Introduction:
Trauma is the most common cause of Intracranial
hemorrhage and CT scan is the first choice to detect the brain damage. Today magnetic resonance imaging (MRI) is increasingly used in order to assess the traumatic brain injuries in emergency departments since it is more sensitive to the focal bleedings and axonal damages in comparison  to  CT  scan.  There is some limited information about the diffusion- weighted (DWI) signals of hematoma in different stages especially in chronic hematomas that there is no agreement between the researchers about it. In this study, we intended to detect the extra-axial hematomas and assess its changes during the time using DWI.
 
Materials and Methods:
This is a cross-sectional study  in  which  the  trauma patients who were hospitalized in  one  of the university hospitals was participated in. the participants were undergone  three  MRI  imaging  in the first day, after 48 hours, and after 3 weeks using different pulse sequences of T1, T2, DWI, and ADC map. The changes of their hematomas were evaluated during three weeks. SPSS v21 was used for statistical analysis and Wilcoxon method was applied to compare the changes. Results:
16 patients participated in this study. MRI was performed in three steps, the first day, after 48 hours and 3 weeks after trauma. The study revealed that over time extra-axial hematoma shows diffusion restriction in DWI. Most of the MRIs (87.5%) in the first day in DWI and 100% in ADC had a signal void. After 48 hours in 75% of DWI and 100% of ADC the signal was hypo-signal and after three weeks all the DWI cases were hyper-signal and the ADCs were hypo-signal.
 
Conclusion:
In this study to the best of our knowledge, we describe DWI changes in brain MRI of the patients with head trauma. According to the results, DWI changes are different from those seen in intracranial hematomas which well describes in literature.
gone  three  MRI  imaging  in the first day, after 48 hours, and after 3 weeks using different pulse sequences of T1, T2, DWI, and ADC map. The changes of their hematomas were evaluated during three weeks. SPSS v21 was used for statistical analysis and Wilcoxon method was applied to compare the changes.