Premature utilization of MRI in the workup of mild hyperprolactinemia
Jennifer A. Mann, Jared Galloway, Sana Ghaznavi, David J. T. Campbell, John Lysack, Kirstie Lithgow
Abstract
Hyperprolactinemia is a common biochemical finding detected in primary care, and guidelines suggest confirmation with a second prolactin measurement to rule out spurious elevation prior to further workup. Premature magnetic resonance imaging (MRI) is a costly potential consequence of improperly worked-up hyperprolactinemia.
Introduction
Elevated serum prolactin (hyperprolactinemia) is a biochemical finding with a broad differential diagnosis [1–3]. Hyperprolactinemia may be detected in the primary care setting during workup of amenorrhea, galactorrhea, hypogonadism, or non-specific complaints such as fatigue, and is a common reason for referral to endocrinology [2,4].
Methods
A retrospective chart review was performed between 2012 and 2021 in the province of Alberta, Canada. Our protocol was approved by the Conjoint Health Research Ethics Board at the University of Calgary (REB22-0273). Potentially eligible cases were identified by a data analyst from Alberta Health Services. In order to allow us to clarify clinical details from each patient chart, we received the raw data with patient identifiers.
Results
We identified 5,740 cases with MRI sella or brain and mildly elevated prolactin (<100 mcg/L) ordered prior to MRI between 2012 and 2021. We screened each case for further eligibility which left 3,715 cases.
Discussion
We identified a large proportion of MRIs in our health region ordered for isolated, mild hyperprolactinemia that were performed prematurely without confirmation by repeat prolactin measurement. Initial work-up of mild hyperprolactinemia should include measurements of macroprolactin, beta hCG, and thyroid stimulating hormone, [5] which we did not assess.
Conclusion
MRI sella for investigation of mild hyperprolactinemia is commonly ordered prematurely without confirmation by repeat prolactin level. In our province, premature imaging generated hundreds of findings of questionable clinical significance (382 over the span of nine years), many of which were probably clinical insignificant non-functioning pituitary microadenomas.
Citation: Mann JA, Galloway J, Ghaznavi S, Campbell DJT, Lysack J, Lithgow K (2026) Premature utilization of MRI in the workup of mild hyperprolactinemia. PLoS One 21(4): e0346134. https://doi.org/10.1371/journal.pone.0346134
Editor: Melissa Orlandin Premaor, Federal University of Minas Gerais: Universidade Federal de Minas Gerais, BRAZIL
Received: December 12, 2025; Accepted: March 16, 2026; Published: April 8, 2026
Copyright: © 2026 Mann et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper and its Supporting Information files.
Funding: The author(s) received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Abbreviations: CT, computed tomography; EMR, electronic medical record; hCG, human chorionic gonadotropin; MRI, magnetic resonance imaging; TSH, thyroid-stimulating hormone
