Delineation of IGTV for stage I lung tumors based on (a) IGTV
, (b) IGTV
, (c) IGTV
, and (d) IGTV
of a 4-D CT data set. MIP-based contours, as shown in panels (a) and (b), are as they appear on the MIP data set. Phase-based contours, as shown in panels (c) and (d), are registered to the peak exhalation phase of the 4-D CT data set.