THE EVALUATION OF DELAYED ENHANCEMENT METHOD AS A TOOL FOR MAGNETIC RESONANCE DIFFERENTIATION BETWEEN THE METASTASES AND NEUROTOXOPLASMOSIS

Abstract

The aimof this study was to evaluate delayed enhancement as the tool for differentiation between metastatic brain lesions and neurotoxoplasmosis.Materials and methods.38 patients with multiple brain lesions with mass-effect and ring-type of contrast enhancement based on CT/MRI have been enrolled in the study. All cases were associated with metastatic brain lesions or toxoplasmosis. For every patient we performed contrast enhanced brain MRI and achieved axial T1WI immediately after contrast injection, in 15, 30 and 45 min. Acquired images were evaluated for the presence of contrast accumulation at delayed images in the central part of the lesions. Overall, we analyzed data for 153 lesions with 64 toxoplasmosis lesions and 89 metastatic.Results.Among 153 lesions with ring-type contrast enhancement central contrast enhancement at delayed images was determined for 83 lesions. Among 89 metastatic lesions 81 demonstrated delayed central enhancement. Among 64 neurotoxoplasmosis lesions only 2 demonstrated delayed central enhancement. The sensitivity of the sign was 88%, specificity 95%.Conclusions.The presence of central contrast enhancement at delayed images significantly increases the probability of metastatic nature of the lesions (specificity 95%). Consequently that sign might be effectively used for the differential between the metastases and neurotoxoplasmosis.