Aplicação clínica da ressonância magnética em pacientes com traumatismo craniencefálico agudo

Abstract

Traumatic brain injury (TBI) is one of the most important causes of morbidity and mortality in the modern world. Neuroimaging provides accurate diagnostic information that will provide subsidies for therapeutical management. Cranial computed tomography (CT) has been used as imaging modality of choice in the initial investigation of TBI. The purpose of this research was to evaluate the clinical application of magnetic resonance (MR) imaging in injured patients with acute TBI considering the possibility of: 1) identify the type, quantity and severity of traumatic brain injuries, and 2) improve clinical-radiological association of patients. A total of 55 injured patients, 34(61.8%) males and 21(38.2%) females, with acute (0 to 5 days) and closed TBI and that not required of immediate neurosurgical procedure by CT and MR. Cranial fractures, extradural and subdural hematomas, subdural hygroma, diffuse axonal injury, single and multiple contusions, intraparenchymal hematoma, subarachnoid and intraventricular hemorrhages, diffuse and hemispheric brain swelling, and ischemia were studied by the two imaging methods and analysed by McNemar test. Associations among mild or moderate/severe TBI and diagnosis by MR of acute subdural hematoma, diffuse axonal injury, multiple contusion, and subarachnoid hemorrhage were verified by Chi-square test. The quantity of injuries and time interval among the imaging diagnosis modalities were assessed by Sign test. The results showed statistical significant differences in the following brain injuries: 1) cranial fractures were detected by CT in 16(29,1%) patients and in 2(3,6%) by MR; 2) subdural hematoma was identified by CT in 6(10.9%) patients and in 20(36,4 %) by MR; 3) diffuse axonal injury was encountered by CT in only 1(1.8%) patient and in 28(50.9%) by MR; 4) multiple contusion was found by CT in only 5(9.1%) patients and in 23(41.8%) by MR, and, 5) subarachnoid hemorrhage was identified by CT in 10(18.2%) patients and in 23(41.8%) by MR. Within the brain injuries diagnosed by MR, there was only significant association among diffuse axonal injury and severity by Glasgow Coma Scale for mild or moderate/severe TBI. Two additional brain injuries per patient were detected by MR when compared to the CT. Time interval among CT and MR examinations was 1 day; 24(43.6%) patients performed on the same day, in 11(20%) the CT was made before MR, and in 20(36.4%) the MR was carried out before CT. The clinical application of MR in acute TBI is useful in diagnosis of diffuse axonal injury. The detection of this injury was associated with severity of acute TBI. MR was statistically higher to the CT in the identification of diffuse axonal injury, subarachnoid hemorrhage, multiple contusion and acute subdural hematoma, however inferior in diagnosis of fractures.