What is the difference between a barium swallow and a modified barium swallow?

Area of interest: The terms are often interchanged though do have differences in medical billing and exact procedure type. A barium swallow is often synonymous with an esophagram to look at the whole of the esophagus. A 'modified barium swallow' is usually performed in conjunction with a Speech Pathologist and is specifically looking at the swallowing mechanism of the mouth and oral phaynx to the upper esophagus.