Journal article
A Comparison of Two Hyperpolarized Xe-129 MRI Ventilation Quantification Pipelines: The Effect of Signal to Noise Ratio
Academic radiology, Vol.26(7), pp.949-959
07/01/2019
DOI: 10.1016/j.acra.2018.08.015
PMCID: PMC6437021
PMID: 30269957
Abstract
Rationale: Hyperpolarized Xe-129 MRI enables quantitative evaluation of regional ventilation. To this end, multiple classifiers have been proposed to determine ventilation defect percentage (VDP) as well as other cluster populations. However, consensus has not yet been reached regarding which of these methods to deploy for multicenter clinical trials. Here, we compare two published classification techniques linear-binning and adaptive K-means to establish their limits of agreement and their robustness against reduced signal-to-noise ratio (SNR).
Methods: A total of 29 subjects (age: 38.4 +/- 19.0 years) were retrospectively identified for inter-method comparison. For each Xe-129 ventilation image, 7 images with reduced SNR were generated with equal decrements relative to the native SNR. All 8 sets of images were then analyzed using both methods independently to classify all lung voxels into four clusters: VDP, low-, medium-, and high-ventilation-percentage (LVP, MVP and HVP). For each cluster, the percentage of the lung it comprised was compared between the two methods, as well as how these values persisted as SNR was degraded.
Results: The limits of agreement for calculating VDP were [+0.2%, +4.0%] with a +1.5% bias for binning relative to K-means. However, the inter-method agreement for the other clusters was moderate, with biases of -5.7%, -8.1%, and -4.0% for LVP, MVP, and HVP, respectively. As SNR decreased below similar to 4, both methods began reporting values that deviated substantially from the native image. By requiring VDP to remain within <= 1.8% of that calculated from the native image, the minimum tolerable SNR values were 2.4 +/- 1.0 for the linear-binning, and 3.5 +/- 1.5 for the K-means.
Conclusions: Both methods agree well in quantifying VDP, but agreement for LVP and MVP remains variable. We suggest a required SNR threshold be two standard deviations above the minimum value of 3.5 +/- 1.5 for robust determination of VDP, suggesting a minimum SNR of 6.6. However, robust quantification of the ventilated clusters required an SNR of 13.4.
Details
- Title: Subtitle
- A Comparison of Two Hyperpolarized Xe-129 MRI Ventilation Quantification Pipelines: The Effect of Signal to Noise Ratio
- Creators
- Mu He - Duke UniversityWei Zha - University of Wisconsin–MadisonFei Tan - Duke UniversityLeith Rankine - Duke UniversitySean Fain - University of Wisconsin–MadisonBastiaan Driehuys - Duke University
- Resource Type
- Journal article
- Publication Details
- Academic radiology, Vol.26(7), pp.949-959
- DOI
- 10.1016/j.acra.2018.08.015
- PMID
- 30269957
- PMCID
- PMC6437021
- NLM abbreviation
- Acad Radiol
- ISSN
- 1076-6332
- eISSN
- 1878-4046
- Publisher
- Elsevier
- Number of pages
- 11
- Grant note
- NIH/NHLBI-U10 HL109168 / SARP grant NIH/NHLBI-P01 HL070831; NIH/NHLBI-R01 HL126771; R01HL105643 / COAST grant R01HL105643 / NATIONAL HEART, LUNG, AND BLOOD INSTITUTE; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Heart Lung & Blood Institute (NHLBI)
- Language
- English
- Date published
- 07/01/2019
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Electrical and Computer Engineering; Health, Sport, and Human Physiology
- Record Identifier
- 9984275058502771
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