The availability of diffusion-weighted imaging with the fluid-attenuated inversion recovery method (FLAIR-DWI) with a low-performance MR unit in chronic ischemia disease

Abstract

Purpose: In magnetic resonance imaging (MRI), the diffusion-weighted image (DWI) is an important technique for diagnosis of acute infarction; however, in a 1.0 Tesla low-performance MR unit, chronic ischemia is often detected as a high signal and misdiagnosed as acute infarction. Fluid-attenuated inversion recovery (FLAIR)-DWI was used in an attempt to solve this problem, and the availability is discussed. Materials and methods: MR imaging was performed in 35 patients, after acute infarction (n = 19), and with chronic ischemia (n = 16). Conventional-DWI (C-DWI) and FLAIRDWI were used for all patients. The echo time (TE) was 140 ms. The signal-to-noise ratio (SNRs) and apparent diffusion coefficient (ADC) map in the region of acute infarction or chronic ischemia and contralateral normal brain were estimated. Results: In all regions, ADC was not significantly different between C-DWI and FLAIR-DWI (p>0.05). In chronic ischemia and acute infarction, the SNR of ischemic regions using FLAIR-DWI was significantly lower than that of C-DWI (p<0.05). Furthermore, the SNR of acute infarction regions was significantly higher than that in chronic ischemic regions (p<0.05). Conclusion: In a low-performance MR unit, the discrimination between chronic ischemia and acute infarction was improved by using FLAIR-DWI. © 2009 Springer-Verlag.