Detection Of Cervical Lymph Node By Diffusion-weighted Imaging And Perfusion-weighted Imaging

Objectives To evaluate the value of diffusion-weighted imaging and perfusion-weighted imaging for detecting cervical lymph nodes.Materials and Methods Two observers measured ADCs in the spinal cord,muscle,submandibular gland and parotid gland of21healthy volunteers and ADCs of lymph nodes of volunteers、16patients with cervical lymph nodes metastasis and2cases lymphoma.The reference site was determined.ADCs and rADC of malignant lymph nodes and nonmetastatic lymp nodes were compared.Semi-quantitative parameters is measured in9patients with cervical lymph nodes metastasis and11healthy volunteers.Maximum Relative Enhancement Time to Peak、Wash in Rate and Wash out Rate were compared.Results1.Pathology results10cases of metastatic lymph nodes derived from nasopharyngeal carcinoma and6cases derived from other carcinoma;2cases non-hodgkin lymphomas;1case tuberculous lymphadenitis;1case suppurative lymphadenitis;1case infectious mononucleosis.2.Coefficient of variation of semispinalis capitis was lowest,interobserver consistency of submandibular gland is best.3.The ADC and rADC of metastatic lymph nodes were less than those of nonmetastatic lymph nodes.4. When b value was600s/mm2,threshold value of ADC was0.826×10-3mm2/s with95.5%sensitivity and100%specificity threshold value of rADC with semispinalis capitis was0.484with90.9%sensitivity and100%specificity,threshold value of rADC with submandibular gland was0.930with the95.5%sensitivity and96.3%specificity. 5.The wash in rate of metastatic lymph nodes was higher than nonmetastatic lymph nodes,Maximum relative enhancement、time to peak、and wash out rate were no different.6.Maximum relative enhancement and wash ni rate decreases with the increase of age,<40years old group was significantly higher than＞40years old group.Conclusions1.Both semispinalis capitis and submandibular gland can be used as reference.2.The ADC and rADC can help in discriminating metastatic and nonmetastatic cervical lymph nodes,however,the diagnostic value of rADC did not improve.3.PWI did not help in the diagnosis of cervical lymph nodes metastatic lymph nodes.4.When analyzing perfusion,individual differences caused by age shoulde be considered.