XXXX : diagnostic accuracy of diffusion-weighted MR imaging.

@entity1 @entity706 @entity5 @entity957 @entity189
PURPOSE: To prospectively determine the diagnostic accuracy of diffusion-weighted magnetic resonance (MR) imaging for discrimination of malignant neck nodes due to @entity957 (SCC), and undifferentiated @entity189 ( @entity189 ), with histologic findings and imaging criteria as reference standards. MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. @entity1 with malignant lymphadenopathy underwent 1.5-T diffusion-weighted MR imaging. A region of interest was drawn around the malignant node on apparent diffusion coefficient (ADC) maps; ADC values were compared (Kruskal-Wallis test). Receiver operating characteristic analysis was employed to investigate whether ADC values could aid in discrimination among @entity5 . RESULTS: Forty-three @entity1 (34 @entity1 , nine @entity1 ; mean age, 54 years) with 43 nodes underwent imaging. Mean ADC values for @entity706 (n = 8), @entity189 (n = 17), and SCC (n = 18) were (0.664 +/- 0.071 [standard deviation]) x 10(-3) mm(2)/sec, (0.802 +/- 0.128) x 10(-3) mm(2)/sec, and (1.057 +/- 0.169) x 10(-3) mm(2)/sec, respectively, with significant differences between SCC and @entity706 or @entity189 (P < .001) and between @entity189 and @entity706 (P = .04). To optimize sensitivity and specificity with equal weighting, ADC threshold values for distinguishing between SCC and @entity189 , between SCC and @entity706 , and between @entity189 and @entity706 were 0.894 x 10(-3) mm(2)/sec, 0.824 x 10(-3) mm(2)/sec, and 0.694 x 10(-3) mm(2)/sec, respectively. To produce a 100% specificity while sensitivity is maximized, the following ADC threshold values were obtained for prediction of differentiation between @entity5 : (a) SCC versus @entity706 , greater than 0.824 x 10(-3) mm(2)/sec (sensitivity, 94%), and @entity706 versus SCC, less than 0.767 x 10(-3) mm(2)/sec (sensitivity 88%); (b) @entity189 versus SCC, less than 0.764 x 10(-3) mm(2)/sec (sensitivity, 47%), and SCC versus @entity189 , greater than 1.093 x 10(-3) mm(2)/sec (sensitivity, 39%); (c) @entity189 versus @entity706 , greater than 0.788 x 10(-3) mm(2)/sec (sensitivity, 53%), and @entity189 , no suitable threshold value. CONCLUSION: Diffusion-weighted MR imaging shows significant differences among malignant nodes of SCC, @entity706 , and @entity189 . ADC threshold values can help distinguish SCC from @entity706 . SUPPLEMENTAL MATERIAL: http://radiology.rsnajnls.org/cgi/content/full/2451061804/DC1.
