GI Radiology > Small Bowel > Imaging Modalities > Follow-Through

Small Bowel Follow-Through (cont.)

The Radiologic Procedure

  1. The patient is placed in the prone position for overhead radiographs.
    • In this position, the center of the abdomen is compressed, making the entire abdomen more uniform in thickness, thus permitting more uniform x-ray penetration through the small bowel.
    • Another advantage to the prone position is that there is better separation and less overlapping of small bowel loops.
    • Additionally, loops of ileum tend to migrate cephalad and become less compacted in the pelvis when the patient is lying on his/her abdomen.
  2. In the interval between films, the patient is generally allowed to walk about or sit in a dressing booth outside the x-ray room.
    • A debilitated patient can be left on the x-ray table between films or can be moved to a stretcher outside the room if it is needed for other examinations.
    • The patient who is unable to sit or stand should be placed in the right-side-down decubitus position to encourage gastric emptying—and then rolled periodically from one side to the other to better distribute the barium and speed its transit by using the assistance of gravity.
  3. Radiographs are taken with high kilovoltage technique (120 -125 kVp).
    • The objective is to achieve good penetration of the barium so that mucosal anatomy and intraluminal pathology can be identified en face.
    • Exposures are made on 14 x 17 inch (35 x 43 cm) films.
    • The interval between exposures depends on the speed of barium transit through the small bowel. Routinely, we obtain films at 15-minute intervals for the first hour and at 30-minute intervals thereafter.
  4. Each radiograph should be carefully examined as soon as it is processed. Any suspected abnormality should be evaluated with fluoroscopy and compression spot films.
    • Many authorities recommend, even in the absence of abnormalities on the overhead films, that periodic fluoroscopic inspections and compression spot films be performed.
    • In any case, after the barium has reached the right side of the colon, compression spot films of the terminal ileum are routinely obtained.