Medical Images and Imaging

Medical imaging is the use of various techniques to create pictures of the inside of the body for diagnosis, treatment and study. Anatomical images and the diagnostic scans produced by imaging equipment let clinicians examine bones, organs and tissues without surgery, making imaging one of the most important tools in modern medicine. Such images are also widely used in teaching, helping students relate the structures of the body to the way they appear on a scan.

Several imaging methods are based on different physical principles. X-ray radiography passes a small dose of radiation through the body and records how much is absorbed, producing clear images of bone and dense tissue. Computed tomography, or CT, combines many X-ray views taken from different angles into detailed cross-sectional slices. Ultrasound uses high-frequency sound waves and their echoes to image soft tissue and is commonly used in pregnancy. Magnetic resonance imaging, or MRI, uses strong magnetic fields and radio waves to show soft tissues such as the brain and muscles in fine detail without ionising radiation.

Beyond diagnostic scans, anatomical illustrations, photographs and labelled diagrams record the structure of the human body and the appearance of healthy and diseased tissue. These visual resources support medical education and research, allowing complex anatomy and the signs of various conditions to be studied and compared. Interpreting any medical image requires training, and findings are always considered alongside a patient's history and other examinations.

Frequently asked questions

What is the difference between a CT scan and an MRI?

A CT scan builds cross-sectional images from X-rays and is fast and good for bone and dense tissue, while an MRI uses magnetic fields and radio waves to show soft tissue in detail without ionising radiation.

Why is ultrasound used during pregnancy?

Ultrasound uses harmless sound waves rather than radiation, making it a safe way to image a developing fetus and monitor its growth and position.

Do all imaging methods use radiation?

No. X-ray and CT use ionising radiation, but ultrasound relies on sound waves and MRI uses magnetic fields and radio waves, neither of which is ionising.