You're excited to book your 3D/4D ultrasound... but then you read something online or hear a comment that makes you pause. "Is it really safe?" "Will it look like my baby?" We get it. Let's clear up the 5 most common myths right now. Myth 1: "Keepsake ultrasounds aren't safe." Fact: This is the biggest concern. The truth is: 3D/4D keepsake ultrasounds use the exact same sound wave technology (sonography) as the 2D medical scan at your doctor's office. There is zero radiation.