The investigation of choice in the condition shown in the picture below is ?
B. CT Angiography
D. Digital segmental angiography.
Ans:B. CT Angiography.
The condition shown in the picture above represents aortic dissection.
Investigations in a case of Aortic dissection
Chest radiography may be normal, or demonstrate a number of suggestive findings, ncluding:
- widened mediastinum (more than 8 cm at the level of the aortic knob on portable anteroposterior chest radiographs) 9,10
- double aortic contour
- irregular aortic contour
- inward displacement of atherosclerotic calcification (more than 1 cm from the aortic margin) 9,11
CT / CT angiography
- CT, especially with arterial contrast enhancement (CTA) is the investigation of choice, able not only to diagnose and classify the dissection but also evaluate for distal complications. It has reported sensitivity and specificity of nearly 100%.
- Non-contrast CT may demonstrate only subtle findings.
- Transoesophageal echocardiography (TOE) has very high sensitivity and specificity for assessment of acute aortic dissection, but due to limited access and invasive nature, it has largely been replaced by CTA (or MRA in some instances).
- Although in general MRA has been reserved for follow-up examinations, rapid non-contrast imaging techniques may see MRI having a larger role to play in the acute diagnosis, particularly in patients with impaired renal function . It has similar sensitivity and specificity to CTA and TOE but suffers from limited availability and the difficulties inherent in performing MRI on acutely unwell patients.
DSA – angiography
- Conventional digital subtraction angiography has historically been the gold standard investigation. CTA has now replaced it as the first line investigation, not only due to it being non-invasive but also on account of better delineation of the poorly opacifying false lumen, intramural haematoma and end-organ ischaemia.
- Angiography still is required for endoluminal repair.
- Risks of angiography include general risks of angiography plus the risk of catheterising the false lumen and causing aortic rupture.