Perbedaan nilai T2* dan T2 relaksometri hipofisis berdasarkan pemeriksaan magnetic resonance imaging dalam deteksi keterlambatan pubertas pada populasi thalassemia mayor (RSCM) = Differences of T2* and T2 relaxometry values of pitutary using magnetic resonance imaging in detecting delayed puberty in thalassemia major patient with hipogonadotropic hipogonadism (RSCM)