High-grade soft-tissue sarcoma: optimizing injection improves MRI evaluation of tumor response.

• Accuracy of response criteria based on contrast enhancement, like the Choi criteria, is dependent on the acquisition delay after gadolinium-chelate injection. • DCE-MRI helps determine the optimal acquisition delay after gadolinium-chelate injection for improving evaluation of tumor response. • In soft tissue sarcoma, an acquisition delay at 60 s optimizes the evaluation of the response and accuracy of the Choi criteria.