1. IMAGE of the week Dr. Prof. Mageshkumar Unit DevendraPatil

2. SyedIlias , 34 / M Investigated outside for focal seizures CT taken outside suggested a mass lesion Pt was started on ATT. Came with complains of Inability to use his left upper and lower limbs Left Focal Seizures with generalization MRI brain was taken.

13. T1w image : Hypointensity is seen in the right fronto parietal region T2w image : A lesion in the region of central fissure with central non-homogenous hyperintensity with a hypointense rim with surrounding hyperintensity T2 FLAIR : The same lesion maintains its hyperintensity and has a non homogenous / nodular like lesion. Inner hyperintensity ; rim of hypointensity ; surrounding hyperintensity. Post Gadolinium: The same rim shows enhancement but the centre is not homogenously hypointense. It shows nodular hyperintensity There are two other lesions seen: A ring enhancing lesion in post central gyrus A homogenous enhancing lesion in sup temporal gyrus

14. d/d for multiple ring enhancing lesions T – Tuberculoma N- Neurocysticerosis M - Metastasis, MS A - Abscess (also cerebritis) G - Glioblastoma, GranulomaI - Infarct (esp. Basal ganglia) C - Contusion (rare) A - AIDS (Toxoplasmosis, etc.) L - Lymphoma (common in AIDS ) D - Demyelination (active) R - Resolving hematoma, Radiation change (necrosis)

15. SESSION GOALS: TUBERCULOMA NEUROCYSTICERCOSIS TOXOPLASMOSIS CEREBRAL ABSCESS

16. TUBERCULOMA

17. It is seen from review of radiological literature that there is no characterstic appearance pathognomonic of TB granuloma and the diagnosis rests upon the use of history , clinical findings and response to treatment and bacteriological and histological examination.

18. Usual mri findings: Central necrosis tends to a hyperintensity in T2 weighted images and peripheral hypointensity. However more solid lesions have a striking hypointense in T2WI as a result of granulation tissue and compressed glial tissue in the central core In some cases the lesion appears to have alternating layers of hyper and hypo intensities due to granulation tissue deposits In almost all cases the lesion appears to be gray mater intensity in T1 WI. On Gd enhancement ring or nodular lesions are seen

19. TUBERCULOMA T1 w IMAGE T2 w IMAGE

20. NEUROCYSTICERCOSIS

21. Neurocysticercosis Different types of intracranial lesions seen viz., parenchymal , subarachnoid , intraventricular and spinal. CT is the best screening tool because : It detects calcification easily It is more cost-effective than MRI. MRI is done if CT inconclusive ,single lesion , abnormal locations , hydrocephalus Its imaging characterstics include 4 stages

22. LIVING ( viable ) Stage : CT - appears as hypodense lesion that doesn’t show ring enhancement or perilesionaloedema “HOLE with DOT appearance ” Similar findings in T1w Images. COLLOIDAL Stage : MRI - represents the acute encephalitic phase of neurocysticerosis. Hence, its associated with perilesional edema and ring enhancement .

25. NODULAR / GRANULAR Stage : MRI - single enhancing lesion hypointense centre in T1 and T2 with hyperintense rim and surrounded by edema /gliosis. CALCIFIED Stage : Not visualised in MRI CT- hyperdense nodules with no edema or enhancement.

27. TOXOPLASMOSIS

28. CT - (70-80 % cases ) multiple B/L hypodense contrast enhancing focal lesions with predispostion to the basal ganglia and subcortical region. A double dose contrast with increased delay scan time may increase the sensitivity. MRI - its more sensitive and hence the imaging of choice when an PLHA has CNS manifestations without any localizing sign. its also indicated when there is single ring enhancing

29. Usual MRI findings On T1w - the lesions are hypointense On T2w - lesions hyperintense , but they can occasionally be isointense to hypointense. Active lesions are often surrounded by edema. Post Gd - Focal nodular or ring enhancement occurs in approximately 70% of patients.

31. CEREBRAL ABSCESS

32. USUAL MRI FINDINGS Abscess center is typically hypointense on T1-weighted images (T1WI) and hyperintense on T2-weighted images (T2WI); surrounding vasogenic edema has similar characteristics. Post Gd imaging : ring enhancement . As the abscess matures, the capsule shows decreased low T2 signal. On trace DWI abscesses are typically hyperintense, indicating decreased diffusion of water.

34. THANK – YOU. REFERENCES :- HARRISON 17/e RADIOLOGY – David Sutton (2007 ) TUBERCULOSIS ( M. MonirMadakour ) ( 2004 ) ACTA TROPICA ( 87 ) (2003 ) (71 – 78 ) (review article )