II. Contraindications

  1. Pregnancy (risk of fetal Thyroid toxicity with iodinated contrast)

III. Indications

  1. General imaging
    1. IV Contrast
      1. Vascular structures (or vascular injury)
        1. Aneurysm
        2. Dissection
      2. Solid organs (especially Abdomen and Pelvis)
      3. Pulmonary Embolism
        1. Consider CT angiogram with venous phase CT of Pelvis and lower extremities (for combination DVT evaluation)
      4. Cancer Staging
    2. Non-contrast
      1. Head Trauma (Closed Head Injury)
      2. Acute Cerebrovascular Accident (<3 hours from onset)
        1. Typically followed immediately by CT-Angiogram (unless Hemorrhagic CVA identified)
      3. Spine Trauma
      4. Extremity Trauma
        1. Use IV contrast if vascular injury suspected
      5. Nephrolithiasis
      6. Diffuse lung disease (unless Lung Mass evaluation)
    3. With and without contrast
      1. Calcified lesion evaluation (obscured by contrast)
  2. CT Abdomen and Pelvis
    1. Oral and IV contrast
      1. Indicated in most cases
      2. Appendicitis
      3. Diverticulitis
      4. Inflammatory Bowel Disease related complications
      5. Pancreatitis
        1. If evaluating Chronic Pancreatitis (calcifications), obtain CT with and without contrast
    2. No contrast
      1. Nephrolithiasis
    3. Rectal and IV contrast
      1. Suspected penetrating colonic injury
      2. Rapid evaluation for Appendicitis (Rectal contrast may not pass above cecum)
  3. Upper GI series (Fluoroscopy)
    1. High concentration Oral Contrast
  4. Barium Enema (Fluoroscopy)
    1. High concentration rectal contrast
  5. Intrathecal Contrast for Myelography (XRay, Fluoroscopy, or CT)
    1. Spinal or basal cistern disease
    2. Cerebrospinal Fluid Leak

IV. Preparations: IV Contrast Agents

  1. Iodinated, water-soluble IV contrast agents (CT contrast)
    1. Ionic Agents (replaced in large part by nonionic contrast agents listed below)
      1. Diatrizoate Sodium (Hypaque)
      2. Iothalamate meglumine (Conray)
      3. Ioxaglate meglumine (Hexabrix)
        1. Low osolality (contrast with other ionic agents) is associated with lower complication rate
    2. Nonionic Agents with low osmolality (LOCM are associated with lower complication rates)
      1. Iodixanol (Visipaque)
      2. Iopamidol (Isovue)
      3. Iopromide (Ultravist)
      4. Ioversol (Optiray)
  2. Gadolinium-based agents (MRI)
    1. See Gadolinium-Associated Nephrogenic Systemic Fibrosis
    2. Avoid Gadolinium in pregnancy (see MRI)
    3. Gadodiamide (Omniscan)
    4. Gadoteridol (ProHance)

V. Preparations: Oral Contrast (or rectal contrast)

  1. Barium Contrast
    1. Fluoroscopy (Upper GI series, Barium Enema) concentration is 20-fold higher than standard Abdominal CT Oral Contrast
    2. High concentration contrast obscures CT Abdomen and Pelvis with artifact
    3. Barium Contrast at any concentration does not obscure MRI
    4. Oral or rectal Barium Contrast has no nephrotoxicity (safe in Renal Failure)
  2. Water-soluble, Iodine-based contrast
    1. Significantly more concentrated form used for fluoroscopy (as with barium)
    2. Oral Iodine-based contrast has no nephrotoxicity (safe in Renal Failure)
    3. Risk of aspiration-induced Pulmonary Edema (with concentrated oral Iodine-based contrast)
      1. Consider alternative agents if Vomiting or aspiration risk or
      2. Consider contrast delivery via Nasogastric Tube

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