Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2001 Oct;22(9):1738-42.

Restricted diffusion within ring enhancement is not pathognomonic for brain abscess

M Hartmann  1 , O Jansen, S Heiland, C Sommer, K Münkel, K Sartor
Affiliations

Restricted diffusion within ring enhancement is not pathognomonic for brain abscess

M Hartmann et al. AJNR Am J Neuroradiol. 2001 Oct.

Abstract

Background and purpose: Recent experience suggests that diffusion-weighted MR imaging may be decisive in the differential diagnosis of ring-enhancing cerebral lesions. Whether restricted diffusion within a ring-enhancing cerebral mass lesion is pathognomonic for abscess was studied.

Methods: Seventeen patients with ring-enhancing cerebral lesions (three abscesses, six glioblastomas, eight metastases) on conventional contrast-enhanced T1-weighted images were examined with echo-planar diffusion-weighted MR imaging. Apparent diffusion coefficient (ADC) maps and the ADCs were calculated for all lesions. Lesions with signs of intralesional hemorrhage on unenhanced T1-weighted images were excluded.

Results: The central portion of all six glioblastomas and seven of eight metastases showed unrestricted diffusion, whereas two of three abscesses showed restricted diffusion (low ADC values) in their cavity. However, restricted diffusion also was found in one metastasis, and one abscess within a postoperative cavity showed unrestricted diffusion within a larger nondependent portion.

Conclusion: In patients with ring-enhancing cerebral mass lesions, restricted diffusion might be characteristic but is not pathognomonic for abscess, as low ADC values also may be found in brain metastases.

PubMed Disclaimer

Figures

<sc>fig</sc> 1.
fig 1.
Metastatic adenocarcinoma. The T2-weighted image (A) shows a hypointense mass lesion surrounded by massive edema. On the contrast-enhanced T1-weighted image (B), there is ring enhancement presumably due to central necrosis. With diffusion weighting (C), the central part of the tumor becomes markedly hyperintense, while the ADC map (D) reveals low values, indicating restricted diffusion. Histopathologic section (E): Note that besides tumor cells, additional geographic necrosis (N), lymphocytes (arrowheads), and connective tissue (arrow) are present (hematoxylin and eosin stain; original magnification, × 200)
<sc>fig</sc> 2.
fig 2.
Pyogenic brain abscess. On the T2-weighted image (A), the lesion has a thick hypointense wall with a hyperintense center, consistent with necrosis. Dense ring enhancement is noted on the contrast- enhanced T1-weighted image (B). The DW image (C) and the ADC map (D) reveal restricted diffusion within the center
<sc>fig</sc> 3.
fig 3.
Pyogenic brain abscess with parafalcial subdural empyema. On T2-weighted image (A) the lesion has a thick hypointense wall. The contrast-enhanced T1-weighted image (B) shows ring enhancement. Evidence for restricted diffusion within the abscess cavity and the parafalcial empyema is provided by the DW image (C) and the ADC map (D)
<sc>fig</sc> 4.
fig 4.
Mean ADC values ± SD (×10−3 mm2/s) of the mean tumor group (n = 13), adenocarcinoma outlier (n = 1), mean abscess group (n = 2), and nondependent and dependent portions of the abscess outlier (n = 1)
<sc>fig</sc> 5.
fig 5.
Postoperative brain abscess. The T2-weighted image (A) shows a hyperintense cavity surrounded by massive edema. The contrast-enhanced T1-weighted image (B) shows ring enhancement. With diffusion weighting (C), the gravity-dependent portion was markedly hyperintense (arrow) and showed markedly hypointense signal on the ADC map, (arrow), indicating restricted diffusion (D). The DW imaging intensity of the nondependent portion was hypointense with corresponding marked hyperintensity on the ADC map
See this image and copyright information in PMC

References

    1. Desprechins B, Stadnik T, Koerts G, Shabana W, Breucq C, Osteux M. Use of diffusion-weighted MR imaging in the differential diagnosis between intracerebral necrotic tumors and cerebral abscesses. AJNR Am J Neuroradiol 1999;20:1252-1257 - PMC - PubMed
    1. Ebisu T, Tanaka C, Umeda M, et al. Discrimination of brain abscess from necrotic or cystic tumors by diffusion-weighted echo planar imaging. Magn Reson Imaging 1996;14:1113-1116 - PubMed
    1. Kim YJ, Chang K-H, Song IC, et al. Brain abscess and necrotic or cystic brain tumor: discrimination with signal intensity on diffusion-weighted MR imaging. AJR Am J Roentgenol 1998;171:1487-1490 - PubMed
    1. Noguchi K, Watanabe N, Nagayoshi T, et al. Role of diffusion-weighted echo-planar MRI in distinguishing between brain abscess and tumour: a preliminary report. Neuroradiology 1999;41:171-174 - PubMed
    1. Tsuchiya K, Yamakami N, Hachiya J, Saito I, Kobayashi H. Multiple brain abscesses: differentiation from cerebral metastases by diffusion-weighted magnetic resonance imaging. Int J Neuroradiol 1998;4:258-262

MeSH terms