CT of Acute Bowel Ischemia

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: 4.00
Procedures: 4.00
Abdomen and Pelvis: 4.00

Registered Radiologist Assistant: 4.00
Procedures: 4.00
Abdominal Section: 3.00
Neurological, Vascular, and Lymphatic Sections: 1.00

Vascular-Interventional Radiography: 2.00
Procedures: 2.00
Vascular Diagnostic Procedures: 2.00

Outline

1. Introduction
2. Anatomy and Physiology
3. Etiology and Pathogenesis
4. Pathology
5. CT Role
   1. Value
   2. Technique
   3. Findings
      1. Bowel Wall Thickening
      2. Dilatation
      3. Stranding and Ascites
      4. Bowel Wall Attenuation
      5. Abnormal Enhancement
      6. Pneumatosis and Portomesenteric Gas
   4. Pitfalls
6. Conclusion

Objectives

Upon completion of this course, students will:

1. understand the causes of bowel ischemia
2. be familiar with which bowel diseases are potentially fatal conditions
3. understand what acute transmural bowel ischemia involves
4. know the anastomotic connections between the SMA and IMA
5. be familiar with the branches of the abdominal aorta
6. be familiar with the vascular supply of the large and small bowel
7. understand the blood supply the celiac axis provides
8. know what the superior mesenteric artery provides blood to
9. know what the Inferior mesenteric artery provides blood to
10. be familiar with the layers of the intestine
11. be familiar with what vessel the Inferior mesenteric vein drains into
12. be familiar with what vessel the superior mesenteric vein drains into
13. know the percentage of cardiac output that supplies the bowel
14. understand to which layer of the bowel the majority of blood supply goes
15. understand what happens to the blood supply to the bowel following eating
16. know what factors can decrease blood supply to the bowel
17. be familiar with the most common causes of acute bowel ischemia
18. understand the characteristics of partial mural bowel wall ischemia
19. be familiar with the localized complications of bowel ischemia
20. know the localized complications of bowel ischemia
21. be familiar with what are not systemic complications of bowel ischemia
22. know the systemic complications of bowel ischemia
23. know the most common origin of the embolism for acute occlusions of the SMA
24. be familiar with the most common cause of SMA occlusion
25. be familiar with the characteristics of mesenteric vein occlusions
26. know the conditions that lead to bowel ischemia
27. know the causes of non-occlusive ischemia
28. be familiar with the cause of occlusive bowel ischemia
29. understand the characteristics of stage I bowel ischemia
30. understand the characteristics of stage III bowel ischemia
31. know during which Stage partial mural bowel ischemia occurs
32. know which stage of acute bowel ischemia is associated with a high rate of death
33. be familiar with what condition bowel wall necrosis is followed by
34. know how various bowel disease states appear in the presence of contrast agents
35. know what types of contrast agents to use when evaluating CT of bowel ischemia
36. understand the timing of contrast enhancement when evaluating CT of bowel ischemia
37. know the proper dosage of IV contrast
38. understand how long following the injection of IV contrast the portal phase occurs
39. understand how long following the injection of IV contrast the arterial phase occurs
40. be familiar with what pathology can be seen on a high quality venous phase scan
41. know what bowel wall changes can be seen on CT
42. understand the reasons for not administering contrast agents
43. know the causes of bowel wall thickening in patients with acute bowel ischemia
44. know the normal range for bowel wall thickness
45. know the most common CT finding in bowel ischemia
46. understand the least specific CT finding in bowel ischemia
47. understand the least common CT finding in bowel ischemia
48. list the extra-intestinal CT findings secondary to bowel ischemia
49. be familiar with the most specific CT finding in bowel ischemia
50. understand the CT finding which indicates a good prognosis