INTRODUCTION Granulomatous inflammation is a distinctive ...

Recommendations

Info

patients. The validity of these findings is not determined; they could be markers of disease activity (Scott, 1993) Hormonal studies It should be performed whenever involvement of the pituitary-hypothalamic axis is suspected. This includes thyroid function tests, prolactin, testosterone, growth hormone, luteinizing hormone, follicle-stimulating hormone, corticotropin-releasing hormone, estradiol, urine osmolality determination, and insulin like growth factor (Bucurescu, 2006). Neuroimaging Both CT scan and MRI of the brain are indispensable in assessing nervous system involvement in sarcoidosis. Yet, MRI has become the modality of choice because of the superior images obtained (Bucurescu, 2006). MR imaging with and without contrast is a very sensitive test. Abnormalities are seen in up to 82% of patients with neurosarcoidosis. There are abnormalities that suggest neurosarcoidosis, but none of the findings are very specific. Contrast MR imaging increases the sensitivity by showing areas of enhancement of the meninges and parenchymal lesions which occurs in 40% of cases. This is consistent with the frequent demonstration of inflammation of the meninges on pathologic examination (Sherman and Stern, 1990). Most common lesions on MRI include: multiple white matter lesions (43% of patients), meningeal enhancement (38% of patients), optic nerve enhancement (28% of patients) and mass lesions in brain parenchyma (Zajicek et al., 1999) Leptomeningeal involvement is best shown on spin-echo contrast-enhanced T1-weighted images (Consensus Conference, 1994). The gadolinium enhancement shows leptomeningeal involvement in cases that unenhanced images might have missed (Figure 18). The enhancement can follow the contour of the brain, extending into the cortical sulci. Leptomeningeal infiltration typically involves the suprasellar and frontal basal meninges but may occur anywhere and is more concentrated in the depths of the sulci. Figure 18. Sarcoidosis. Enhanced TI-weighted axial image. Enhancement around midbrain and cerebellar hemisphere (straight arrows) indicates breakdown of blood-CSF barrier. Optic chiasm involvement (curved arrow). (John and Barney, 1990) Granulomatous lesions are accompanied by varying degrees of fibrosis and hyalinization.
Occasionally, granulomas coalesce to form mass like lesions, particularly in the region of the chiasma, floor of the third ventricle, and pituitary stalk. Clinical symptoms correlate with the location of the lesion on MR images. Furthermore, it was found that these lesions recur frequently (Ando et al., 1985). Disease entities that can involve the basal leptomeninges and mimic leptomeningeal sarcoidosis on imaging include granulomatous disease (such as TB), Wegener granulomatosis and fungal meningitis, pyogenic meningitis, leptomeningeal lymphoma, demyelination, meningoangiomatosis, acute lymphocytic leukemia, and leptomeningeal carcinomatosis (Brooks et al., 1982). Dural/epidural mass lesions have an imaging appearance similar to that of meningioma/epidural lymphoma and are not associated with intraparenchymal extension. Dural/epidural sarcoidosis probably represents blood borne deposits of the disease in the epidural spaces. The annual incidence of these lesions exceeds the annual incidence of meningiomas (2.3 per 100,000) by 130 times. These lesions tend to be isointense with gray matter on T1-weighted MR images and hypointense on T2- weighted images, and they enhance uniformly (Figure 19). This hypointensity on T2-weighted images has been reported previously (Chaflenor et al., 1984) and is thought to be related to fibrocollagenous buildup. Unfortunately, this is not a unique finding. Eighteen percent of meningiomas (typically fibroblastic or transitional types) demonstrate low signal on T2-weighted images. Figure 19. Sarcoidosis. Contrast-enhanced T1-weighted coronal image. Nodular enhancing sarcoid granulomatous mass is on right (arrowheads). There is erosion of inner table of calvaria (straight arrow). Falx is involved also (curved arrow). (John and Barney, 1990) In addition to meningioma, differential considerations for sarcoidosis involvement of the dura should include other causes of chronic meningitis, such as lymphoma, adenocarcinoma, Wegener, idiopathic hypertrophic cranial pachymeningitis (IHCP), granulomatous infection, and leukemia (Chan et al., 1985). Enhancing Brain Parenchymal Lesions show in T2 weighted and gadolinium-enhanced T1 weighted MR imaging as high-signal intensity lesions, especially in periventricular regions (Figure 20), Enhancing brain parenchymal lesions commonly start in the subependymal or the pial (leptomeningeal) microvascular systems then invade the brain in a centrifugal or centripetal ways forming multiple enhancing masses in the periventricular or corticomedullary regions.
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 and 12: PCR assay The advent of detection p
Page 13 and 14: Figure 2. CT scan in a patient with
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: Imaging Studies Chest x-rays have b
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
Page 75 and 76: 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
Page 83 and 84: 56. Carol A Langford (2003), Wegene
Page 85 and 86: Infectious Diseases;26:781-805 89.
Page 87 and 88: 119. Feely M, Sternberg M (1977). A
Page 89 and 90: Press :675-705. 151. Hadi M, Boncoe
Page 91 and 92: 182. Jones Richard E. ; Chatham W.
Page 93 and 94: Medicine; 76: 423-31 214. Levy RM,
Page 95 and 96: 245. Metwally Y.(2006-4); Neurologi
Page 97 and 98: 278. Oksanen V, Salmi (1986). Visua
Page 99 and 100: 311. Ribes, J. A., C. L. Vanover-Sa
Page 101 and 102: enhanced MR images; AJNR;. 11:915-9
Page 103 and 104: 373. Tuzun M, Altinors N, Arda IS,
Page 105:
transplantation patients: CT and MR
show all

INTRODUCTION Granulomatous inflammation is a distinctive ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?