Questions about radiologic technologist and sonography (ultrasound) technologist?)?

It used to be that you had to have a license as an RT before you could apply to Ultrasound school, but that's not the case anymore. All the other modalities (MR, CT, IVR) require that before most programs will look at you. US is a growing field and has more options to it (OB, Vascular, etc.) than one would find in say, MR or CT. Also, keep in mind that if you plan to travel with this career (which can be very lucrative and help you see some sights) you will need to have a 4yr degree to work outside the country. Hope that helps, let me know if you'd like more info.