I wasn't sure where to ask this question but I decided to write it under Treatment. What is the difference of the 2 types of test? What can a pet scan see that the CT Scan could not see? A pet scan is about Php150,000 or $3,750. For checking the spread or mets of the cancer, what is more exact?

Note: Joyce never had a Pet Scan due to cost. Would there be a huge impact on her treatment and diagnosis in the past? present?

Joyce March 1940 to January 2014
A wife, a mother, grandmother and great grandmother.
She fought oral cancer from late 2009 to Early 2014.
2 Timothy 4:7 I have fought the good fight, I have finished the race, I have kept the faith.