You only need one ball to the play the game

“Getting two or three CT scans of the abdomen exposes you to the same amount of radiation as people who lived near the atomic blast that ravaged Hiroshima in 1945”

http://www.reuters.com/article/2011/01/05/us-patients-underestimate-ct-scan-radiat-idUSTRE7044RO20110105

Great…I only get one every 3 months. I get chest/abdomen/pelvis with and without contrast, so it likes a double dose too. Just great.