Changes in regional airflow obstruction over time in the lungs of patients with asthma: evaluation with 3He MR imaging.

Abstract

PURPOSE:

To determine changes in regional airflow obstruction over time in the lungs of patients with asthma, as demonstrated with hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging, and to assess correlations with disease severity and use of asthma medications.

MATERIALS AND METHODS:

Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study. Use of (3)He was approved by the U.S. Food and Drug Administration. Forty-three patients underwent 103 MR imaging studies in total; 26 were imaged twice within 42-82 minutes (same day), and 17 were imaged on 3 days between 1 and 476 days (multiday). Each day, spirometry was performed, disease severity was determined, and the use of asthma medications was recorded. Images were reviewed in a pairwise fashion to determine total ventilation defect number, defects in same location between imaging studies, and size. Parametric and nonparametric statistical methods were used.

RESULTS:

For the same-day examinations, the mean number of defects per image section was similar at baseline and repeat imaging (1.8 +/- 1.9 [standard deviation] vs 1.6 +/- 1.9, respectively; P = .15), with 75% of defects remaining in the same location and 71% of these not changing size. For the multiday examinations, the mean number of defects per section was higher for study 2 (2.4 +/- 1.5) than study 1 (1.7 +/- 0.9, P = .02), was lower for study 3 (1.5 +/- 1.1) than for study 2 (P < .01), and was similar for studies 1 and 3 (P = .56). Time between examinations was not associated with change in mean number of defects per section (median intrasubject correlation [r(m)] = 0.01, P = .64) or change in spirometric values (range of r(m) values: -0.56 to -0.31; range of P values: .09-.71). Defects in the same location decreased with time (r(m) = -0.83, P < .01), with 67% persisting between studies 1 and 2 (median interval, 31 days), 43% persisting between studies 2 and 3 (median interval, 41 days), and 38% persisting between studies 1 and 3 (median interval, 85 days); 46%-58% of defects remained unchanged in size. These trends were the same regardless of disease severity or medication use.

CONCLUSION:

In asthma, focal airflow impediment within the lungs can be markedly persistent over time, regardless of disease severity or treatment.

• Authors: Eduard E de Lange, Talissa A Altes, James T Patrie, John J Battiston, Adam P Juersivich, John P Mugler 3rd, Thomas A Platts-Mills
• Journal: Radiology (Radiology) Vol. 250 Issue 2 Pg. 567-75 (Feb 2009) ISSN: 1527-1315 [Electronic] United States
• PMID: 19188325 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Helium

Topics

• Adolescent
• Adult
• Analysis of Variance
• Asthma (physiopathology)
• Female
• Helium
• Humans
• Lung (physiopathology)
• Magnetic Resonance Imaging (methods)
• Male
• Severity of Illness Index
• Spirometry
• Statistics, Nonparametric