Exacerbation of luminal dilatation after corticosteroid therapy. Luminal dilatation (A and C, patient 10 in Table 1; E, patient 9) of the periaortic/periarterial lesions at the time of diagnosis was exacerbated after corticosteroid therapy (B, D and F, respectively). Red lines in each of the three paired images (A and B, C and D, and E and F, respectively) have the same length. Of five lesions from four patients with luminal dilatation, three lesions from two patients (red and yellow) in the maximum luminal diameter increased (G), whereas no obvious increase was observed in the 28 lesions of the 26 patients without luminal dilatation (H). Tx, Treatment.