Diagnostic Criteria for Brain Abscesses

Imaging Characteristics

The center of a brain abscess appears markedly hyperintense on diffusion-weighted imaging (DWI), distinguishing it from surrounding brain tissue, with a sensitivity of 92% and specificity of 91% for diagnosis 1, 2, 3
The combination of DWI and ADC mapping achieves a sensitivity of 92% and specificity of 91% for the diagnosis of brain abscess, with a positive predictive value of 88% and negative predictive value of 90% 1, 2
The American College of Radiology recommends using DWI and ADC mapping for the diagnosis of brain abscesses, as it is superior to conventional MRI with contrast, which has a sensitivity of only 60% and specificity of 27% 1, 2, 3

The area under the ROC curve for DWI is 0.92, compared to 0.44 for T1-weighted imaging with contrast, demonstrating statistically significant superiority (P<0.001) 1, 2
The European Society of Radiology recommends using DWI and ADC mapping for the diagnosis of brain abscesses, as it provides high sensitivity and specificity 1, 2, 3

The hyperintense signal on DWI decreases and ADC values increase progressively with effective antibiotic treatment or successful surgical drainage 1, 2, 5
The normalization of the signal on DWI with elevation of ADC correlates with good therapeutic response 1, 2, 5