[Movement analysis of chest MR image under rest breath using realignment of SPM]

Analyses of diaphragm and chest wall motion are good indicators to evaluate clinical status and pulmonary function before and after surgery for respiratory disease. Noninvasive MR images using fast gradient recalled echo techniques recently have received a great deal of attention for their assessment of inspiratory motion. However, it is laborious to analyze a large number of dynamic MR images. Therefore, we performed movement analyses of chest 2D MR images by using the public domain software statistical parametric mapping(SPM)Realignment sub-routine, which is commonly used for the motion correction of brain functional MRI analyses. First, dynamic 2D MR images of a glue-stick phantom were measured as a simple reciprocal movement model and were numerically analyzed by the SPM Realignment. The resulting translation to each axis coincided with the measured values. Then the dynamic images of normal volunteers under free breathing were analyzed by the same method, and we found that the inspiratory motions were quantitatively shown as the translation to each axis. These results revealed that the SPM Realignment is a useful tool for screening the magnitude and characteristics of inspiratory motion.