Книги по МРТ КТ на английском языке / MR Imaging in White Matter Diseases of the Brain and Spinal Cord - K Sartor Massimo Filippi Nicola De Stefano Vincent Dou
.pdfViral and Non-Viral Infections in Immunocompetent and Immunocompromised Patients |
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Fig. 27.12a, b. Toxocariasis. |
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Flair MR imaging. Several |
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lesions of the subcortical |
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white matter (a) and of the |
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cortex (b). The imaging |
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findings are not sufficient |
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to make the diagnosis, |
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which requires blood se- |
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rology for Toxocara canis |
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or Toxocara cati |
a b
by the smallest fungi like Cryptococcus neoformans |
27.6.3 |
or small to extensive infarcts following occlusion of |
Mucormycosis |
the vessels by bigger fungi such as Aspergillus and |
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Candida. |
Most CNS mucormycosis-infected patients are dia- |
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betic, drug abusers, or patients receiving long-term |
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antibiotics and corticosteroids. It has a secondary |
27.6.1 |
focus in skin, nasal mucosa and lungs. Rhinocerebral |
Cryptococcosis |
mucormycosis is a common feature. It provokes ne- |
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crosis and vasculitis with hemorrhage. |
The patient usually presents with a meningoencepha- |
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litis (Harris and Enterline 1997). The infection |
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is fatal without appropriate treatment using ampho- |
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tericin B. Lumbar puncture is the single most use- |
27.7 |
ful test. After reaching the CSF, the organisms may |
Granulomatous Infections and |
extend along the perforating arteries in the perivas- |
Immunoreactive Diseases |
cular Virchow-Robin spaces. The signal intensity is |
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similar to the cerebrospinal fluid. Cerebral edema |
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rarely occurs. |
27.7.1 |
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Granulomatous Infections |
27.6.2 |
Granulomas correspond to cellular mass with T-cells, |
Aspergillosis |
macrophages and histiocytes without liquefied ne- |
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crotic debris. Caseous (“cheesy”) necrosis is typical |
It is relatively rare in the AIDS population, but is |
of tuberculous granulomas. |
more common in patients under corticosteroids. The |
Granulomatous infections can result from di- |
organisms invade the lung parenchyma and spread |
verse pathogens, including bacteria (Mycobacterium, |
hematogenously. Aspergillus may reach the CNS via |
Nocardia, Actinomyces, spirochetes), fungi (aspergil- |
direct spread from the paranasal sinuses or orbits. |
losis or mucormycosis), and parasites. Sarcoidosis is |
Aspergillus abscesses have a nonspecific appear- |
an idiopathic granulomatous disease that most com- |
ance. |
monly affects young, otherwise healthy adult patients |
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(Ulmer and Ester 1991). Most granulomatous in- |
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fections affect the meninges. The brain parenchyma |