PT  - JOURNAL ARTICLE
AU  - V. Tomar
AU  - A. Yadav
AU  - R.K.S. Rathore
AU  - S. Verma
AU  - R. Awasthi
AU  - V. Bharadwaj
AU  - B.K. Ojha
AU  - K.N. Prasad
AU  - R.K. Gupta
TI  - Apparent Diffusion Coefficient with Higher b-Value Correlates Better with Viable Cell Count Quantified from the Cavity of Brain Abscess
AID  - 10.3174/ajnr.A2674
DP  - 2011 Dec 01
TA  - American Journal of Neuroradiology
PG  - 2120--2125
VI  - 32
IP  - 11
4099  - http://www.ajnr.org/content/32/11/2120.short
4100  - http://www.ajnr.org/content/32/11/2120.full
SO  - Am. J. Neuroradiol.2011 Dec 01; 32
AB  - BACKGROUND AND PURPOSE: DWI by using higher b-values provides tissue diffusivity with less T2 shinethrough effect. VCD in the abscess cavity correlates with ADC values. The purpose of this study was to investigate which b-value−derived ADC correlates better with VCD. MATERIALS AND METHODS: Thirty patients with brain abscess underwent conventional MR imaging and DWI with b = 1000, 2000, and 3000 s/mm2 on a 3T MR imaging scanner. ADC values were quantified by placing regions of interest inside the abscess cavity in all sections where the lesion was apparent on coregistered ADC maps derived from different b-values. VCD was measured on pus aspirated. RESULTS: An increase in b-value was associated with a decrease in ADC values in normal parenchyma as well as in the abscess cavity. The most significant negative correlation of VCD was observed with b = 3000 s/mm2 (r = −0.98, P = .01). CONCLUSIONS: VCD in the abscess cavity can be best assessed at b = 3000 s/mm2 secondary to the reduction in the T2 shinethrough effect. DWI with b = 3000 s/mm2 is of promising value in the assessment of the therapeutic response of brain abscess. ADCapparent diffusion coefficientCNWMcontralateral normal white matterDWIdiffusion-weighted imagingFLAIRfluid-attenuated inversion recoveryFWMfrontal white matterGMgray mattersppspeciesVCDviable cell densityWMwhite matter