Abstract

Aim: was to identify possibilities of MRI with contrast enhancement in assessment of differentiation

grade of liver metastases of neuroendocrine tumors (NET).

Materials and methods: 103 patents with morphologically confirmed liver metastases of NET were enrolled in the study. All patients underwent abdominal contrast-enhanced MRI. A total of 241 lesions were assessed. In the region of interest, which corresponded to the rounded locus in solid port-contrast T1-weighted images. Obtained data were compared in groups of different grade of tumor tissues differentiation; the correlation of MRI parameters with Ki67 was also evaluated.

Results: study demonstrated that Grade (G) 1 of NET metastases are characterized by a more active accumulation of MR contrast agent (MRCA) and a higher SI in arterial (p=0,0002, p=0,0003, respectively) and venous (p=0,0003, p=0,0001, respectively) phases of contrast enhancement compared with G2 and G3. Also, well-differentiated NETs had higher SI in the delayed phase of contrast enhancement (p = 0,0038) and the more rapid wash-out of MRCA (p=0,0314). The Ki67 index inversely correlated with the degree of MRCA accumulation in arterial and venous phases of MRI with contrast enhancement. Revealed consistency may be useful for guided tissue sampling in biopsy and identification of the grade "migration" phenomenon, which will allow competently and timely choose/change treatment modality.

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