The patient has appendicitis with a fecolith visualized in the appendiceal lumen. He under went a laproscopic removal of his appendix and was discharged home in 2 days.
Appendicitis
Using ultrasound to diagnose appendicitis is not a new technique, having first appeared in the literature in 1986. Multiple studies have illustrated the benefits of graded compression ultrasound to diagnose appendictis, with sensitivities ranging from 89-95% and specificitites of 95-100%. In this technique, the sonologist uses a linear high freqency transducer to apply a constant pressure to the right lower quadrant. Bowel loops will normally compress or become displaced from view when pressure is applied. In the case of appendicitis, the appendix is inflamed and non-compressible. It appears as a blind ended tubular pouch, which lacks peristalsis and compressibility. It should measure >6mm in diameter and may contain a fecolith, which will appear as a hyperechoic structure in the lumen with distal shadowing. Other signs that confirm appendicitis are an increase in the brightness or echogenicity of the periappendiceal fat. When color flow is applied to the acutely inflamed appendix, there may be a increased amount of flow in the wall circumferentially.
The easiest way to perform graded compression ultrasound to diagnose appendicitis is to have the patient localize their maximal point of pain with 1 finger. This has been shown to increase the ability to find the appendix and also can reduce exam time. Using a constant pressure to displace overlying bowel, the RLQ should be interrogated in both longitudinal and transverse planes. The appendix is easiest to identify in the transverse plane, appearing as a target with multiple layers of echogenicity, corresponding to the different layers within the bowel wall.
Once it has been identified, it should be examined in both planes. Attempts at compressibility should be made- if the appendix compresses or "winks" at you, then it is unlikely to be appendicitis. In appendicitis, the appendix may be displaced posteriorly, but the walls should not compress. Measurements of the diameter should be taken and color flow may also be placed on the appendix to denoted an increase in color flow. Interrogate the entire appendix before making your final diagnosis to ensure that you are not missing a fecolith or fluid collection that may indicate and abscess.
Puylaert JB. Acute appendicitis: US evaluation using graded compression. Radiology. 1986; 158(2):355 -60