Semiquantitative magnetic resonance imaging parameters for differentiating parotid pleomorphic adenoma from Warthin tumor

Shao-Nan He; Ren-Cai Lu; Jia-Long Zhou; Bo Wang; Guo-Li Bi; Kun-Hua Wu

doi:10.21037/qims-22-1445

Semiquantitative magnetic resonance imaging parameters for differentiating parotid pleomorphic adenoma from Warthin tumor

Quant Imaging Med Surg. 2023 Sep 1;13(9):6152-6163. doi: 10.21037/qims-22-1445. Epub 2023 Jul 27.

Authors

Shao-Nan He^#^{1

2}, Ren-Cai Lu^#³, Jia-Long Zhou^{1

2}, Bo Wang^{1

2}, Guo-Li Bi^{1

2}, Kun-Hua Wu^{1

2}

Affiliations

¹ Magnetic Resonance Imaging Department, the First People's Hospital of Yunnan Province, Kunming, China.
² Magnetic Resonance Imaging Department, the Affiliated Hospital of Kunming University of Science and Technology, Kunming, China.
³ PET-CT Center, the First People's Hospital of Yunnan Province, Kunming, China.

^# Contributed equally.

Abstract

Background: Accurately distinguishing between pleomorphic adenoma (PA) and Warthin tumor (WT) is beneficial for their respective management. Preoperative magnetic resonance imaging (MRI) can provide valuable information due to its excellent soft tissue contrast. This study explored the value of semiquantitative contrast-enhanced MRI parameters in the differential diagnosis of PA and WT.

Methods: Data from 106 patients, 62 with PA and 44 with WT (confirmed by histopathology) were retrospectively and consecutively analyzed. The tumor-to-spinal cord contrast ratios (TSc-CR) based on the mean, maximum, and minimum signal intensity (T₁-mean TSc-CR, T₁-max TSc-CR, and T₁-min TSc-CR, respectively) in the early and delayed phases were calculated on contrast-enhanced T₁-weighted images as semiquantitative parameters, and then compared between PA and WT. Receiver operating characteristic (ROC) curve analysis and areas under the curve (AUCs) were used to determine the performance of these parameters in the differential diagnosis of PA from WT.

Results: Except T₁-min TSc-CR in the early phase, all semiquantitative MRI parameters differed significantly between PA and WT (all P<0.05). T₁-max TSc-CR showed higher sensitivity {70.45% [95% confidence interval (CI): 0.548-0.832]} and specificity [70.97% (95% CI: 0.581-0.818)] and had a higher AUC [0.707 (95% CI: 0.610-0.791)] in the early phase when using a cutoff value of 1.89. T₁-max TSc-CR showed higher sensitivity [88.64% (95% CI: 0.754-0.962)], specificity [72.58% (95% CI: 0.598-0.831)], and AUC [0.854 (95% CI: 0.772-0.915)] in the delayed phase when using a cutoff value of 2.33. The sensitivity, specificity, and AUC were improved to 90.91% (95% CI: 0.783-0.975), 93.55% (95% CI: 0.843-0.982), and 0.960 (95% CI: 0.903-0.988), respectively, after combination of all semiquantitative parameters in the early and delayed phases. The two radiologists had excellent interobserver agreement on TSc-CRs [all interclass correlation coefficient (ICC) >0.75].

Conclusions: Semiquantitative parameters using TSc-CR are valuable in distinguishing PA from WT, and a combination of these parameters can improve the differential diagnostic efficiency.

Keywords: Magnetic resonance imaging (MRI); Warthin tumor (WT); adenoma; pleomorphic.