Diffusion-Weighted Imaging of Fungal Cerebral Infection
Paola Gaviania,
Richard B. Schwartze,g,
E. Tessa Hedley-Whyteb,g,
Keith L. Ligonf,g,
Ari Robicsekc,
Pamela Schaeferd,g and
John W. Hensona,d,g
a Stephen E. and Catherine Pappas Center for Neuro-oncology Unit, Massachusetts General Hospital, Boston
b Stephen E. and Catherine Pappas Center for Neuropathology Unit, Massachusetts General Hospital, Boston
c Stephen E. and Catherine Pappas Center for Infectious Disease Unit, Massachusetts General Hospital, Boston
d Division of Neuroradiology, Massachusetts General Hospital, Boston
e Division of Neuroradiology, Brigham and Women’s Hospital, Boston
f Division of Neuropathology, Brigham and Women’s Hospital, Boston
g Harvard Medical School, Boston
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FIG 1. Patient 1. Fungal cerebritis due to Rhizopus infection of the left basal ganglia and corona radiata.
A, On Gd-enhanced T1-weighted imaging, the lesion is hypointense with minimal peripheral enhancement.
B, On FLAIR imaging, the lesion has heterogeneous signal intensity with moderate surrounding edema.
C and D, DWI (C) and ADC (D) images show predominantly decreased diffusion (short arrow in D) with a smaller region of elevated diffusion (long arrow in D).
E, Hematoxylin-eosin stain (40x) shows perivascular ring hemorrhages and necrosis. Moderate amount of acute and chronic inflammation was also found (data not shown).
F, Methenamine silver stain (450x) shows fungal organisms predominantly in the lumen of blood vessels (arrows).
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FIG 2. Patient 7. Fungal abscess due to Scedosporium infection.
A, On Gd-enhanced T1-weighted imaging, the lesion is ring enhancing.
B, On FLAIR imaging, the lesion is isointense to brain parenchyma, with moderate surrounding edema.
C and D, DWI (C) and ADC (D) images show homogeneously decreased diffusion in the center of the lesion, similar to that seen with pyogenic abscess.
E and F, Hematoxylin-eosin (E) (450x) and methenamine silver stain (F) (250x) stains show fungal organisms (arrow) in necrotic tissue and chronic inflammation.
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FIG 3. Patient 6. Fungal abscess due to Aspergillus infection.
A, On Gd-enhanced T1-weighted imaging, the lesion is ring enhancing.
B, On FLAIR imaging, the lesion is hyperintense to brain parenchyma, without surrounding edema.
C and D, DWI (C) and ADC (D) images show homogeneously decreased diffusion in the center of the lesion.
E, Hematoxylin-eosin stain (100x) shows a lesion discrete from brain with a well-defined capsule (arrows). Lesions were composed of granulomatous chronic inflammation with numerous histiocytes and giant cells engulfing fungal organisms (asterisk).
F, Methenamine silver stain (250x) shows fungal organisms (arrow) with 45° angle branching, consistent with Aspergillus infection.
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FIG 4. Patient 3. Early fungal abscess due to Aspergillus infection.
A, On Gd-enhanced T1-weighted imaging, the lesion has a thin rim of peripheral enhancement.
B, On FLAIR imaging, the lesion has heterogeneous signal intensity with minimal surrounding edema.
C and D, DWI (C) and ADC (D) maps show peripherally decreased diffusion, with elevated diffusion in the center of the lesion.
E, Hematoxylin-eosin stain (100x) shows acute and chronic inflammation in the brain parenchyma, without a well-defined capsule.
F, Methenamine silver stain (250x) shows septate and 45°-branching hyphae in necrotic parenchyma.
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