Protocols

Enterovesical fistula (Filling the urinary bladder)

• Native phase.
• Fill the bladder with minimum 100 mL NaCl + (1:10 contrast), e.g.:
  • 10 mL contrast + 90 mL NaCl
  • 20 mL contrast + 180 mL NaCl
• Repeat the native Phase.
• Venous phase (70-80s post-injection)

Rectovesical fistula (Rectal filling)

• Rectal filling with Gastrografin (30 mL + 1L NaCl). Infuse min. 500 mL
• Venous phase (70-80s post-injection)

Liver/Pancreas tumor

• Native Phase: liver
• CTA: thorax/liver
• Portal venous: liver
• Late venous: Complete abdomen
• Oral water: 500mL 10 min before exam, another 250 mL on CT-table

Anomalous pulmonary venous connection

• Venous phase over thorax
• Trigger in left atrium
• Flow: 3.5 – 4 max
• Contrast: 60 mL

Looking for aortic valve abscess

• ECG-gated coronary angiography + venouse phase over aortic valve (30s interscan Delay)
• Flow: 3 mL
• Contrast: 50 mL

Looking for Paraganglioma/Pheochromocytoma

• Neck + Thorax + Abdomen: arterial phase
• Abdomen: venous phase

Indications of oral contrast in abdominal CT

• Suspected perforation
• Postoperative anastomotic leakage
• GI-Fistula
• Oncologic staging
• Nonspecific acute abdomen

Postoperative oral contrast-protokols¹

• Esophagus/gastric pullup: 100 mL of 5% gastrografin on the table
• Stomach/esophagojejunostomy/duodenum: 200 mL 5% gastrografin slowly, 5 min before scan
• Small bowel: 1000 mL 5% gastrografin slowly, 60 min before scan
• Rou-en-Y (gastrectomy + small bowel anastomosis): 300 mL 5% gastrografin slowly, 30 min before scan, 100 mL 5% gastrografin on table

Using water als contrast medium

• GI bleeding (two phases)
• Assessing mucosal enhancement of the bowel
• Assessing arterial supply of a pathologic process

Fasting before a CT exam

• 3 hours are enough

Abdominal CT: Phases of Contrast Enhancement

1. RP 2020, Postop Abdomen – Vikas Shah[↩]