Centro MĆ©dico Profesional Rosancar. Barquisimeto, Estado Lara, Venezuela.
Introduction
The thymus has been studied in fetuses with conotruncal anomalies as a marker of microdeletion 22q11. More recently, it has also been investigated in relation to its immune function in association with prolonged rupture of membranes and intrauterine growth restriction. The thymus can be identified on the three-vessel view of the upper mediastinum, but its visualization is not always straightforward.
Paladini [1] reported a simple way to locate the thymus, so called "Thymus-box". The internal mammary arteries course laterally to the thymus identifying its lateral borders, and by using color doppler ultrasonography with a low repetition frequency these vessels and, consequently, the thymic area, are readily displayed in the fetus from the first to the third trimester of pregnancy [1].
Case report
Here we present two uncomplicated pregnancies where we identified the normal looking thymus using the internal mammary arteries as landmarks. TheĀ third caseĀ is a case of thymic hypoplasia diagnosed at 23 weeks of gestation.
Case 1
Images 1-3: 23 weeks, Images are showing normal looking thymus which is located between the right and left mammary artery.