Dynamic Ventilation ^3He MRI for the Quantification of Disease in the Rat Lung

• Published in: IEEE transactions on biomedical engineering Vol. 59; no. 3; pp. 777 - 786
• Main Authors: Kyriazis, Angelos, Rodriguez, I., Nin, N., Izquierdo-Garcia, J. L., Lorente, J. A., Perez-Sanchez, J. M., Pesic, J., Olsson, L. E., Ruiz-Cabello, J.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2012; Institute of Electrical and Electronics Engineers
• Subjects: Animals; Biological and medical sciences; Biomedical imaging; Computerized, statistical medical data processing and models in biomedicine; Diffusion Magnetic Resonance Imaging - methods; Disease Models, Animal; Elastase-treated rats; Equations; Female; Helium; hyperpolarized ^3 He MRI; inflation rate; Isotopes; Lungs; Magnetic resonance imaging; Medical management aid. Diagnosis aid; Medical sciences; Pancreatic Elastase; Pulmonary Emphysema - diagnosis; Pulmonary Emphysema - pathology; pulmonary ventilation; Rats; Rats, Wistar; regional flow; Sensitivity and Specificity; Ventilation; Elastase-treated rats; hyperpolarized; Disease; Rat; Lung; Rodentia; inflation rate; Respiratory system; Nuclear magnetic resonance imaging; Vertebrata; Mammalia; Treatment; regional flow; Animal; Medical imagery; He MRI; Pulmonary ventilation; Respiration; Biomedical engineering
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/TBME.2011.2179299

Pulmonary diseases are known to be largely inhomogeneous. To evaluate such inhomogeneities, we are testing an image-based method to measure gas flow in the lung regionally. Dynamic, spin-density-weighted hyperpolarized 3 He MR images performed during slow inhalation of this gas were analyzed to quantify regional inflation rate. This parameter was measured in regions of interest (ROIs) that were defined by a rectangular grid that covered the entire rat lung and grew dynamically with it during its inflation. We used regional inflation rate to quantify elastase-induced emphysema and to differentiate healthy ( n = 8) from elastase-treated ( n = 9) rat lungs as well as healthy from elastase-treated areas of one rat unilaterally treated with elastase in the left lung. Emphysema was also assessed by gold standard morphological and well-established hyperpolarized 3 He MRI diffusion measurements. Mean values of regional inflation rates were significantly different for healthy and elastase-treated animals and correlated well with the apparent diffusion coefficient of 3 He and morphological measurements. The image-based biomarker inflation rate may be useful for the assessment of regional lung ventilation.