About to start chemotherapy...

The gated heart pool scan was my oncologist preferred method actually and I had them throughout chemo and herceptin. It measures the output of your heart...it's efficiency. They take some blood...add some radioactive type stuff to it and give it back then do a CT scan following the blood flow. It takes about 20 mins. My tip is to be well hydrated so that the jelco is easier to insert. 

Here is a link explaining it:
https://www.insideradiology.com.au/nm-gated-blood-pool-scan/

And if you want...research on comparing the 2. Long story shirt. Both accurate.

https://www.ncbi.nlm.nih.gov/m/pubmed/18059128/