Abstract:

Objective   To investigate the application value of diffusion-weighted imaging (DWI) in diagnosing delayed encephalopathy after carbon monoxide(CO) poisoning. Methods   31 patients with delayed encephalopathy after CO poisoning were enrolled in this study. All of them underwent MR imaging 15-90 days after exposure to CO. DW images were acquired using a single-shot echoplanar imaging sequence in the transverse plane(TR/TE, 2900ms/84ms) with b values of 0 and 1000s/mm2. Conventional MR images, DWIs, and apparent diffusion coefficient(ADC) maps of lesions in the white matter were evaluated. ADC values in the white matter lesions were calculated and compared with normal white matter. Results   In all patients, DWIs showed bilateral areas of diffuse high signal intensity in the periventricular white matter and centrum semiovale, similar to areas shown on T2-weighted and FLAIR images. White matter lesions showed hypo-intensity or iso-intensity on ADC maps. Mean ADC values of the white matter lesions were significantly lower than those of the normal-looking white matter(P<0.05). Conclusion   The degree and duration of low ADC values in the white matter are correlated with the clinical course, which may enable us to predict development and prognosis of delayed encephalopathy after CO poisoning.

Key words:  Magnetic resonance imaging； Diffusion-weighted imaging； Carbon monoxide poisoning; Delayed encephalopathy