Gastrointestinal Radiology > Procedures > Upper GI > Upper GI (3)


Upper G.I. Tract Biphasic-Contrast Exam (cont.)

Preliminary

  1. About using the fluoroscope.. .. The fluoroscope has an image intensifier or digital panel that permits a maximum field of view (FOV) that may be from 12 inches to 16 inches in diameter, depending upon the equipment installed in the room. Each fluoroscope has 3 or 4 levels of electronic magnification or "zoom". The largest FOV with the least electronic magnification will cover the largest area of the patient during live fluoroscopy and on spot images. The largest FOV also exposes the patient (and medical personnel) to the least radiation dose. Each level of electronic magnification approximately doubles the radiation output; thus, going from a 12-inch FOV to a 9-inch FOV doubles the radiation. Going from the 12-inch FOV to 6-inch and 4-inch fields increases the radiation roughly 4X and 8X, respectively. Thus, you should scan or pan over the patient using the largest appropriate FOV and only "zoom in" with electronic magnification for short periods of time, like when you are about to take a close-up spot image. In addition, collimating or "coning-in" your FOV will improve the quality of the image-and at the same time reduce the radiation dose to you and your patient. Also, making the effort to use live fluoroscopy intermittently and/or with pulsed fluoroscopy will reduce radiation exposure. Don't have a lead foot!.

  2. A biphasic-contrast exam should be attempted on all patients. If it turns out that the patient is uncooperative or too debilitated, the study can be completed as a single-contrast exam by skipping the double-contrast parts of the study. 

  3. Question the patient about: 
    1. relevant symptoms
    2. previous abdominal surgery
    3. having been NPO since midnight
    4. the possibility of pregnancy 

  4. Explain the procedure to the patient. Describe how to perform breath-holding during spot filming (e.g. "Don't take in a breath; just stop breathing"). Caution the patient not to belch after drinking the "bubbly barium".

  5. If the patient is to have both a cervical esophageal barium swallow (BS) and UGI, start with the UGI and do the examination of the hypopharynx and cervical esophagus at the end of the study.