Toxic Megacolon

Preliminary Diagnosis: Toxic Megacolon

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

Plain radiograph of the abdomen and pelvis.

II. Describe the advantages and disadvantages of this technique for diagnosing toxic megacolon.

Advantages
  • Highly portable and relatively inexpensive imaging modality.

  • Exposes patients to minimal ionizing radiation.

  • Moderately sensitive and moderately specific for diagnosing toxic megacolon.

Disadvantages
  • Offers limited sensitivity and specificity in characterizing and evaluating the surrounding soft tissues, osseous structures, and vasculature.

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 imaging of the abdomen and pelvis.

V. Describe the advantages and disadvantages of the alternative techniques for diagnosing toxic megacolon.

Advantages
  • Offers more exquisite visualization of the surrounding soft tissues, vasculature, and osseous structures than plain radiography

  • Highly sensitive and specific in detecting, characterizing, and diagnosing toxic megacolon.

  • More sensitive and specific in characterizing the primary process and detecting any secondary complications than plain radiography

Disadvantages

Exposes patients to more ionizing radiation than plain radiography.

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

May be contraindicated in pregnant patients.