What are the key differences between CT scans, MRIs, X-rays, and ultrasounds, particularly regarding their underlying technology and radiation use?

Here's how to differentiate the medical imaging techniques:

1. CT Scan (Computed Tomography Scan): Uses X-rays from multiple angles and computer processing to create detailed cross-sectional images of bones, soft tissues, and blood vessels. It involves ionizing radiation.
2. MRI (Magnetic Resonance Imaging): Uses a strong magnetic field and radio waves to produce highly detailed images of soft tissues, organs, and the brain. It does not use ionizing radiation.
3. X-Ray: Uses a small dose of ionizing radiation to create 2D images, primarily effective for visualizing bones and dense structures.
4. Ultrasound: Uses high-frequency sound waves to create real-time images of soft tissues, organs, and blood flow. It is non-invasive and does not use radiation.