MRI features and radiomics of the pineal gland in girls do not show significant changes at onset of puberty

Introduction: The gold standard for diagnosing central precocious puberty(CPP) is the gonadotropin-releasing hormone stimulation test, along with magnetic resonance imaging(MRI) of the brain and hypothalamus-pituitary region to rule out central organic causes. Recent advancements have led to a new medical imaging approach called radiomics. Our recent study showed that pituitary gland radiomics is a promising tool for diagnosing CPP. However, the role of the pineal gland in the onset of puberty has long been debated. Therefore, we investigated radiomic features of the pineal gland associated with puberty onset to identify changes that could assist physicians in the diagnostic workup of CPP. Methods: 45 girls with a confirmed diagnosis of CPP and 47 pre-pubertal, ageand sex-matched subjects(controls) were retrospectively enrolled. Two readers (R1, R2) with different levels of expertise in pediatric neuroradiology blindly segmented the pineal gland on MRI studies for radiomic features(RFs) calculation and manually evaluated the number and diameter of pineal cysts. Cross-validated linear discriminant analysis was used to develop, for each reader, both a radiomic model and a reference model based on pineal cyst features. Radiomics was evaluated in terms of predictive performances(ROC-AUC) and reliability of predictors between readers (intraclass correlation coefficient). Finally, the correlation between cysts' features and basal/peak gonadotropin and estradiol levels was also investigated. Results: Two radiomic features were identified as the most predictive of CPP for both readers. However, these features were not the same for R1 and R2 readers and their values showed poor inter-reader reliability. Unpromising performance in the validation set was observed for pineal gland radiomics (ROC-AUC of 0.64 for R1 and 0.59 for R2). Similarly, the reference model based on pineal cyst features demonstrated a poor performance (ROC-AUC = 0.52, both readers). No significant correlations between cyst features and basal/peak gonadotropin levels were observed. Conclusion: Radiomic features of the pineal gland in girls did not show consistent and relevant changes with the onset of puberty and do not hold promise for the CPP diagnosis at variance with previous findings in the pituitary gland. Similarly, the number and size of cysts were not found to be specific for the onset of puberty.