emission tomography (PET) are also being preferred over CT and MRI with whole new methods which are considered safer and easier and cost-effective. 

A group of inflammatory diseases of colon, small and large intestine, collectively are referred to as Inflammatory bowel diseases (IBD). Crohn’s disease and ulcerative colitis are prime examples of IBD, wherein they affect small and large intestine, esophagus, mouth, rectum, anus, and stomach as well. IBD, in most cases, are treated as a case of autoimmune disease, while in few cases they are either caused by microbial infection, Behçet's disease and sometimes are indeterminate. They are treated either through surgeries, or drug therapies, nutritional or diet controls or through microbiome transplants, especially fecal microbiota transplant. Although, most of the times, patients prefer traditional or alternative medicines to the regular medicines. Stem cell therapy is also increasingly used in treating IBD. 

Imaging is a crucial approach for the treatment of cancer- right from the initial stages of detection to stages classification and response assessment and follow-up. Approaches to image a tumor of the gastrointestinal tract are generally multimodality imaging where gastroesophageal, pancreatic, hepatocellular, abdominal lymphomas, stromal cancers, renal, and cervical cancers are screened and investigated. Various stages of oncologic imaging include screening for early cancer, diagnosing and staging cancer, treatment, monitoring the response of the treatment, and monitoring the recurrence of cancer. Interventional oncology is a minimally invasive image-guided technique is gradually assuming a larger role in treating cancer. 

The advances and innovations in technology have brought a revolution in the field of endoscopy and abdominal imaging and they have improved beyond the expectations of traditional imaging techniques and explorative surgeries. These advanced imaging modalities improve visualization of the vascular and tissue characterization aiding in precise diagnosis. The advances include chromoendoscopy, narrow band imaging and autofluorescence endoscopy, endo-cystoscopy and confocal endomicroscopy. These novel imaging technologies help in visualizing the internal organs and complications, which could earlier be seen only through biopsy and histological studies. Chromoendoscopy, Digital chromoendoscopy, Narrow band imaging, I scan or Fuji Intelligent Chromo Endoscopy, Autofluorescence endoscopy, Trimodal imaging, Optical biopsy, Endocytoscopy, Confocal laser endomicroscopy, Optical coherence tomography and 360-degree view Fuse endoscopes are few examples of these advances and are a product of better and improved technology.