Venous vessel-wall assessment with superb microvascular imaging in Behçet syndrome

Superb microvascular imaging (SMI) provides a more sensitive assessment of small vessels compared with power and colour Doppler ultrasonography (PDUS and CDUS). We aimed to investigate the potential of SMI for use in research and clinical practice in Behçet syndrome (BS) and to gain a better understanding of erythema nodosum (EN) like and superficial thrombophlebitis (STM) lesions using SMI.

We studied 51 patients with BS and 31 patients with non-BS with red palpable lesions on physical examination. B-mode US, CDUS, PDUS and SMI were performed and recorded by the same radiologist and recorded images were additionally evaluated independently by another radiologist. Vessel-wall signal intensity of STM lesions by SMI was graded in four groups according to the percentages of the affected vessel-wall area (Grade 0: no signal, Grade 1: < 25%, Grade 2: 25%-50%, Grade 3: 50%-75% and Grade 4: >75%).

The lesions of 26 patients with BS and 17 patients with non-BS were diagnosed as STM with CDUS. SMI of STM lesions revealed vessel-wall signals in 21/26 patients with BS (81%), in contrast to only 3/17 (18%) patients with non-BS. While 16 of 21 patients with BS (76%) had at least grade 2 signal, only 1 of 3 non-BS had it. Lesions of 25 BS and 11 non-BS were diagnosed as EN by CDUS and SMI showed no vessel-wall signal in these patients.

Evaluation of the vessel wall with SMI in BS may be a promising approach for showing inflammation as an inexpensive, non-invasive and reliable imaging method that does not require a contrast agent.