For a long time, people have believed that gastroscopy and colonoscopy are the only methods for diagnosing gastrointestinal discomfort. However, these procedures are quite painful, and the need for general anesthesia for painless gastroscopy and colonoscopy can make people hesitate. So, are there any other non-invasive, painless, and radiation-free methods? Yes, there is: gastrointestinal ultrasound.
Currently, the effectiveness of gastrointestinal ultrasound (GIUS) has been recognized by the World Federation for Ultrasound in Medicine and Biology[1] and the European Federation of Societies for Ultrasound in Medicine and Biology[2]. This article uses benign gastric tumors and Crohn’s disease as examples to illustrate the specific scanning procedures and imaging characteristics of gastrointestinal ultrasound, helping clinicians master this efficient diagnostic tool.
What is Gastrointestinal Ultrasound?
Gastrointestinal color Doppler ultrasound is a non-invasive medical examination method. It provides doctors with clear, real-time images of the gastrointestinal tract, helping to determine the presence of inflammatory bowel disease, bowel obstruction, gastrointestinal neoplasms, and assess gastrointestinal function and blood flow.
Many gastrointestinal diseases (such as acute appendicitis or intussusception) often have a rapid onset, progress quickly, and are accompanied by severe pain. Handheld ultrasound allows for immediate bedside assessment. Therefore, gastrointestinal ultrasound is not only a safe and non-invasive examination method but also suitable as a “first line of defense” for initial screening.
Handheld Ultrasound Settings for GI Scanning
Probe Selection and Frequency
Convex probe: 3.5–6 MHz; linear probe: 7.5–12 MHz.
Use higher frequencies to improve resolution when the probe depth allows.
Depth
Since most of the intestine is located relatively shallowly, the imaging depth is usually set to ≤8 cm.
Gain, Dynamic Range, and Harmonics
Lower gain is beneficial for displaying the gastrointestinal wall containing gas.
A narrower dynamic range facilitates harmonic imaging, clearly revealing the layered structure of the gastrointestinal wall.
Patient Preparation
Fasting for at least 4 hours is recommended; fasting overnight for at least 8 hours is even better, if possible.
During the examination, the doctor may ask the patient to change position (such as lying on the left side, right side, or prone) or hold their breath to observe various parts more clearly.
Using Handheld Ultrasound Scan Benign Gastric Tumors
Benign gastric tumors are a type of disease characterized by abnormal growth in the stomach. Several factors, including a poor daily diet, excessive reliance on medication, and unhealthy lifestyle habits, can impact the digestive system. Real-time dynamic ultrasound images can provide information on the location, size, and shape of gastric tumors, as well as the presence of gastric ulcers and inflammation.
Gastric Ultrasound Scan Procedure
Step 1: Scanning the Cardia
- Patient position: Supine
- Place the probe just below the xiphoid process, slightly to the left of the costal margin, and scan the cardia area.
Step 2: Scanning the Fundus
- Patient position: Supine
- Place the probe obliquely in the left 9th-10th intercostal space and scan the fundus area.
Step 3: Scanning the Continuous Short Axis of the Stomach
- Patient position: Right lateral decubitus
- Place the probe under the left costal margin and move it downwards and to the right along the course of the stomach to continuously scan the short axes of the fundus, body, angle, and antrum.
Step 4: Scanning the Continuous Coronal Plane of the Stomach
- Patient position: Right lateral decubitus
- Place the probe under the left costal margin at approximately a 45-degree angle. Using the probe’s tail end as an axis, rotating counterclockwise allows for sequential scanning of continuous coronal sections of the gastric fundus, body, angle, and antrum.
Step 5: Scanning the pyloric region of the gastric antrum
- Patient position: Supine or right semi-recumbent position
- With the probe positioned below the right costal margin, the pylorus is adjacent to the gallbladder neck. The long axis of the gastric antrum resembles a swollen gallbladder. Using this standard section as a reference, laterally moving the probe allows for a relatively complete scan of the gastric antrum.
Benign Gastric Tumor Ultrasound Imaging
1. The lesion protrudes from the gastric mucosa into the lumen and varies in shape.
2. The tumor is mostly of heterogeneous intermediate echogenicity.
Using Handheld Ultrasound Scan Crohn's Disease
Crohn’s disease is a chronic inflammatory bowel disease of unknown cause that can affect the entire digestive tract from the mouth to the anus, but most commonly occurs in the terminal ileum, colon, and perianal area. Diarrhea, abdominal pain, and weight loss are common symptoms of CD.
Inflammatory bowel disease (IBD) has a long course and a high relapse rate; therefore, patients need frequent hospital visits for examination to improve prognosis and reduce complications. Intestinal ultrasound can show the location and extent of intestinal wall lesions, intestinal stenosis, intestinal fistulas, and abscesses. Ultrasound examination is convenient, non-invasive, and well-accepted by patients, and is important for initial screening of CD and follow-up of disease activity after treatment.
Intestinal Ultrasound Scan Procedure
1. First, scan the entire abdomen using a 3.5-5 MHz convex probe.
2. Then, carefully observe the intestinal wall using a 4-13 MHz high-frequency linear probe.
3. The probe is used to scan the abdomen sequentially along the ileocecal junction, ascending colon, transverse colon, descending colon, sigmoid colon, and each group of small intestine in longitudinal, transverse, and oblique multi-section views.
This allows observation of any intestinal lesions. If lesions are found, focus on observing the thickness, layers, and blood flow of the affected intestinal wall; the presence of fistulas and abscesses; narrowing and dilation of the intestinal lumen; abnormalities in the perianal omentum and adipose tissue; enlarged perianal lymph nodes; and the presence of ascites.
Crohn's Disease Ultrasound Imaging
1. Segmental thickening of the intestinal wall (colon wall thickness >4 mm, small intestine wall thickness >3 mm).
2. Increased blood flow signal in the intestinal wall compared to normal (Limberg classification).
3. Blurred or absent layering of the normal intestinal wall structure.
4. Increased echogenicity of the surrounding fat layer, also known as the “creeping fat sign,” can be seen in transmural inflammation.
5. Other complications such as intestinal stenosis, intestinal fistula, and abdominal abscess.
Medtribs Select
1. Composed of two probes: integrating a convex (with cardiac preset) and a linear probe. A single device can perform whole-body clinical scans, ranging from the deep abdomen and gastrointestinal tract to the superficial blood vessels.
2. Frequency: 3.2/5.0MHz, 7.5/10MHz, 2.5/5.0MHz. Doctors can flexibly switch frequencies according to the depth of anatomical structures to ensure clear images.
3. Weighing only 120 grams, it can be easily stored in a white coat pocket, effectively reducing the burden on doctors during frequent ward rounds and long-term operations.
4. Offers multiple imaging modes, including B, M, Color, PW, and PDI. Color Doppler can reveal irregular blood flow signals.
5.Supports WiFi and USB connectivity, allowing simultaneous charging and use, eliminating concerns about insufficient battery affecting scanning.
We highly recommend this multi-functional dual-probe ultrasound scanner. The MOQ is just 1 unit, and it comes with an 18-month warranty. Meanwhile, if you are still struggling to choose which ultrasound model to use, we are willing to provide you with a more detailed consultation. Contact us for more details.
Conclusion
With the widespread application of ultrasound in various clinical fields, doctors have gradually shifted from concerns about misdiagnosing or missing important lesions to recognizing that the rational use of gastrointestinal ultrasound can improve diagnostic accuracy, even surpassing simple clinical examinations. Therefore, systematically training gastroenterologists and residents in ultrasound skills and equipping clinics with appropriate gastrointestinal ultrasound equipment are crucial steps in improving the quality of diagnosis and treatment. Ready to introduce the right gastrointestinal ultrasound to your clinic? Visit Medtribs to compare products and learn about our key advantages.
References:
[1]Atkinson, N. S., Bryant, R. V., Dong, Y., Maaser, C., Kucharzik, T., Maconi, G., … & Dietrich, C. F. (2016). WFUMB position paper. Learning gastrointestinal ultrasound: theory and practice. Ultrasound in medicine & biology, 42(12), 2732-2742.
[2]Nylund, K., Maconi, G., Hollerweger, A., Ripolles, T., Pallotta, N., Higginson, A., … & Gilja, O. H. (2017). EFSUMB recommendations and guidelines for gastrointestinal ultrasound-part 1: examination techniques and normal findings (long version). Ultraschall in der Medizin-European Journal of Ultrasound, 38(03), e1-e15.
