Objective: Fetal goitrous hypothyroidism is a rare and potentially lethal condition. Consequently, its early diagnosis and treatment improve prognosis. Thyroid hormone measurement in either fetal serum or amniotic fluid implies important risks. Here we present a fetal goiter and the follow-up procedure, both done by the traditional method and by using 3-dimensional power Doppler (3DPD) imaging and virtual organ computer-aided analysis (VOCAL). Methods: A single well-documented case of fetal goiter was followed weekly from 22 weeks until delivery. Amniocentesis for thyrotropin (TSH) and free thyroxine (T4) measurement as well as levothyroxine injections were performed at every control. In addition to amniocentesis, every control involved a sonographic evaluation, which included standard measurements of the gland and the capture of volume image sets in gray scale and 3DPD. Volume calculation of the gland was done using VOCAL software. Vascularization of the gland was evaluated by the vascularization index (VI) included in the software. Results: With treatment, TSH levels decreased progressively until normalization. Free T4 levels increased toward the end of gestation. Sonographic measurements of the gland volume to estimated fetal weight ratio decreased across treatment as levels of TSH did. The VI clearly depicted the vascular regression of the goiter, decreasing throughout treatment in a consistent way until 24 hours before delivery. Conclusions: Gray scale and 3DPD evaluations of the thyroid gland have been validated under similar circumstances and might be reliable complements to the invasive methods used in the management of this fetal condition. © 2010 by the American Institute of Ultrasound in Medicine.
- 3-dimensional power Doppler sonography
- 3-dimensional sonography
- Fetal hypothyroidism
- Virtual organ computer-aided analysis