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Semiautomated Ventilation Defect Quantification in Exercise-induced Bronchoconstriction Using Hyperpolarized Helium-3 Magnetic Resonance Imaging: A Repeatability Study
Journal article   Peer reviewed

Semiautomated Ventilation Defect Quantification in Exercise-induced Bronchoconstriction Using Hyperpolarized Helium-3 Magnetic Resonance Imaging: A Repeatability Study

Wei Zha, David J Niles, Stanley J Kruger, Bernard J Dardzinski, Robert V Cadman, David G Mummy, Scott K Nagle and Sean B Fain
Academic radiology, Vol.23(9), pp.1104-1114
09/2016
DOI: 10.1016/j.acra.2016.04.005
PMCID: PMC9436394
PMID: 27263987
url
https://www.ncbi.nlm.nih.gov/pmc/articles/9436394View
Open Access

Abstract

This study aimed to compare the performance of a semiautomated ventilation defect segmentation approach, adaptive K-means, with manual segmentation of hyperpolarized helium-3 magnetic resonance imaging in subjects with exercise-induced bronchoconstriction (EIB). Six subjects with EIB underwent hyperpolarized helium-3 magnetic resonance imaging and spirometry tests at baseline, post exercise, and recovery over two separate visits. Ventilation defects were analyzed by two methods. First, two independent readers manually segmented ventilation defects. Second, defects were quantified by an adaptive K-means method that corrected for coil sensitivity, applied a vesselness filter to estimate pulmonary vasculature, and segmented defects adaptively based on the overall low-intensity signals in the lungs. These two methods were then compared in four aspects: (1) ventilation defect percent (VDP) measurements, (2) correlation between spirometric measures and measured VDP, (3) regional VDP variations pre- and post exercise challenge, and (4) Dice coefficient for spatial agreement. The adaptive K-means method was ~5 times faster, and the measured VDP bias was under 2%. The correlation between predicted forced expiratory volume in 1 second over forced vital capacity and VDP measured by adaptive K-means (ρ = -0.64, P <0.0001) and by the manual method (ρ = -0.63, P <0.0001) yielded almost identical 95% confidence intervals. Neither method of measuring VDP indicated apical/basal or anterior dependence in this small study cohort. Compared to the manual method, the adaptive K-means method provided faster, reproducible, comparable measures of VDP in EIB and may be applied to a variety of lung diseases.
Bronchoconstriction - physiology Spirometry Reproducibility of Results Humans Respiratory Function Tests - methods Magnetic Resonance Imaging - methods Male Lung - diagnostic imaging Lung - physiopathology Helium Forced Expiratory Volume Young Adult Exercise Adult Female Isotopes

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