Hi Dear, An MRI is a series of detailed picture of your brain, as they were at the time the MRI was done. They are valid as long as no other changes occur. Basically, if somebody has an MRI today that is normal, and have a stroke or hernia tomorrow, obviously the result will change (You never know).
Undo an action. Press Ctrl+Z or click (Undo) in the ribbon until you've fixed your mistake. You can't undo some actions, such as clicking commands on the File tab or saving a file. If you can't undo an action, the Undo command is dimmed.
del - Computer Definition An internal DOS/Windows command that erases a file from the disk. When a file is deleted from the command line, it cannot be retrieved from the recycle bin, so be careful!