The goal of this study was compare the effect of Endorem on the signal intensity of the spleen in patients with normal liver tissue and in patients with liver cirrhosis. Thirty patients with normal liver tissue and 47 with liver cirrhosis were examined before and after i.v. Endorem administration. The patients were examined with a 1.5-T magnet system (Magnetom Vision) using a semiflexible cp-array coil. Three different pulse sequences were used: a T1-weighted gradient-echo sequence, a T2-weighted fast spin-echo sequence with spectral fat suppression, and a T2*-weighted gradient-echo sequence. The signal-to-noise ratios (SNRs) of two areas of the liver and spleen were determined. The mean SNRs of the liver and spleen in patients with and without liver cirrhosis were compared. For assessment of statistical significance, the t-test at a level of P < 0.05 was applied. After i.v. administration of Endorem, no differences were seen with the T1-weighted gradient-echo sequence for the liver and spleen and, with the T2-weighted fast spin-echo sequence, no differences were found for the spleen. Significant differences between both groups were seen for the liver with the T2-weighted fast spin-echo sequence. The SNR in the noncirrhotic liver group was 57.4% lower than the SNR in the cirrhotic liver group. With the T2*-weighted gradient-echo sequence, the SNRs of the liver and spleen in the noncirrhotic liver group, compared with the cirrhotic liver group, were 126.8% and 45.6% less, respectively. The effect of Endorem on the liver in patients with Child C-stage liver cirrhosis was 32.1% less than in patients with Child B-stage liver cirrhosis. Likewise, the Endorem effect on the spleen was 27.1% less in patients with Child C-stage compared with Child B-stage liver cirrhosis. Hepatic and splenic uptake of Endorem is significantly decreased in patients with liver cirrhosis.
The pore space of a sediment column (diameter 10 cm,
length 20 cm), filled with natural sediments, was imaged with
magnetic resonance tomography (MRT) at a spatial
resolution of 0.5 × 0.5 × 0.5 mm3. Apart from the evaluation
of the resulting images, the statistical evaluation provides
additional data to assess the pore size distribution.
While the porosity of pores >0.2 mm can be measured
directly, for smaller pores a calibration is necessary. Flow
and diffusion processes were measured at a spatial
resolution of 1.32 × 1.32 × 5 mm3. The time between two
measurements of a cross-sectional area is <10 s. The
coefficients of molecular diffusion can be measured directly
and are in good agreement with data in the literature.
Flow was measured in a range of 0.9−40 cm/min. A calibration
within one part of the sediment column was performed.
The results of the flow investigations are in good agreement
with the values obtained from a tracer experiment and
from a numerical model. At the given spatial resolution, flow
in preferential flow paths and larger pores can be
measured individually. Regions of different flow velocities
can be mapped. A monitoring of flow processes is
possible. Since the method is based on the movement of
protons in a magnetic field, no tracer was needed to examine
the dynamic processes within the column. We believe
that MRT has great potential to fill the gap between lab-scale investigations and field tests by providing reliable data
on the pore geometry and the occurring flow velocities.
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