Use the Reset Images tool to revert all changes applied since the study was last saved in this session or, if it has not been saved, since it was opened. Changes that are reversed include any window leveling, markups, calibration changes, geometry changes, tab stop additions, and magnification applied since the last save.
To reset to last save
From the Image area top toolbar, click Reset Images.
All changes applied to images in the study are reverted to the previously saved state.