Two-dimensional shear wave elastography can improve the diagnostic accuracy of ultrasonography in acute appendicitis

Abstract

Aim: We aimed to evaluate the effectiveness of combining 2-dimensional shear wave elastography (2D-SWE) with ultrasonography (US) in diagnosing acute appendicitis in patients with suspected acute appendicitis.

Methods: Clinical and laboratory findings, gray-scale US and 2D-SWE imaging features, operation information, and pathology results of 48 patients diagnosed with acute appendicitis who presented with right lower quadrant pain were prospectively evaluated. We compared the findings to the US and SWE imaging features of 79 asymptomatic patients.

Results: Mean Alvarado score and appendix diameter were statistically significantly higher for acute appendicitis (p < 0.001). In patients with acute appendicitis, mesenteric lymphadenopathy and fat stranding were also more frequent (p < 0.001). The mean velocity and kPa values for appendix and mesenteric fat were statistically significantly higher in acute appendicitis (p < 0.001).

Conclusion: In the diagnosis of acute appendicitis, 2D-SWE increases the diagnostic performance of gray-scale US in the differentiation of inflamed and normal appendixes.

Keywords: Acute appendicitis; Shear wave elastography; Sonography.

Fig. 1

A 18-year-old symptomatic girl was admitted to the emergency department with complaints of nausea, vomiting, and non-localized abdominal pain. On physical examination, there was no defense or rebound in the right lower quadrant of the abdomen. Body temperature was 37.8 °C and leukocytosis (> 10.000 white blood cells, leukocytosis with left shift) was present. The patient's Alvarado score was six. In the sonographic examination performed, there were reactive lymph nodes (arrows) with a short axis smaller than 1 cm in the mesenteric fat planes in the right lower quadrant of the abdomen (a). Appendix diameter was 8 mm and did not respond to compression (b), there was mesenteric fat stranding adjacent to the appendix (mesenteric fat stranding width was 9 mm) and minimal free fluid (arrow head) (c). Quantitative elasticity values were measured in the anterior, posterior, medial, and lateral walls of the distal appendix, and in the mesenteric fat planes adjacent to the appendix on the propagation (d), speed(m/s) (e) and elasticity(kPa) (f) mode in the axial plane, using the round ROI. The mean of four measurements from the appendix wall was calculated (T1 + T2 + T3 + T4 / 4). The mean quantitative elasticity values were measured as 2.9125 m/s and 26.075 kPa

Fig. 2

Receiver operating characteristic (ROC) analyses of the 2-dimensional shear wave elastography (2D-SWE) with ultrasonography (US) in diagnosing acute appendicitis