Table 3.

Advantages and disadvantages of different imaging modalities^a.

	Ultrasound	CT-scan	MRI
Advantages	Widely available Allows for estimating valve function No radiation exposure	Rapidly available Nearly 100% specific and sensitive Can diagnose dissection Can visualize entire aorta	Nearly 100% specific and sensitive No radiation exposure Can visualize entire aorta
Disadvantages	Time consuming compared to CT-scan (center dependent) Inter-observer variability Arch not visualized Difficulty visualizing portions distal to the sinotubular junction	Radiation exposure Contrast nephropathy	Time consuming compared to CT-scan Many contraindications Contraindicated in advanced renal failure More expensive

^aChest X-ray has not been included in this table for the reasons outlined below.