PT  - JOURNAL ARTICLE
AU  - C.H. Toh
AU  - K.-C. Wei
AU  - S.-H. Ng
AU  - Y.-L. Wan
AU  - C.-P. Lin
AU  - M. Castillo
TI  - Differentiation of Brain Abscesses from Necrotic Glioblastomas and Cystic Metastatic Brain Tumors with Diffusion Tensor Imaging
AID  - 10.3174/ajnr.A2581
DP  - 2011 Oct 01
TA  - American Journal of Neuroradiology
PG  - 1646--1651
VI  - 32
IP  - 9
4099  - http://www.ajnr.org/content/32/9/1646.short
4100  - http://www.ajnr.org/content/32/9/1646.full
SO  - Am. J. Neuroradiol.2011 Oct 01; 32
AB  - BACKGROUND AND PURPOSE: The differentiation of abscesses from glioblastomas and metastases may not always be possible on the basis of DWI. Our hypothesis was that differences in diffusion properties as detected by DTI allow differentiation of abscess from glioblastomas and metastasis. Furthermore, diagnostic performance of tensor metrics quantifying anisotropy or tensor shapes is better than that of ADC in measuring mean diffusivity for this purpose. MATERIALS AND METHODS: DTI was performed in 15 abscesses, 15 necrotic glioblastomas, and 26 cystic metastases. In each lesion, manually segmented into 4 regions of interest (ie, cystic cavity, enhancing rim, and immediate [edema most adjacent to the enhancing rim] and distant zones of edema), FA, ADC, Cl, Cp, and Cs values were measured and statistically compared among groups and evaluated with ROC curve analysis. The presence of a hyperintense FA rim (a rim of edematous tissue that was hyperintense on the FA map) was assessed visually. RESULTS: Abscess was significantly different from glioblastoma for all tensor metrics measured in the cystic cavity and immediate zone of edema and for all except Cl in the enhancing rim. Abscess was significantly different from metastasis for all tensor metrics measured in the cystic cavity and enhancing rim and for FA, ADC, and Cl in immediate zone of edema. The incidence of a hyperintense FA rim was significantly higher in glioblastoma and metastasis compared with abscess. The 3 tensor metrics with the highest performance in differentiating abscess from glioblastoma and metastasis were FA, Cl, and Cs of the cystic cavity. CONCLUSIONS: DTI is able to differentiate abscess from glioblastoma and metastasis. FA, Cl, and Cs outperformed ADC in diagnostic performance comparisons. ADCapparent diffusion coefficientAUCarea under the curveCCcystic cavityCllinear tensorCpplanar tensorCsspheric tensorDTIdiffusion tensor imagingDWIdiffusion-weighted imagingDZEdistant zone of edemaERenhancing rimFAfractional anisotropyGBglioblastomaIZEimmediate zone of edemaMetsmetastasisMPRAGEmagnetization-prepared rapid acquisition of gradient echoNAWMnormal-appearing white matterROCreceiver operating characteristic