Open your eyes, and you will see
76 yo F, past h/o lung cancer presents with flank pain and fever. Conventional CT obtained. Very subtle signs of pyelonephritis on the right, with cortical hypoperfusion.
Turn on spectral, and the cortical hypoperfusion is very easy to appreciate. But, lo and behold, a previously invisible gallstone is also now visible!
Spectral CT will make it easy to see what you need to see, but will also show you what you do not expect to see.