A Preliminary Study On The Definition Of Penumbra In Trauma Using Combined Susceptibility-weighted Imaging And Perfusion-weighted Imagin

Objective: This study aims to combine the use of magnetic weighted imaging(SWI),diffusion weighted imaging(DWI)and perfusion weighted imaging imaging(PWI)to investigate the changes of blood perfusion in the penumbra area and surrounding areas of brain trauma.Methods: A total of 25 patients with moderate cerebral contusion in Hunan Brain Hospital(the Second People’s Hospital of Hunan Province)were collected.MRI plain scan、DWI、SWI and PWI were examined within 24 hours after admission,and re-examined one month later.The SWI/T2-Fluid attenuated inversion recovery(T2-FLAIR)mismatched area was defined as the traumatic penumbra,and the volume of SWI/DWI mismatched area was used as the control standard to evaluate the consistency of the two methods in detecting the penumbra.The two SWI mismatched areas were defined as necrotic areas.Combined with PWI,Cerebral blood flow(CBF)、Cerebral blood volume(CBV)、Mean transit time(MTT)and Time to peak(TTP)values of the penumbra area and necrotic area were measured,and the measured values were statistically analyzed.Results: In 25 patients,the necrotic area CBF value(30.45±5.58)ml/100g/min and CBV value(4.44±1.34)ml/100 g were lower than those in penumbra area(44.46±6.16)ml/100g/min and(5.67±1.30)ml/100 g.The MTT value of necrotic area was(9.26±1.17)s,higher than that of penumbra area(7.63±1.47)s.There was no significant difference in TTP value between necrotic area(29.31±3.00)s and penumbra area(28.56±2.58)s.The volume of SWI/T2-FLAIR and SWI/DWI mismatched area was statistically significant(t=0.640,p<0.00),and the two methods were consistent in detecting penumbra.According to ROC curve,CBF was the most sensitive index affecting the final development of traumatic penumbra,with a sensitivity of 89.3% and a specificity of 92.9%.Conclusion: SWI/T2-FLAIR mismatch area can be used to define the penumbra in traumatic brain.The penumbra can change dynamically over time.The cerebral blood perfusion around brain contusion and laceration is lower than normal.When the cerebral blood flow is reduced to a certain level,the traumatic penumbra area may develop into a necrotic area.