CT scans are valuable for finding cancers, but deliver a lot of radiation in the process. That's an especially big concern for children. iStockphoto hide caption itoggle caption iStockphoto Shots - Health News Tiny Iron Particles Help Find Cancer Without Using Risky Radiation February 20, 2014 CT scans are good at finding cancer, but their hefty dose of X-rays increases the risk of future cancers. Children are especially vulnerable. A new form of MRI can find tumors without radiation.