Fig. 7

Examples of false-positive and false-negative diagnosis of Meckel diverticulum. a A 4-year-old boy with false-positive diagnosis of Meckel diverticulum which later proved to be Henoch–Schonlein purpura. Transverse ultrasound at the level of the gall bladder showed a lesion mimicking the pseudogestational sac sign. Nuclear study done after 4 days was negative. Clinical and follow-up assessment confirmed the diagnosis of Henoch–Schonlein purpura. b A 2-year-old girl with false-positive diagnosis of Meckel diverticulum and later diagnosed to be duplication cyst. Nuclear study done on the following day was negative. Retrospective analysis revealed a characteristic “gut signature” formed by the echogenic mucosa (open green arrow) and hypoechoic muscle layer (open red arrow). c, d A false-negative case of Meckel diverticulum diagnosed as acute appendicitis by ultrasound in a 6-year-old boy. Nuclear study performed on the following day showed a focus on increased updated at the right lower quadrant of the abdomen (read arrow). The findings were confirmed on surgery and histopathology