Plicae palmatae on MRI in the pediatric population.

PURPOSE: To examine the presence of ridge of plicae palmatae (RPP) in pediatric population and evaluate its depiction rate and appearance on magnetic resonance imaging (MRI).

MATERIALS AND METHODS: Consecutive pelvic MRI examinations of female patients aged 0-19 years between January 2005 and April 2017 were retrospectively reviewed. Patients with underlying diseases affecting the uterus and whose MRI data were not available on the picture archiving and communication system were excluded. Thus, 171 pelvic MRI cases were included (mean patient age, 11 years). Morphologic appearance of RPP was evaluated. RPP depiction rate was evaluated in the following age groups: group A, 0-2 years; B, 3-6 years; C, 7-10 years; and D, 11-19 years. Pearson Chi square test or Fisher's exact test was used to assess statistical significance of differences in RPP visualization frequencies between the groups using SPSS for Windows, version 11.0.0.1 J. Statistical significance was set at P < 0.05.

RESULTS: RPP appeared as a folded structure rather than tumorous in all cases. Depiction rate varied according to age: group A, 8/21 (38.1%); B, 0/16 (0%); C, 6/24 (25.0%); and D, 62/110 (56.4%). Depiction rate in group B was the lowest and significantly lower than those in groups A and D. However, RPP was most frequently observed in group D, and was significantly more frequent than in groups B and C.

CONCLUSION: RPP could be observed on MRI in a pediatric population, and careful interpretation is necessary in such cases, although no case with tumorous appearance was observed. Depiction rate varies according to age, probably reflecting uterine maturity.