'Overused' health test given to millions each year linked to startling explosion in cancers | 14 April 2025 | A medical test used to detect cancer may actually be contributing to the disease, research suggests. California researchers estimate more than 100,000 new cancers will have been caused by computerized tomography (CT) scans from exams done in 2023 alone. They warn the scans, which use X-rays to create detailed images of the body, emit unsafe levels of radiation which fuel the formation of tumors. In 2009, researchers estimated high doses of radiation from CT scans were responsible for two percent of all cancers (or roughly 30,000 per year). However, the new research published this week estimated "CT-associated cancer could eventually account for five percent of all new cancer diagnoses annually."