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The neonatal diaphragmatic crura are hypertrophied: a necessary preparation for the first breath?

Maria J Moes1, Roy A Filly

  • 1Department of Radiology, University of California, San Francisco, San Francisco, California 94143-0628, USA. maria.moes@radiology.ucsf.edu

Journal of Ultrasound in Medicine : Official Journal of the American Institute of Ultrasound in Medicine
|July 17, 2003
PubMed

Insights

Neonatal diaphragmatic crura are significantly larger than adult crura, as shown by ultrasound measurements. This hypertrophy likely aids lung expansion in newborns.

Area of Science:

  • Pediatric Radiology
  • Anatomy
  • Neonatal Physiology

Background:

  • The anatomy of the diaphragm and its crura is crucial for respiratory function.
  • Understanding neonatal anatomical variations is important for diagnosing congenital conditions.

Purpose of the Study:

  • To sonographically demonstrate significant hypertrophy of the neonatal diaphragmatic crura compared to adults.
  • To establish normative sonographic measurements for neonatal and adult diaphragmatic crura.

Main Methods:

  • Abdominal sonography was performed on two groups: neonates (0-2 months) and adults (18-40 years), with 50 patients in each group.
  • A single longitudinal plane was used to measure the anteroposterior diameter of the aorta and the diaphragmatic crus.
  • The ratio of the aorta to the crus was calculated and compared between the two age groups.

Main Results:

  • A statistically significant difference was observed in the size of the diaphragmatic crura between neonates and adults when using the aorta as an internal standard.
  • The mean ratio of the aorta to the right crus was 2.95 in neonates versus 1.04 in young adults (P < .0001).

Conclusions:

  • Neonatal diaphragmatic crura are markedly hypertrophied at birth.
  • This hypertrophy is hypothesized to facilitate the expansion of atelectatic and fluid-filled lungs in neonates.
  • Sonography provides a reliable method for assessing diaphragmatic crus size in neonates.
Abstract

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