It is crucial to continually expand your knowledge and stay updated with the latest advancements in ultrasound imaging.
This CPD article aims to provide an overview of the ultrasound features of appendicitis, a common and potentially serious condition. By recognising the key ultrasound findings associated with appendicitis, sonographers can play a pivotal role in aiding accurate diagnosis and timely intervention.
This article will outline six key points followed by five reflection points to enhance your expertise in detecting appendicitis through ultrasound imaging.
Six Key Points
1. Clinical Presentation and Prevalence: Appendicitis typically presents with right lower quadrant abdominal pain and tenderness.
It is a frequent cause of acute abdomen, accounting for a significant number of emergency department visits.
2. Ultrasound Technique: A high-frequency linear array transducer (7-12 MHz) is the preferred choice for assessing the appendix.
Begin by evaluating the right lower quadrant, focusing on the McBurney's point as the initial landmark.
3. Normal Appendix and Sonographic Variants: A normal appendix appears as a blind-ending tubular structure measuring less than 6mm in diameter.
Recognise variations such as a retrocecal or pelvic appendix, which may influence the diagnostic approach.
4. Direct Sonographic Signs of Appendicitis: Appendiceal non-compressibility: Inflamed appendices are non-compressible due to edema and inflammation.
Increased wall thickness: A normal appendix wall measures less than 2-3mm, whereas a thickened wall (>6 mm) suggests inflammation.
Target or pseudo-kidney sign: A cross-sectional view may demonstrate concentric hypoechoic and hyperechoic layers.
5. Indirect Sonographic Signs of Appendicitis: Peri-appendiceal fluid collection: Sonolucent fluid accumulation adjacent to the appendix suggests inflammation.
Appendicolith: A calcified or hyperechoic appendicolith within the lumen may indicate appendiceal obstruction.
Hyperemia and increased vascularity: Doppler evaluation can reveal increased blood flow in the inflamed appendix.
6. Limitations and Challenges: Obesity and bowel gas can hinder appendix visualization; applying graded compression techniques can improve the imaging quality.
Diagnostic accuracy heavily relies on sonographer expertise, emphasizing the importance of
continuous learning and practice.
Reflection Prompts
- Reflect on the challenges faced during ultrasound examinations for suspected appendicitis cases and identify potential solutions to improve diagnostic accuracy.
- Discuss the role of ultrasound in differentiating appendicitis from other causes of right lower quadrant pain, such as ovarian pathology or diverticulitis.
- Reflect on cases where the ultrasound findings were inconclusive or atypical for appendicitis and explore the appropriate course of action.
- Evaluate the impact of incorporating point-of-care ultrasound (POCUS) in the emergency setting for timely diagnosis and management of appendicitis.
- Reflect on the importance of interdisciplinary collaboration between sonographers, radiologists, and clinicians to optimise patient care in cases of suspected appendicitis.
Further Reading
Di Saverio, S. Podda, M. De Simone, B. et al (2020) Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World Journal of Emergency Surgery. 15 (1): 27. doi:10.1186/s13017-020-00306-3.
Doria, A. Moineddin, R. Kellenberger, C. et al. (2006) US or CT for diagnosis of appendicitis in children and adults? A Meta-Analysis. Radiology. 241 (1): 83-94. Doi: 10.1148/radiol.2411050913
Echevarria, S. Rauf, F. Hussain, N. et al (2023) Typical and atypical presentations of appendicitis and their implications for diagnosis and treatment: A literature review. Cureus. 15 (4): e37024. doi:10.7759/cureus.37024.