Abstract

PurposeTo develop and optimize a rapid dynamic hyperpolarized 129Xe ventilation (DXeV) MRI protocol and investigate the feasibility of capturing pulmonary signal‐time curves in human lungs.Theory and MethodsSpiral k‐space trajectories were designed with the number of interleaves N int = 1, 2, 4, and 8 corresponding to voxel sizes of 8 mm, 5 mm, 4 mm, and 2.5 mm, respectively, for field of view = 15 cm. DXeV images were acquired from a gas‐flow phantom to investigate the ability of N int = 1, 2, 4, and 8 to capture signal‐time curves. A finite element model was constructed to investigate gas‐flow dynamics corroborating the experimental signal‐time curves. DXeV images were also carried out in six subjects (three healthy and three chronic obstructive pulmonary disease subjects).ResultsDXeV images and numerical modelling of signal‐time curves permitted the quantification of temporal and spatial resolutions for different numbers of spiral interleaves. The two‐interleaved spiral (N int = 2) was found to be the most time‐efficient to obtain DXeV images and signal‐time curves of whole lungs with a temporal resolution of 624 ms for 13 slices. Signal‐time curves were well matched in three healthy volunteers. The Spearman's correlations of chronic obstructive pulmonary disease subjects were statistically different from three healthy subjects (P < 0.05).ConclusionThe N int = 2 spiral demonstrates the successful acquisition of DXeV images and signal‐time curves in healthy subjects and chronic obstructive pulmonary disease patients. Magn Reson Med 79:2597–2606, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Highlights

  • Functional pulmonary imaging techniques including hyperpolarized (HP) gas (3He and 129Xe) MRI are a growing field for the non-invasive assessment of regional lung function [1,2,3,4]

  • We describe the successful application of a multi-slice dynamic hyperpolarized 129Xe ventilation (DXeV) imaging technique in human lungs

  • Simulated signal-time curves from H1 to H5 are derived for the Nint 1⁄4 1 spiral from Eq [1] for N 1⁄4 1 to N 1⁄4 5, respectively, as shown in Figure 3b with a time step of 0.5 s over a total simulation time of 6 s similar to the DXeV images of phantom

Read more

Summary

Introduction

Functional pulmonary imaging techniques including hyperpolarized (HP) gas (3He and 129Xe) MRI are a growing field for the non-invasive assessment of regional lung function [1,2,3,4]. Hyperpolarized gas MRI enables the evaluation of ventilation and gas diffusion, which is typically carried out in a static imaging fashion during a breath-hold interval, following inhalation of 3He or 129Xe, and demonstrates homogeneous signal intensity in healthy lung regions [5,6,7,8]. Dynamic ventilation imaging with HP gas MRI is possible during a complete breath cycle, including the inhalation and exhalation intervals, using fast non-Cartesian kspace sampling strategies [11,12,13,14,15].

Objectives
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call