Sinograms
  • Performed after the drainage of an abscess to assess the size of the cavity and any fistulous connection to bowel or sinus tracts. (Some cavities are flushed with saline by a VON)
     
  • Before performing the procedure, ask the patient about the amount of drainage per day and check the previous sinogram to estimate cavity size.


Equipment

  • Contrast:
    • Hypaque 30%
       
  • Tubes:
    • Use the existing drainage catheter/red rubber catheter or small angiocath sheath (for fistulagrams)


Technique

  • Take AP and lateral scout views of the cavity area
     
  • Inject Hypaque slowly and watch for the sinus tracts, fistula and size of cavity
     
  • Do not over inject or forcefully inject contrast
     
  • The maximum cavity capacity is reached when the following occurs:
    • the patient develops pain or discomfort
    • contrast tracks along the catheter onto the skin surface
    • Fistulas, sinus tracts or extravasation occur
       
  • Take representation radiographs to show:
    • cavity size
    • cavity depth from the skin
    • sinus or fistula tracts
       
  • At the end of the exam, aspirate all the contrast out of the cavity
     


Pearls

  • Do not over-distend the cavity
     
  • With fistulagrams, you can occlude the Foley catheter opening (may inflate the balloon) to prevent contrast leakage
     
  • Lateral view radiographs are important to assess cavity depth
     
  • Scout radiographs are important in assessing the presence of surgical clips or contrast from previous exams which may mimic sinus tracts or extravasation.


Radiographs

Value of Orthogonal Views:
AP sinogram view of a pelvic abscess drained. The cavity is completely obliterated. Lateral Orthogonal sinogram view of a pelvic abscess. There is a sinus tract extending anteriorly (not shown on AP view).
 

Value of Careful Distension/Filling of the Abscess Cavity:
AP view of a sinogram of a Tubo-ovarian abscess. Initial study shows the collapsed fallopian tube. AP view of a sinogram of a Tubo-ovarian abscess. On further distension the patient had severe pain causing her to place her hand over the site (see the hand).
 

Value of Adequate Filling of the Abscess Cavity:
AP view of a sinogram of a peri-Kock’s pouch abscess cavity. Initial sinogram done showed no communication to pouch. Tube was removed. Abscess recurred requiring further drainage. This is a scout film. AP view with adequate filling of te abscess cavity showing a fistula to the pouch (see contrast at the tip of the Medina catheter within the pouch).