As ultrasound becomes more immersed within our routine bedside evaluation of patients, its use is becoming more pervasive. Ultrasound can now be used to evaluate the abdomen for pathology such as appendicitis, small bowel obstruction, and intussusception. Given that most cases of appendicitis and intussusception occur more often in younger patients, the utility of ultrasound is particularly advantageous to prevent unnecessary radiation. This chapter will review indications for performing an abdominal ultrasound, basic abdominal anatomy, image acquisition, normal ultrasound anatomy, and interpretation of pathology.
KeywordsAppendicitis Small bowel obstruction Large bowel obstruction Intussusception Ascites Pneumoperitoneum
Appendicitis. Acute appendicitis, as identified in this image, can be identified as an aperistaltic, noncompressible, blind-ended tubular structure (MP4 1945 kb)
Target sign. In short axis, acute appendicitis will often look similar to a target thereby earning the classic finding of “target sign” (MP4 2092 kb)
Appendicolith. Within the inflamed appendix may be a fecalith, or appendicolith, which is visualized as a hyperechoic rounded structure with posterior acoustic shadowing (MP4 2059 kb)
Appendicitis with surrounding fluid. Periappendiceal fluid can also be seen in acute appendicitis (MP4 2159 kb)
Small bowel obstruction. Small bowel obstruction can be identified by dilated, noncompressible small bowel that is greater than 2.5 cm in diameter. There will typically be echogenic material within the lumen of the bowel exhibits and to-and-fro whirling pattern (MP4 1938 kb)
Keyboard sign. Keyboard sign can be seen with small bowel obstruction due to prominent plicae circulares, representing piano keys, silhouetted against small bowel contents (MP4 1952 kb)
Ascites. Ascites is identified by anechoic free intraperitoneal fluid within the abdomen often appearing as if the bowel is floating within the fluid (MP4 1844 kb)
Free intraperitoneal air. Free intraperitoneal air will appear as an echogenic line (arrow) with reverberation artifact as seen in this image of a patient with perforated gastric ulcer (MP4 2296 kb)
Thickened bowel wall. Bowel wall thickening greater than 4 mm is suggestive of colitis, as seen in this image of a patient with pancolitis (MP4 1980 kb)
- 1.Gray JE, Mizell JS. Anatomy of the abdominal wall. UpToDate website. https://www.uptodate.com/contents/anatomy-of-the-abdominal-wall. Updated November 5, 2015. Accessed 17 Apr 2017.
- 2.Ogata M. Chapter 9: General Surgery Applications. In: Ma OJ, Mateer JR, Blaivas M, editors. Emergency ultrasound. 2nd ed. Columbus, OH: The McGraw-Hill Companies, Inc.; 2008. p. 193–228.Google Scholar
- 3.SonoSim Ultrasound Training Solution [Video]. Santa Monica, CA: SonoSim Inc.; 2017.Google Scholar
- 4.Chao A & Gharahbaghian L. Tips and tricks: ultrasound in the diagnosis of acute appendicitis. American College of Emergency Physicians website. https://www.acep.org/Content.aspx?id=101803. April 2015. Accessed 15 Apr 2017.
- 5.Paspulati RM. Chapter 23: Ultrasonography of Bowel Disorders. In: Dogra V, Rubens D, editors. Ultrasound secrets. Philadelphia, PA: Elsevier Health Sciences; 2004. p. 207–11.Google Scholar
- 6.Old JL, Dusing RW, Yap W, Dirks J. Imaging for suspected appendicitis. Am Fam Phys. 2005; 71(1):71–78. http://www.aafp.org/afp/2005/0101/p71.html. Accessed 15 Apr 2017.
- 7.Hefny AF, Abu-Zidan FM. Sonographic diagnosis of intraperitoneal free air. J Emerg Trauma Shock. 2011; 4(4):511–513. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3214511/. Accessed 17 Apr 2016.