Purpose: The purpose was to determine whether the diffusion weighted imaging (DWI) was able to differentiate necrotic tumor or metastatic lesions from infected necrotic lesions such as abscesses and necrotic lymphadenitis in the neck.
Materials and methods: DWI was performed on 37 consecutive patients with 85 head and neck necrotic and cystic lesions. The lesions were classified into four categories: metastatic lymph node involvement including lymphoma, necrotic tumor, abscesses and necrotic lymphadenitis. Each lesion was histopathologically studied and proved.
Results: In 12 patients, there were 35 necrotic lymphadenitis (necrotic tuberculosis lymphadenitis, n=18; necrotic nonspecific suppurative lymphadenitis, n=17). Of the 15 necrotic metastatic nodes, 11 lesions were lymphomatous involvement and 4 lesions were other tumor involvement. Other 11 patients have abscesses. Thirteen primary tumoral necrotic lesions arose in the neck of nine patients. All of the abscesses and necrotic lymphadenitis showed hyperintensity on DWI, in contrast to necrotic tumor and necrotic nodal metastasis that showed hypointensity on DWI. DWI successfully differentiated metastatic nodes and necrotic tumors from necrotic lymphadenitis and abscesses.
Conclusion: DWI may be supportive for differentiating necrotic tumor lesions such as necrotic tumor and metastatic necrotic nodes from the infective necrotic lesions such as necrotic lymphadenitis and abscesses in the head and neck.