Brain abscess in cyanotic hea disease is commonly antibody is a surrogate marker of one of the following:

Brain abscess resulting from cyanotic hea disease tend to embolize to the distribution of middle cerebral aery. Localization of brain abscesses: Localization Mean frequency Frontal lobe 37% Temporal lobe 24% Parietal lobe 22% Occipital lobe 10% Cerebellum 7% Sella 1% Basal ganglia 1% So frontal lobe is the single best answer of choice. Ref: Infections of The Central Nervous System By W. Michael Scheld, Richard J Whitley, Christina M Marra, Page 486; The 5-Minute Pediatric Consult By M. William Schwaz, Page 186.