Magnetic resonance in traumatic brain injury: A comparative study of the different conventional magnetic resonance imaging sequences and their diagnostic value in diffuse axonal injury

Objective: To compare the identification capability of traumatic axonal injury (TAI) by different sequences on conventional magnetic resonance (MR) studies in traumatic brain injury (TBI) patients. Material and methods: We retropectevely analyzed 264 TBI patients to whom a MR had been performed in the first 60 days after trauma. All clinical variables related to prognosis were registered, as well as the data from the initial computed tomography. The MR imaging protocol consisted of a 3-plane localizer sequence T1-weighted and T2-weighted fast spin-echo, FLAIR and gradient-echo images (GRET2*). TAI lesions were classified according to Gentry and Firsching classifications. We calculated weighted kappa coefficients and the area under the ROC curve for each MR sequence. A multivariable analyses was performed to correlate MR findings in each sequence with the final outcome of the patients. Results: TAI lesions were adequately visualized on T2, FLAIR and GRET2* sequences in more than 80% of the studies. Subcortical TAI lesions were well on FLAIR and GRET2* sequences visualized hemorrhagic TAI lesions. We saw that these MR sequences had a high inter-rater agreement for TAI diagnosis (0.8). T2 sequence presented the highest value on ROC curve in Gentry (0.68, 95%CI: 0.61-0.76, p <0.001, Nagerlkerke-R-2 0.26) and Firsching classifications (0.64, 95%CI 0.57-0.72, p < 0.001, Nagerlkerke-R-2 0.19), followed by FLAIR and GRET2* sequences. Both classifications determined by each of these sequences were associated with poor outcome after performing a multivariable analyses adjusted for prognostic factors (p <0.02). Conclusions: We recommend to perform conventional MR study in subacute phase including T2, FLAIR and GRET2* sequences for visualize TAI lesions. These MR findings added prognostic information in TBI patients. (C) 2017 Sociedad Espanola de Neurocirugia. Published by Elsevier Espana, S.L.U. All rights reserved.