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Chronic acquired hepatic failure: MR imaging of the brain at 1.5 T
J A Brunberg1, E Kanal, W Hirsch
1Department of Radiology, University of Michigan Medical Center, Ann Arbor 48105-0030.
Abstract:
The results of MR imaging of the brain at 1.5 T in 42 adults with non-Wilsonian chronic hepatic failure are reported. T1-weighted images demonstrated increased signal in the globus pallidus in 30 patients and in the putamen in 21, while T2-weighted images demonstrated no corresponding alteration in signal intensity. Symmetric low intensity in the central portion of the globus pallidus on spin-density and T2-weighted images in two patients correlated with regions of calcification on CT scans. Increased intensity on T1-weighted images also occurred in the mesencephalon surrounding the red nucleus (17/42) and in the quadrigeminal plate (4/42). Three patients demonstrated increased intensity in the pons on T2-weighted images unassociated with clinical brainstem dysfunction. Increased intensity on T1-weighted images was seen in the anterior pituitary in 28 of 35 patients. Alterations in signal intensity were not demonstrated in the cerebral cortex or cerebellum. MR findings did not correlate with laboratory indices of hepatic or thyroid function, with histologic liver diagnosis, or with neurologic status at the time of MR evaluation. Increased signal intensity in the basal ganglia, pituitary gland, and mesencephalon surrounding the red nuclei is characteristic of chronic hepatocellular dysfunction. Deposition of an as yet unidentified paramagnetic substance or altered intracellular water relaxation associated with the proliferation of astrocyte cytoplasmic organelles is postulated as the likely mechanism for this previously undescribed MR manifestation of chronic acquired hepatic failure.
Insights
Magnetic resonance (MR) imaging reveals characteristic brain signal changes in chronic hepatic failure. These findings in the basal ganglia and pituitary gland are linked to liver dysfunction but not directly to lab results or neurological status.
Area of Science:
- Neuroradiology
- Hepatology
- Neuroimaging
Background:
- Chronic hepatic failure can lead to neurological complications.
- The brain's appearance on magnetic resonance (MR) imaging in non-Wilsonian chronic hepatic failure requires further characterization.
- Understanding MR imaging findings can aid in diagnosing and managing hepatic encephalopathy.
Purpose of the Study:
- To report and characterize MR imaging findings in the brains of adults with non-Wilsonian chronic hepatic failure.
- To investigate the correlation between MR imaging findings and clinical, laboratory, and histological data.
- To postulate potential mechanisms for observed MR imaging abnormalities.
Main Methods:
- MR imaging (1.5 T) was performed on 42 adult patients with non-Wilsonian chronic hepatic failure.
- T1-weighted, T2-weighted, and spin-density images were analyzed for signal intensity alterations.
- Findings were correlated with laboratory indices, liver histology, and neurological status.
Main Results:
- Increased T1-weighted signal intensity was observed in the globus pallidus (30/42) and putamen (21/42).
- Increased T1-weighted signal intensity was also noted in the mesencephalon (17/42) and anterior pituitary (28/35).
- No correlation was found between MR findings and laboratory indices, liver histology, or neurological status.
Conclusions:
- Increased signal intensity in the basal ganglia, pituitary gland, and mesencephalon is characteristic of chronic hepatocellular dysfunction.
- The underlying mechanism may involve deposition of a paramagnetic substance or altered intracellular water relaxation.
- These MR imaging findings represent a previously undescribed manifestation of chronic acquired hepatic failure.