gastric ultrasonography

The biggest advantage of gastric ultrasound is that the sound beam can penetrate the stomach wall, which can show the stomach wall hierarchy. As a non-invasive diagnostic method, it can provide clinical location, size and shape of gastric wall cancer, and sometimes it can estimate the extent of lesion invasion of the stomach wall. Early gastric cancer can also be found, especially to understand the metastasis of peri-stomach organs, to make up for the deficiency of gastroscopy and X-ray examination, and to provide a basis for clinical selection of treatment plans, which is unique to ultrasound for gastric cancer examination. At present, the detection rate of gastric cancer by transabdominal ultrasonography is low, and the sensitivity to early gastric cancer is only 15%, so it is not used as a screening method for gastric cancer. With the clinical application of endoscopic ultrasound, the clinical value of gastric ultrasound is further improved. Basic Information Specialist classification: Digestive examination classification: ultrasound Applicable gender: whether men and women apply fasting: fasting Tips: When using a gastric filling agent, generally drink 500-600ml, up to 1000ml. Normal value 1. Normal stomach sound image on fasting: The sonogram of the fasting stomach varies with the amount of retention fluid, contraction state and section, and can be expressed as "crescent shape", "saddle shape" and oval shape. The strong echo in the center is the mixed echo of the gas, mucus and contents in the cavity. If there is a lot of gas in the stomach, the sound is often accompanied by sound and shadow. The hypoechoic zone between the central strong echo and the surrounding strong echo is the normal stomach wall echo. 2, after drinking water, normal stomach sound image after drinking water, the gastric cavity is filled with no echo zone, there are scattered echoes formed by tiny bubbles and mucus, easy to float. The normal stomach wall structure can be displayed around the stomach cavity. The display of the normal stomach wall structure is affected by the vertical extent of the probe beam and the stomach wall, the degree of filling of the stomach cavity, and the degree of focus of the local sound beam. In contrast, the posterior wall of the gastric antrum is easy to display, while the bottom of the stomach and the anterior wall of the corpuscle show difficulty. 3. The normal gastric image after the echo-filling agent is used. When the stomach filling agent is used, the ultrasound image clearly shows the passage and retention of the filling agent in the lower esophagus and the cardia. The fundus, corpus callosum, and antrum of the stomach are clearly displayed, and the stomach wall can be clearly displayed. Under the high-resolution probe, the five strong and weak five-layer structure echoes are displayed, starting from the endometrium, the first strong echo and the second. The weak echo line represents the echogenic range from the mucosal surface interface to the mucosal muscle layer and submucosal interface. The third strong echo line indicates the submucosal to superficial muscle layer, the fourth weak echo line represents most of the gastric muscularis, and the fifth strong echo line indicates the subserosal, serosal layer and its surrounding interface echo. The distance between the two strong echo lines inside and outside the stomach wall represents the thickness of the stomach wall. The thickness of the stomach wall of normal people ranges from 2 to 5 mm (the average is mostly between 4.0 and 5.0 mm), and the wall thickness of the gastric pylorus muscle does not exceed 6.0 mm. 4. About 1-3 peristaltic waves can be seen on the sonogram of a normal person with gastric wall peristaltic wave. The waveform has rhythm, symmetry and no sudden interruption. Clinical significance First, peptic ulcer Peptic ulcers include gastric ulcers, gastroduodenal ulcers, and duodenal ulcers. The most common site of the disease is the small sacral side of the stomach and the duodenal bulb. The basic pathology of ulcer disease is a localized depression of the mucosa, which is deeper than the mucosal muscle layer; the mucosa surrounding the ulcer is often accompanied by inflammatory changes such as edema, congestion or hyperplasia. 1, fasting ultrasound examination can be found in the ulcer site has a limited degree of thick wall thickening, showing a low echo. In the case of acute larger ulcers, localized mucosal defects of the gastric wall occur. 2. Under the condition of gastric filling, the localized gastric ulcer has localized thickening of the mucosa and submucosa, and there is a relatively smooth ulceration in the center, showing a small "crater"-like sign. 3, small and shallow ulcers are only the only manifestation of limited thickening. 4, pyloric tube ulcer with edema and congestion of the local thickening as the main feature, often accompanied by delayed gastric emptying; acute phase, often pyloric spasm and gastric retention, pyloric stenosis, liquid difficult to pass. 5. Ultrasound manifestations of duodenal bulb ulcers are localized thickening of the wall, deformation of the bulb, rapid passage of fluid through the bulb (irritation); most duodenal ulcers are relatively small, ultrasound is not It's too easy to find. 6. The display of the three-dimensional ultrasound on the ulcer surface approximates the image of the gastric endoscope. Gastric smooth muscle tumors are mesenchymal tumors originating from the gastric muscle layer and are classified into benign gastric leiomyoma and malignant leiomyosarcoma. Sonogram of gastric smooth tumor: 1, sonographic features 1 Localized mass in the stomach wall, mostly spherical, can also be dumbbell-shaped or irregular. 2 tumors occur in the upper part of the stomach, more common in single hair, the size is usually within 5.0cm, but also up to 9.0cm. 3 The mass of the tumor is hypoechoic, the boundary is clear, and the internal echo is uniform or even. The mucosal surface of the 4 lesions was accompanied by ulceration depression. 2, sonogram classification The intraluminal mass is located under the mucosa and grows into the cavity. The mucosal layer is lifted up, and the local gastric cavity is narrowed in the cross section. 2 The intermuscular muscle layer has a mass at the same time and grows to the inside and outside of the cavity, so that the mucosa in the cavity is bulged, and the serosal layer outside the cavity protrudes. 3 Dirty external masses mainly grow outside the cavity, the serosal surface bulges obviously, and the mucosal surface does not bulge significantly. Sonogram of gastric leiomyosarcoma: 1. The tumor originates from the muscular layer of the stomach wall, the shape is irregular, and the peripheral echo is slightly rough. The internal echo is not homogeneous. 2, the enlargement of the mass can be seen in the formation of liquefied areas, and some are accompanied by a small amount of irregular enhanced echo. The mucosal surface often has deep and large ulcers, and the shape of the ulcer depression is irregular, and can penetrate with the liquefaction zone, so that a pseudocavity is formed inside the tumor. 3. Metastatic lesions may appear in the liver or surrounding lymph nodes. Second, stomach cancer Gastric cancer is a common malignant tumor, which occurs in the antrum of the stomach, especially in the small antrum of the stomach. The pathological type is more common with adenocarcinoma. Gastric staging has early gastric cancer and advanced gastric cancer. Early gastric cancer refers to lesions only invading the mucosa and submucosa. Ultrasound examination through the abdomen shows difficulty, and endoscopic ultrasonography is of great value. In the advanced gastric cancer of advanced gastric cancer, the depth of invasion of the cancerous lesion has exceeded the submucosal layer, reaching the deeper muscular layer, usually divided into three types: 1 lumps type; 2 ulcer type; 3 diffuse type. The basic sonogram changes to abnormal thickening and swelling of the stomach wall, usually with heterogeneous hypoechoic, irregular shape, and structural damage to the stomach wall. 1. Mass type: The localized bulge of the stomach wall protrudes to the stomach cavity, and the surface may not form a cauliflower-like hypoechoic or disordered echo mass, and the surrounding stomach wall may also have varying degrees of thickening. Sometimes it can be seen that the cancer destroys the serosa to grow out of the stomach, forms an exogenous mass, and has signs of adhesion to the surrounding organs or direct metastasis. 2. The surface of the stomach wall of the ulcer-type bulge forms irregular depressions. The bottom of the concave surface is not smooth, and small nodular echoes are visible. The circumference of the depression is irregular, the thickness is not uniform, and the depression is stiff. The surrounding stomach wall can also be irregularly thickened and bulged. 3. Most of the diffuse stomach wall is diffusely thickened and bulged, and its thickness is greater than 15mm. When the mucosal surface is irregularly ruptured or eroded, the local part is strongly echoed, and the severe long-axis section of the stomach is “linear” gastric cavity. The short-axis section of the fasting is a "false kidney sign", and the thickened stomach wall is clearer after drinking water. Ultrasound examination of residual gastric cancer Ultrasound examination of gastric cancer is focused on the discovery of metastatic lesions in target organs including liver, retroperitoneum, and pelvis. Due to the deep location of the residual stomach, there are many factors involved in the interference. Ultrasound examination can not easily negate the diagnosis of clinical residual gastric cancer, and should be combined with other examinations. Gastric polyps are divided into two types: false and true. Pseudopolyps are formed by mucosal inflammatory hyperplasia; true polyps, also known as polypoid adenomas, are more common and are composed of hyperplastic mucosal glandular epithelium, mostly single. The surface is nodular, mostly pedicled, and the size is generally less than 2cm. Polypoid adenomas are precancerous lesions. The sonogram shows that the gastric mucosa protrudes into the gastric cavity, which is a low echo or medium echo mass, about 1-2 cm in size, and the base is narrow and pedicled. Mostly single. Changing the position cannot be separated from the stomach wall. The layers of the stomach wall are continuously normal. The diagnosis of gastric polyps should be differentiated from polypoid gastric cancer and gastric giant wrinkles. Polypoid type gastric cancer grows fast, more than 2cm, the base is wide, and it is infiltrated into the stomach wall, and the mucosa is interrupted at the attachment. The sonogram of the giant wrinkle of the stomach is characterized by a large echo of the mucosal wrinkles, which is "keyed". Third, gastrointestinal perforation 1. Gas echo in the peritoneal cavity When the patient is in the supine position, a strong gas echo can be seen in the anterior hepatic space between the leading edge of the liver and the abdominal wall, followed by multiple reflexes. A seat examination allows the liver to display a gas echo between the top of the diaphragm and the liver. 2, peritoneal effusion The gastric acid and bile after perforation often accumulate in the right hepatic space. As the amount of exudation increases, the exudate can flow to the hepatic-kidney space and descend to the cecum and pelvic cavity through the right colon. Abnormal liquid echoes can be displayed at these locations. Due to the presence of gastric contents or the formation of abscesses in the liquid, typical anechoic areas are sometimes not displayed. 3, often intestinal peristalsis weakened or disappeared, intestinal gas accumulation and other changes. 4, perforation limitation, can form a disordered echo mass with abscess or blurred edges and uneven echo. B-ultrasound has its unique advantages in the diagnosis of gastrointestinal perforation. Ultrasound examination can achieve the same effect as X-ray fluoroscopy in the diagnosis of free gas in peritoneal cavity. Sometimes it is possible to display a gas that is confined to the anterior interhepatic space that cannot be found by X-ray examination. The detection of intra-abdominal fluid is much more accurate than X-ray examination. Especially in the identification of other acute abdomen such as biliary tract, pancreas, obstetrics and gynecology, rupture of parenchymal organs, ultrasound can be the first choice. High results may be diseases: gastric teratoma, gastric reactive lymphatic hyperplasia, gastric septum precautions Contraindications before examination: Foods that are gastrointestinally irritated are forbidden before examination. Requirements for inspection: 1, when using the stomach filling agent, generally drink 500-600ml, up to 1000ml. In order to avoid excessive filling, affect the observation of the thickness and level of the stomach wall. 2. For the purpose of observing the structure of the stomach wall, after drinking the filling agent, it should be kept for 3-5 minutes to eliminate the bubbles of the filling agent. In order to slow down the gastric emptying rate, atropine 0.5mg or 654-210mg can be injected in the first half hour of the examination. If it is necessary to observe the gastric motility function, the drug affecting the gastric contraction function should be avoided. 3. Disable stomach filling for patients with suspected gastric perforation. 4, no echo and echo filling agent have their own characteristics: An echo-free filling agent (such as a gastric rapid developer, etc.) can visualize a mucosal layer that exhibits a moderate or strong echo, which is mainly manifested in the observation of the posterior wall of the stomach. However, due to the reverberation interference of the high acoustic impedance interface, the layers of the front wall of the stomach are often organized into a fuzzy strong echo zone. In addition, such contrast agents need to be used in combination with general drinking water, and the development effect is affected by drinking water. The echo filling agent can match the sound resistance difference of the stomach wall tissue, eliminating the reverberation interference and facilitating the discovery of small lesions on the stomach wall. And does not produce a posterior echo enhancement effect, which is conducive to the display of adjacent organs and lesions of the stomach. 5, due to X-ray and endoscopy, it is easy to miss the small curvature of the stomach and the lesions of the fundus. Therefore, during ultrasound examination, special attention should be paid to the gastric fundus and high stomach scan to avoid missed diagnosis. Inspection process An empty stomach check should be classified as a routine for the purpose of: 1 Understand the sonogram of the stomach when it is fasting, in order to compare with the sonogram after filling and expanding the stomach cavity. 2 Observe the presence or absence of retention fluid in the stomach during fasting and estimate the amount. This is valuable for evaluating pyloric function. 3 Observe the presence or absence of metastatic lesions in other organs of the abdomen and pelvis, and whether there are ascites and peritoneal implants. Not suitable for the crowd Inappropriate people: Generally there are no people who are not suitable. Adverse reactions and risks Gastric filling is contraindicated in patients with suspected gastric perforation.