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Aman Jalali, Masaru Ishii, Johan M. Edvinsson, Liang Guan, Maxim Itkin, David A. Lipson, James E. Baumgardner, and Rahim R. Rizi
Several radiological imaging modalities are available to assist with the clinical diagnosis of pulmonary embolism (PE). The most frequently used techniques—nuclear medicine ventilation-perfusion (VP) scan, computed tomography (CT), magnetic resonance angiography (MRA), and pulmonary angiography (PA)—all have literature-supported, substantial limitations with respect to timeliness and patient safety. Hyperpolarized 3He magnetic resonance gas distribution imaging (HP 3He MRI) recently has shown potential as a safer and faster alternative. In this study, we performed HP 3He MRI on a porcine model (N = 6) of simulated PE using selective occlusion balloon catheterization (N = 4) and nonselective aged autologous clot injection (N = 1). The technique was also performed on a normal pig and again after the animal was killed. Temporal depletion of regional HP 3He MRI signal intensity provided for a qualitative assessment of simulated PE (N = 4), and regional PAO2 (alveolar partial pressure of oxygen) was calculated in affected airspaces for a quantitative assessment of simulated PE (N = 1). The preliminary results suggest that HP 3He MRI shows promise as a means of assessing regional pulmonary perfusion abnormalities in the porcine models of simulated PE that were used in this study.
Magn Reson Med. 51:291–298, 2004. |
