MRI of extracranial masses in children: the usefulness of gadolinium-chelate enhancement

Abstract

Objective: This study evaluated the usefulness of gadolinium (Gd) chelates in magnetic resonance imaging (MRI) of extracranial pediatric mass lesions.

Materials and methods: Seventy-five MRI studies were obtained on 60 children (mean age 5.06 years) with pathologically proven mass lesions. Post-contrast T1-weighted (T1W) images were compared with pre-contrast T1-weighted, T2-weighted (T2W) and both T1W and T2W images. They were evaluated for their ability to demonstrate lesion margins and extent, to add additional information, and to increase confidence in or change a diagnosis. In all patients post-contrast images were also evaluated for degree and pattern of enhancement.

Results: Malignant lesions enhanced much more intensely than benign lesions (P<0.0005). Lack of enhancement was seen only in benign lesions. A heterogeneous pattern of enhancement was more frequently seen in malignancy (P<0.05). Additional information was provided on Gd-enhanced T1W images in 36% of cases compared to unenhanced T1 and T2W images. Diagnostic confidence was improved in 29%. The Gd-enhanced images changed the diagnosis correctly in 5% and incorrectly in 1%.

Conclusion: Post-contrast images clarified specific issues, better defined lesion extent and margins in a majority of cases, and gave additional useful information in selected cases.