Regional Heterogeneity of Lobar Ventilation in Asthma Using Hyperpolarized Helium-3 MRI

Wei Zha, Stanley J. Kruger, Robert V. Cadman, David G. Mummy, Michael D. Evans, Scott K. Nagle, Loren C. Denlinger, Nizar N. Jarjour, Ronald L. Sorkness, Sean B. Fain

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Rationale and Objectives: To determine lobar ventilation patterns in asthmatic lungs with hyperpolarized 3 He magnetic resonance imaging (HP 3 He MRI). Materials and Methods: Eighty-two subjects (14 normal, 48 mild-to-moderate asthma, and 20 severe asthma) underwent HP 3 He MRI, computed tomography (CT), and pulmonary function testing. After registering proton to 3 He images, we segmented the lungs from proton MRI and further segmented the five lung lobes (right upper lobe [RUL], right middle lobe [RML], and right lower lobe [RLL]; left upper lobe and left lower lobe [LLL]) by referring to the lobar segmentation from CT. We classified the gas volume into four signal intensity levels as follows: ventilation defect percent (VDP), low ventilation percent, medium ventilation percent, and high ventilation percent. The local signal intensity variations in the ventilated volume were estimated using heterogeneity score (Hs). We compared each ventilation level and Hs measured in the whole lung and lobar regions across the three subject groups. Results: In mild-to-moderate asthma, the RML and RUL showed significantly greater VDP than the two lower lobes (RLL and LLL) (P ≤.047). In severe asthma, the pattern was more variable with the VDP in the RUL significantly greater than in the RLL (P =.026). In both asthma groups, the lower lobes (RLL and LLL) showed significantly higher high ventilation percent and Hs compared to the three upper lobes (all P ≤.015). Conclusions: In asthma, the RML and RUL showed greater ventilation abnormalities, and the RLL and LLL were more highly ventilated with greater local heterogeneity. These findings may facilitate guided bronchoscopic sampling and localized airway treatment in future studies.

Original languageEnglish (US)
Pages (from-to)169-178
Number of pages10
JournalAcademic radiology
Volume25
Issue number2
DOIs
StatePublished - Feb 2018
Externally publishedYes

Keywords

  • Asthma
  • hyperpolarized gas imaging
  • magnetic resonance imaging
  • ventilation defect percent
  • ventilation heterogeneity

Fingerprint Dive into the research topics of 'Regional Heterogeneity of Lobar Ventilation in Asthma Using Hyperpolarized Helium-3 MRI'. Together they form a unique fingerprint.

Cite this