MR imaging of the normal appendix in children

Our objective was to assess the ability of MR imaging in the detection of the normal appendix, and to describe the MR appearance of the normal appendix. There were 15 healthy volunteers (11 girls, 4 boys; mean age 12.3 years) who underwent MR imaging on a 1.0-T unit. The imaging protocol included axial and coronal T2-weighted ultra turbo spin-echo (UTSE)-weighted images, axial T1-weighted turbo spin-echo (TSE) and coronal short tau inversion recovery (STIR)/TSE sequences. Confidence regarding the detection was scored from 1 (high confidence) to 3 (low confidence). Thickness was measured and MR appearance described. Clinical control after 2 weeks revealed no signs or symptoms of acute appendicitis. The normal appendix was seen in 86% on T2/UTSE-weighted images and in 73% on T1/TSE-weighted images and in none on STIR/TSE images. On axial T2/UTSE-weighted images, normal appendix had a hyperintense center and a hypointense wall, and was mostly hypointense on T1/TSE-weighted images, with a mean thickness of 4.5 mm. Magnetic resonance imaging seems to be an accurate method for the assessment of the normal appendix in children; thus, MR imaging might be an alternative to CT if US examinations are inconclusive.