Third ventricle: size and appearance in normal fetuses through gestation.

Publication/Presentation Date

6-1-1997

Abstract

PURPOSE: To define the size and appearance of the normal fetal third ventricle.

MATERIALS AND METHODS: The third ventricle was prospectively assessed in 441 consecutive normal second- and third-trimester fetuses. The fetuses were divided into six gestational age ranges. Data regarding the size and configuration of the third ventricle were analyzed for each group.

RESULTS: The third ventricle was seen in 435 of 440 (98.9%) fetuses. It appeared as a single echogenic line between the thalami in 171 (38.9%) fetuses, as parallel echogenic lines outlining a fluid-filled lumen in 243 (55.2%) fetuses, and as divergent lines delineating a V-shaped fluid-filled structure in 21 (4.8%) fetuses. The single-line configuration was most common early in the second trimester. Later in pregnancy, the ventricle walls could be discerned as separate parallel or divergent lines outlining a fluid-filled lumen. The average width of the ventricle was relatively constant at approximately 1 mm from 12 to 28 weeks. After this time, it enlarged, reaching a maximum 1.9 mm.

CONCLUSION: The third ventricle can be imaged in most second- and third-trimester fetuses. Its size and configuration evolve through the second and third trimesters. This evolution must be considered in the evaluation of normality. At any gestational age, a third ventricle greater than 3.5 mm in width should be viewed with concern for abnormality.

Volume

203

Issue

3

First Page

641

Last Page

644

ISSN

0033-8419

Disciplines

Diagnosis | Medicine and Health Sciences | Other Analytical, Diagnostic and Therapeutic Techniques and Equipment | Radiology

PubMedID

9169682

Department(s)

Department of Radiology and Diagnostic Medical Imaging

Document Type

Article

Link to Full Text

Share

COinS