Full-body MRIs are all the rage. Celebrities and influencers tout the benefits of such scans that could find asymptomatic aneurysms and cancers lurking in your body. Sometimes, they're life-saving.

The rise of full-body MRI scans has been framed as a victory for consumer empowerment. Skip the referrals. Skip the waiting. Pay out of pocket and finally see what is happening inside your body, ...