An audit of the use of CT pituitary scans to exclude a pituitary macroadenoma.

Background: Pituitary imaging is often required to exclude an adenoma suspected clinically or biochemically. Although magnetic resonance (MR) is the gold standard, computerised tomography (CT) is faster, cheaper and induces less claustrophobia. Our audit at Auckland City Hospital, New Zealand, investigated whether the use of CT of the pituitary as the first line imaging to assess for a pituitary macroadenoma reduces the need for MR.

Methods: We investigated the usefulness of CT pituitary imaging in the exclusion of pituitary macroadenoma between 2012 and 2020. A re-audit was then undertaken for a period of one year between March 2021 and March 2022 to assess outcomes once a departmental policy change was implemented. At Auckland City Hospital, 32 patients across eight years were eligible for this analysis, of which 31 had data available. In our re-audit, 29 patients were eligible for this analysis. We collected data on patient demographics, relevant hormone levels, indication for imaging and imaging results and subsequent management.

Results: After CT pituitary imaging, 28/31 (90%) of patients did not require further imaging because the clinical question had been addressed. One year after routine initial CT pituitary imaging was implemented by the Auckland City Hospital Endocrinology Department, 29 CT pituitary scans were performed to exclude a pituitary macroadenoma. Of these patients one required further imaging due to the finding of an expanded pituitary sella but not a pituitary macroadenoma.

Conclusion: CT pituitary imaging to exclude a pituitary macroadenoma is a useful test that may reduce the need for MR pituitary scans.

Trial registration: Not applicable. This was an audit as defined by the New Zealand National Ethics Advisory Committee guidelines. Please see 'Declarations' section.