Ultrasound image of acute appendicitis

The article is professionally consulted by MSc, BS. Dang Manh Cuong - Doctor of Radiology - Department of Diagnostic Imaging - Vinmec Central Park International General Hospital. The doctor has over 18 years of experience in the field of ultrasound - diagnostic imaging.

Acute appendicitis is a surgical emergency with a very high incidence: 4-5 cases per 1000 population and approximately 6% of the general population will develop appendicitis in their lifetime. The ultrasound image of appendicitis plays an important role in the diagnosis and giving appropriate treatment.

1.1. What is appendicitis? In the lower right abdomen, there is a small, narrow pouch-shaped bowel, several centimeters in length, attached to the cecum called the appendix.
According to normal physiology, this segment of intestine is true to its name, they will not participate in bodily functions but are easily damaged, causing acute appendicitis and dangerous to humans. disease if not treated promptly.
Acute appendicitis is a surgical emergency with the highest incidence, most commonly seen in the 20–30s age group. Of these, only about 70% of patients have typical symptoms. The remaining atypical portion will depend heavily on imaging studies, especially ultrasound of appendicitis.
1.2. Ultrasound of appendicitis

Ultrasound technique for appendicitis appeared since 1986 and is increasingly developed, playing an important role in early diagnosis and emergency treatment of acute appendicitis.
Similar to ultrasound of other sites in the body, ultrasound of appendicitis also uses high-frequency sound waves emitted from the transducer and receives feedback waves to help survey and evaluate the condition of the inflamed appendix. The combination of clinical examination and ultrasound image of appendicitis makes the diagnosis very high, up to 98%.
However, there are still atypical cases, when ultrasound is difficult to accurately record the condition of the appendix, then the patient needs to be computed tomography of the abdomen for a clearer diagnosis.
Advantages of appendicitis ultrasound are non-invasive, low cost, fast results and can be performed in most medical facilities today.
However, ultrasound still has inadequacies such as depending heavily on the expertise of the reader of the results and limited diagnostic ability in difficult cases such as obese people, distended abdomen or pregnant...

Ultrasonography of appendicitis is an easy-to-implement imaging test, helping to quickly diagnose right iliac fossa abdominal pain. The common images of appendicitis on ultrasound are: increased bowel diameter, non-collapsed pressure, edematous intestinal wall, fatty infiltration and surrounding fluid.
Of these, fat infiltration is the most important because it suggests inflammation. However, depending on the clinical situation, there will be different signs.
2.1. Simple acute appendicitis Appendicitis on ultrasound alone can record the following signs:
The axial view shows a tubular appendix shape, one end is closed, also known as the “mark” finger signal”; Axial cross-section of the appendix nodule is bullet-shaped and has concentric rings; The diameter of the inflamed appendix is ​​over 6mm, pressure is not collapsed; Appendiceal wall over 3mm, between layers of intestinal wall unclear boundary due to inflammation and edema; McBurney's sign on ultrasound (+): When the doctor uses the probe to press on the suspected area, it will cause pain to the patient; Doppler ultrasound showed increased signal in the appendix wall suggestive of congestive vascular inflammation; Some other signs such as appendiceal stones, abnormal fluid collection around the appendix or low-grade fluid collection.
2.2. Purulent necrotizing appendicitis

Ultrasonography of pyogenic necrotizing appendicitis has suggestive images such as:
The wall of the appendix is ​​thickened but uneven, the layers lose normal structure and the echogenicity is reduced; In some cases, the inflamed appendix wall can be seen thin, the inside is filled with purulent fluid; Doppler ultrasound examination reduced signal. 2.3. Appendiceal Abscess Abscesses with poor echogenicity or mixed echoes with air with fairly well defined limits; If acute appendicitis is completely necrotic and the appendix is ​​not detected on ultrasound, the most important finding to detect is appendicitis within the abscess.

Symptoms and signs of the patient:
Right iliac fossa pain: Typically, the patient usually has pain in the epigastrium, around the navel, then localized in the right iliac fossa. The patient has a dull pain that gradually increases; Vomiting and nausea (with or without); Diarrhea or constipation (may or may not be present). When examining, the doctor can detect the following symptoms:
Mild fever, if high fever is a warning sign of possible complications such as peritonitis, appendicitis; Abdominal wall reaction in the right iliac fossa: This is the most valuable sign in the diagnosis of acute appendicitis. If in doubt, it must be examined, followed up many times and compared with the opposite side. Positive focal pain points such as McBurney score, Clado score, Lanz score...

Ultrasound of appendicitis has many advantages for early detection of appendicitis. However, there are still difficult cases where ultrasound is not as effective as usual:
Obese patients; Stomach bloating too much;

Pregnant patients over 6 months; The occurrence of complications such as paralytic ileus or small bowel obstruction causes gas in the intestinal lumen, which limits the investigation; The bladder is too distended; The appendix is ​​in an abnormal position; The sonographer is inexperienced and inexperienced.

Acute appendicitis, if not detected and treated, can lead to dangerous complications such as:
Generalized peritonitis when the appendix is ​​inflamed, necrotic, ruptured and purulent into the abdomen; Appendiceal abscess; Appendiceal masses: When the patient is healthy and has high resistance, the inflamed appendix is ​​covered by loops of intestine and omentum, preventing dangerous progression. Ultrasound is a non-traumatic imaging method that can be performed quickly in all medical facilities. The image of appendicitis on ultrasound helps doctors diagnose and determine the stage of the disease for effective treatment. In addition, ultrasonography is also useful in the differential diagnosis of other gastrointestinal diseases such as ileocecal inflammation, mesenteric lymphadenitis, cecal diverticulitis, and gynecological or urological diseases. However, in order to have accurate ultrasound results, patients should choose reputable and specialized facilities with a team of qualified doctors and a modern ultrasound machine system.
Vinmec International General Hospital system uses the most modern generations of ultrasound machines today to examine and treat patients. One of them is GE Healthcarecar's Logiq E9 ultrasound machine with full options, HD resolution probes for clear images, accurate assessment of lesions. In addition, a team of experienced doctors and nurses will greatly assist in the diagnosis and early detection of abnormal signs of the body in order to provide timely treatment.