Question

Write short notes on the sonographic evaluation of:

​a. Bowel loops

​b. Intussusception

​c. Appendicitis

​d. Hypertrophic pyloric stenosis

Answer 1

1.Bowel loop sonography ;

Intestinal obstruction (IO) is a common cause of acute abdominal pain. The recent increased use of sonography in the initial evaluation of abdominal pain has made point-of-care ultrasound a valuable tool for the diagnosis of IO. Sonography is as sensitive, but more specific, than plain abdominal X-ray in the diagnosis of IO. Point-of-care ultrasound can answer specific questions related to IO that assist the acute care physician in critical decision making. Sonography can also help in the resuscitation of patients by serial measurement of the IVC diameter. We review the sonographic findings of IO and the role of point-of-care ultrasound in the management of patients having IO

The sonographic findings of an obstructed bowel include dilated fluid- filled bowel loops with hyperechoic spots of gas moving within the fluid. The normal small intestine diameter is 3-4 cm while the diameter of the large intestine 4-5 cm.Those dilated loops may show thickened wall (normally up to 3 mm),thickened vavulae conniventes (normally up to 2 mm), and increased to-and-fro motion of the bowel contents

Real-time sonography may differentiate between mechanical and functional IO. The movement of the mechanically obstructed bowel will initially increase but will decrease later with the progress of the obstruction and development of bowel ischemia.Akinesis of the loop can be detected by absence of bowel peristalsis for more than 5 minutes. The site of IO is determined by following the course of obstructed bowel by ultrasound probe and by the pattern of valvulae conniventes.

The transit point is the point between the dilated proximal and collapsed distal bowel loops  It is important to search for the cause of IO at the transit point. Ultrasound may detect the cause of IO with specific sonographic findings such as: External hernias, intestinal intussusception, tumors, ascariasis, superior mesenteric artery syndrome, bezoars, foreign bodies and Crohn's disease.

A decision for early surgery is one of the most important decisions that point-of-care ultrasound can assist the surgeon with. Sonographic findings suggesting a need for surgery include; intraperitoneal free fluid , bowel wall thickness of more than 4 mm, and decreased or absent peristalsis in previously documented mechanically obstructed bowel. Bowel wall perfusion can be assessed by Doppler sonography and the presence of free intraperitoneal air indicates bowel perforation. Under ultrasound guidance, aspiration of bloody intraperitoneal fluid may indicate bowel gangrene that needs urgent surgery.In critically ill patients having IO and a hypovolemic shock, ultrasound can help in the diagnosis and resuscitation of these patients by serial measurement of the IVC diameter

2. Intussusception ;

Intussusception is the most common cause of intestinal obstruction in very young children. Ultrasound imaging is the diagnostic imaging examination of choice due to its high sensitivity, specificity, pathologic characterization, and lack of ionizing radiation. Pediatric radiologists at Benioff Children’s Hospital at the University of California San Francisco also recommend its use to monitor intussusception reduction. This recommendation is made in an article describing past and present diagnostic and treatment practices of intussusception published in Pediatric Radiology. The authors explain that children under the age of one year represent about half of the intussusceptions that are diagnosed and that boys develop these twice as much as girls. They also caution that symptoms overlap multiple other abdominal disease processes. An accurate diagnosis is essential as failure to treat results in ischemia

Real-time imaging monitoring is predominantly performed using fluoroscopy. However, the authors advocate the use of ultrasound imaging. Unfortunately very few pediatric radiologists use ultrasound. The authors cited a 2015 survey which reported only a 4% adoption rate. The authors attribute this to lack of knowledge, experience, and comfort about using ultrasound for real-time monitoring of the procedure and lack of experienced sonographers after hours at many hospitals. At Benioff Children’s Hospital, the radiologists use a combination of ultrasound imaging and fluoroscopy in the diagnosis and treatment of routine intussusception

3. Appendicitis ;

The abdominal ultrasound usually will be done in the radiology department of a hospital or in a radiology center. Parents usually can accompany their child to provide reassurance and support.

Your child will be asked to change into a cloth gown and lie on a table. The room is usually dark so the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging will spread a clear, warm gel on the skin of the abdomen. This gel helps with the transmission of the sound waves.

The technician will then move a small wand (transducer) over the gel. The transducer emits high-frequency sound waves and a computer measures how the sound waves bounce back from the body. The computer changes those sound waves into images to be analyzed. Sometimes a doctor will come in at the end of the test to meet your child and take a few more pictures. The procedure usually takes less than 30 minutes

The abdominal ultrasound is painless. Your child may feel a slight pressure on the belly as the transducer is moved over the body, and the gel may feel wet or cold. You'll need to tell your child to lie still during the procedure so the sound waves can reach the area effectively. The technician may ask your child to lie in different positions or hold his or her breath briefly