(1)H and hyperpolarized (3)He MR imaging of mouse with LPS-induced inflammation.
OBJECTIVE
To evaluate the lipopolysaccharide (LPS) model of chronic obstructive pulmonary disease (COPD) in mouse with (1)H and hyperpolarized (HP) (3)He MR imaging.


METHODS
Axial slices of the lung volume were acquired with HP (3)He and (1)H MRI at 4, 24, and 48 h after LPS exposure. A quantitative ventilation index was calculated from two HP (3)He acquisitions. A bronchoalveolar lavage (BAL) for a cell count was performed following magnetic resonance imaging (MRI).


RESULTS
The LPS exposure resulted in a significant increase of cells in BAL, with maximum at 48 h. Lesions on (3)He images were characterized by ventilation defects, whereas lesions on (1)H images were hyperintense and were attributed to edema. The number of lesions was at maximum at 48 h. At this time point, and for both (3)He and (1)H MRI, the volume of the lesions was significantly higher for LPS-exposed mice compared to controls. At 4, 24, and 48 h the ventilation index from the (3)He data was significantly smaller for the LPS-exposed animals compared to controls.


CONCLUSIONS
The time point 48 h after LPS exposure was advantageous for MRI evaluation. Functional read-out with (3)He MRI seems to be more sensitive than conventional (1)H MRI.
Olsson
Lars E
LE
DECS/Imaging, AstraZeneca R&D, Mölndal, Sweden. lars.e.olsson@astrazeneca.com
Smailagic
Amir
A
Onnervik
Per-Ola
PO
Hockings
Paul D
PD
D000818:Animals; D018893:Bronchoalveolar Lavage; D005260:Female; D006371:Helium; D006859:Hydrogen; D007554:Isotopes; D008070:Lipopolysaccharides; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D029424:Pulmonary Disease, Chronic Obstructive / Q000139:chemically induced / Q000473:pathology*
D007554:Isotopes; D008070:Lipopolysaccharides; D006371:Helium; D006859:Hydrogen