Hepatic cirrhosis: magnetisation transfer contrast in the globus pallidus

Abstract

The magnetisation transfer ratio (MTR), a quantitative tissue characteristic, and the pallidal index were measured in the globus pallidus of 37 patients with hepatic cirrhosis and 37 control subjects. The MTR decreased with severity of the disease, as indicated by the serum total bililubin, indocyanine green 15-min retention rate, and plasma ammonia. The pallidal index correlated significantly with haematological parameters, although the correlation coefficients tended to be lower than those between MTR and haematological parameters. This change in MTR corresponded to the results of the manganese chloride experiments. T1 shortening in the pallidum of patients with cirrhosis is presumably caused by paramagnetic effects, and possibly attributed to manganese deposition.

Globus pallidus magnetization transfer ratio, T1 and T2 in primary biliary cirrhosis: Relationship with disease stage and age

“…Regrettably, it was not possible to recruit further advanced-disease patients to examine the advanced-disease relationship with MR in more detail. There are presently few studies measuring the MTR, T 1 , or T 2 of GP at 3.0T with which to compare our values, but the values for MTR, T 1 , and T 2 are in line with measurements made at 1.5T (14,15,30). Two studies have measured shorter T 2 values for the studied Figure 2.…”

“…Manganese is a relaxation agent effecting both T 1 and T 2 , although for the relaxation times found in the brain at 3T, the percentage T 1 change is greater than the percentage change in T 2 (12). Studies of the GP have shown hyperintensity in T 1 w imaging (9,13), or alternatively a reduction in the magnetization transfer ratio (MTR) (14,15). Furthermore, T 2 brain abnormalities in other fatigue-associated diseases (multiple sclerosis, MS) have confirmed a relationship between reduced T 2 signal in the basal ganglia and neuropsychological dysfunction (16), thought to be due to the accumulation of iron.…”

Quantitative magnetic resonance imaging in patients with cirrhosis: a cross-sectional study

“…(Iwasa et al, 1998) and also reported similar findings in the surrounding white matter (Iwasa et al, 1999). Similar findings of a reduction in MTR have been reported by others (Balata et al, 2003; Cordoba et al, 2001;Iwasa et al, 1999;Rovira et al, 2001;Taylor-Robinson et al, 1995), with the exception of one group (Restuccia et al, 2004), who found no difference in MTR between patients and controls, but they used a different MR sequence to the majority of other groups.…”

“…There are several possible explanations for the reduction observed in MTR including damage to myelin or to the axonal membrane (Lexa et al 1994;van Waesberghe et al 1999), deposition of paramagnetic substances (Iwasa et al 1998) and low-grade cellular/cerebral oedema (Balata et al 2003; Cordoba et al 2001).…”

Demonstration of interstitial cerebral edema with diffusion tensor MR imaging in type C hepatic encephalopathy†

“…5 Magnetic resonance (MR) imaging studies including MR spectroscopy, magnetization transfer (MT), and diffusion-weighted imaging (DWI) have improved our understanding of basic neuroanatomical and pathophysiological alterations in patients with hepatic encephalopathy (HE). [6][7][8][9][10][11][12] High signal intensity in the globus pallidus, putamen, and portions of the internal capsule on T 1 -weighted imaging along with brain atrophy, particularly in frontal lobes, has been described in 50% to 88% of patients with liver cirrhosis and HE. 8,13,14 Although various causes have been proposed 8,14 for this hyperintensity, deposition of manganese is regarded as the most likely explanation, 12 with no direct correlation of pallidal hyperintensity and grade of encephalopathy.…”