Medical Imaging Techniques

1. X-ray (Radiography)

✅ How It Works:

• Uses ionizing radiation (high-energy X-rays) to create images of bones and tissues.

• X-rays pass through the body, and denser structures (like bones) appear white on the image.

📌 Uses:

✔️ Diagnosing fractures and bone injuries
✔️ Detecting infections in bones or lungs (e.g., pneumonia)
✔️ Identifying tumors and abnormal growths

🚨 Limitations:

• Cannot provide detailed images of soft tissues.

• Exposure to ionizing radiation carries a small health risk.

2. MRI (Magnetic Resonance Imaging)

✅ How It Works:

• Uses strong magnetic fields and radio waves to create detailed images of internal organs and soft tissues.

• No ionizing radiation involved.

• Produces high-resolution, 3D images.

📌 Uses:

✔️ Brain and spinal cord imaging (e.g., stroke, tumors)
✔️ Joint and muscle injuries
✔️ Heart and blood vessel issues
✔️ Soft tissue abnormalities (e.g., ligaments, tendons)

🚨 Limitations:

• Time-consuming (takes 30–90 minutes).

• Expensive.

• Not suitable for patients with metal implants (e.g., pacemakers).

3. MRA (Magnetic Resonance Angiography)

✅ How It Works:

• A type of MRI focused on blood vessels.

• Uses magnetic fields and radio waves, often with a contrast agent (like gadolinium) to enhance visibility of blood vessels.

📌 Uses:

✔️ Detecting aneurysms (weakened blood vessels)
✔️ Identifying blockages or narrowing in blood vessels
✔️ Planning vascular surgery

🚨 Limitations:

• Same limitations as MRI (metal implants, time, cost).

• Some patients may be allergic to the contrast agent.

4. PET (Positron Emission Tomography)

✅ How It Works:

• Involves injecting a small amount of radioactive tracer (usually glucose-based).

• Active cells (e.g., cancer cells) absorb the tracer and emit positrons, which are detected to create an image.

📌 Uses:

✔️ Cancer detection and staging
✔️ Brain disorders (e.g., Alzheimer’s, Parkinson’s)
✔️ Heart disease and blood flow issues

🚨 Limitations:

• High cost.

• Radiation exposure (small dose).

• Poor structural detail — often combined with CT or MRI for better accuracy.

5. CT (Computed Tomography)

✅ How It Works:

• Uses X-rays to take cross-sectional images of the body (like slices).

• A computer assembles the slices into a 3D image.

📌 Uses:

✔️ Trauma (e.g., head injuries, internal bleeding)
✔️ Cancer detection and monitoring
✔️ Lung and heart issues
✔️ Bone fractures and spinal problems

🚨 Limitations:

• Higher radiation exposure than standard X-rays.

• Lower soft tissue contrast compared to MRI.

Comparison Table