Micro magnetic resonance angiography of the finger in systemic sclerosis

Objective. To characterize vascular lesions in SSc disease with high-resolution magnetic resonance angiography (Micro-MRA) of the finger. Methods. Eight SSc subjects and eight age- and sex-matched healthy controls were recruited for this study. Among the SSc subjects, the mean ± s.d. age was 54.5 ± 4.9 yrs, and the mean ± s.d. duration of disease was 8.3 ± 8.4 yrs. The numbers of SSc subjects that had telangiectasia, calcinosis and impaired finger flexion were 3, 2 and 3, respectively. The 2D time-of-flight micro-MRA was performed on a 3T clinical MRI scanner using a custom-designed finger coil with an in-plane resolution of 0.16 times; 0.21 mm² and slice thickness of 1.2 mm. The data for the proper palmar digital artery lumen area, the number of visible dorsal digital veins and a semi-quantitative vascular score, which evaluates the overall integrity of digital vessels, were independently evaluated by two experienced reviewers who were blinded to the status of the subject. Results. Micro-MRA detected significant differences in the digital vasculature between SSc subjects and healthy volunteers. The SSc subjects had a significantly decreased digital artery lumen area (0.13 ± 0.06 vs 0.53 ± 0.26 mm², P<0.001), a reduced number of digital veins (0.63 ± 1.06 vs 3.13 ± 0.99, P=0.001) and a lowered overall vascular score (1.75 ± 1.04 vs 3.5 ± 0.53, P=0.001). The study also found that both the digital artery lumen area (Pearson's; r= -0.72, P=0.044) and vascular scores (Spearman's ρ=-0.75, P=0.047) of the SSc subjects were inversely correlated with the duration of the disease. Conclusions. Micro-MRA can be used to identify and quantitatively characterize the vascular disease in SSc fingers. The parameters derived from micro-MRA could potentially be used as prospective biomarkers for clinical evaluation.