ஐ.எஸ்.எஸ்.என்: 2155-9937
Dechun Zheng, Yunbin Chen, Yuqi Yao, Zhongshi Du and Xiaohong Deng
Purpose: To study the utility of Diffusion-Weighted Magnetic Resonance Imaging to distinguish among Nasopharyngeal Carcinoma (NPC), lymphoma, tuberculosis and nasopharyngitis which originates in nasopharynx.
Materials and Methods: Our hospital’s institutional review board approved this retrospective study. Forty-two patients with early stage NPC, sixteen with lymphoma, eleven with tuberculosis, and twenty-six with nasopharyngitis were included in this retrospectively study. All patients underwent both nasopharynx and skull base region MR Imaging and nasopharyngo-fiberscope biopsy in our hospital, and were finally diagnosed with histopathologically proven (n = 86) and clinical follow-up (n = 9). The Apparent diffusion coefficient (ADC) values were investigated by experienced radiologist, and averaged ADC value of per patient was compared in groups. Mean ADC values between two groups were compared by independent - samples T-test, and one-way Analysis of Variance was used to analyze mean ADC values among four groups.
Results: Mean ADC values of malignant nasopharyngeal lesions (early stage NPC and lymphoma) and benign nasopharyngeal lesions (tuberculosis and nasopharyngitis) were (0.708 ± 0.158) and (0.913 ± 0.168) × 10-3 mm2/s respectively (t = 6.05, P < 0.01). Mean ADC values of nasopharyngeal lesions of early stage NPC, lymphoma, tuberculosis and nasopharyngitis were (0.753 ± 0.135), (0.590 ± 0.156), (0.855 ± 0.137), and (0.935 ± 0.179) × 10-3 mm2/s respectively (F = 18.89, P < 0.01), and post multiple comparisons showed that they were all Statistical significance on 0.05 level between NPC, lymphoma, tuberculosis and nasopharyngitis except subgroup tuberculosis and nasopharyngitis (p = 0.55); An ADC value lower than or equal to 0.828 × 10-3 mm2/s was used as threshold for nasopharyngeal malignancy, with a sensitivity 82.8% and specificity of 70.3%. When the same ADC value ≤ 0.828 × 10-3 mm2/s was used as threshold to differentiate early stage NPC from nasopharyngitis, sensitivity and specificity were 78.6% and 69.2% respectively. When an ADC value ≤ 0.681 × 10-3 mm2/s was used as threshold to differentiate lymphoma from early stage NPC, sensitivity and specificity were 81.3% and 71.4% respectively.
Conclusion: MR DWI has a potential value in differentiating nasopharyngeal diseases.