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CT Abdomen
Aka: CT Abdomen, Abdominal CT, CT Abdomen and Pelvis, Abdominopelvic CT
- See Also
- Abdominal Pain Evaluation
- CT Abdomen in Appendicitis
- Background
- Modern CT Scanners capture isotropic voxels (3 dimensional pixels)
- Voxels allows for software recompositing of imaging into any slice plane (e.g. coronal slices)
- Does not require specific instructions beyond overall imaging technique (e.g. IV contrast)
- Jaffe (2007) Radiology 242:175-81 [PubMed]
- Indications: Acute Abdominal Pain (Oral water and IV Contrast unless otherwise noted)
- Appendicitis
- Diverticulitis
- Bowel Obstruction
- Acute Pancreatitis
- Ureterolithiasis or Nephrolithiasis (no contrast)
- Abdominal Aortic Aneurysm (IV contrast only)
- Mesenteric Ischemia
- Crohn's Disease (CT enterography)
- Abdominal Trauma (IV contrast only)
- Intraabdominal abscess (with Oral Contrast in addition to IV contrast)
- Technique: Oral Contrast
- Most Abdominal CT protocols require oral water only (no Oral Contrast)
- Patients with increased abdominal fat require less contrast
- Evaluation for Appendicitis or Diverticulitis does NOT require Oral Contrast
- Low Attenuation Contrast (air, water) is usually preferable to high attenuation Oral Contrast (e.g. barium, diatrizoate)
- High attenuation contrast may obscure malignancy and intestinal Hemorrhage
- Air alone is an excellent contrast due to low attenuation (-1000 Hounsfield Units)
- Allows for pneumoperitoneum (perforation) detection
- Oral water (400-600 ml) immediately prior to CT helps identify gastric lesions
- Water distends Stomach and differentiates gastric masses from Stomach wall
- References
- Broder (2018) Crit Dec Emerg Med 32(6): 12-3
- High Attentuation Oral Contrast (Gastrografin/Gastroview, Omnipaque, Readi-Cat/Barium) Indications
- Patient indications for Oral Contrast
- Lean patient (e.g. BMI <19-20 kg/m2)
- Age <18 years old
- Condition indications for Oral Contrast
- Bowel Fistula
- Bowel perforation or peptic ulcer perforation
- Intraabdominal Abscess
- References
- Anderson (2005) Am J Surg 190(3): 474-8 [PubMed]
- Garcia (2013) Acad Emerg Med 20(8): 795-800 [PubMed]
- Harrison (2013) West J Emerg Med 14(6): 595-7 [PubMed]
- Adverse Effects: Children
- Sold-tumor risk from CT radiation exposure in children
- See CT-associated Radiation Exposure
- Girls: 1 new cancer per 300-390 CT Abdomen and Pelvis
- Boys: 1 new cancer per 670-760 CT Abdomen and Pelvis
- Miglioretti (2013) JAMA Pediatr 167(8): 700-7 [PubMed]
- References
- Ashoo, Orman and Hollander in Herbert (2015) EM:Rap 15(6): 17