Comparison of Hyperpolarized 3 He and 129 Xe MR Imaging in Cystic Fibrosis Patients

• Published in: Academic radiology Vol. 29 Suppl 2; p. S82
• Main Authors: Shammi, Ummul Afia, D'Alessandro, Michelle Felicia, Altes, Talissa, Hersman, F William, Ruset, Iulian C, Mugler, 3rd, John, Meyer, Craig, Mata, Jamie, Qing, Kun, Thomen, Robert
• Format: Journal Article
• Language: English
• Published: United States 01-02-2022
• Subjects: Cystic Fibrosis - diagnostic imaging; Helium; Humans; Lung - diagnostic imaging; Magnetic Resonance Imaging - methods; Male; Reproducibility of Results; Xenon Isotopes; Ventilation defect percentage; Hyperpolarized MRI; Lung defects; Cystic fibrosis; MRI scan
• ISSN: 1878-4046

In this study, we compared hyperpolarized
He and
Xe images from patients with cystic fibrosis using two commonly applied magnetic resonance sequences, standard gradient echo (GRE) and balanced steady-state free precession (TrueFISP) to quantify regional similarities and differences in signal distribution and defect analysis.
Ten patients (7M/3F) with cystic fibrosis underwent hyperpolarized gas MR imaging with both
He and
Xe. Six had MRI with both GRE, and TrueFISP sequences and four patients had only GRE sequence but not TrueFISP. Ventilation defect percentages (VDPs) were calculated as lung voxels with <60% of the whole-lung hyperpolarized gas signal mean and was measured in all datasets. The voxel signal distributions of both
Xe and
He gases were visualized and compared using violin plots. VDPs of hyperpolarized 3 He and 129 Xe were compared in Bland-Altman plots; Pearson correlation coefficients were used to evaluate the relationships between inter-gas and inter-scan to assess the reproducibility.
A significant correlation was demonstrated between
Xe VDP and
He VDP for both GRE and TrueFISP sequences (ρ = 0.78, p<0.0004). The correlation between the GRE and TrueFISP VDP for
He was ρ = 0.98 and was ρ = 0.91 for
Xe. Overall,
Xe (27.2±9.4) VDP was higher than
He (24.3±6.9) VDP on average on cystic fibrosis patients.
In patients with cystic fibrosis, the selection of hyperpolarized
Xe or
He gas is most likely inconsequential when it comes to measure the overall lung function by VDP although
Xe may be more sensitive to starker lung defects, particularly when using a TrueFISP sequence.