Fig. 9.

Kidney mass imaged at DECT. a) Portal venous phase coronal CT image shows a high density renal mass (arrow) that is ambiguous for enhancing tumor versus a hemorrhagic cyst. The DECT scan material decomposition images show B) high density in the lesion on the water / virtual unenhanced image without high density in the C) iodine density image. These findings confirm that the lesion does not enhance with intravenous contrast material and is not a renal cell carcinoma. Instead, the lesion is diagnosed as a benign hemorrhagic cyst and requires no further follow up. Were it not for the material decomposition images, additional imaging workup would have been required for this patient to assess for enhancement.