title: Congenital Hypothyroidism: Role of Nuclear Medicine.
abstract: Thyroid scintigraphy holds a key place in the etiologic workup of neonatal hypothyroidism. Routine screening for this disorder in maternity hospitals in industrialized countries, for nearly 40 years, has permitted early treatment and thereby helped to prevent its physical and mental complications. Neonatal hypothyroidism affects approximately 1 in 3000 births. The most common causes are abnormal thyroid gland development and defective hormone synthesis by an eutopic thyroid gland. The incidence of the latter has risen in recent years, for reasons that remain unclear. A thorough etiologic workup helps to determine the disease type. Current guidelines recommend thyroid imaging by means of ultrasound and scintigraphy. Ultrasound should be done by a practitioner trained to examine the cervical region of newborns, as the thyroid is very small and must be distinguished from the particular aspect of the "thyroid empty lodge." Ultrasound lacks sensitivity for detecting small ectopic glands but is the gold standard for measuring thyroid dimensions. Scintigraphy provides an etiologic diagnosis in most cases. The two isotopes used in this setting are technetium-99m and iodine-123. The latter isotope gives more contrast and allows the perchlorate discharge test to be performed to detect abnormal iodide organification in the neonate with an eutopic thyroid. If scintigraphy cannot be performed during the neonatal period, a postponed procedure can be achieved after 3 years of age. Close cooperation between the nuclear medicine physician and the pediatric endocrinologist is crucial for timely and optimized scintigraphy.
authors.affiliation: Service de Médecine Nucléaire Pédiatrique, Hôpital d'Enfants Armand Trousseau, Paris, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Keller-Petrot
authors.affiliation: Service d'Endocrinologie Diabétologie Pédiatrique, Centre de Référence des Maladies Endocriniennes Rares de la Croissance, Assistance Publique-Hôpitaux de Paris, Hôpital Robert Debré, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut National de la Santé et de la Recherche Médicale (Inserm), Unité 1141, DHU Protect, Paris, France.
authors.forename: Juliane
authors.initials: J
authors.lastname: Leger
authors.affiliation: Service de Médecine Nucléaire Pédiatrique, Hôpital d'Enfants Armand Trousseau, Paris, France.
authors.forename: Aline
authors.initials: A
authors.lastname: Sergent-Alaoui
authors.affiliation: Service de Médecine Nucléaire Pédiatrique, Hôpital d'Enfants Armand Trousseau, Paris, France; UPMC Univ Paris 06, Biophysique, Paris, France. Electronic address: claire.vaylet@aphp.fr.
authors.forename: Claire
authors.initials: C
authors.lastname: de Labriolle-Vaylet
mesh_terms: D003409:Congenital Hypothyroidism / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism; D006801:Humans; D015994:Incidence; D009683:Nuclear Medicine / Q000379:methods*; D010472:Perchlorates / Q000378:metabolism; D011877:Radionuclide Imaging; D017670:Sodium Compounds / Q000378:metabolism
chemical_list: D010472:Perchlorates; D017670:Sodium Compounds; C031068:sodium perchlorate