Intravoxel incoherent motion MR imaging of early cervical carcinoma: correlation between imaging parameters and tumor-stroma ratio

Objectives: To investigate if intravoxel incoherent motion (IVIM) MR imaging can predict the tumour-stroma ratio (TSR) in patients with early cervical carcinoma.

Methods: Fifty-four patients with early cervical carcinoma were prospectively enrolled into this study. All patients underwent IVIM imaging and parameters including D, D* and f value were measured. The tumours were classified into stroma-rich and stroma-poor group according to TSR, and comparisons of IVIM parameters between two groups were performed. The relationships between IVIM parameters and TSR were analysed by using a multivariate multi-regression analysis.

Results: D and f values were significantly lower in stroma-poor tumours than in stroma-rich tumours (p=0.02, 0.04), while the difference in D* value between two groups didn't achieve statistical significance (p=0.09). The areas under ROC curves of D and f values in discriminating stroma-rich and stroma-poor tumours were 0.835 (95%CI=0.616~0.905) and 0.686 (95%CI=0.575~0.798). In multiple linear regression analysis, D value, pathologic type, histologic grade, tumour size and f value were independently correlated with TSR of cervical carcinoma.

Conclusions: D and f values are independently correlated with TSR of cervical carcinoma and have the potential for quantitative measurement of TSR.

Key points: • TSR is a recognized independent prognostic factor in many solid tumours. • D and f values measured by IVIM MRI are independently correlated with TSR while D* is not. • IVIM offers the potential to predict TSR.