Characteristics of dynamic magnetic resonance image enhancement in prolactinomas resistant to dopamine agonist therapy

Qinghua Guo, Bradley J. Erickson, Alice Y. Chang, Dana Erickson

Research output: Contribution to journalArticlepeer-review


Objective: The objective of this study was to determine whether dynamic magnetic resonance imaging (dMRI) enhancement parameters could predict dopamine agonist (DA) resistance in prolactinomas. Methods: We retrospectively identified patients with prolactinomas who were treated with DA and underwent dMRI from 2001 through 2012 at Mayo Clinic (Rochester, MN). Intensities of the adenoma and pituitary gland were measured by drawing regions of interest on the images. Enhancement ratio, enhancement peak, prepeak slope (PPS), and enhancement time were compared between DA-resistant and DA-responsive groups, between DA-treated and DA-naive groups, and between the first and follow-up dMRIs. Results: We identified 49 patients with prolactinomas, with 6 (12.2%) showing DA resistance. Thirty-seven patients (75.5%) underwent dMRI while receiving treatment, 12 (25.5%) underwent dMRI before starting therapy, and 10 (20.4%) had follow-up dMRI after DA therapy. The PPS of the tumor was higher in the treatment-resistant group versus the responsive group (mean [SD], 4.42 [3.19] vs 2.65 [1.59]; P = 0.03), whereas no differencewas noted in the pituitary gland (5.79 [2.21] vs 4.06 [2.48]; P = 0.11). Logistic regression analysis indicated that tumor PPS was associated with DA resistance (odds ratio, 1.71; 95% confidence interval, 1.07Y3.27; P = 0.02). Conclusions: Dynamic MRI with PPS analysis potentially can be used early in the treatment course to evaluate DA resistance in pituitary prolactinomas.

Original languageEnglish (US)
Pages (from-to)529-533
Number of pages5
JournalJournal of Investigative Medicine
Issue number3
StatePublished - Mar 11 2015


  • adenoma
  • magnetic resonance imaging
  • neurotransmitter agents
  • pituitary neoplasms

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology


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