SYSTEM AND METHOD FOR IMPROVED DETECTION AND ASSESSMENT OF CHANGES IN LUNG-TISSUE STRUCTURE

摘要

A method and system is described for measuring the apparent diffusion coefficient of Xe129 in the lung as a means to detect and assess changes in lung-tissue structure such as those that occur in certain pulmonary diseases. The main steps of this process include: polarizing the Xe129 gas; introducing said gas into the lung; acquiring sets of Xe 129 MR signals with various diffusion sensitizations; calculating Xe 129 ADC values; and evaluating said ADC values by comparison of the values in a region of interest to those in different regions of the lung or to normative values. Diffusion measurements with Xe 129 will likely yield increased sensitivity for the detection of certain pulmonary pathologies compared to established methods because the lengths that can be probed with Xe129 are: (i) smaller than those that can be probed with established methods that are based on He3 and (ii) similar to the physical dimensions of healthy alveoli. This increased sensitivity, combined with the fact that Xe129 is a natural component of the atmosphere whereas He3 is a rare isotope that, on Earth, comes primarily from the decay of tritium and is therefore relatively expensive and in very limited supply, suggests that diffusion imaging with Xe 129 may develop into the method of choice for detecting and quantifying changes in lung-tissue structure.