Response to: 'Correspondence to 'Slope sign: a feature of large vessel vasculitis? by Milchert et al

We are grateful for the interest in our article and agree with Milchert et al1 that the slope sign deserves a precise definition. Intimal medial thickness (IMT) of the axillary artery is the current way of assessing large vessel giant cell arteritis (LV-GCA) by ultrasound (US), with a cut-off value of greater than 1.0 mm suggesting LV-GCA.2 Other causes of arterial wall thickening can mimic vasculitis such as atherosclerosis and it is often challenging to differentiate between atherosclerosis and vasculitis related thickening of the axillary artery.3 ‘Slope sign’ is a visual definition of a smooth, homogenous, gradual transition from an abnormal axillary arterial segment with increased IMT to an arterial segment with normal IMT. This should help differentiate between vasculitic and atherosclerotic wall thickening.4 We suggest that sonographers should seek to demonstrate the slope sign in all cases of suspected LV-GCA through...