In this week's BMJ, a systematic review by Collins and colleagues compares the diagnostic accuracy of duplex ultrasound, magnetic resonance angiography, and computed tomography angiography for assessing peripheral arterial disease of the lower limb.1 The review also evaluates the impact of these assessment methods on patient outcomes. It found that contrast enhanced magnetic resonance angiography seemed to be more specific than computed tomography angiography (better at ruling out stenosis of 50% or more in a lower limb vessel) and more sensitive than duplex ultrasound (better at ruling in stenosis of 50% or more). Magnetic resonance angiography was also generally preferred by patients over contrast angiography. So what do these results mean for practising clinicians?

In developed countries up to a fifth of the population over the age of 60 has lower limb peripheral arterial disease, as defined by absent pulses or a reduced ankle brachial pressure index. About a quarter of these people have symptoms—most commonly intermittent claudication. …