Abstract:

Objective To investigate the value of ¹⁸F-FDG PET/CT imaging in the diagnosis and differential diagnosis of the primary central nervous system lymphoma (PCNSL),and to illustrate the characteristics of imaging findings,and to provide the reference and basis for clinical treatment.Methods A retrospective analysis of 55 cases of ¹⁸F-FDG PET/CT image data and immunohistochemical results including 8 cases of PCNSL,19 cases of gliomas and 28 patients with cerebral metastatic carcinoma confirmed by pathology was performed;the maximum standardized uptake value (SUV_max) was compared between three kinds of diseases.Results PCNSL ¹⁸F-FDG PET/CT performed as an abnormal radioactivity uptake showed strong together as nodular,crumb,bunch of ribbon,and the surrounding tissue boundary was not clear and the edema was rare.The radioactivity uptake of glioma in ¹⁸F-FDG PET/CT imaging depended on the pathological types,and the uptake of fluoredeoxyglucose(FDG) of generally low grade glioma was reduced,and the SUV_max was 2.2-4.3;the uptake of FDG of high grade glioma was increased,and the SUV_max was 9.3-17.2;the uptake of tracer in lesion was not homogeneous,and the flake edema could be seen around the lesions.Typical cerebral metastatic carcinoma performed as the increasing uptake of the radioactivity lesions, and the flake edema could be seen around the lesions. The SUV_max of PCNSL patients was higher than that of cerebral metastatic carcinoma patients (P<0.05);there was no statistically significant difference of SUV_max beweteen PCNSL and glioma patients(P>0.05).Conclusion The ¹⁸F- FDG PET/CT imaging of PCNSL patients has certain imaging characteristics,which can be used for differential diagnosis with other central nervous system tumors.

Key words: primary central nervous system lymphoma, tomography, positron emission tomography, ¹⁸F-fluoredeoxyglucose