Diagnostic imaging analysis to differentiate struma ovarii from mucinous carcinomas, encompassing T2*-based imaging, diffusion-weighted imaging, and dynamic contrast-enhanced imaging

Br J Radiol. 2024 Nov 1;97(1163):1843-1849. doi: 10.1093/bjr/tqae165.

Abstract

Objectives: To clarify the differences between struma ovarii (SO) and mucinous carcinomas (MC) on CT and MRI, including T2*-based images, diffusion-weighted images (DWI), and time-intensity curve (TIC) patterns, which have not been previously reported.

Methods: We retrospectively compared the presence of low intensity on T2-weighted and T2*-based images, high intensity on T1-weighted images, hyperattenuation on non-contrast CT, TIC pattern, T2 ratio, T1 ratio, CT value, and apparent diffusion coefficient (ADC) value in 15 patients with SO and 27 patients with MC.

Results: SO exhibited a significantly higher frequency of low intensity on T2-weighted and T2*-based images, and hyperattenuation on non-contrast CT than MC (P < .001, <.001, and .006, respectively). The T2 ratios and CT attenuation of the locules were also significantly different (P < .001, and .006, respectively). In SO, sites of low intensity on T2-weighted and T2*-based images and sites of hyperattenuation on CT images always coincided. Regarding the TIC pattern, most SO showed a high-risk pattern, with a significant difference (P = .003). The ADC values of SO were significantly lower, and only one case of SO showed high signal intensity on DWI.

Conclusions: SO were more frequently with low intensity on T2-weighted and T2*-based images, and hyperattenuation on non-contrast CT, and showed high-risk TIC patterns without diffusion restriction.

Advances in knowledge: SO shows a high-risk TIC pattern but can be specifically diagnosed in combination with the lack of diffusion restriction and loculi with marked hypointensity on T2-weighted and T2*-based images consistent with hyperattenuation on non-contrast CT.

Keywords: CT; MRI; mucinous carcinoma; ovary; struma ovarii.

MeSH terms

  • Adenocarcinoma, Mucinous* / diagnostic imaging
  • Adenocarcinoma, Mucinous* / pathology
  • Adult
  • Aged
  • Contrast Media*
  • Diagnosis, Differential
  • Diffusion Magnetic Resonance Imaging* / methods
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods
  • Middle Aged
  • Ovarian Neoplasms* / diagnostic imaging
  • Retrospective Studies
  • Struma Ovarii* / diagnostic imaging
  • Tomography, X-Ray Computed* / methods

Substances

  • Contrast Media