Iodinated contrast prior to evaluation for thyrotoxicosis

Area of Science:

• Endocrinology
• Radiology
• Nuclear Medicine

Background:

• Radioactive iodine is crucial for diagnosing and treating thyrotoxicosis.
• Iodinated contrast administration for diagnostic imaging, particularly computed tomography (CT) scans, frequently prevents radioactive iodine testing.
• This study addresses the impact of iodinated contrast on thyrotoxicosis management in hospitalized patients.

Purpose of the Study:

• To assess the frequency of iodinated contrast use in newly diagnosed inpatient thyrotoxicosis cases.
• To evaluate the clinical utility of diagnostic studies involving iodinated contrast in these patients.

Main Methods:

• Retrospective chart review of 1171 inpatient endocrinology consultations over a 4-year period.
• Identification of patients with newly diagnosed thyrotoxicosis.
• Analysis of iodinated contrast administration, study types, and impact on management.

Main Results:

• 45% of patients with newly diagnosed thyrotoxicosis received iodinated contrast within two weeks prior to evaluation.
• CT scans accounted for the majority of contrast administrations (43 patients).
• Only 16% of CT scans revealed findings that potentially altered inpatient management, with only one requiring emergent treatment.

Conclusions:

• A significant proportion of hospitalized thyrotoxicosis patients undergo iodinated contrast studies before endocrinology evaluation.
• Acute findings from contrast-enhanced imaging that necessitate changes in patient management are infrequent.
• Awareness of this clinical scenario can improve the care of hospitalized patients with thyrotoxicosis.