Yun Zhang, Presenter: Nothing to Disclose

Biling Liang MD, Abstract Co-Author: Nothing to Disclose

Jian-yu Chen, Abstract Co-Author: Nothing to Disclose

Li Gao MD, PhD, Abstract Co-Author: Nothing to Disclose

To evaluate the apparent diffusion coefficient (ADC) both of parenchyma and necrosis in pathologic lymph node in differentiating cervical lymphadenopathy.

36 patients with cervical lymph nodes metastasis from the head and neck squamous cell carcinomas, 19 patients with lymphoma and 23 patients with cervical lymph nodes tuberculosis underwent DWI. All images were obtained on a 1.5T MR scanner (Gyroscan Intera Master, Philips Medical Systems) with syn-head/neck coils, and parameters were: slice orientation is axial, TR/TE=6800ms/70ms, TI=180ms, shot mode=single shot, EPI factor=47, SENSE factor=2, matrix=160×256, slice thickness/gap=4mm/0mm, b value=800s/mm2, NSA=10. The ADC values both of parenchyma and of necrosis in 177 pathologic lymph nodes confirmed by histopathology or clinical follow-up were measured and compared.

The mean ADC values of parenchyma in metastatic nodes (n=84), lymphoma (n=40) and tuberculous nodes (n=53) were 0.93±0.16×10-3mm2/s, 0.64±0.13×10-3mm2/s and 1.01±0.11×10-3mm2/s respectively. The ADC values of necrosis in metastatic and tuberculous nodes were 2.02±0.36×10-3mm2/s and 1.25±0.15×10×10-3mm2/s respectively. The ADC value of lymphoma was significantly lower than that of metastatic and tuberculous nodes (p<0.01).The ADC value of necrosis in metastatic nodes increased in comparison with those of tuberculous nodes with significant difference (p<0.01). When an ADC value of parenchyma lower than 0.77×10−3mm2/s was used as the threshold for lymphoma and metastasis, we obtained accuracy of 88%, sensitivity of 83%, specificity of 90%, and positive predictive value of 79% and negative predictive value of 93%. When an ADC value of necrosis greater than 1.60×10-3mm2/s was used as the threshold for metastatic nodes, we obtained accuracy of 97%, sensitivity of 92%, specificity of 100%, and positive predictive value of 100% and negative predictive value of 95%.

The ADC value both of parenchyma and necrosis in pathologic lymph nodes, especially which of necrosis is useful in the differential diagnosis of cervical lymph nodes lesions.

 DWI is useful in diagnosing cervical lymphadenopathy. When necrosis is detected in lymph nodes, measuring the ADC value of necrosis is more valuable that of parenchyma for diagnosis.

Zhang, Y, Liang, B, Chen, J, Gao, L, The ADC Value of Lymph Node Parenchyma and Necrosis in Cervical Lymphadenopathy: Differential Diagnostic Value.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6010254.html