Mechanical delivery of aerosolized gadolinium-DTPA for pulmonary ventilation assessment in MR imaging.
OBJECTIVE
To evaluate a new technique with mechanical administration of aerosolized gadolinium (Gd)-DTPA for MR visualization of lung ventilation.


METHODS
Ten experimental procedures were performed in six domestic pigs. Gd-DTPA was aerosolized by a small-particle generator. The intubated animals were mechanically aerosolized with the nebulized contrast agent and studied on a 1.5-T MR imager. Respiratory gated T1-weighted turbo spin-echo images were obtained before, during, and after contrast administration. Pulmonary signal intensity (SI) changes were calculated for corresponding regions of both lungs. Homogeneity of aerosol distribution was graded independently by two radiologists.


RESULTS
To achieve a comparable SI increase as attained in previous trials that used manual aerosol ventilation, a ventilation period of 20 minutes (formerly 30 minutes) was sufficient. Mean SI changes of 116% were observed after that duration. Contrast delivery was rated evenly distributed in all cases by the reviewers.


CONCLUSIONS
The feasibility of applying Gd-DTPA as a contrast agent to demonstrate pulmonary ventilation in large animals has been described before. The results of this refined technique substantiate the potential of Gd-based ventilation MR imaging by improving aerosol distribution and shortening the nebulization duration in the healthy lung.
Department of Diagnostic Radiology, University of Technology Aachen, Aachen, Germany. haage@rad.rwth-aachen.de
P
P
Haage
G
G
Adam
S
S
Karaagac
J
J
Pfeffer
A
A
Glowinski
S
S
Döhmen
R W
RW
Günther
D000336:Aerosols; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D008168:Lung / Q000033:anatomy & histology / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D012123:Pulmonary Ventilation; D013382:Subtraction Technique; D013552:Swine
D000336:Aerosols; D003287:Contrast Media; D019786:Gadolinium DTPA