Diffusion-weighted imaging to differentiate metastatic from non-metastatic retropharyngeal lymph nodes in nasopharyngeal carcinoma

Abstract

Objectives: To evaluate the diagnostic value of diffusion-weighted MRI for differentiating metastatic from non-metastatic retropharyngeal lymph nodes (RLNs) in patients with nasopharyngeal carcinoma (NPC). Methods: Untreated patients with NPC (n 5 145) were scanned with both morphological MRI and diffusion-weighted imaging (DWI). RLNs (n 5 335) were classified as metastatic on the basis of response to therapy as assessed on follow-up MRI. Morphological (short-and long-axial diameters) and functional [mean apparent diffusion coefficient (ADC) and minimum ADC values] parameters of the RLNs were derived from DWI and compared between metastatic and non-metastatic groups. A receiver operating characteristic curve and the area under the curve were used to evaluate the effectiveness of individual criteria and to generate threshold values to diagnose RLN metastases. Results: Statistically significant differences between metastatic and non-metastatic RLNs were found for all four parameters derived from DWI (p , 0.001). At threshold values, accuracies of the ADC-based criteria (0.938 and 0.965 for mean and minimum ADC values, respectively) were greater than that of size-based criteria (0.838 and 0.809 for short-and longaxial diameters). The minimum ADC value at the threshold of 0.89 3 10 23 mm 2 s 21 was the most effective of all parameters in differentiating metastatic from non-metastatic RLNs with the sensitivity of 95.7%, specificity of 95.1% and accuracy of 96.5%. Conclusions: DWI is feasible for differentiating metastatic RLNs from non-metastatic nodes in patients with NPC with high accuracy, and the minimum ADC derived from DWI could serve as a standard clinical marker for disease status. Dentomaxillofacial Radiology (2015Radiology ( ) 44, 20140126. doi: 10.1259 Cite this article as: Li H, Liu X-W, Geng Z-J, Wang D-L, Xie C-M. Diffusion-weighted imaging to differentiate metastatic from non-metastatic retropharyngeal lymph nodes in nasopharyngeal carcinoma. Dentomaxillofac Radiol 2015; 44: 20140126.

Contrast-enhanced dynamic and diffusion-weighted magnetic resonance imaging at 3.0�T to assess early-stage�nasopharyngeal carcinoma

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Multiple b values of diffusion-weighted magnetic resonance imaging in evaluation of solid head and neck masses

“…Our study had revealed that mean ADC values in metastatic node (n = 10) {range (0.530-0.815) × 10 −3 s/mm 2 } mean 0.691 × 10 −3 s/mm 2 were significantly lower than that of benign nodes (n = 14){range (1.86-2.45) × 10 −3 s/mm 2 } mean 2.11 × 10 −3 s/mm 2 . Li et al [21] had shown that the mean ADC between metastatic and non-metastatic retropharyngeal nodes were statistically significant differences by DWI (P < 0.001). Holzapfel et al [22] had also demonstrated that mean ADC values (× 10 −3 s/mm 2 ) of benign cervical lymph nodes (1.24 ± 0.16) were significantly higher than that of metastatic lymph nodes (0.78 ± 0.09).…”

Role of quantitative intravoxel incoherent motion parameters in the preoperative diagnosis of nodal metastasis in patients with rectal carcinoma

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