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Updated: Aug 3, 2025
Author Spotlight: Standardization and Best Practices for Advancing Lung Imaging Using 129Xe MRI
Published on: November 21, 2023
129Xe MRI Ventilation Defects in Asthma: What is the Upper Limit of Normal and Minimal Clinically Important
Marrissa J McIntosh1, Alexander Biancaniello1, Harkiran K Kooner1
1Robarts Research Institute, Western University, London, Canada; Department of Medical Biophysics, Western University, London, Canada.
Rationale And Objectives:
The minimal clinically important difference (MCID) and upper limit of normal (ULN) for MRI ventilation defect percent (VDP) were previously reported for hyperpolarized 3He gas MRI. Hyperpolarized 129Xe VDP is more sensitive to airway dysfunction than 3He, therefore the objective of this study was to determine the ULN and MCID for 129Xe MRI VDP in healthy and asthma participants.
Materials And Methods:
We retrospectively evaluated healthy and asthma participants who underwent spirometry and 129XeMRI on a single visit; participants with asthma completed the asthma control questionnaire (ACQ-7). The MCID was estimated using distribution- (smallest detectable difference [SDD]) and anchor-based (ACQ-7) methods. Two observers measured VDP (semiautomated k-means-cluster segmentation algorithm) in 10 participants with asthma, five-times each in random order, to determine SDD. The ULN was estimated based on the 95% confidence interval of the relationships between VDP and age.
Results:
Mean VDP was 1.6 ± 1.2% for healthy (n = 27) and 13.7 ± 12.9% for asthma participants (n = 55). ACQ-7 and VDP were correlated (r = .37, p = .006; VDP = 3.5·ACQ + 4.9). The anchor-based MCID was 1.75% while the mean SDD and distribution-based MCID was 2.25%. VDP was correlated with age for healthy participants (p = .56, p =.003; VDP = .04·Age-.01). The ULN for all healthy participants was 2.0%. By age tertiles, the ULN was 1.3% ages 18-39 years, 2.5% for 40-59 years and 3.8% for 60-79 years.
Conclusion:
The 129Xe MRI VDP MCID was estimated in participants with asthma; the ULN was estimated in healthy participants across a range of ages, both of which provide a way to interpret VDP measurements in clinical investigations.
Insights
This study determined the minimal clinically important difference (MCID) and upper limit of normal (ULN) for 129Xe MRI VDP in healthy and asthma patients. These values aid in interpreting 129Xe MRI VDP measurements for clinical investigations.
Area of Science:
- Pulmonary Medicine
- Medical Imaging
- Respiratory Physiology
Background:
- Previous studies established MCID and ULN for 3He MRI VDP.
- 129Xe MRI VDP offers higher sensitivity to airway dysfunction compared to 3He MRI.
- Establishing normative data for 129Xe MRI VDP is crucial for clinical application.
Purpose of the Study:
- To determine the upper limit of normal (ULN) for 129Xe MRI VDP in healthy individuals.
- To determine the minimal clinically important difference (MCID) for 129Xe MRI VDP in participants with asthma.
- To provide interpretative benchmarks for 129Xe MRI VDP in clinical settings.
Main Methods:
- Retrospective evaluation of healthy and asthma participants undergoing spirometry and 129Xe MRI.
- MCID estimation using distribution-based (SDD) and anchor-based (ACQ-7) methods.
- ULN estimation based on the 95% confidence interval of VDP in relation to age.
Main Results:
- Mean VDP was 1.6% in healthy and 13.7% in asthma participants.
- Anchor-based MCID was 1.75%, distribution-based MCID was 2.25%.
- ULN for healthy participants was 2.0% overall, with age-specific values (1.3% to 3.8%).
Conclusions:
- The study successfully estimated MCID for 129Xe MRI VDP in asthma patients.
- ULN for 129Xe MRI VDP was established for healthy individuals across different age groups.
- These findings provide essential reference values for interpreting 129Xe MRI VDP in clinical research and practice.
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