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Dynamic Imaging
MedQIA is experienced in functional lung analysis using dynamic CT and MRI lung imaging protocols (Brown 2000). In a dynamic CT protocol (flow study) images are acquired at a single anatomical level (i.e. no table movement) during an expiratory maneuver. The segmentation of three images (of a total of 12) from a flow series are shown below from an emphysema patient post-single lung transplant as well as plots of median attenuation (HU) and cross-sectional area vs. time during the expiratory maneuver. These graphs indicate the comparative rate of increasing attenuation and decreasing area that reflect the change of air content and volume consequent on airflow. The native, emphysematous right lung shows relatively little change in attenuation and area compared with the transplant left lung. Thus QIA is able to provide comparative information about the individual lungs that is not possible with conventional PFTs that provide only global measures of lung function.
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| (a) t=0 sec |
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(b) t=1.5 sec |
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(c) t=3.0 sec |
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Selected segmented images from a flow series at different time points.
Graphs from a flow study showing indices of individual lung function for a native right lung and transplant left lung.
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(a) Plot of median attenuation vs.
time during an expiratory maneuver. |
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(b) Plot of cross-sectional area
vs. time. |
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