Radiography and CT of Adult Large-Bowel Obstruction

Targeted CE per ARRT’s Discipline, Category, and Subcategory classification:
[Note: Discipline-specific Targeted CE credits may be less than the total Category A credits approved for this course.]

Computed Tomography: 1.50
Procedures: 1.50
Abdomen and Pelvis: 1.50

Radiography: 0.50
Procedures: 0.50
Head, Spine and Pelvis Procedures: 0.50

Registered Radiologist Assistant: 2.00
Procedures: 2.00
Abdominal Section: 2.00

Outline

1. Introduction
2. Clinical Findings and Pathophysology
3. Abdominal Radiography Technique
   1. Merits of Abdominal Radiography
   2. Challenges of Abdominal Radiography in Patients with LBO
4. Multidetector CT
   1. CT Technique
   2. Pitfalls of CT Imaging of LBO
5. The Contrast Enema
6. LBO: Major Causes
   1. Colon Carcinoma
   2. Volvulus
   3. Sigmoid Volvulus
   4. Cecal Volvulus
   5. Transverse Colon Volvulus
   6. Diverticulitis
   7. Adult Intussusception
   8. Intraluminal Contents Causing LBO
   9. Hernias
   10. Inflammatory Bowel Disease
   11. Adhesions
   12. External Compression
7. ACPO or Ogilvie Syndrome: An Important Mimic of LBO

Objectives

Upon completion of this course, students will:

1. describe the anatomy and function of the colon
2. understand the symptoms of LBO
3. describe both common and less common causes of LBO
4. know the frequency of LBO compared to SBO
5. describe the key topographic anatomical landmarks of the abdomen
6. know the main anatomical sites in the colon where LBO occurs
7. describe a volvulus and where they occur
8. understand how abdominal sounds relate to LBO
9. describe the quadrants that make up the abdominal cavity
10. describe the radiographic projections used in an abdominal radiographic series
11. know which radiographic views are able to show air/fluid levels in the abdomen
12. understand the sensitivity of abdominal radiography in diagnosing LBO
13. describe pneumatosis intestinalis and the associated CT findings
14. describe ACPO and its alternative names
15. understand the role CT plays in diagnosing LBO
16. understand the role a contrast enema plays in diagnosing LBO
17. know the relationship between colon malignancy and LBO
18. know the various radiographic signs related to a sigmoid volvulus
19. describe a cecal volvulus
20. know the abdominal radiography, CT and contrast enema findings of a cecal volvulus
21. describe the CT findings of ischemia associated with cecal volvulus
22. describe a volvulus of the transverse colon and its findings on a contrast enema
23. know the relationship between diverticulitis and LBO
24. know how diverticulitis is characterized with CT
25. describe adult intussusception and its relationship to LBO
26. know the classic appearance of adult intussusception on a contrast enema
27. know how intraluminal contents relate to LBO
28. know the various types of internal hernias and their relationships to LBO
29. describe the relationship between Crohn disease and LBO
30. understand how adhesions and external compression from masses relate to LBO