Answer for BIR CoW 07 Aug 2022
Fungal abscess
Findings
T1 hypointense/ T2 hyperintense lesion with T2 hypointense crenated margins which shows peripheral restricted diffusion and moderate perilesional edema noted in right frontal region. On MRS with long TE, lipid lactate peak noted at 1.3 and on short TE trehalose peak noted at 3.6 – 3.8. Impression: Features suggestive of right frontal fungal abscess.
Discussion
Most CNS fungal infections are opportunistic. Their prevalence is rising as the number of immunocompromised patients increases worldwide. Imaging features Crenated thick wall Hypointense center, hyperintense rim on T1 W1 Hyperintense center, hypointense rim on T2 W2 Hemorrhagic blooming foci on T2 Peripheral wall restriction on DWI Strong enhancement on T1 Contrast MRS lactate in 90%, lipids and amino acids in 50% , multiple peaks at 3.6-3.8 ppm
Major differential diagnosis
Brain metastasis: Thicker ring enhancement, usually no diffusion in the necrotic center.
Infarction: gyral enhancement or no enhancement, distribution confined to vascular territory.
Pyogenic abscess: thicker ring enhancement and central diffusion restriction.
Toxoplasmosis: Thicker ring enhancement. Usually no restricted diffusion.
Demyelinating lesion: Incomplete ring enhancement, Usually no restricted diffusion or leading edge diffusion restriction.
Findings
T1 hypointense/ T2 hyperintense lesion with T2 hypointense crenated margins which shows peripheral restricted diffusion and moderate perilesional edema noted in right frontal region. On MRS with long TE, lipid lactate peak noted at 1.3 and on short TE trehalose peak noted at 3.6 – 3.8. Impression: Features suggestive of right frontal fungal abscess.
Discussion
Most CNS fungal infections are opportunistic. Their prevalence is rising as the number of immunocompromised patients increases worldwide. Imaging features Crenated thick wall Hypointense center, hyperintense rim on T1 W1 Hyperintense center, hypointense rim on T2 W2 Hemorrhagic blooming foci on T2 Peripheral wall restriction on DWI Strong enhancement on T1 Contrast MRS lactate in 90%, lipids and amino acids in 50% , multiple peaks at 3.6-3.8 ppm
Major differential diagnosis
Brain metastasis: Thicker ring enhancement, usually no diffusion in the necrotic center.
Infarction: gyral enhancement or no enhancement, distribution confined to vascular territory.
Pyogenic abscess: thicker ring enhancement and central diffusion restriction.
Toxoplasmosis: Thicker ring enhancement. Usually no restricted diffusion.
Demyelinating lesion: Incomplete ring enhancement, Usually no restricted diffusion or leading edge diffusion restriction.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!