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Magnetic resonance imaging of the normal fetal esophagus
Author(s) -
Brugger P. C.,
Weber M.,
Prayer D.
Publication year - 2011
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1002/uog.9002
Subject(s) - medicine , sagittal plane , gestational age , magnetic resonance imaging , esophagus , anatomy , fetus , nuclear medicine , radiology , pregnancy , biology , genetics
Objectives To establish the appearance on magnetic resonance imaging (MRI) of the normal fetal esophagus and to provide biometric data from 20 to 39 gestational weeks. Methods In this retrospective study of 250 fetal MRI examinations (20–39 gestational weeks) the visibility of the upper (E1, cervical to tracheal bifurcation) and lower (E2, tracheal bifurcation to diaphragm) esophageal segments was assessed separately in each of three section planes. Segments were scored as being visible or not, and whether they were fluid‐filled was noted. Maximum esophageal diameters were recorded. To study the age dependency of esophageal visualization, fetuses were divided into three age groups: 20–25, 26–31 and 32–39 weeks. In 19 cases, there were dynamic studies and these were analyzed for the duration of fluid‐filling. Results Segment E1 was visualized only when it was fluid‐filled and it was visible in 16.8% of axial, 4% of frontal and 22.4% of sagittal acquisitions. Segment E2 could also be detected in the unfilled state, when it appeared solid; it was seen in 96.4% of axial, 74% of frontal and 39.6% of sagittal acquisitions, being fluid‐filled in 62.7–88.9% of these. Depending on the amount of fluid‐filling and the gestational age, E2 segments had a variable appearance. Dynamic scans showed E1 segments to be fluid‐filled for periods of 0.5–1.5 s and E2 segments for periods of 3–35 s. Both the frequency of visualization and the maximum diameter increased linearly with gestational age. Conclusion Visualization of the fetal esophagus by MRI depends on section plane, segment and gestational age, with considerable differences between the two segments: while E1 requires fluid‐filling related to fetal swallowing, the E2 portion can usually be demonstrated independent of fluid‐filling, as a consequence of its topographical relationships. The frequently fluid‐filled state of E2 may reflect the immature nature of esophageal neuromuscular activity, and the lack of an anti‐reflux mechanism due to the short length of the abdominal esophagus. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.