MRI vs CT Scan
Soft tissue detail beats bone and bleeding urgency — and vice versa.
MRI uses magnetic fields to produce detailed soft-tissue images. CT uses X-rays for fast cross-sectional views. They answer different clinical questions; doctors don't usually substitute one for the other.
Side by side
| Factor | MRI | CT Scan |
|---|---|---|
| Scan time | 20-60 min | 5-10 min |
| Radiation | None | Moderate |
| Soft tissue detail | Excellent | Good |
| Bone detail | Good | Excellent |
| Acute bleeding | Slower to detect | Very fast to detect |
| Claustrophobia | Significant — long, enclosed | Short, open-ring |
| Cost (relative) | Higher | Lower |
| Best for | Brain, spine, joints, ligaments | Trauma, strokes, chest, abdomen |
Choose MRI when
- Knee, shoulder, or spinal ligament injury
- Suspected MS or brain tumour
- Pituitary imaging
- Liver lesion characterisation
Choose CT Scan when
- Acute trauma and head injury
- Suspected stroke (first-line)
- Pulmonary embolism
- Kidney stones
- Acute abdominal pain workup
The verdict
You don't choose between these — your doctor does, based on the clinical question. If you have both options offered, ask which answers the question better and which involves less radiation for your age.