Diagnostic History of Traumatic Axonal Injury in Patients with Cerebral Concussion and Mild Traumatic Brain Injury

Cerebral concussion and mild traumatic brain injury (TBI) have been used interchangeably, although the two terms have different definitions. Traumatic axonal injury (TAI) is a more severe subtype of TBI than concussion or mild TBI. Regarding the evidence of TAI lesions in patients with concussion or mild TBI, since the 1960’s, several studies have reported on TAI in patients with concussion who showed no radiological evidence of brain injury by autopsy. However, conventional CT and MRI are not sensitive to detection of axonal injury in concussion or mild TBI, therefore, previously, diagnosis of TAI in live patients with concussion or mild TBI could not be demonstrated. With the development of diffusion tensor imaging (DTI) in the 1990’s, in 2002, Arfanakis et al. reported on TAI lesions in live patients with mild TBI using DTI for the first time. Subsequently, hundreds of studies have demonstrated the usefulness of DTI in detection of TAI and TAI lesions in patients with concussion or mild TBI. In Korea, the term “TAI” has rarely been used in the clinical field while diffuse axonal injury and concussion have been widely used. Rare use of TAI in Korea appeared to be related to slow development of DTI analysis techniques in Korea. Therefore, we think that use of DTI analysis techniques for diagnosis of TAI should be facilitated in Korea.

The value of diffusion weighted combined susceptibility weighted imaging in evaluation of traumatic axonal injury / 中华老年医学杂志

Objective To explore the value of diffusion weighted imaging (DWI) in combination with susceptibility weighted imaging (SWI) in prognosis prediction of traumatic axonal injury (TAI).Methods A retrospective study of 75 patients with TAI was performed to analyze the clinical data and the follow-up prognosis in the 6 months after injury.The detection rate of TAI lesion by DWI,SWI and conventional MRI was compared.Multiple factors analysis applied logistic regression analysis to analyze the relationship between associated factors and prognosis.Results The average detected TAI lesions were (19.92 ± 8.62) by DWI and (22.17 ± 11.72) by SWI,which had no significant differences (t=1.24,P＞0.05),but there was a significant difference bettween by conventional MRI and by DWI or SWI (all P＜0.05).DWI was more sensitive to non-hemorrhagic lesions and SWI was more sensitive to hemorrhagic lesions.However,the lesions revealed by them existed the overlap of location and pathology of lesions.Patients with poor outcomes had more number of central lesions than those patient with good outcomes (t=2.455,P＜ 0.05).Logistic regression analysis revealed that the predictive accuracy provided by the combination with imaging and clinical factors was 95.7 ％.Conclusions DWI and SWI both are sensitive to TAI lesions,and have ability to detect the lesions with different pathological characteristics,separately.Accurate prognosis prediction for patients with TAI may be provided by the combination of clinical and imaging factors.