INTRODUCTION Granulomatous inflammation is a distinctive ...

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meninges, especially in basilar regions. Ventricular enlargement is present in a majority of patients. The degree of hydrocephalus correlates with the duration of the disease (Muralidhar, 2004). Infarcts are another characteristic imaging feature of tuberculous meningitis (Ahuja et al., 1994). The reported frequency of infarcts demonstrated by CT varies from 20.5% to 38%, however, in general, the incidence of infarction is significantly higher on MRI than on CT. In addition, a large number of infarcts are seen to be haemorrhagic in nature on MRI, a finding not well documented on CT scan. The majority of infarcts are seen in thalamic, basal ganglion, and internal capsule regions (Berger, 1994). Thick basilar exudates appear by CT as intensely enhancing areas in the basal cisterns (spider-leg appearance) and in the sylvian fissures (Figure 1)(Ahuja et al., 1994). The thickening of the meninges is better visualized by MRI after enhancing the contrast with gadolinium. MRI shows marked linear enhancement of the ependymal surface of the ventricle following gadolinium injection (Chang et al.,1990). Figure 1. Contrast-enhanced CT scan in a patient with tuberculosis meningitis demonstrates marked enhancement in the basal cistern and meninges, with dilatation of the ventricles (Peter, 2004) CT and MRI show hydrocephalus in 50–80% of cases, cerebral infarctions in 25–30% (Figure 2), and perivascular edema and tuberculomas in 10–20%. In general, all other kinds of lesions associated with TBM are demonstrated better on MRI than on CT scan (Chang et al., 1990). Tuberculomas are infrequently seen on CT or MRI of patients with tuberculous meningitis. Davis et al (1993) found tuberculomas in 16% of patients with culture-positive or presumptive tuberculous meningitis (Davis et al., 1993). Multiple small intracranial tuberculoma are frequent when tuberculous meningitis is part of miliary TB (Gee et al., 1992; Eide et al., 1993). The carotid or MR angiogram shows changes in vessels of the circle of Willis. These changes include uniform narrowing of large segments, small segmental narrowing, irregular beaded appearance and complete occlusion (Jinkins et al., 1995).
Figure 2. CT scan in a patient with tuberculosis meningitis showing extensive right basal ganglia and internal capsule infarcts after the appearance of vasculitis in the thalamoperforating arteries . (Peter, 2004) Tuberculomas on CT are characterized as low- or high-density and rounded or lobulated masses and show intense homogenous or ring enhancement after contrast administration (Figure 3). They have an irregular wall of varying thickness. Moderate to marked perilesional oedema is frequently present (Jinkins, 1988). Tuberculomas may be single or multiple and are more common in frontal and parietal, lobes, usually in parasagittal areas. On CT, the ‘target sign’, a central calcification or nidus surrounded by a ring that enhances after contrast administration, is considered pathognomonic of tuberculoma (Van Dyk, 1988). In developing countries like India, tuberculomas are frequently confused with cysticercus granuloma. Figure 3. Contrast-enhanced CT of brain showing multiple tuberculomas in a patient with tuberculous meningitis; (Ravindra,1999 On CT scanning, tuberculoma measure more than 20 mm in diameter, are frequently irregular in outline, and are always associated with marked cerebral oedema (leading to midline shift) and progressive focal neurological deficit (Bhargava and Tandon, 1980).
Page 1 and 2: INDEX Master degree thesis presente
Page 3 and 4: Necrosis usually minimal and focal,
Page 5 and 6: Most tuberculous infections of the
Page 7 and 8: A predominantly spinal form of tube
Page 9 and 10: neuroimaging characteristics. Evide
Page 11: PCR assay The advent of detection p
Page 15 and 16: Treatment of CNS tuberculosis In co
Page 17 and 18: Presence of tuberculomas Basilar e
Page 19 and 20: aspergillosis was the most common c
Page 21 and 22: There are few reported cases of pat
Page 23 and 24: growth (Geol et al., 1996; Nadkarni
Page 25 and 26: Neuroimaging The imaging findings r
Page 27 and 28: emains very poor (Brad et al., 2005
Page 29 and 30: (Talmi et al., 2002). Although evid
Page 31 and 32: disease and can be used as a basis
Page 33 and 34: immunocompetent patients. Symptoms
Page 35 and 36: Table 4. Diagnostic criteria for ne
Page 37 and 38: Giant cysts, measuring more than 50
Page 39 and 40: Toxoplasmosis is caused by an intra
Page 41 and 42: Despite the lower sensitivity of CT
Page 43 and 44: Diagnosis is primarily made by imag
Page 45 and 46: mesenteric veins draining the large
Page 47 and 48: Sarcoidosis Sarcoidosis is a granul
Page 49 and 50: sequentially in approximately one t
Page 51 and 52: Furthermore, the majority of the pa
Page 53 and 54: Imaging Studies Chest x-rays have b
Page 55 and 56: Occasionally, granulomas coalesce t
Page 57 and 58: Patients with spinal cord sarcoidos
Page 59 and 60: Monthly tapering after 8 months ove
Page 61 and 62: patients with spinal cord involveme
Page 63 and 64:
weighted contrast-enhanced spin-ech
Page 65 and 66:
identified within the CNS (Calabres
Page 67 and 68:
Balancing control of the disease wi
Page 69 and 70:
Two major patterns of white matter
Page 71 and 72:
By MRI, cholesteatomas are hypointe
Page 73 and 74:
non invasive investigations are not
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overlapping features however in sar
Page 77 and 78:
Aspergillosis is another form of fu
Page 79 and 80:
cyclophosphamide (Scolding et al.,
Page 81 and 82:
24. Behri M, Raj M, Ahuja GK et al
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56. Carol A Langford (2003), Wegene
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Infectious Diseases;26:781-805 89.
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119. Feely M, Sternberg M (1977). A
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Press :675-705. 151. Hadi M, Boncoe
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182. Jones Richard E. ; Chatham W.
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Medicine; 76: 423-31 214. Levy RM,
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245. Metwally Y.(2006-4); Neurologi
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278. Oksanen V, Salmi (1986). Visua
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311. Ribes, J. A., C. L. Vanover-Sa
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enhanced MR images; AJNR;. 11:915-9
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373. Tuzun M, Altinors N, Arda IS,
Page 105:
transplantation patients: CT and MR
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