Which non-invasive technique uses magnetic fields to produce an image of soft tissues and requires the patient to remain still for prolonged periods, being extremely expensive?

• A. Venography
• B. X-ray
• C. Myelography
• D. MRI

Answer: (D)

Imaging with magnetic fields relies on aligning hydrogen protons in the body using a powerful magnet and then using radiofrequency pulses to generate signals that are converted into highly detailed images of soft tissues such as the brain, spinal cord, and joints. It is non-invasive because nothing must enter the body and there is no ionizing radiation. However, the scan times are relatively long, so patients must stay very still to avoid motion artifacts, which can be uncomfortable and require the patient to remain motionless for extended periods. The equipment and technology are expensive to install and maintain, contributing to the high cost. These factors together point to MRI as the best choice for imaging soft tissues with excellent contrast, despite the cost and the need for stillness.