Figure 3

Acute appendicitis by tissue harmonic imaging sonography (THI) using linear transducer with 7.5 MHz revealed: A. Longitudinal scan showing a well defined adequately demarcated aperistaltic non compressible blind ended tubular structure with distinct thickened wall layers and diameter > 6 mm associated with intraluminal curvilinear calcification with posterior acoustic shadowing that reflects an appendicolith. B. Transverse scan showing target sign appearance with the appearance of the appendicolith with its characteristic posterior acoustic shadowing.