The significance of fluoroscopy, usually combined thoracoabdominal fluoroscopy, is to understand whether the symptoms of acute abdomen are caused by a chest lesion. The diaphragm movement and the presence of free gas under the diaphragm due to organ perforation can be understood, and the presence of distended gastrointestinal cavity and the formation of abnormal fluid-gas planes can be roughly understood. However, fluoroscopy cannot reveal subtle lesions, and in some complex cases a combination of abdominal radiographs is required to make a correct diagnosis.
The significance of fluoroscopy, usually combined with thoracoabdominal fluoroscopy, is to understand whether the symptoms of acute abdomen are caused by a chest lesion. The diaphragm movement and the presence of free gas under the diaphragm due to organ perforation can be understood, and the presence of a distended gastrointestinal cavity and the formation of abnormal fluid-gas planes can be roughly understood. However, fluoroscopy cannot reveal subtle lesions, and in some complicated cases, a combination of abdominal radiographs is required to reach a correct diagnosis.
Abdominal plain film Barium meal of digestive tract Barium meal of digestive tract can observe the mucosa, contour, peristalsis, emptying and occupying lesions, ulcers, polyps, etc. In the diagnosis of digestive tract diseases, the relationship between barium examination and endoscopy and endoscopic ultrasonography techniques is that they complement and do not replace each other. In addition to indirectly understanding the origin of mucosal and submucosal lesions, barium contrast examination can also understand the structural morphological changes of organs, such as hernias, stenosis, torsion, diverticula, etc. To understand the functional changes of the organ, such as swallowing disorders, achalasia, reflux and reflux damage. To understand the effect of adjacent lesions on the GI tract, e.g., the effect of pancreatic head cancer on the duodenal circle. Especially for those who have undergone gastric surgery, barium examination has an irreplaceable role in understanding the anatomy and emptying of the organ. Therefore, in general, barium examination should be the examination method of choice for gastrointestinal diseases. Endoscopy and endoscopic ultrasonography can visualize gross pathological changes in the mucosa, and biopsies can be taken. In addition, endoscopic ultrasonography can detect lesions in the submucosal wall and peri-organic changes.
Imaging DSA, also known as digital subtraction angiography, is used to diagnose vascular lesions of the gastrointestinal tract, such as vascular embolism, aneurysms and arteriovenous vascular malformations, and to search for vascular-rich tumors in the small intestine, such as carcinoid tumors and ectopic pheochromocytomas. To understand the etiology and location of gastrointestinal bleeding. ERCP (endoscopic retrograde cholangiopancreatography) is mainly used to diagnose pancreatic diseases and determine the cause of biliary obstruction, and it can also be used to remove stones from the common bile duct and place stents in the common bile duct stenosis. PTC (percutaneous hepatic cholangiography) is used to identify the cause of obstructive jaundice and determine the site of obstruction, but now it is only used for patients whose diagnosis cannot be confirmed by CT, ultrasound or MRI, or for patients considering biliary drainage. PTC should be closely monitored for complications such as bleeding and bile leakage. Postoperative trans-T-tubular imaging is mainly used to understand the presence of residual stones in the bile duct, the patency of the bile duct and duodenum and the presence of postoperative complications, e.g., if residual stones are found, they can now be removed extracorporeally via the T-tube.
CT is the first choice for the examination of abdominal organs and retroperitoneal lesions. CT plays a leading role in the diagnosis and differential diagnosis of liver, biliary, pancreatic and spleen diseases, and in combination with ultrasound, CT can correctly diagnose most diseases. In the imaging diagnosis of gastrointestinal diseases, CT examination is mainly used for tumor diagnosis, but its purpose is not to detect tumors, but to understand the presence and extent of tumor invasion, the relationship with surrounding organs and tissues, and the presence of lymph node metastasis and distant organ metastasis. Thus, it can help to stage the tumor, provide a basis for formulating treatment plan and estimating prognosis, and help to follow up and observe after surgery, radiotherapy and drug treatment of malignant tumor. Therefore, CT examination should be performed as needed after lesions are detected by gastrointestinal imaging.
Magnetic resonance Magnetic resonance, in addition to providing excellent anatomical images, can also be used to analyze the nature of lesions based on signal characteristics for cases where differential diagnosis by ultrasound and CT is difficult. MRI is valuable for the examination and qualitative diagnosis of liver lesions, especially for the differential diagnosis of hepatocellular carcinoma and hepatic cavernous hemangioma. Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive test that uses water imaging technology to clearly show the whole picture of the pancreaticobiliary duct without contrast injection, which is valuable for the diagnosis of obstructive lesions of the pancreaticobiliary duct and can partially replace ERCP. Ultrasound Because of the popularity of ultrasound and ultrasound examination does not depend on liver and biliary function, it can be used for the diagnosis of obstructive lesions of the bile duct. Because of the popularity of ultrasound and ultrasound examination does not depend on liver and biliary function, and its sensitivity and specificity for the diagnosis of biliary diseases are higher than other methods, so X-ray plain film, oral or intravenous cholecyst and biliary imaging are rarely used in clinical practice. It is also because ultrasound is the most effective/cost effective in the diagnosis of biliary diseases and can also detect lesions of the liver, gallbladder, pancreas and spleen that it is often used as the preferred method of examination in clinical practice. It can be used for the diagnosis and intervention of focal and diffuse lesions of the liver. For the diagnosis of pancreatic cancer, CT is better than ultrasound in showing pancreatic cancer and its invasion of surrounding vessels and organs, but ultrasound is easier and more effective than CT in showing bile duct dilatation. Ultrasound examination of the spleen is simple and easy to perform, and it is more sensitive and accurate for solid and cystic occupying lesions of the spleen. It is also particularly suitable for screening, investigation and follow-up of disease. Usually, the patient should fast for more than 8 hours before the examination to reduce excessive gas caused by food in the stomach, which interferes with the ultrasound transmission.