الفهرس 
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Abstract
With the continued increased prevalence of liver disease (mostly due to
nonalcoholic fatty liver disease and HCV infection), MRI play an increasingly
important role in the evaluation of patients with chronic liver disease because of the
lack of ionizing radiation and the possibility of performing multiparametric imaging
combining conventional and functional sequences. However, more clinical evidence is
needed to determine which method or combination of methods achieves the best
accuracy for assessment of fibrosis, fat, and iron deposition.
In phase and opposed phase MR imaging allows reliable detection of focal
steatosis hepatis owing to the chemical shift cancellation artifact. Areas of steatosis
demonstrate signal loss on opposed phase images. In addition, T2* effects allow
reliable detection of iron storage diseases related susceptibility artifacts. Areas of iron
storage demonstrate pronounced signal loss on the image with the longer echo time.
MR spectroscopy has potential tool utility for assessment of metabolic function,
particularly with respect to liver fat quantification. It also may provide useful
information about other aspects of diffuse liver disease (eg, inflammation and fibrosis).
However, in vivo application of MR spectroscopy in the abdomen and pelvis is limited
by spectral resolution, SNR, and motion. In summary, MR spectroscopy of the liver is
a novel evolving technology with the potential to improve tissue characterization when
used in conjunction with other conventional MR sequences.
Diffusion weighted imaging and ADC maps of the liver offer functional and even
quantitative information about hepatic tissue that can be used in conjunction with other
MRI sequences to help with diagnosis of disease, treatment planning, and assessing
treatment success. A major advantage of DWI over the use of intravenous contrast
enhanced liver imaging is that it can be used in patients with compromised kidney
function and not put them at risk for necrotizing systemic fibrosis. There is also less
risk and fewer complications compared with biopsy and other invasive methods of
assessing the liver. Diffusion weighted imaging is being used more often in the liver
because it can provide useful diagnostic information in a short amount of time. As
MRI software and hardware continues to evolve, the quality of DWI will continue to
improve and it is likely to become even more useful in the clinical setting.