Question
Investigation of choice in aortic dissection is
| A. |
USG |
| B. |
CT Scan |
| C. |
MRI |
| D. |
Digital substraction Angiography |
Show Answer
|
Correct Answer » B Explanation |
 |
Aortic dissection occurs when a tear develops in the intima of the aorta, allowing blood to enter the media and create a false lumen.
Typical presentation:
- Sudden severe “tearing” or “ripping” chest pain
- Pain radiating to the back
- Pulse deficits
- Blood pressure differences between limbs
Why Option B is Correct
CT Angiography (CTA) is currently the investigation of choice in most patients with suspected aortic dissection because it is:
- Rapid
- Widely available
- Highly sensitive and specific
- Able to identify:
- Intimal flap
- True and false lumens
- Extent of dissection
- Branch vessel involvement
Sensitivity and specificity are both typically >95%.
Why Other Options are Incorrect
A. Ultrasonography (USG)
- Routine abdominal or chest ultrasound is not adequate.
- Transesophageal echocardiography (TEE) can diagnose dissection, especially in unstable patients, but is not represented by the option “USG.”
C. MRI
- Extremely accurate.
- Excellent sensitivity and specificity.
- Limitation:
- Time-consuming
- Less available in emergencies
- Not suitable for unstable patients
Historically considered the most accurate test, but not the practical investigation of choice in acute settings.
D. Digital Subtraction Angiography (DSA)
- Previously considered the gold standard.
- Largely replaced by CT angiography due to its invasive nature and lower speed.
