Thalamic volume measurement in normal fetuses using three-dimensional sonography

Authors

  • Alexandros Sotiriadis MD, PhD,

    Corresponding author
    1. Fourth Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Ippokrateion Hospital, 49 Konstantinoupoleos Street, 54642 Thessaloniki, Greece
    • Fourth Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Ippokrateion Hospital, 49 Konstantinoupoleos Street, 54642 Thessaloniki, Greece
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  • Ioannis Dimitrakopoulos,

    1. GE Healthcare Hellas, Phillipos Business Center, 57010 Thessaloniki, Greece
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  • Makarios Eleftheriades MD, PhD,

    1. EmbryoCare, 194 Alexandras Avenue, 10522 Athens, Greece
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  • Theodoros Agorastos MD, PhD,

    1. Fourth Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Ippokrateion Hospital, 49 Konstantinoupoleos Street, 54642 Thessaloniki, Greece
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  • George Makrydimas MD, PhD

    1. Department of Obstetrics and Gynecology, University Hospital of Ioannina, Stavros Niarchos Avenue, 45500 Ioannina, Greece
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Abstract

Purpose.

Brain thalami are important for a wide range of sensorimotor and neuropsychiatric functions. This study was carried out to calculate normative values for thalami volume during fetal life.

Methods.

Fetal thalami volumes were measured using 3D ultrasound in 122 normal, singleton fetuses at 20+0–34+6 weeks' gestation. Virtual Organ Computer-aided AnaLysis (VOCAL) was used to obtain a sequence of six sections of each thalamus, starting from the transthalamic view of the brain at an axial plane. Thalamic contour was drawn manually. Volume contrast imaging was used to enhance image quality when needed. The volume of the thalamus distal to the transducer was also measured by a second operator in 30 randomly selected cases, blind to the measurements of the first, to calculate interobserver agreement.

Results.

Thalamic volume increased with gestational age, following a quadratic equation (R2 = 0.83). There was no significant difference in volume between the right and left thalamus. The mean volume of each thalamus increased from 0.45 ml at 20+0 weeks, to 1.39 ml at 28+0 weeks, to 2.17 ml at 34+0 weeks. The 95% limits of interobserver agreement for thalamic volume were −14.3% to +17.2%.

Conclusions.

The increase in thalamic volume with gestation can be described adequately by a quadratic equation. The moderate interobserver repeatability is attributed to the similar echogenicity between the thalamus and its surrounding structures. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012

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