Non-invasive fetal lung assessment using diffusion-weighted imaging

Authors

  • W. Lee,

    Corresponding author
    1. Division of Fetal Imaging, Department of Obstetrics and Gynecology, William Beaumont Hospital, Royal Oak, MI, USA
    2. Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA
    3. Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, USA
    • Division of Fetal Imaging, William Beaumont Hospital, 3601 West Thirteen Mile Road, Royal Oak, MI 48073-6769, USA
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  • A. Krisko,

    1. Division of Fetal Imaging, Department of Obstetrics and Gynecology, William Beaumont Hospital, Royal Oak, MI, USA
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  • A. Shetty,

    1. Department of Diagnostic Radiology, William Beaumont Hospital Research Institute, Royal Oak, MI, USA
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  • L. Yeo,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, USA
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  • S. S. Hassan,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, USA
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  • F. Gotsch,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA
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    • The contribution of F. Gotsch and R. Romero to this article was prepared as part of their official duties as United States Government employees.

  • S. Mody,

    1. Department of Pediatric Imaging, Wayne State University, Detroit, MI, USA
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  • L. F. Gonçalves,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, USA
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  • R. Romero

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI, USA
    3. Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA
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    • The contribution of F. Gotsch and R. Romero to this article was prepared as part of their official duties as United States Government employees.


Abstract

Objectives

The main goal was to develop a reproducible method for estimating the diffusion of water in human fetal lung tissue using diffusion-weighted imaging (DWI). A secondary objective was to determine the relationship of the apparent diffusion coefficients (ADCs) in the fetal lung to menstrual age and total lung volume.

Methods

Normal pregnant volunteers were scanned on a 1.5-Tesla (T) magnetic resonance imaging (MRI) system. The MRI system was equipped with 40-mT/m gradients (slew rate 200 T/m/s, rise time 0.2 ms). A six-channel body array coil was used for signal reception. Single-shot DWI utilized TE/TR 125/3400 ms, slice thickness 4 mm, field of view 280 mm × 280 mm, interslice gap 0.8 mm and a matrix of 128 × 128. The voxel size was 2.5 mm × 2.5 mm × 4.0 mm. Two b-values (0 and 1000) were chosen along three orthogonal directions. ADC maps were created using assigned b-values. Simple linear regression was performed with Pearson correlation coefficient. Interexaminer and intraexaminer bias, and 95% limits of agreement (LOA) were determined using Bland–Altman plots.

Results

Forty-seven scans were performed at a mean ± SD of 29.2 ± 4.5 weeks. The median coefficient of variation for ADC was 5.6% (interquartile range, 4.0–8.1%). No differences in ADC values were found between right and left lungs. Normally distributed ADC measurements were not significantly correlated with either total lung volume (r2 = 0.0001, P = 0.94) or menstrual age (r2 = 0.003, P = 0.70). The mean ADC value was 1.75 (95% CI, 1.63–1.86). Mean ± SD intraexaminer bias was −0.15 ± 2.3 (95% LOA, −4.7 to + 4.4) and interexaminer bias was 2.2 ± 3.5 (95% LOA, −4.7 to + 9.1).

Conclusions

Our findings suggest that ADC measurements of the fetal lung are reproducible between blinded examiners and are independent of menstrual age, as well as lung volume. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.

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