MR factor analysis: Improved technology for the assessment of 2D dynamic structures of benign and malignant salivary gland tumors

Purpose: To establish an MR factor analysis technique for two-dimensional (213) MR dynamic structures of benign and malignant salivary gland tumors. Materials and Methods: Dynamic contrast-enhanced MRI using a surface coil was performed on 36 patients with benign (N = 24) or malignant (N = 12) salivary gland tumors. Signal intensity kinetics in each pixel of the tumors after contrast medium injections were semiautomatically categorized into four patterns (slow uptake, rapid uptake with high washout, rapid uptake with low washout, and flat). The 2D distributions of the kinetic patterns in the tumors were compared with the histological features of the corresponding parts of the excised tumors and with overall kinetics obtained by a conventional analysis. Results: The MR factor analysis technique allowed the pixel-to-pixel evaluation of the contrast enhancement kinetics of the salivary gland tumors. The 2D distributions of the time-intensity curve MC) patterns correlated well with the histological features of the salivary gland tumors and allowed more detailed dynamic structures of the tumors compared with the results obtained by the conventional dynamic study analysis. Conclusion: The proposed MR factor analysis would be clinically feasible to diagnose salivary gland tumors and turoor-like lesions.