Glandular function in Sjogren syndrome: Assessment with dynamic contrast-enhanced MR imaging and tracer kinetic modeling - Initial experience

Purpose: To prospectively use dynamic contrast material-enhanced magnetic resonance (MR) imaging and a tracer kinetic model to compare parotid gland microvascular characteristics in patients who have Sjogren syndrome (SS) with those in healthy volunteers. Materials and Methods: The local research ethics committee approved the study, and written informed consent was obtained from all participants. Twenty-one Patient's (19 women, two men; age range, 31-73),ears) with a diagnosis of SS and 1.1 healthy volunteers (10 women, one man; age range, 41-68 years) underwent three-dimensional T1-weighted dynamic contrast-enhanced MR imaging of the parotid gland at 1.5 T. A voxel-wise tracer kinetic model aid a model-free analysis were applied to the dynamic MR data. Parameter medians and standard deviations were computed to summarize gland microvascular characteristics and gland heterogeneity, respectively. Differences were investigated by using multivariate analysis of variance, t, or U tests. Further investigation was performed by using linear discriminant and receiver operating characteristic analyses. Results: Compared with the healthy volunteers,, the patients with SS had highly significant, elevations (P <<.001) in the model-free parameter initial area tinder the curve and in tracer kinetic model parameters, including transcapillary contrast agent transfer constant (P <.001) aid extracellular extravascalar volume (P <.001). Gland heterogeneity was significantly greater (P <.001) in the Patients with SS. Parameter medians and standard deviations enabled excellent differentiation (areas under receiver operating characteristic curve, 0.96 and 1.00, respectively) between the patients with SS and the healthy volunteers. Conclusion: Dynamic contrast-enhanced MR imaging has the potential to be used in clinical settings to quantify microvascular function in SS and to differentiate between patients with and those without SS.