Acute abdominal series: Difference between revisions

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To differentiate Large and small bowel, remember:
==Technique==
3 Films:
#Upright chest film
#*Rule-out free air
#Upright abdominal film
#*Look for air-fluid levels
#Supine abdominal film (''KUB = just supine film'')
#*Width of bowel loops most visible (estimate of amount of distention)


''If patient does not tolerate upright position, left lateral decubitus abdominal film can substitute''


1) Large bowel have haustra which appear as lines 1/3-1/2 of the way through the bowel, but not all the way through.
==Interpretation==
<gallery mode="packed">
File:Medical X-Ray imaging ALP02 nevit.jpg|Normal
File:SBO plain.png|[[Small bowel obstruction]]
File:Cecalvolvulus.png|Large bowel obstruction (Cecal [[volvulus]]; black arrows).
File:Free air under diaphram.png|Free intra-abdominal air below the diaphragm.
File:Abdominal foreign body.png|Body-packing with multiple foreign bodies ("balls" of hashish).
File:Battery in stomach.png|[[Esophageal foreign body|Button battery in stomach.]]
File:StonesXray.png|[[Gallstones]] (not sensitive)
File:Toxisches Megacolon bei Colitis ulcerosa.jpg|[[Toxic megacolon]]
File:Rectal_fb.JPG|[[Rectal foreign body]]
</gallery>


2) Small bowel have lines (plica circulares) all the way through the bowel
===Differentiating large and small bowel===
{| class="wikitable"
| align="center" style="background:#f0f0f0;"|'''Location'''
| align="center" style="background:#f0f0f0;"|'''Size'''
| align="center" style="background:#f0f0f0;"|'''Lines'''
|-
| Small bowel||3 cm||All the way through the bowel (plica circulares)  
|-
| Colon||6 cm||Only halfway through the bowel (haustra)
|-
| Cecum||9 cm||
|}


===[[Small bowel obstruction]]===
*Air in colon or rectum makes complete obstruction less likely (esp if symptoms >24hr)
*Abdominal x-ray has poor Sn and Sp for [[SBO]]
**If concerned need CT


==Indications==
*Ruling out free air under the diaphragm (e.g. perforated ulcer)
*Ruling out radio-opaque abdominal foreign body (e.g. swallowed battery)
*Ruling '''in''' bowel obstruction (i.e. to avoid need for subsequent CT scan)


Acute Abd XR have poor sensitivity and specificity for SBO...if you are really concerned, get the CT.
;Do NOT use as the sole study to rule out bowel obstruction (poor sensitivity)
;Do NOT use to rule out generalized peritonitis (almost no sensitivity for diagnoses such as [[appendicitis]])
;Do NOT use to diagnose constipation (many patient with acute abdomen will have "copious stool")


==Incidental findings==
*[[Gallstones]] (not always radiodense)


==See Also==
*[[Abdominal pain]]


 
[[Category:GI]]
[[Category:Rads]]
[[Category:Radiology]]

Latest revision as of 13:57, 18 March 2019

Technique

3 Films:

  1. Upright chest film
    • Rule-out free air
  2. Upright abdominal film
    • Look for air-fluid levels
  3. Supine abdominal film (KUB = just supine film)
    • Width of bowel loops most visible (estimate of amount of distention)

If patient does not tolerate upright position, left lateral decubitus abdominal film can substitute

Interpretation

Differentiating large and small bowel

Location Size Lines
Small bowel 3 cm All the way through the bowel (plica circulares)
Colon 6 cm Only halfway through the bowel (haustra)
Cecum 9 cm

Small bowel obstruction

  • Air in colon or rectum makes complete obstruction less likely (esp if symptoms >24hr)
  • Abdominal x-ray has poor Sn and Sp for SBO
    • If concerned need CT

Indications

  • Ruling out free air under the diaphragm (e.g. perforated ulcer)
  • Ruling out radio-opaque abdominal foreign body (e.g. swallowed battery)
  • Ruling in bowel obstruction (i.e. to avoid need for subsequent CT scan)
Do NOT use as the sole study to rule out bowel obstruction (poor sensitivity)
Do NOT use to rule out generalized peritonitis (almost no sensitivity for diagnoses such as appendicitis)
Do NOT use to diagnose constipation (many patient with acute abdomen will have "copious stool")

Incidental findings

See Also