Distinguishing hepatic metastases from hemangiomas: qualitative and quantitative diagnostic performance through dual echo respiratory-triggered fast spin echo magnetic resonance imaging

To determine the relative value of qualitative (reader opinion) and quantitative (values derived from dual echo T2 fast spin echo [FSE]) measures in distinguishing hepatic metastases from hemangiomas.

Forty-nine patients with hemangiomas and 23 with metastases were studied with dual echo respiratory-triggered FSE and dynamic 2-dimensional spoiled gradient echo (GRE) imaging. Lesion T2 was estimated from signal intensity ratios on the first and second echoes. Two experienced radiologists independently evaluated groups of images based on 5 separate qualitative measures: first echo FSE, second echo FSE, first and second echo FSE, dynamic GRE, and all images together.

The mean calculated T2s were 226 +/- 74 milliseconds for hemangiomas and 105 +/- 22 milliseconds for metastases (P < 0.001). A T2 cutoff of 130 milliseconds distinguished metastases from hemangiomas with a sensitivity of 94%, specificity of 91%, and accuracy of nearly 94%. There was no significant difference between the best quantitative measure and the best qualitative measure for either reader.

Liver lesion T2 relaxation times calculated from dual echo FSE images provide information useful in discriminating metastases from hemangiomas, as does reader opinion.