Prevalence of Rathke cleft cysts in children on magnetic resonance imaging.

PURPOSE: The purposes of this study were to estimate the prevalence of Rathke cleft cysts (RCC) in a pediatric population on brain MRI, to describe their appearance, and to estimate interobserver agreement in the detection of RCC.

MATERIALS AND METHODS: The brain MRI examinations of 460 children were retrospectively reviewed by two radiologists for the presence of RCC. There were 223 boys and 237 girls with a mean age of 8.8±4.3 (standard deviation [SD]) years (range: 0.1-14.9 years). When present, RCC were analyzed with respect to internal contain and further classified as serous RCC (i.e., high signal on T2-weighted sequences and iso or low signal on T1-weighted sequences) or mucosal RCC (i.e., low signal on T2-weighted sequences and high or iso signal on T1-weighted sequences). Cohen's Kappa coefficient was used to estimate interobserver agreement between the interpretations performed by the two radiologists for the presence of RCC.

RESULTS: A total of 14 children had a RCC present on brain MRI, yielding a prevalence of 3.04% (14/460); of these, 3/14 RCCs (21%) were of serous type and 11/14 (79%) were of mucosal type. Interobserver agreement for the presence of RCC was strong (Kappa=0.85; 95% CI: 0.70; 0.99).

CONCLUSION: The results of our study suggest that the prevalence of RCC in children is greater than previously described.