Quantitative dynamic contrast-enhanced ultrasound for the functional evaluation of the skeletal muscle microcirculation in systemic sclerosis.

PURPOSE: The purpose was to evaluate skeletal muscle microcirculation by means of quantitative dynamic contrast-enhanced ultrasound (DCEUS) in patients with systemic sclerosis (SSc).

METHODS

DCEUS imaging of the gastrocnemius muscle was performed with phospholipid-stabilized microbubbles filled with sulfur hexafluoride in 12 patients with SSc and 12 healthy volunteers. The fitted time intensity curves (TIC) during the first 3 minutes after administration of the contrast agent bolus were analysed. Time course parameters of the TIC were compared between patients and healthy volunteers.

RESULTS

Peak enhancement, wash-in area under the curve and was-out area under the curve was decreased in the patient group versus healthy volunteers (168 versus 248 AU p = 0.291; 2193 versus 3314 p = 0.198; 4948 AU x sec versus 8948 AU x sec p = 0.037). In the SSc patients the mean transit time and wash-in perfusion index were numerically, but not statistically lower than in the healthy volunteers, but rise and fall time were similar.

CONCLUSION

On the microvascular level in SSc patients versus their healthy counterpart key parameters related to blood volume were decreased and perfusion parameters showed a slight diminishment in the patient population. These results suggest a component of impaired skeletal muscle microcirculation in SSc patients.