To evaluate the value of 18F-FDG and 11C-CHO PET-CT in differentiation of brain annular enhanced lesion on MRI imaging

Objectives To evaluate the value of 18F-FDG and 11C-CHO PET-CT in differentiation of brain annular enhanced lesion on MRI imaging.

Methods Forty patients with the brain annular enhanced lesion on MRI imaging and atypical clinical in our hospital from September 2007 to May 2012 underwent 18F-FDG and 11C-CHO PET-CT brain scan in adjacent two days. Among them, 10 patients who were suspected to have brain metastasis received body scan by 18F-FDG PET-CT. Both images were analyzed visually and semi-quantitatively and all of lesion were confirmed by pathology.

Results Fourty-eight of 56 brain of annular enhanced lesions on MRI of 40 patients were found in 18F-FDG PET-CT brain imaging , including 17 low metabolism lesions ,20 moderate metabolism lesions and 10 high metabolism lesions. Twenty-seven lesions were correctly diagnosted tumor by 18F-FDG PET-CT, 17 lesions of false negative and 3 lesions false positive. Sensitivity, specificity and accuracy of the diagnostic malignant neoplasm were respectively 61.4% (27/44), 34.6% (9/26) and 64.3% (36/56). Fifty-six of 56 brain annular enhanced lesions on MRI of 40 patients were found in the 11C-CHO PET-CT brain imaging, including 8 low metabolism lesions ,10 moderate metabolism lesions and 38 high metabolism lesions, Fourty lesions of 18F-FDG PET-CT correct diagnostic tumor , 7 cases of false negative and 2 cases of false positive. Sensitivity, specificity and accuracy of the diagnostic malignant neoplasm are respectively 85.0% (40/47), 77.8% (7/9) and 83.9% (47/56).

Conclusions Both 18F-FDG and 11C-CHO PET-CT are useful in differentiation of brain ringlike-enhanced lesions on MRI imaging. 11C-CHO PET-CT is far superior to (18)F-FDG especially for low malignant neoplasm and metastatic tumor. 18F-FDG PET-CT body scanning is helpful for founding primary tumor.Combination of 18F-FDG and 11C-CHO PET-CT scans can improve the accuracy of differential diagnosis for annular enhanced brain lesions on MRI imaging.