Comparison of hyperpolarized (3)He MRI with Xe-enhanced computed tomography imaging for ventilation mapping of rat lung.

Journal article

Lung ventilation was mapped in five healthy Brown Norway rats (210-377 g) using both hyperpolarized (3)He MRI and Xe-enhanced computed tomography (Xe-CT) under similar ventilator conditions. Whole-lung measurements of ventilation r obtained with (3)He MRI were not significantly different from those obtained from Xe-CT (p = 0.1875 by Wilcoxon matched pairs test). The ventilation parameter r is defined as the fraction of refreshed gas per unit volume per breath. Regional ventilation was also measured in four regions of the lung using both methods. A two-tailed paired t-test was performed for each region, yielding p > 0.05 for all but the upper portion of the right lung. The distribution of regional ventilation was evaluated by calculating ventilation gradients in the superior/inferior (S/I) direction. The average S/I gradient obtained using the (3)He MRI method was found to be 0.17 ± 0.04 cm(-1) , whereas the average S/I gradient obtained using the Xe-CT method was found to be 0.016 ± 0.005 cm(-1) . In general, S/I ventilation gradients obtained from both methods were significantly different from each other (p = 0.0019 by two-tailed paired t-test). These regional differences in ventilation measurements may be caused by the manner in which the gas contrast agents distribute physiologically and/or by the imaging modality.

Authors: Santyr, G; Couch, M; Lam, W; Ouriadov, A; Drangova, M

• Publication status: Published
• Journal: NMR in biomedicine
• Volume: 24
• Issue: 9
• Pages: 1073-1080
• Publication date: 2011-11-01
• DOI: 10.1002/nbm.1659
• EISSN: 1099-1492
• ISSN: 0952-3480
• Language: English
• Keywords: Rats; Male; Rats, Inbred BN; Respiration; Lung; Animals; Helium; Pulmonary Ventilation; Tomography, X-Ray Computed; Xenon; Isotopes; Magnetic Resonance Imaging