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Regional pulmonary perfusion using model-free analysis of contrast-enhanced MRI in meconium-aspirated piglets

✍ Scribed by Pia Ryhammer; Michael Pedersen; Steffen Ringgaard; Hanne Ravn


Publisher
John Wiley and Sons
Year
2007
Tongue
English
Weight
325 KB
Volume
26
Category
Article
ISSN
1053-1807

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✦ Synopsis


Abstract

Purpose

To investigate if dynamic contrast‐enhanced MRI in lungs could add new information to pulmonary hypertension in a newborn piglet model.

Materials and Methods

Six newborn piglets were subjected to instillation of meconium following treatment with sildenafil. Before and after both of these events, dynamic contrast‐enhanced MRI was performed to determine pulmonary blood flow (PBF) using a model‐free deconvolution of the dynamic signal‐time curve, together with invasive measurements of mean airway pressure (PAW), cardiac output (CO), and oxygenation index (OI).

Results

Meconium instillation caused a significant increase in PAW (P < 0.05) accompanied by a marked increase in OI, the average PBF in the four lung regions (apical‐anterior, apical‐posterior, distal‐anterior, and distal‐posterior) decreased significantly by 33% (P < 0.001), but it did not significantly affect CO. On the other hand, infusion of sildenafil caused a significant increase in CO (P < 0.01), and administration resulted mainly in an increased PBF in the distal parts of the lungs.

Conclusion

By using dynamic contrast‐enhanced MRI, we demonstrated a marked decrease in PBF following instillation of meconium, which was not followed by an equivalent decrease in CO, suggesting that measurements of CO inadequately reflect the intrapulmonary changes in the blood circulation. J. Magn. Reson. Imaging 2007;26:296–303. © 2007 Wiley‐Liss, Inc.