The patient in this image was referred for characterization of a lesion in the kidney, suspected to be a kidney cyst when viewed on conventional CT. The cystic lesion is visible in the conventional contrast CT image (top left), but that gives little information about what it is. Switching to a visualization that enhances iodine and suppresses water (top right), the measurement indicates that there is iodine uptake and the lesion is metabolically active. Looking at the effective atomic number (bottom center), it can be seen that the Zeff value is 8.3, well above the value of water. The bottom right image is virtual non-contrast, filtering out all iodine signal and showing just the anatomy of the kidney. All spectral information in this case assisted in confirming this kidney malignancy, with just a single scan. In yet another view it is possible to check the heterogeneity of the lesion. Tumor heterogeneity is used as a guide to create more refined treatment strategies and response to therapy.