Diagnostic Imaging of Primary Brainstem Injury Using Magnetic Resonance Imaging

Abstract

Traumatic primary brain stem injury is brain stem injury caused by mechanical head trauma. Before the development of diagnostic imaging, a pathological examination has been the nearly only diagnostic method of primary brain stem injury. Because magnetic resonance imaging (MRI) has a high resolution and CT demonstrates much artifact around the brain stem, MRI became a powerful tool for investigating primary brain stem injury. There are some types of primary brain stem injury. The author herein reviews the recent clinical studies of MRI of primary brain stem injury. The importance of early MRI examination appears to be a consensus. Our study demonstrated that small superficial lesion may be detected only a few days after injury. The acute phase within a few days after a head injury may show an unstable vital sign, thus intensive monitoring of the vital sign and manual or mechanical ventilation during a MRI examination should be employed. Direct brain stem contusion has a good prognosis compared with brain stem injury associated with diffuse axonal injury (DAI). Small superficial lesions are detected only within a few days after a head injury. Recent studies of MRI in patients with head injuries could not determine the pathology. However, the differentiation of the pathophysiology must be clinically important because the prognoses are different and distinguishable using only acute stage MRI.