Zollinger-Ellison Syndrome

Preliminary Diagnosis: Zollinger-Ellison Syndrome

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

The first line imaging modality is ultrasound of the pancreas and surrounding abdominal organs. (Endoscopic sonography offers better evaluation than transabdominal sonography).

II. Describe the advantages and disadvantages of this technique for diagnosing Zollinger Ellison-Syndrome.

Advantages

• Highly portable.

• Does not expose patients to ionizing radiation.

• Highly specific in detecting and detailing the surrounding vasculature.

Disadvantages

• Highly operator dependent.

• Limited in patients with a large body habitus and those with prominent bowel gas.

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

No specific contraindications to ultrasound exist.

IV. What alternative imaging techniques are available?

• CT imaging with IV contrast.

• MR imaging with IV contrast.

• Nuclear medicine imaging utilizing indium labeled octreotide.

V. Describe the advantages and disadvantages of the alternative techniques for diagnosing Zollinger-Ellison Syndrome.

CT imaging with IV contrast

Advantages

• Highly sensitive and specific in detecting any primary pancreatic/gastric/hepatic neoplasm and any surrounding metastatic lesions.

• May help guide percutaneous biopsy, treatment, and therapy.

• Better characterizes the primary process and any secondary complications than other imaging modalities.

Disadvantages

• Exposes patients to ionizing radiation.

MR imaging with IV contrast

Advantages

• Does not expose patients to ionizing radiation.

• Highly sensitive and specific in detecting any primary pancreatic/gastric/hepatic abnormalities and any suspicious metastatic lesions.

Disadvantages

• Expensive.

• Time consuming.

• Less adept in directing percutaneous biopsy.

• May be subject to motion and susceptibility weighted artifact, degrading image quality.

Nuclear medicine imaging utilizing indium labeled octreotide

Advantages

• Highly sensitive and specific in detecting a gastrinoma, particularly an extra hepatic and extra pancreatic gastrinoma.

• Sensitive and specific in detailing distant metastatic deposits.

Disadvantages

• Less adept in detailing the surrounding soft tissues, vasculature, and osseous structures.

• False positive studies may be seen in patients with granulomatous disease, thyroid disease, arthritis, lymphoma, and infections.

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

CT imaging with IV contrast

May be contraindicated in pregnant patients.

MR imaging with IV contrast

May be contraindicated in patients with non MR compatible hardware.

Nuclear medicine imaging utilizing indium labeled octreotide

May be contraindicated in pregnant patients and those who are breast feeding.