Quantitative MRI in distinguishing bladder paraganglioma from bladder leiomyoma

To investigate the feasibility of quantitative MRI in the differentiation of bladder paraganglioma from bladder leiomyoma.

From 2014 to 2021, 11 patients with bladder paraganglioma and 14 patients with bladder leiomyoma confirmed by surgical pathology were retrospectively collected. All patients underwent multiparametric scanning with a 3.0 T MR system. Quantitative parameters including the SI-ratio on T₁WI between the solid component of tumours and piriformis, ADC value and E-rate of the solid component of tumours were assessed. Independent sample t test or Mann-Whitney U test was used to compare these parameters between the two groups. The diagnostic efficiency of the parameters was examined using ROC curve analysis and the DeLong test.

There were significant differences in SI-ratio on T₁WI (P < 0.001), ADC value (P = 0.002) and the E-rate (P = 0.040) between the paraganglioma group and the leiomyoma group. The cutoff value of SI-ratio on 3 leiomyoma was 1.241, and the AUC was 1.000 (0.858-1.000). The cutoff value of the ADC value was 0.979 × 10^-3mm²/s, and the AUC was 0.907 (0.717-0.987). The cutoff value of E-rate was 98.7%, and the AUC was 0.714 (0.495-0.878). The AUCs of the SI-ratio on T₁WI and ADC value were significantly higher than the E-rate AUC (P = 0.015 and 0.034, respectively).

Quantitative MRI can effectively distinguish bladder paraganglioma from bladder leiomyoma with the SI-ratio on T₁WI or ADC value.