Computed tomography and magnetic resonance imaging of diffuse axonal injury in brain trauma in young children: retrospective study
Authors: Zaitseva E. S. , Akhadov T. A. , Mamatkulov A. D. , Bozhko O. V. , Ublinsky M. V. , Novoselova I. N. , Ponina I. V. , Melnikov I. A. , Khusainova D. N. 
Published: October 2023

INTRODUCTION: Traumatic brain injury (TBI) is the leading cause of death and disability in children. Children’s TBI is associated with a number of characteristics that distinguish it from adults. Although the death rate associated with TBI has decreased over the past 2 decades, the disability of children who survived TBI continues to have a significant impact on the economy and public health of society as a whole.

OBJECTIVE: To show the possibilities of computed tomography and magnetic resonance imaging in the diagnosis of traumatic diffuse axonal injuries in infants and young children.

MATERIALS AND METHODS: In this work, we analyzed the CT and MRI data of 1334 children under 3 years of age with acute TBI who were treated at the Clinical and Research Institute of Emergency Pediatric Surgery and Trauma (730 boys, 604 girls). The age of the children was from 23 days to 3 years, the average age was 1 year 6 months. Computed tomography scans were performed on a 128-slice Ingenuity Elite scanner (Philips). Scanning of the area of interest (head + cervical spine) was carried out with the maximum possible reduction in indicators to minimize the radiation dose, including the iDose4 program. MRI was performed on a Phillips Achieva 3 T scanner with multiplanar T1- and T2WI, 2D and 3D isotropic images, FLAIR, SWI, DWI/DTI, and magnetic resonance angiography (MRA). No contrast enhancement was applied. Statistics: data processing was carried out using the GraphPad Prism 9 software package. The computing and graphic capabilities of the Excel spreadsheet editor were used. To compare the mean values of the data samples, ANOVA analysis of variance wasused; differences were considered significant at a significance level of p<0.05.

RESULTS: 824 (61.8%) of 1334 children had a concussion, 510 (38.2%) had traumatic injuries of skull and brain from uncomplicated cephalohematomas and linear fractures to massive intracranial hematomas and total brain edema. Diffuse axonal injuries(DAI) type I and II on CT, further confirmed by MRI, were detected in 32 (6.27%) of all 510 children with TBI. 19 out of 32 hada combination with brain contusions, 13 with epi — and / or subdural hematomas of a small volume. MRI was performed in 89 out of 510 children under 3 years of age with intracranial injuries, in whom CT was initially performed. DAI of various types were detected by MRI in 92.13% (82/89) of the patients.

DISCUSSION: DAI is one of the most common types of TBI, occurring in both mild and severe forms, and is a brain injury characterized by axonal disruption, resulting in lesions of white matter tracts over a wide area. Taking into account the fact that children with TBI were admitted to the institute with a significant spread (from 1 hour to 7 days), the initial CT scan was performed no later than one hour after admission and was supplemented by MRI. The criteria for CT and MRI prescribements after TBI were: clinical and neurological status at the time of admission. CT has low sensitivity for detecting DAI, as only large hemorrhagic (hyperdense) lesions of DAI are detected. The use of multiplanar reconstruction, as well as various options, such as 3D reconstruction, MIP and MinIP (maximum and minimum intensity projection) and others, allows for a detailed assessment of the brain parenchyma and increases the detection of DAI. In our study, DAI using MRI was detected in 92.13% of patients, and the most critical type of DAI III was detected in 100% of children with severe TBI with poor outcome and death of patients.

CONCLUSION: Head CT is the preferred method for emergency radiology of TBI patients due to its affordability, speed of data acquisition, and ability to detect lesions requiring urgent neurosurgical intervention. In acute cases, MRI is chosen for patients with severe neurological impairment despite the absence of structural brain damage on CT. MRI is the method of choice for subacute and chronic TBI