Preliminary Diagnosis: Gas Gangrene

I. What imaging technique is first-line for this diagnosis?

Plain radiograph.

II. Describe the advantages and disadvantages of this technique for diagnosing gas gangrene.

  • Highly portable.

  • Inexpensive.

  • Fast imaging modality.

  • Expose patients to minimal ionizing radiation.

  • Less adept in detecting and characterizing the primary pathologic process and any secondary complications compared to companion cross sectional imaging.

III. What are the contraindications for the first-line imaging technique?

No specific contraindications to plain radiography exist. Some institutions may require consent for pregnant patients.

IV. What alternative imaging techniques are available?

  • CT.

  • MRI with contrast.

V. Describe the advantages and disadvantages of the alternative techniques for diagnosing gas gangrene.

  • Highly sensitive and specific in diagnosing and characterizing the primary process and characterizing any secondary complications.

  • May help guide treatment and therapy.

  • Offers exquisite detail of the gas and its extension.

  • Exposes patients to ionizing radiation.

  • More expensive and less portable compared to plain radiographs.

MRI with contrast
  • More sensitive and specific in detecting and characterizing any underlying osteomyelitis.

  • Offers more exquisite detail of the underlying soft tissues.

  • Does not expose patients to ionizing radiation.

  • Expensive.

  • Time consuming.

  • Requires significant patient cooperation to minimize motion artifact.

  • Gas is not well identified on MR imaging.

VI. What are the contraindications for the alternative imaging techniques?

  • May be contraindicated in pregnant patients.

MRI with contrast
  • Contraindicated in patients with non-MR compatible hardware.

  • Gadolinium contrast is contraindicated in patients with a GFR ≤ 30.