Dose and pulse sequence considerations for hyperpolarized (129)Xe ventilation MRI

Mu He; Scott H Robertson; S Sivaram Kaushik; Matthew S Freeman; Rohan S Virgincar; John Davies; Jane Stiles; William M Foster; H Page McAdams; Bastiaan Driehuys

doi:10.1016/j.mri.2015.04.005

Dose and pulse sequence considerations for hyperpolarized (129)Xe ventilation MRI

Magn Reson Imaging. 2015 Sep;33(7):877-85. doi: 10.1016/j.mri.2015.04.005. Epub 2015 Apr 30.

Authors

Affiliations

¹ Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
² Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA; Medical Physics Graduate Program, Duke University, Durham, NC, USA.
³ Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA; Department of Biomedical Engineering, Duke University, Durham, NC, USA.
⁴ Department of Medicine Pulmonary, Duke University Medical Center, Durham, NC, USA.
⁵ Medical Physics Graduate Program, Duke University, Durham, NC, USA; Department of Medicine Pulmonary, Duke University Medical Center, Durham, NC, USA.
⁶ Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA; Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Radiology, Duke University Medical Center, Durham, NC, USA; Medical Physics Graduate Program, Duke University, Durham, NC, USA. Electronic address: bastiaan.driehuys@duke.edu.

Abstract

Purpose: The aim of this study was to evaluate the effect of hyperpolarized (129)Xe dose on image signal-to-noise ratio (SNR) and ventilation defect conspicuity on both multi-slice gradient echo and isotropic 3D-radially acquired ventilation MRI.

Materials and methods: Ten non-smoking older subjects (ages 60.8±7.9years) underwent hyperpolarized (HP) (129)Xe ventilation MRI using both GRE and 3D-radial acquisitions, each tested using a 71ml (high) and 24ml (low) dose equivalent (DE) of fully polarized, fully enriched (129)Xe. For all images SNR and ventilation defect percentage (VDP) were calculated.

Results: Normalized SNR (SNRn), obtained by dividing SNR by voxel volume and dose was higher for high-DE GRE acquisitions (SNRn=1.9±0.8ml(-2)) than low-DE GRE scans (SNRn=0.8±0.2ml(-2)). Radially acquired images exhibited a more consistent, albeit lower SNRn (High-DE: SNRn=0.5±0.1ml(-2), low-DE: SNRn=0.5±0.2ml(-2)). VDP was indistinguishable across all scans.

Conclusions: These results suggest that images acquired using the high-DE GRE sequence provided the highest SNRn, which was in agreement with previous reports in the literature. 3D-radial images had lower SNRn, but have advantages for visual display, monitoring magnetization dynamics, and visualizing physiological gradients. By evaluating normalized SNR in the context of dose-equivalent formalism, it should be possible to predict (129)Xe dose requirements and quantify the benefits of more efficient transmit/receive coils, field strengths, and pulse sequences.

Keywords: Hyperpolarized (129)Xe MRI; Pulse sequence; Signal-to-noise ratio; Ventilation defect.

Publication types

Controlled Clinical Trial
Research Support, N.I.H., Extramural

MeSH terms

Administration, Inhalation
Algorithms
Contrast Media / administration & dosage
Dose-Response Relationship, Drug
Female
Humans
Image Enhancement / methods
Image Interpretation, Computer-Assisted / methods
Imaging, Three-Dimensional / methods
Lung / diagnostic imaging*
Magnetic Resonance Imaging / methods*
Male
Middle Aged
Pulmonary Ventilation*
Reproducibility of Results
Respiration Disorders / diagnostic imaging*
Sensitivity and Specificity
Signal Processing, Computer-Assisted*
Signal-To-Noise Ratio
Ultrasonography
Xenon Isotopes / administration & dosage*

Substances

Contrast Media
Xenon Isotopes

Abstract

Publication types

MeSH terms

Substances

Grants and funding