Chapter 108: Neurologic Imaging

Brain atrophy in a 42-year-old patient. T1-weighted axial image shows bilateral sulci thickening and bilateral enlargement not in keeping with the patient's age. Marked brain atrophy is a common finding in patients with end-stage liver disease. This condition may eventually partially revert after transplantation.

A 37-year-old patient with end-stage liver disease. T1-weighted axial image reveals bilateral symmetric hyperintense signal in the basal ganglia (arrows). This is a common finding in this patient population and is due to manganese deposition.

(A–B) Axial unenhanced computed tomography (CT) images of 2 different patients showing hyperattenuating lesions consistent with acute hematomas (H). Notice the hypodense halo of perilesional edema (yellow arrows).

(A–C) Axial T1-weighted (A and B) and T2-weighted (C) magnetic resonance imaging (MRI) images showing a heterogeneous, deeply located, temporo-occipital acute hematoma (H) in a posttransplant patient. The MRI appearance of hematomas varies according to the timing after the bleed and may result in confusing images on the hyperacute phase, potentially mimicking a brain tumor. Surrounding perilesional edema is seen. Notice the hyperintense basal ganglia signal due to manganese deposition (asterisks).

Axial CT image shows bilateral subdural mixed-density collections compatible with subdural hematomas (arrows). Heterogeneous density is due to an admixture of old and new blood secondary to rebleeding. Notice the medial compression of brain parenchyma due to the mass effect exerted by the hematomas, as well as edema manifested as sulci effacement.

(A–D) Axial T1-weighted (A), fluid-attenuated inversion recovery (FLAIR) (B), axial (C), and coronal (D) T2-weighted images show a centrally and symmetrically located low-T1 and high-T2 signal lesion (arrows). This type of osmotically mediated myelin damage presents this typical appearance with sparing of the corticospinal tracts.

(A–B) Two different patients with liver transplants under treatment with calcineurin inhibitors who developed an acute neurologic syndrome consistent with posterior reversible encephalopathy syndrome (PRES). Unenhanced CT images reveal hypodense edematous changes located posteriorly (arrows). In spite of the name of the syndrome, patients may develop bleeding in the affected regions, and the clinical evolution may be irreversible. Also more anterior regions may be involved.