Imaging cns tb

Imaging cns tb
Dr. Rahi Kiran.B
Senior Resident, Neurology
Govt Medical College, Kota

1. CLINICAL RADIOLOGY OF CEREBRAL TUBERCULOSIS Dr. Rahi kiran.B SR Neurology GMC, KOTA

2. Approximately 10% of all patients with Tuberculosis have CNS involvement. Greater prevalence in immunocompromised patients and is seen in ~ 15-20 % of cases of AIDS-related TB. Synchronous Extraneural TB may be present in ~50% cases and may serve as an important clue to the diagnosis of CNS TB.

3. Recommendations regarding Imaging All patients should have a CXR as part of the diagnostic assessment (A,II) Every patient with TBM should be imaged with CECT either before the start of treatment or within the first 48 h of treatment (A,II) All patients with suspected cerebral tuberculoma or spinal cord TB should be investigated by MRI (A,II) Stereotactic brain biopsy should be considered for the diagnosis of tuberculoma if other investigations fail to confirm active extra-neural tuberculosis (A,II) G. Thwaites et al. BRITISH INFECTION SOCIETY GUIDELINES. Journal of Infection (2009) ;59:167-187

4. Classification of CNS TB Intracranial Tuberculous meningitis Tuberculous encephalopathy Tuberculous vasculopathy SOLs like tuberculoma,tuberculous abscess Spinal Pott’s spine and Pott’s paraplegia Tuberculous arachnoiditis Non-Osseous spinal tuberculoma Spinal meningitis

5. TUBERCULAR MENINGITIS (TBM) Diagnostic triad of tubercular meningitis:- Presence of basal exudates Infarcts and Hydrocephalus. It is considered almost 100% specific but has lower sensitivity,

6. Tuberculous meningitis Axial T1C - florid meningeal enhancement, most pronounced within the basal cisterns Most common manifestation of CNS TB in all age groups. Meningeal enhancement has been found in up to 90% of cases and is considered to be the most sensitive feature of tubercular meningitis.  CECT - acute hydrocephalus and meningeal enhancement.

7. No obvious abnormality in the T1- and T2-weighted images. Miliary CNS tuberculosis T1C + image shows numerous bilateral tiny enhancing nodules scattered throughout the brain parenchyma.

8. Ischemic infarcts - in 20-40% cases, mostly within basal ganglia and internal capsule regions, resulting from vascular compression and occlusion of small perforating vessels, particularly Lenticulostriate and Thalamoperforating arteries. ( Necrotizing Arteritis ). Plain CT Brain- infarcts in right BG and internal capsule Cranial nerve involvement is seen in 17-40% cases, most commonly affecting II,III,IV and VII th cranial nerves.

9. TBM with CVT Postcontrast T1 C+ image demonstrates a filing defect within dilated left sigmoid sinus 45-year-old male who presented with headache and cerebrospinal fluid PCR positive for Mycobacterium tuberculosis. MRV - non-visualization of Left transverse and sigmoid sinuses

10. Tuberculoma On NCCT - iso , hyper or of mixed density. On CECT - ring enhancing or irregular nonhomogeneous enhancement. Target sign - central calcification with surrounding ring enhancement. calcified lesion in the left periventricular region, with associated hydrocephalus .

11. Non- caseating granuloma : iso -/hypo on T1, hyper on T2, T1 C+  Homogeneous Granuloma with liquid centre : iso /hypo on T1, hyper on T2 with a peripheral hypo rim, DWI–may show restriction Caseating Solid centre : hypo on T1 , strikingly hypo on T2, DWI – no restriction multiple enhancing Caseating and Non- Caseating tuberculomas , Tuberculoma

12. Imaging TBM Depends on stage of disease : I (normal in 30 %), II (Normal in 10 %), III (Abnormal in all ) Hydrocephalus ( 70-85 %), basal meningeal enhancement ( 40 %), infarction ( 15-30 %), tuberculoma ( 5-10 %) Precontrast hyperdensity in basal cisterns is the most specific radiological sign also help in prognostication TUBERCULOMA Lesion may be solitary, multiple, or Miliary . Most common- within the frontal and parietal lobes, Infratentorial - children. usually - CMJ and periventricular region

13. T2-weighted MRI of a biopsy-proven, Right parietal tuberculoma . Note the low–signal-intensity rim of the lesion and the surrounding hyperintense vasogenic edema.

14. T2-W axial MR image shows hypointense lesions in the bilateral gangliothalamic regions (R>L), with perilesional oedema and associated hydrocephalus Post-contrastT1 W axial image shows multiple ring-enhancing lesions, along with abnormal leptomeningeal enhancement Caseating tuberculoma without liquefaction

15. T2-W axial MR image shows a centrally hyperintense granuloma with a peripheral hypointense rim with associated perilesional oedema Gadolinium-enhanced T1-W axial image shows peripheral ring enhancement of the same lesion. Caseating tuberculoma with liquefaction

16. Multiple supra- and infratentorial tuberculomas in a 27-year-old female with history of Pulmonary tuberculosis. Tuberculomas are seen as multiple small ring enhancing lesions without peripheral edema in Axial and Sagittal postcontrast T1-weighted MR images

17. Tubercular Abscess 4% to 7.5% of patients with CNS TB solitary and larger (> 3 cm in diameter), and progress much more rapidly than tuberculomas . CT - hypodense with edema and mass effect T2- granuloma with a liquid centre T1C +  ring enhancement that is usually thin and uniform

18. Tuberculous Encephalopathy exclusively present in infants and children convulsions, stupor and coma without signs of meningeal irritation or FND CSF – grossly normal Axial T2-W MR images show diffused white matter hyperintensity with oedema and Hydrocephalus. responsive to steroids

19. TUBERCULOUS CEREBRITIS CT imaging shows intense focal gyral enhancement On MR imaging , focal cerebritis appears hypointense on T1, hyperintense on T2 and small areas of patchy enhancement on post-contrast scan. CECT- focal gyral enhancement in left sylvian fissure, with surrounding cerebral oedema

20. EPIDURAL TB Iso on T1W,mixed on T2W images. In post-contrast images, peripheral enhancement is seen if true epidural abscess formation or caseation has developed . Epidural Tuberculous abscess may occur as primary lesions or may be seen in association with an underlying tuberculous focus.

21. Tuberculous abscess with epidural and subdural empyema and calvarial osteomyelitis Coronal and sagittal postcontrast T1-Wt MRI images demonstrate epidural and subdural collections over the bifrontal cerebral convexities with intraparenchymal and calvarial extension. Peripheral edema, irregular marked enhancement of the lesion as well as dural enhancement are evident. The bony destructive lytic lesions are seen in the bone window CT image

22. Spinal TB-Radiographic manifestations I ntraosseous and paraspinal abscess formation. subligamentous spread of infection. vertebral body destruction and collapse resulting in s ignificant instability and deformity of the spine. extension into the spinal epidural space.

23. Focal areas of erosion and osseous destruction in the anterior corners of the vertebral body are typical plain film findings. Contiguous vertebral body involvement , Destruction of IVD Compression fracture and secondary osteosclerosis Plain radiograph

24. CT findings Vertebral body collapse,Disk space narrowing,Large paraspinal soft tissue masses representing abcess formation Cloaca formation may be visualised resulting from spontaneous decomprssion of the vertebral body abcess In chronic stages there is marked bone destruction with sequestrum formation

25. MR findings T1 -decreased signal within the affected vertebral bodies, loss of disk height and paraspinal soft tissue masses T2 -non specific increased signal intensity within areas of osseous and soft tissue changes, Extent of paraspinal abcess formation anteriorly is better visualised . Contrast enhanced sequences are helpful in distinguishing tuberculous lesions from other granulomatous diseases. The presence of thick rim of enhancement around the paraspinal and intraosseous abcesses is found to be diagnostic of spinal tuberculosis.

26. Neurocysticercosis

27. multiple nodular calcified lesions Hypo foci in the calcified stage, minimal residual edema in the Granular stage GRE - multiple "blooming black dots“ characteristic of nodular calcified NCC. enhancement of healing granular nodular NCC cysts, "Shaggy” enhancement with adjacent edema-colloidal vesicular stage. Solitary colloidal vesicular cyst with FLAIR hyperintense scolex with perilesional edema and "shaggy” enhancement

28. Echinococcosis CT –mc - large, unilocular , thin-walled cyst without calcification, edema, or enhancement Occasionally, a single large cyst with multiple "daughter cysts"

29. Echinococcosis MR shows that cyst fluid is iso with CSF on T1WI and T2WI detached germinal membrane and hydatid "sand" can be seen in the dependent portion of the cyst

30. numerous irregular cysts that—unlike HC—are not sharply demarcated from surrounding brain, enhance following contrast Irregular peripheral or ring-like, heterogeneous, nodular, and cauliflower-like patterns have been reported Echinococcosis alveolaris

31. Cerebral malaria NECT - normal or focal infarcts in the cortex, basal ganglia, and thalami. MR T2/FLAIR shows focal hyperintensities , multifocal "blooming" petechial hemorrhages, do not enhance on T1 C+

32. Differential diagnosis of Multifocal white matter petechial hemorrhages: fat emboli syndrome, acute hemorrhagic leukoencephalitis , diffuse vascular injury Thrombotic microangiopathies such as disseminated intravascular coagulopathy . Cerebral malaria

33. TBM and tuberculoma with hydrocephalus enhancing exudate throughout the basal cisterns and subarachnoid spaces T2WI – multifocal tuberculomas as hypointense foci surrounded by edema T1 C+- additional lesions with punctate ring enhancement

34. NCC- Vesicular vs Colloidal stage Vesicular (cyst + scolex , no edema) Colloidal stage with a scolex With striking surrounding edema.

35. Tuberculoma T1W – mixed intensity mass in the corpus callosum and left parietooccipital lobe. Axial T2WI - several areas Of hypointensity T1 C+ multiple conglomerate foci of ring and solid ﬇enhancement 21y postpartum woman with seizures

36. NCC in fourth ventricle with hydrocephalus obstructive hydrocephalus with enlargement of the lateral, third, and fourth With solitary NCC cyst in the bottom of the 4th ventricle. Axial FLAIR – cyst wall, scolex and interstitial fluid around the obstructed 4 th ventricle. A 26y woman with headaches

37. Racemose NCC numerous variable-sized cysts fill the basal cisterns with hydrocephalus, with mild/moderate rim enhancement around the "bunch of grapes" cysts

38. Tuberculous spondylodiscitis ( Pott disease ) T12/L1 spondylodiscitis - with avid contrast enhancemen involving the T11-L2 vertebral bodies, T12/L1 disk space and the adjacent paravertebral collections.

39. Neurocysticercosis .  Lesions of various stages. 

40. THANK YOU