Eléonore Blondiaux1, Lydia Chougar2, Antoinette Gelot3, Stéphanie Valence4, Etienne Audureau5, Hubert Ducou le Pointe2, Jean-Marie Jouannic6, Ferdinand Dhombres6, Catherine Garel2. 1. Service de Radiologie, Hôpital Trousseau, Hôpitaux Universitaires de l'Est Parisien (APHP), Université Pierre et Marie Curie, Sorbonne Universités, Paris, France. eleonore.blondiaux@aphp.fr. 2. Service de Radiologie, Hôpital Trousseau, Hôpitaux Universitaires de l'Est Parisien (APHP), Université Pierre et Marie Curie, Sorbonne Universités, Paris, France. 3. Service d'anatomie pathologique, Hôpital Trousseau, Hôpitaux Universitaires de l'Est Parisien (APHP), Université Pierre et Marie Curie, Paris, France. 4. Service de Neurologie Pédiatrique, AP-HP, Hôpitaux Universitaires de l'Est Parisien, Hôpital Trousseau, Paris, France. 5. Service de Santé Publique et épidémiologie, Hôpital Henri Mondor, Assistance Publique, Hôpitaux de Paris, Université Paris Est Créteil, Créteil, France. 6. Service de médecine fœtale, Hôpital Trousseau, Hôpitaux Universitaires de l'Est Parisien, (APHP), Sorbonne Universités, Paris, France.
Abstract
BACKGROUND: Evaluation of subcutaneous fetal fat layer thickness on T1-weighted sequences can be used to predict birth weight. Little is known about normal MR signal patterns of subcutaneous tissue throughout pregnancy. OBJECTIVE: To establish developmental patterns of subcutaneous fetal fat signal on T1-weighted sequences during the 2nd and 3rd trimesters. MATERIALS AND METHODS: We retrospectively examined T1-weighted images of 110 fetal MRI scans. We measured signal intensity of subcutaneous fat on thighs, buttocks, trunk, nuchal region, chin and scalp. We then calculated the ratios of the obtained values with fetal muscle, amnios and maternal fat signal, and compared the results with those of immunohistochemical examination of adipose tissue extracted from the abdominal wall of fetuses as part of standard autopsy protocol. RESULTS: We included 60 MRI scans in fetuses without intra-uterine growth restriction or macrosomia of non-diabetic mothers (range 23-37 weeks of gestation). Fat T1 intensity of all anatomical regions was low in all fetuses before 26 weeks of gestation. It became more hyperintense with increasing gestational age, in the following order: chin and nuchal region, then buttocks, thighs and trunk, and eventually the scalp at 33 weeks of gestation. After 33 weeks of gestation, all fetal subcutaneous tissues demonstrated overall hyperintense signal. This progression followed the conversion at immunohistochemistry of fetal adipose tissue composition from predominant brown to white adipose cells in 19 fetuses (19-41 weeks of gestation). CONCLUSION: Between 26 weeks and 33 weeks of gestation, subcutaneous fetal fat signal changed in an orderly pattern from chin to buttocks and scalp. This may reflect the conversion from predominant brown to white adipose tissues in subcutaneous fetal fat.
BACKGROUND: Evaluation of subcutaneous fetal fat layer thickness on T1-weighted sequences can be used to predict birth weight. Little is known about normal MR signal patterns of subcutaneous tissue throughout pregnancy. OBJECTIVE: To establish developmental patterns of subcutaneous fetal fat signal on T1-weighted sequences during the 2nd and 3rd trimesters. MATERIALS AND METHODS: We retrospectively examined T1-weighted images of 110 fetal MRI scans. We measured signal intensity of subcutaneous fat on thighs, buttocks, trunk, nuchal region, chin and scalp. We then calculated the ratios of the obtained values with fetal muscle, amnios and maternal fat signal, and compared the results with those of immunohistochemical examination of adipose tissue extracted from the abdominal wall of fetuses as part of standard autopsy protocol. RESULTS: We included 60 MRI scans in fetuses without intra-uterine growth restriction or macrosomia of non-diabetic mothers (range 23-37 weeks of gestation). Fat T1 intensity of all anatomical regions was low in all fetuses before 26 weeks of gestation. It became more hyperintense with increasing gestational age, in the following order: chin and nuchal region, then buttocks, thighs and trunk, and eventually the scalp at 33 weeks of gestation. After 33 weeks of gestation, all fetal subcutaneous tissues demonstrated overall hyperintense signal. This progression followed the conversion at immunohistochemistry of fetal adipose tissue composition from predominant brown to white adipose cells in 19 fetuses (19-41 weeks of gestation). CONCLUSION: Between 26 weeks and 33 weeks of gestation, subcutaneous fetal fat signal changed in an orderly pattern from chin to buttocks and scalp. This may reflect the conversion from predominant brown to white adipose tissues in subcutaneous fetal fat.
Entities:
Keywords:
Adipose tissue; Body composition; Fetus; Magnetic resonance imaging
Authors: A Atallah; A Lacalm; M Massoud; J Massardier; P Gaucherand; L Guibaud Journal: Ultrasound Obstet Gynecol Date: 2018-01-05 Impact factor: 7.299
Authors: D Anblagan; R Deshpande; N W Jones; C Costigan; G Bugg; N Raine-Fenning; P A Gowland; P Mansell Journal: Ultrasound Obstet Gynecol Date: 2013-09 Impact factor: 7.299