A nuclear magnetic resonance investigation of the upper airways in ferrets. II. Contrast-enhanced imaging to distinguish vascular from other nasal fluids.

Proton magnetic resonance imaging (MRI), used in conjunction with the intravascular contrast agent albumin-(Gd-DTPA), provides a means to distinguish vascular fluids from other nasal fluids in the upper airways. Ferrets were given an intravenous dose of albumin-(Gd-DTPA) followed by an intranasal challenge with either histamine (HS) or methacholine (MC). An observed increase in image intensity indicates that HS and MC both cause an accumulation of fluids in the nasal turbinate region. The MRI data are also influenced by the presence of blood, which contains the contrast agent, and a clear distinction can be made between vascular fluids and other nasal fluids (i.e., cellular and glandular secretions). The results show that HS causes an increase in vascular fluids in the nasal turbinates while MC does not. This methodology represents a new means to investigate airway pharmacology and the pathophysiology associated with various pharmacological agents, allergens, or viral infections.