IVIM imaging may be helpful for differentiation between benign and malignant salivary gland tumors.

The nodal architecture and apparent diffusion coefficient levels on MR microimaging may provide useful information in diagnosing benign and malignant nodes in the neck.

Diffusion-weighted echoplanar MR imaging may reveal diseased states of the salivary glands.

Sonography performed significantly better than CT in depicting cervical metastatic nodes. Sonography could be a useful adjunct to CT in surveying cervical metastatic nodes.

We evaluated the diagnostic ability of diffusion-weighted imaging for the differentiation between lymphomas and carcinomas in the pharynx and between carcinomas with different histological types in the pharynx. T1-weighted, fat-suppressed T2-weighted, and diffusion-weighted MR imaging was performed on 14 patients with pharyngeal lymphomas, 26 patients with carcinomas of the pharynx, 5 patients with adenoidal hypertrophy, and 22 patients with normal tonsils. Apparent diffusion coefficients (ADCs) were determined by using two b factors (500 and 1,000 s/mm(2)). The ADCs of lymphomas were significantly smaller (0.454 +/- 0.075 x 10(-3) mm(2)/s) than those of carcinomas (0.863 +/- 0.238 x 10(-3) mm(2)/s). The ADCs of poorly differentiated and undifferentiated carcinomas (0.691 +/- 0.149 x 10(-3) mm(2)/s) were significantly smaller than those of moderately differentiated and well-differentiated carcinomas (0.971 +/- 0.221 x 10(-3) mm(2)/s), but were significantly larger than those of lymphomas. When an ADC smaller than 0.560 x 10(-3) mm(2)/s was used for predicting lymphomas, we obtained the highest accuracy of 96%, with 100% sensitivity and 94% specificity, 86% positive predictive value, and 100% negative predictive value. Therefore, ADC measurements effectively differentiate lymphomas from carcinomas in the pharynx and could be a useful adjunct to biopsy-based development of treatment planning.

BACKGROUND AND PURPOSE:IVIM MR imaging provides perfusion and diffusion information with a single diffusion-weighted MR image. We determined whether PP and D differ among various types of head and neck tumors.

BACKGROUND AND PURPOSE:CT and MR imaging features of benign and malignant sinonasal lesions are often nonspecific. Therefore, we evaluated the ADC-based differentiation of these lesions.

Purpose:To establish an MR factor analysis technique for two-dimensional (2D) 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 ϭ 24) or malignant (N ϭ 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 (TIC) 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 tumor-like lesions.